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Dizalice
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ENERGIJA I OKOLIŠ
ENERGY AND
THE ENVIRONMENT2016

PRILAGODBA KLIMATSKIM PROMJENAMAI ENERGETSKA SIGURNOST NA JUGOISTOKU EUROPE
CLIMATE CHANGE AND ENERGY SECURITY
IN SOUTH-EAST EUROPE
ČISTA ENERGIJA ZA BOLJI SVIJET
CLEAN ENERGY FOR A BETTER WORLD

Deutschlands nachhaltigste
Marke 2011

strateškim
projektom
održivosti„EffizienzPlus“umogu postići
već danas,s na tržištu
dostupnom
tehnisjedištuuAllendorfu(Eder).
Više
informacijakom, već i dokazuje da se zaštita okoliša i učinkovitostmožetenašojuweb-stranici:
resursapronaći
mogu nadovestisklad s ekonomskim uspje-

ENERGIJA I OKOLIŠ 2016 / ENERGY AND THE ENVIRONMENT 2016

Na području učina od 1,5 kW do 120 MW

Solarni sistemi

OPATIJA, HRVATSKA /CROATIA
listopad /October 26-28, 2016Međunarodni kongres
ENERGIJA I OKOLIŠ 2016
PRILAGODBA KLIMATSKIM PROMJENAMA I
ENERGETSKA SIGURNOST NA JUGOISTOKU EUROPE
ČISTA ENERGIJA ZA BOLJI SVIJET
XXV. znanstveni skup o energiji i zaštiti okolišaInternational Congress
ENERGY AND THE ENVIRONMENT 2016
CLIMATE CHANGE AND ENERGY SECURITY
IN SOUTH-EAST EUROPE
CLEAN ENERGY FOR A BETTER WORLDXXV Scientific Conference on Energy and the Environment

Organizatori / Organized by:

Sveučilište u Rijeci /University of Rijeka

Hrvatsko udruženje za sunčevu energiju, Rijeka /Croatian Solar Energy Association, Rijeka
Fakulteta za strojništvo,Univerza v Ljubljani, Slovenija /Faculty of Mechanical Engineering,
Universitiy of Ljubljana, Slovenija

Izdavanje ovog zbornika svojim doprinosom su pomogli
The publishing of this Book of Proceedings was helped by:
Ministarstvo znanosti, obrazovanja isporta Republike Hrvatske /Ministry of Science, Education andSports of the Republic of Croatia

HOPS - Hrvatski operator prijenosnog sustava, Viessmann,
Rockwool, Weishaupt, HEP - TE Plomin
Opatija - Croatia
October 20160HÿXQDURGQLNRQJUHVENERGIJA I OKOLIŠ 2016.
XXV. znanstveni skup o energiju i zaštiti okolišaInternational Congress
ENERGY AND THE ENVIRONMENT 2016
25th Scientific Conference on Energy and the Environment
Opatija – Croatia
October 26 – 28, 2016

POD POKROVITELJSTVOM / UNDER THE PATRONAGE OF:
HAZU – Hrvatska Akademija Znanosti i Umjetnosti
Croatian Academy of Sciences and ArtsU SURADNJI S / IN COOPERATION WITH:
IIR – 0HÿXQDURGQLPLQVWLWXWRP]DKODÿHQMH3DUL])UDQFXVND
IIR – International Institute of Refrigeration, Paris, France
HATZ –+UYDWVNDDNDGHPLMDWHKQLþNLK]QDQRVWL
Croatian Academy of Engineering, Zagreb
UNESCO – Ured pri ministarstvu kulture RH
The United Nations Educational, Scientific and Cultural Organization, office in Ministryof Culture, Croatia*HRWHKQLþNLIDNXOWHW9DUDåGLQ6YHXþLOLãWHX=DJUHEXFaculty of Geotehnical Engineering, University of Zagreb$UKLWHNWRQVNLIDNXOWHW6YHXþLOLãWHX=DJUHEX
Faculty of Architecture, University of Zagreb'UXãWYRP]DVXQþHYX energiju, Rijeka
Solar Energy Society, Rijeka
Energetskim institutom “Hrvoje Požar“, Zagreb
Energy Institute “Hrvoje Požar”, Zagreb+UYDWVNLPVWURMDUVNLPLEURGRJUDÿHYQLPLQåHQMHUVNLPVDYH]RP=DJUHE
Croatian Mechanical and Naval Architecture Engineering Association, Zagreb, Croatia.RQþDU- Institutom za elektrotehniku d.d., Zagreb.RQþDU- Electrical Engineering Institute, Inc, Zagreb, Croatia
IEEE – Hrvatska sekcija, Zagreb
IEEE – Croatian section, Zagreb, Croatia

ORGANIZACIJSKI ODBOR / ORGANISING COMMITTEE
Prof. dr. VF%)UDQNRYLü
Predsjednik/President

7HKQLþNLIDNXOWHW6YHXþLOLãWDX5LMHFL

Dr. sc. P. BlecichDoc. dr. VF,%RQHIDþLü
Prof. dr. sc. B. %RãQMDNRYLü

7HKQLþNLIDNXOWHW6YHXþLOLãWDX5LMHFL
7HKQLþNLIDNXOWHW6YHXþLOLãWDX5LMHFL
Former Regional Adviser for Environment of the UN
Economic Commission for Europe, Geneva, Switzerland
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Regionalna energetska agencija Kvarner
AT ENEKO d.o.o.
HEP d.d., DP Elektroprimorje, Rijeka
Primorsko-goranska županija
7HKQLþNLIDNXOWHW6YHXþLOLãWDX5LMHFLTE Plomin d.o.o.
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7HKQLþNLIDNXOWHW6YHXþLOLãWDX5LMHFL
7HKQLþNLIDNXOWHW6YHXþLOLãWDX5LMHFL
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Fakultet kemijskog inženjerstva i tehnologije
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Hrvatska gospodarska komora, Sektor za industriju
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7HKQLþNLIDNXOWHW6YHXþLOLãWDX5LMHFL

Doc. dr. sc. O. Bukovac
Dr. VF9'UDJLþHYLü
Doc. dr. sc. V. Glažar
D. Jardas
9.QHåHYLü
Doc. dr. sc. V. Komen
Doc. dr. sc. Lj. Krpan
Prof. dr. VF./HQLü
00LUNRYLüProf. dr. VF70UDNRYþLüDr. sc. V. Mrzljak
03HUþLü
Prof. dr. sc. Z. Prelec
Doc. dr. VF76HQþLü
Prof. dr. VF,6XWORYLü
K. ŠtihProf. dr.sc. A. Trp
Doc. dr.sc. I. Wolf

ZNANSTVENI ODBOR / SCIENTIFIC COMMITTEE
Prof. dr. VF%%RãQMDNRYLü

Former Regional Adviser for Environment of the UN
Economic Commission for Europe, Geneva, Switzerland

Predsjednik/President
3URIGUVF9$QGURþHF
Prof. dr. sc. V. Butala
Prof. d. - ing. A. Can
Prof. dr. sc. S. Car
Prof. d. sc. R. Ciconkov
3URIGUVF7ûXUNR
Prof. dr. sc. ,'HNDQLü
Dr. sc. U. Desnica
Prof. dr. VF1'XLüProf. dr. I. Farkas
Prof. dr. sc. V. Filipan
Prof. dr. VF%)UDQNRYLü'RFGUVF')UDQNRYLüProf. dr. VF$*DORYLü
Prof. dr. sc. M. Golub
Prof. dr. sc. B. Halasz'UVF7,YRãHYLü
Dr. VF%-HODYLüProf. dr. sc. B. Klarin
Prof. dr. sc. Ž. Kristl
Prof. dr. sc. J. Krope
Prof. dr. VF./HQLüProf. dr. sc. V. Medica
Prof. dr. sc. S. Medved
Prof. GU,0H]LüProf. dr. VF/M0LãþHYLü
Prof. dr. sc. P. Novak
3URIGUVF,2UOLüProf. dr. VF'3HþRUQLN
Prof. dr. sc. Z. Prelec
Prof. dr. VF65LVRYLü
Dr. sc. V. K. Sharma
Prof. dr. sc. A. Trp
Prof. dr. sc. S. Zelenika+UYDWVNDDNDGHPMDWHKQLþNLK]QDQRVWLFakulteta za strojništvo Univerze v Ljubljani, Slovenija
Dean Faculty of Engineering and Architecture Istanbul Arel
University, Istanbul, Turkey.RQþDU-Institut za elektrotehniku d.d. Zagreb
Faculty of Mechanical Engineering, University “Sv. Kiril i
Metodij”, Skopje, Macedonia)DNXOWHWVWURMDUVWYDLEURGRJUDGQMH6YHXþLOLãWDX=DJUHEX5XGDUVNRJHRORãNRQDIWQLIDNXOWHW6YHXþLOLãWDX=DJUHEX,QVWLWX5XÿHU%RãNRYLü)DNXOWHWVWURMDUVWYDLEURGRJUDGQMH6YHXþLOLãWDX=DJUHEX„Szent Istvan“ University, Godollo, Hungary
Fakultet kemijskog inženjerstva i tehnologije
6YHXþLOLãWDX=DJUHEX7HKQLþNLIDNXOWHW6YHXþLOLãWDX5LMHFL
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Rudarsko-geološko-QDIWQLIDNXOWHW6YHXþLOLãWHX=DJUHEX)DNXOWHWVWURMDUVWYDLEURGRJUDGQMH6YHXþLOLãWDX=DJUHEXAgencija za odgoj i obrazovanje
Energetski institut “Hrvoje Požar”, Zagreb
7HKQLþNLIDNXOWHW6YHXþLOLãWDX6SOLWX
Fakulteta za gradbeništvo in geodezijo
Univerze v Ljubljani, Slovenija
Fakulteta za kemijo in kemijsko tehnologijo
Univerze v Mariboru, Slovenija
7HKQLþNLIDNXOWHW6YHXþLOLãWDX5LMHFL
7HKQLþNLIDNXOWHW6YHXþLOLãWDX5LMHFL
Fakulteta za strojništvo Univerze v Ljubljani, Slovenija
University of California, Santa Barbara, SAD$UKLWHNWRQVNLIDNXOWHW6YHXþLOLãWDX=DJUHEXHigh School for Technologies and Systems, Novo Mesto,
Slovenia
2GMHO]DIL]LNX6YHXþLOLãWDX5LMHFL
TH - Mannheim, Fakultät für Maschinenbau,
Deutschland
7HKQLþNLIDNXOWHW6YHXþLOLãWDX5LMHFLâXPDUVNLIDNXOWHW6YHXþLOLãWDX=DJUHEXENEA Research Centre Trisaria
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7HKQLþNLIDNXOWHW6YHXþLOLãWDX5LMHFLPOýASNI ODBOR / COMMITTEE OF HONOUR$NDGHPLN=.XVLüPredsjednik/President

Predsjednik Hrvatske akademije znanosti i umjetnosti

Prof. dr. sc. A. Barbieri
R. Carek
D. Coulomb
PUVF/ýDUDSRYLüProf. dr. VF**UDQLüProf. dr. VF=*X]RYLü

5HNWRU6YHXþLOLãWD-XUMD'REULOHX3XOL
Ministarstvo kulture RH, Hrvatsko povjerenstvo za UNESCOIIR – International institute of refrigeration
Predsjednik Hrvatske komore inženjera strojarstva
Ravnatelj Energetskog instituta “Hrvoje Požar”, Zagreb
Dekan )DNXOWHWDVWURMDUVWYDLEURGRJUDGQMH6YHXþLOLãWDX
ZagrebuŽupan Primorsko-goranske županije
Hrvatski inženjerski savez
Rektor SveXþLOLãWDX5LMHFL
Dekan *HRWHKQLþNRJIDNXOWHWD9DUDåGLQ6YHXþLOLãWDX=DJUHEX
Grad Rijeka
Dekan Fakulteta za strojništvo, Univerza v Ljubljani
Centar za plin Hrvatske+UYDWVNDDNDGHPLMD]QDQRVWLLXPMHWQRVWL=QDQVWYHQRYLMHüH
za energetiku
INTEL TRADE d.o.o.
Hrvatska gospodarska komora, Županijska komora Rijeka+UYDWVNDDNDGHPLMD]QDQRVWLLXPMHWQRVWL=QDQVWYHQRYLMHüH
za naftu i plin HAZU

Z. Komadina
Prof. dr. sc. V. Krstelj
3URIGUVF3/XþLQ
Prof. dr. sc. J. Mesec
mr. sc. V. Obersnel
Prof. dr. sc. B. Širok
Prof. dr. VF0âXQLü
$NDGHPLN%8GRYLþLü
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3URIGUVF99XMLü$NDGHPLN0=HOLü0(Ĉ81$52'1,.21*5(6INTERNATIONAL CONGRESSENERGIJA I OKOLIŠ 2016.
ENERGY AND THE ENVIRONMENT 2016

OPATIJA, 2016

Nakladnik / Publisher:+UYDWVNLVDYH]]DVXQþHYXHQHUJLMX5LMHND9XNRYDUVND
Hrvatska
Croatian Solar Energy Association Rijeka, Vukovarska 58,
Croatia

Za nakladnika )RU3XEOLVKHU3URIGUVF%HUQDUG)UDQNRYLü
Urednik / Editor:

Bernard )UDQNRYLü

6WUXþQLXUHGQLci / Technical Editors: 0DUNR3HUþLü, Paolo Blecich
Recenzenti / Reviewers:
Branko, %RãQMDNRYLü Tannay, Switzerland; Paolo Blecich, Rijeka; Stjepan Car, Zagreb;
Mladen ýUQMDU Rijeka; -XOLMDQ'REULQLü, Rijeka; Mihajlo Firak, Zagreb; Bernard )UDQNRYLü
Rijeka; Miroslav Golub, Zagreb; 7DWMDQD ,YRãHYLü Rijeka; Vladimir Kercan, Ljubljana,
Slovenija; 6HUÿR .ODSþLü 1HGHãüLQD; Branko Klarin, Split; Vladimir Knapp, Zagreb; Kristian/HQLü Rijeka; Vladimir Medica, Rijeka; Sašo Medved, Ljubljana, Slovenija; Tomislav
0UDNRYþLü Rijeka; ,YR2UOLüRijeka; 'DPLU3HþRUQLNMannheim; Zmagoslav Prelec, Rijeka;
Tomislav 6HQþLü, Rijeka; Nedjeljko âNLILü Rijeka; Miljenko âXQLü Zagreb; Ivan 9LOLþLü
Rijeka; Igor Wolf, Rijeka.
Kategorizacija u publikaciji - &,3 ]DSLV GRVWXSDQ X UDþXQDOQRP NDWDORJX 6YHXþLOLãQH NQMLåQLFH
Rijeka pod brojem 131020098.
UDK 620.91 + 504.06 / (063) (082) = 862 = 200(Ĉ81$52'1I kongres Energija i okoliš 2016 (2016; Opatija)
Energija i okoliš 2016 = Energy and the Environment 2016  0HÿXQDURGQi kongres Energija iokoliš 2016 = International Congress Energy and the Environment 2016, October 26 - 28, 2016,
Opatija, Hrvatska;
XUHGQLN  HGLWRU %HUQDUG )UDQNRYLü - 5LMHND  +UYDWVNL VDYH] ]D VXQþHYX HQHUJLMX  &URDWLDn
Solar Energy Association, 2016. – 1 sv. ; 24 cm
Tekst na hrv. i engl. jeziku.
ISBN 978-953-6886-23-4
ISBN 978-953-6886-23-4

Radovi su podvrgnuti PHÿXQDURGQRM ]QDQVWYHQRM L VWUXþQRM UHFHQLML 1LMH dozvoljena
UHSURGXNFLMDLOLXPQRåDYDQMHXELORNRMHPREOLNXEH]VXJODVQRVWLL]GDYDþDThe papers have been revised by international reviewers. No part of this publication may
be reproduced in any form, without the permission of the publisher.
Tisak / Print: Tisak Zambelli – Rijeka
3ULMHYRGL&KHULVH$OH[LV0LKHOþLü, 3DROR%OHFLFK,JRU%RQHIDþLü9HGUDQ0U]OMDN
Lektura za engleski jezik: Cherise $OH[LV0LKHOþLü
Kompjuterski slog / Electronic typesettings: 03HUþLü, P. %OHFLFK06WDUþHYLü
Korice / Cover: M S F
Naklada / Edition: 200 primjeraka / pcs

PREDGOVOR
Prilagodba klimatskim promjenama i energetska sigurnost na Jugoistoku
EuropeČista energija za bolji svijetMeđunarodni kongres Energija i okoliš 2016. je 25. po redu znanstveni skup koji sebienalno održava u Opatiji. Organizatori Kongresa, a i njegovi dugogodišnji vjerni
učesnici, posebno su počašćeni visokim pokroviteljstvom Hrvatske akademije znanosti iumjetnosti nad ovim jubilarnim međunarodnim znanstvenim skupom. I ove godine,supokrovitlji
Kongresa su International Institute of Refrigerationr Paris i svjetskaorganizacija UNESCO - ured za Hrvatsku što daje skupu dodatnu vrijednost.
Radovi objavljeni u ovom zborniku grupirani su u dva tematska područja kao logičan sljeddvaju konferencija u organizaciji Kongresa: prva pod nazivom Prilagodba klimatskim
promjenama i energetska sigurnost na Jugoistoku Europe i druga pod krilaticom Čista
energija za bolji svijet.
Prva konferencija Prilagodba klimatskim promjenama i energetska sigurnost na
Jugoistoku Europe u duhu je Paris Climate Change Conference 2015. koja se po mnogima
smatra veliki uspjehom današnjeg čovječanstva. Danas, predstoje veliki napori kako bi se
dogovoreni ambiciozni ciljevi u pogledu ograničavanja i sprečavanja globalnog
zatopljenja implementirali. S obzirom da je radikalna dekarbonizacija zadana kao jedan odključnih ciljeva. Konferencija je posvetila posebnu pažnju klimatskim promjenama isigurnosti opskrbljivanja energijom, s naglaskom na područje Jugoistočne Europe.
Dotaknuti problemi analizirani su preko relevantnih čimbenika: okoliš, etika, društvo,ekonomija i gospodarstvo te sigurnost. Većina objavljenih radova na ovu temu bit će
izvrsna podloga za implementaciju zaključaka pariške konferencije i naš svakodnevniživot.
Druga konferencija, Čista energija za bolji svijet temelji se na činjenici da je energija
jedna od temeljnih potreba čovjeka u svakodnevnom żivotu, isto tako kako su to hrana,voda, proizvodnja, transport... Sve veća potreba za energijom u svijetu te sve veća svjest outjecaju čovjeka na okoliš postavlja stroge uvjete na buduće energetske sustava. Napredne
energetske tehnologije i rješenja kao rezultat sinergije raznih znanstvenih i znanstvenostručnih grana sve više se oslanjanu na multidisciplinarnost razvojnih metoda. U ovom
multidisciplinarnom duhu razvoja novih tehnologija, te uz velike napore istraživača ivelika financijska ulaganja postižu se zapaženi rezultati ka sve široj uporabi obnovljivih
izvora energije i optimizaciji korištenja postojećih konvencionalnih izvora.
U tom svjetlu jubilarni međunarodni konges Energija i okoliš 2016. i ove godine jeprezentirao rezultate najnovijih istraživanja, dosadašnjih iskustava, i praktičnih iskustava
u području energetike i zaštite okoliša kroz spektar tema koje oslikavaju
multidisciplinarnost ovih važnih područja čovjekova djelovanja, a data su i buduća
viđenja.

Zbornik radova na 676 stranica sadrži 62 rada koji su sadržajno složeni sukladno
izlaganjima po tematskim područjima programa Kongresa. Uvjereni smo da radovi
objavljeni u Zborniku su sadržajno vrijedan doprinos promicanju učinkovitom korištenju
energije, poticanju korištenja obnovljivih izvora energije i brizi o zaštiti okoliša.

Za organizacijski odbor
Branko Bošnjaković i Bernard Franković

FOREWARD
Climate Change and Energy Security in South East Europe
Clean Energy for a Better World
The international congress Energy and the Environment 2016 is the 25 consecutive
symposium, which is held biannually in Opatija, Croatia. The organisers of the Congress
and its long-time loyal participants are especially honored by the endorsement of the
Croatian Academy of Sciences and Arts in the name of this international scientificcommemoratory conference. Once again this year, the co-founders of the Congress are theInternational Institute of Refrigeration, Paris and the the world organisation UNESCO –Office for Croatia, which contribute essential added value to this gathering.
th

The works published in these Proceedings are grouped into two thematic areas as a logicaloutcome of the two conferences in the organisation of the Congress program: the first isentitled Climate change and energy security in South East Europe and the second comesunder the slogan of Clean energy for a better world.
The first conference, Climate change and energy security in South East Europe, in thespirit of the Paris Climate Change Conference of December 2015 has been lauded bymany as a great success of modern civilization. Today, huge efforts will be needed to
implement the very ambitious goals agreed upon in preventing global warming. Since
radical decarbonization is one of the key objectives, the present conference addresses theissues of climate change and the security of the energy supply, with the focus upon SouthEast Europe. The issues discussed are analysed with regard to the relevant factors:
environment, ethics, society, economy and security. Most of the the published works on
this topic will be an excellent foundation for the implementation of the conclusions of theParis Conference as well as our daily lives.
The second conference, Clean energy for a better world, is based on the fact that energy is
one of the basic needs of people in everyday life, just as are food, water, production,transportation, etc. The constantly growing demand for energy in the world, and theincreasing awareness of the impact of man upon the environment, imposes stringent
conditions on future energy systems. Advanced energy technologies and solutions, as aresult of the synergy between various scientific branches, increasingly rely upon
multidisciplinary developmental methods. In the spirit of this multidisciplinary
development of new technologies, and through the efforts of researchers along withconsiderable financial investment, great strides towards an ever-wider use of renewableenergy sources and optimization of existing conventional sources have been achieved.
In this light, the commemorative international congress Energy and the Environment 2016
has presented the results of the latest research, past experiences, and practical experiencesin the field of energy and environmental protection through a full range of topics thatreflect the multidisciplinary nature of these important areas of human activity, and herein
are given the resulting visions for the future.

The proceedings contain 676 pages and 62 papers that are arranged according to thepresentations, arranged by thematic area, in the Congress program. We believe that thearticles published in the Proceedings present a valuable content that contributes to thepromotion of energy efficiency and encourages the use of renewable energy as well as
environmental protection.

For the Organising Committee
Branko Bošnjaković and Bernard Franković

SADRŽAJ - CONTENTS

1. KONFERENCIJA%UDQNR%RãQMDNRYLüClimate Change, Energy Security and Innovation: Geopolitical Challenges tothe EU
Klimatske promjene, energetsNDVLJXUQRVWLLQRYDFLMH*HRSROLWLþNLL]D]RYLSUHG
EU.................................................................................................................................. 1
Nirvana )UDQNRYLü0LKHOM'5DGRã93DOþLü
ZnaþDMVHNWRUDNRULãWHQMD]HPOMLãWDSURPMHQDXNRULãWHQMX]HPOMLãWDLšumarstva (LULUCF-a) u ispunjvanju obveza Republike Hrvatske pookvirnoj konvenciji UN-a o promjeni klime i Kyotskom protokolu
The Importance of the Land Use, Land Use Change and Forestry (LULUCF) Sector
for Fulfilling the Obligations of the Republic of Croatia Under the UN Framework
Convention on Climate Change and Kyoto Protocol……............................................

21=YRQLPLUDâYHUNR*UGLüPolitika prilagodbe klimatskim promjenama i njeno financiranje
Climate Change Adaptation Policy and its Financing…..…………………………...

31

Domagoj Vulin, '.DUDVDOLKRYLü6HGODU/-XNLü
Oil and Gas Industry and Challenges from Climate Change Regulations
Naftna i plinska industrija i izazovi koje postavljaju propisi o klimatskim
promjenama………………………………………..…………….................................

41

7DWMDQD,YRãHYLü,2UOLü0ýDUJRQMD
Two Years (2013-2015) of Fine Aerosol Monitoring in Rijeka, Croatia
Dvije godine (2013-2015) analize fine frakcije aerosola u Rijeci................................

49

Martin Janda, 7'ORXK\3%OHFLFK%)UDQNRYLü
Comparison of Boilers for Treated and Untreated Waste
UsporedbDNRWORYD]DREUDÿHQLLQHREUDÿHQLRWSDG.....................................................

59

VLNWRU6LPRQþLü, 00LOLþLü
6DPRRGUåLYRVWXSRVWXSDQMXVRWSDGRPQLMHPRJXüHEH]LVNRULãWDYDQMD
energetskog potencijala ostatka otpada – posebno ne na otocima
Sustainability in Waste Management is not Possible Without Exploitation of theEnergy Potential rest of Waste – Especially not on the Islands…..….......................... 69

0DULQ0LOHWLü9'UDJLþHYLü
Energy Potential from Municipal Solid Waste in South East Europe(QHUJHWVNLSRWHQFLMDONRPXQDOQRJNUXWRJRWSDGDX-XJRLVWRþQRM(XURSL..................... 75
Anant Wadhwa, A. Kumar, S. Awasthi
Prevention of Ozone Layer Depletion Using Cloud Seeding
6SUHþDYDQMHRãWHüHQMDR]RQVNRJRPRWDþDNRULãWHQMHPWHKQRORJLMH]DVLMDYDQMD
oblaka……………………………………...….............................................................

81

Juma Haydary, L. Jelemesnky, J. Dudaš, J. Markoš
Design of a Network of Pyrolysis Units with a Central Gasification Plant for
Thermochemical Conversion of Dispersed Waste Biomass
2EOLNRYDQMHPUHåHSLUROLWLþNLKMHGLQLFDVDVUHGLãQMLPSRVWURMenjem za uplinjavanje
za termokemijsku pretvorbu raspršene otpadne biomase..............................................

89

Rafael Leal-Arcas
The Transition Towards Decarbonization: A Legal and Policy Exploration of
the European Union
Tranzicija prema dekarbonizaciji: istraživanje pravnog i zakonodavnog okvira
Europske Unije…………………………….................................................................

99

2. KONFERENCIJA

Bálint Katona, T. Laza
Biomass Based CHP Production with Stirling Engine
Kogeneracija na bazi biomase sa Stirlingovim motorom............................................

111'LQNRĈXUÿHYLü
Biogas Facilities as a Carbon Sinks with the Production of New Materials
with Low Carbon Footprint%LRSOLQVNDSRVWURMHQMDNDRPMHVWRSRQRUDVWDNOHQLþNLKSOLQRYDX]SURL]YRGQMXQRYLKPDWHULMDODVQLVNLPXJOMLþQLPRWLVNRP«……………...................................

123*UHJRU7DYþDUT. Katrašnik
A Mechanistically Based Real-time Capable System Level Model of PEM Fuel
Cells
0HKDQLVWLþNLXWHPHOMHQPRGHO3(0JRULYQLKüHOLMDQDUD]LQLVXVWDYDVSosoban za
rad u stvarnom vremenu......................................................................…………........

135Željko Penga, F. Barbir
Computational Fluid Dynamics Model of High Performance Proton Exchange
Membrane Fuel Cell without External Humidification
1XPHULþNRPRGHOLUDQMHVWUXMDQMDYLVRNRXþLQNRYLWRJPHPEUDQVNRJJRULYRJþODQND
bez potrebe za vanjskim ovlaživanjem reaktanata………………………………...
147$PDQGD$OMLQRYLüG. Radica, F. Barbir
Analysis of Cogeneration System with Fuel Cell
AnDOL]DNRJHQHUDFLMVNRJVXVWDYDVDJRULYLPþODQFLPD……………...........................

157

István Farkas, I. Fekete
Building Enclosure Elements as Integrated Solar Collectors(OHPHQWLRPRWDþD]JUDGHNDRLQWHJULUDQLVXQþHYLNROHNWRUL........................................ 169
6DQGUR1LåHWLü, Ž. Penga, M. Arici
Numerical simulations of the solar chimney power plant concept with short
diffuser
1XPHULþNDVLPXODFLMDNRQFHSWDVRODUQHHOHNWUDQHVDNUDWNLPGLIX]RURP...................

177

Maytham A. Al-Neama, I. Farkas
Energy Analysis of Active Solar Drying System Connected with Photovoltaic
Modules
Energijska analiza aktivnog solarnog sušionog sustava spojenog sa fotonaponskim
modulima……….......................................................................................................... 187
Marius Viljoen, C. Pienaar
Design of a 3kW PV Power System for a Residental Home
3URMHNW)1VXVWDYDVQDJHN:]DVWDPEHQXNXüX ………………………………….. 197
Mohamed El-Shimy, B. ĈXULn
Techno-Economic Evaluation of Solar Photovoltaic-PV and Wind Energy
Sources for Irrigation Water Pumping
Tehnološki-ekonomsko vrednovanje solarnih fotonaponskih-FN izvora energije iizvora energije vjetra za crpljenje vode za navodnjavanje………………...................

209

Istvan Ervin Haber, I. Farkas
Smart PV System Using Building’s Heat Storage
Sustav nadzora fotonaponskog sustava visoke snage spojen na sustav upravljanja
zgradom…...……………………………………………………….............................. 221
DXEUDYNR)UDQNRYLü9.LULQþLü'.D]DODF-Miljan
Photovoltaic Power Plant Riteh-1 – Lessons Learned
Fotonaponska elektrana Riteh-1 – 6WHþHQDLVNXVWYD..................................................... 229

SDãD6ODGLü7'RãHQ/'DQþXORYLü
Bidirectional Power Converter for Photovoltaic Applications: Design
Considerations%LGLUHNFLMVNLXþLQVNLSUHWYDUDþ]DSULPMHQXXIRWRQDSRQVNLPVXVWDYLPD««……...

239

Goran Gregov, Z. Bilandžija
1XPHULþNDVLPXODFLMDKLGUDXOLþNRJVXVWDYD]DSR]LFLRQLUDQMHSDUDEROLþQRJ
solarnog kolektora
Numerical Simulation of a Hydraulic System for a Parabolic Solar Collectors
Posittioning……………………………………………………………………...……

247

Zoltan Kapros
A Dynamic Data-Driven Forecasting Methodology for Small-Scale
Photovoltaic Power Systems
0HWRGRORJLMDSURJQR]HSRPRüXGLQDPLþNLKSRGDWDND]DPDOHIRWRQDSRQVNHVXVWDYH
napajanja....................................................................................................................... 257
Johan Bekker, M. Viljoen
Mobile Solar-Powered Business Unit for Off-Grid Areas in South Africa
0RELOQLVRODUQLSRVORYQLXUHÿDM]DSRGUXþMDL]YDQPUHåHX-XåQRDIULþNRM5HSXEOLFL

267

JakRYâLPXQRYLüF. Barbir
Simulation and Analysis of an Electrolyzer Operation in a Stand Alone
Renewable Energy System
Simulacija i analiza radnog procesa elektrolizatora u neovisnom sustavu
obnovljivih izvora energije...........................................................................................

277

RREHUW*UDGHþNL/M0LãþHYLü,VWUDåLYDþNRPHGLFLQVNLFHQWDUQDJHRWHUPDOQRPL]YRULãWX
Medical Research Centre on a Wellhead......................................................................

287

Luka Boban, V. 6ROGR00DQGLüBorehole Temperature Distribution During Thermal Response Test
Razdioba temperatura u bušotini tijekom ispitivanja toplinskog odziva tla................. 295
Mitja Košir, 5.XQLþ%+XGRELYQLN/3DMHN
Transient Thermal Response Analysis of Opaque Building Envelopes forEnergy Efficient Construction$QDOL]DQHVWDFLRQDUQRJWRSOLQVNRJRG]LYDQHSUR]LUQLKRPRWDþD]JUDGH]DHQHUJHWVNLXþLQNRYLWXJUDGQMX………………………………………………………

305

Leila Luttenberger, L. Runko Luttenberger
3RYHüDQMHXþLQNRYLWRVWLMDYQHUDVYMHWH
Increasing the Efficiency of Street Lightning.............................................................

315

MDULQHOD.UVWLQLü1LåLü
8þLQNRYLWR NRULãWHQMHHQHUJLMHXWXULVWLþNLPREMHNWLPD
Energy Efficiency Solutions in Tourist Facilities …………………………………..

327%RMDQĈXULQ/%DLü
Functional Dependencies of the Size of Certain Parts of the Energetically andHydraulically Sustainable Urban Water Supply System Driven by Solar
Photovoltaic Energy)XQNFLRQDOQH]DYLVQRVWLYHOLþLQDSRMHGLQLKGMHORYDHQHUJHWVNLLKLGUDXOLþNLodrživog urbanog vodoopskrbnog sustava pokretanog solarnom fotonaponskom
energijom…………………………………………………………….......................... 337
Živa Kristl
Implementation of Innovative Energy Retrofitting Measures in Heritage
Buildings – A Review
Provedba mjera energetske prilagodbe u zgradama baštine - pregled……………….

349

Katharina Karner
Smart City through Synergies with Industry
Pametni grad kroz sinergiju s industrijom…………………………………………...

359

Vedran Mrzljak, 76HQþLü, I. Poljak
Thermodynamic Property Analysis of Operating Substances in Diesel Engine
Cylinder Process$QDOL]DWHUPRGLQDPLþNLKVYRMVWDYDUDGQLKWYDULXFLOLQGru dizelskog motora……..

369'RPDJRM3HUOLü0RGHOLUDQMHLXSUDYOMDQMHKLEULGQLPHOHNWULþQLPSRJRQRPgradskog autobusa
Modeling and Control of a Hybrid Electric City Bus………………………………

381

TRPLVODY6HQþLü/6ODYLþHN7*XELü
Simulacija potrošnje goriva u realnim uvjetima cestovnog prometa
Consuption for Real Road Traffic Conditions……………….……………………..

395

Goran Gregov, '%UQþLü
Numerical Simulation of a Parallel Hydraulic Hybrid System for a Delivery
Van
1XPHULþNDVLPXODFLMDSDUDOHOQRJKLGUDXOLþNRJKLEULGQRJVXVWDYD]DGRVWDYQR
vozilo...........................................................................................................................

409

Ahmet Can, G. Inkun, M. Baspinar
High Heat Efficient Heater Core and Experimental Studies
9LVRNRXþLQNRYLWDMH]JUDJULMDüHJWLMHODLHNVSHULPHQWDOQHVWXGLMH…………………

415

Stipe 9XOHWLüP. Blecich, B. )UDQNRYLü
7HUPRGLQDPLþNDDQDOL]DSORþDVWRJL]PMHQMLYDþDWRSOLQH
Thermodynamic Analysis of a Plate Heat Exchanger………………........................

425

,JRUýDWLü, A. .QHåHYLü(Tro)jedinstvo informacije, energije i materijeTri(uni)ty of Information, Energy and Matter…..…………………………………..

435

7LQD%DXWRYLü=.RUGLü53DãLþNR
Bringing Decentralized Energy Solutions in Central Asia
8YRÿHQMHGLVWULEXLUDQLKHQHUJHWVNLKUMHãHQMDXFHQWUDOQRM$]LML.................................

447

Stjepan Strelec ,M. Golub , K. Grabar , M. Marciuš
2GUHÿLYDQMHSDUDPHWDUDYRGRQRVQLND]DSRWUHEHVXVWDYDGL]DOLFDWRSOLQH
Aquifer Parameters for the Purposes of Heating Pump System…………………….. 457
Peter Novak
Exergy as Measure of Sustainability of Energy System
Eksergija kao mjera održivosti energetskog sustava..……........................................

467

Vedran Mrzljak, T. 0UDNRYþLü, I. Poljak
Quasi-Dimensional Numerical Model of Fuel Evaporation and Combustion in
Diesel Engine
Kvazi-GLPHQ]LMVNLQXPHULþNLPRGHOLVSDUDYDQMDJRULYDLL]JDUDQMDXGL]HOVNRP
motoru ………………………………………………………………………………

483,YDQâRLüP. Blecich, B. )UDQNRYLü
7HUPRGLQDPLþNDDQDOL]DL]PMHQHWRSOLQHLprijenos tvari u rashladnom tornju
Thermodynamic Analysis of Heat and Mass Transfer in a Cooling Tower………… 497
Sabina Jordan, J. Hafner, F. Knez, A. Legat, M. Zbašnik-6HQHJDþQLN
Feedback Information on the Dynamic Simulations with Trnsys Model of
Office Equipped with Radiant Heating and Cooling Ceiling Panel System
3RYUDWQHLQIRUPDFLMHGLQDPLþNHVLPXODFLMH7UQV\VPRGHODXUHGVNRJSURVWRUDRSUHPOMHQRJVXVWDYRPJULMDQMDLKODÿHQMDSRPRüXVWURSQLKSORþD«««................

509

5REHUW%HGRLüV. Filipan
Impact of Real Working Media Properties on the Energy Characteristics of aCompression Heat Pump
Utjecaj karakteristika realnih radnih tvari na enHUJLMVNH]QDþDMNHNRPSUHVLMVNH
dizalice topline ……………………………………………………………………....

519$ULV7HUOHYLü3%OHFLFK%)UDQNRYLü
Korištenje infracrvene termografije za pREROMãDQMHHQHUJHWVNHXþLQNRYLWRVWL
opreme u procesnoj energetskoj industriji
Using Infrared Thermography to Improve the Energy Efficiency of Equipmentin
the Process Energy Industry…………………………………………………………

529

0DWHR.LULQþLü, K. /HQLü$7US(QHUJHWVNDLHNVHUJHWVNDDQDOL]DFLMHYQRJL]PMHQMLYDþDWRSOLQH
Energy and Exergy Analysis of a Shell and Tube Heat Exchanger………………...

537

Borna Doracic, T. Puksec, T. Novosel, N. Duic
Renewable District Heating: Case Study Croatia
2EQRYOMLYLFHQWUDOL]LUDQLWRSOLQVNLVXVWDYL$QDOL]D+UYDWVNRJVOXþDMD……………..

547

Miha Praznik
2SWLPLUDQMHXJUDÿHQHLRSHUDWLYQHHQHUJLMHWHSULSDGDMXüLKHPLVLMD&22 u
HQHUJHWVNLXþLQNRYLWLP]JUDGDPD
Optimization of Embodied and Operational Energy and Corresponding CO2
Emissions in Energy-Efficient Buildings……………………………………………

559

Miha Praznik, Z. 9HUãLü
Utjecaj naprednog energetskog modeliranja na optimiranje energetskih
koncepta zgrada
Impact of Advanced Energy Modeling in the Optimization of Building Energy
Concept ……………………………………………………………………………...

569

0DWLMD3DYLþHYLü71RYRVHO73XNãHF1'XLü
Anual Heat Storage Optimisation in Urban Regeneration Projects from an
Energy Planning Perspective
2SWLPL]DFLMDYHOLþLQHWRSOLQVNRJVSUemnika na godišnjoj razini u projektima
urbane obnove iz perspective energetskog planiranja………………………………

581

DieJR.R]ORYLü
Energetic Rehabilitation of a Protected Historical Building in Rijeka - Croatia(QHUJHWVNDREQRYD]DãWLüHQHSRYLMHVQH]JUDGH u Rijeci.............................................

595

Tomislav 6HQþLüR. Ljubek
Simulacija procesa u komori izgaranja plinske turbine
Gas Turbine Combustion Chamber Process Simulation………………………….....

605

5DGRYDQ.DUDEDLü
Ostvarenje i iskXVWYRQDSDVLYQRMNXüL6DODWLüQDRWRNX.UNX&RQVWUXFWLRQDQG([SHULHQFHRI3DVVLYH+RXVH6DODWLüRQ,VODQG.UN………….….

615

Frano Barbir
Role of Hydrogen in Energy Systems with Large Share of Renewable Energy
Uloga vodika u energetskom sustavu s velikim udjelom obnovljivih izvora
energije………………………………………………………………………………

617

MDUN0LãþHYLü/M0LãþHYLü
3UYDSDVLYQDNXüDVSUHGJRWRYOMHQLPIDVDGQLPVXVWDYRPRGUHFLNOLUDQRJJUDÿHYLQVNRJDJUHJDWDThe First Passive House with Prefabricated Façade System of Recycled Building
Agregate..……………………………………………………………………………

619

Wilhelm Servis
Utjecaj sniženja temperature rashladnog spremnika na karakteristike
Stirlingova motora
Influence of Lowering the Cooling Temperatures on the Stirling Engine
Characteristics………………………………………………………………………

629

Indeks autora
Author Index……………………………………………………………………..…

647

1. KONFERENCIJA

Energy and the Environment (2016) 1-20

1

CLIMATE CHANGE, ENERGY SECURITY, AND INNOVATION:GEOPOLITICAL CHALLENGES TO THE EU
Branko Bošnjaković1
Château de Tannay, CH-1295 Tannay, Switzerland
Tel: 0041227769416; Email: branko.bosnjakovic@bluewin.ch

Abstract : EU sees itself still as a world leader in coping with the challenge of climatechange. But outbursts of geopolitical conflicts in its neighbourhood – Ukraine, Middle East,
North Africa - have demonstrated how vulnerable its security, and in particular the energy
supply security is due to EU’s dependence on import oil and gas. The Paris Climate
Agreement is a challenge to the EU in geopolitical terms both at the global and the Union
membership level. The paper addresses the interlinkages and prospects of EU’s climate andenergy policies with respect to global responsibility and national security interests. The
ethical dimension is addressed in terms of how to fairly allocate responsibility among nations,regions and states, both by reducing GHG emissions to non-dangerous levels, and byadapting to (inevitable) consequences of climate change. At the same time the fundamental
values of the EU may be at stake if the security dimension of all EU member states is notguaranteed. Both ethical and security challenges EU is confronted with point strongly
towards accelerated introduction of a low-carbon economy and corresponding infrastructure,with renewables, and energy efficiency to play central roles in the medium/long term. A
review of the literature shows that continuing import dependence on oil and gas, includingfrom Russia, is a risk factor both in economic, political and environmental terms. The paper
refers also to the globalinterlinkage between innovation, investment and government policies,
as highlighted in the latest IEA report. Some recently proposed or implemented policy
responses within the EU are briefly reviewed and critically evaluated.
Key words: Climate change policy, Energy security, EU, Geopolitics.

Introduction
In his recent annual State of the European Union speech, European Commission President
Juncker stated the EU is facing an existential crisis [1]. Whereas he implied that commonality
between EU member states has never been so low, one could add as well old and new externalrisks – in particular the geopolitical ones – that may hamper or even endanger the functioningof the Union.
The present paper attempts to give a sketchy impression of risks (including opportunities)
that might be qualified as geopolitical – mainly generated by recent developments outside theUnion, but in some cases also within – that are relevant for the highly connected areas of1

Dr. Bošnjaković is former Regional Adviser for Environment of the UN Economic Commission for Europe,
Geneva.

2

B. Bošnjaković: Climate change energy security and innovation…

climate change, energy security, and innovation. The paper will not try to give in all cases a
detailed analysis of the underlying issues. When discussing the challenges, the focus will beon the alternatives, dilemmas and controversies experienced within the EU around a numberof selected issues, and the possible ways how to resolve them. Much of the material is basedon a previous paper by the author [2]. The selected issues may by no means be considered as
exhaustive.
The paper is subdivided into two main chapters: geopolitics of climate change, geopolitics ofenergy security; plus a shorter one on innovation and investment. Each chapter consists of anumber of sections, the titles of which are often formulated with question marks. The chapters
are followed by conclusions, and a list of selected literature.

Geopolitics of climate change
Is the EU still the leading player on the path to mitigate climate change?
In a recent critical evaluation of the December 2015 Paris Climate Agreement, Raymond
Clémencon argues that it does not provide a blueprint for achieving the stabilisation objectiveof 2°C – even less a 1.5 °C warming – over pre-industrial times. In this sense, the Parisoutcome is an aspirational global accord that will trigger and legitimise more climate action
around the world. It will not occur without determined and far-reaching government
intervention in energy markets in the next few years, particularly in the largest polluting
countries [3]. The Paris Agreement is built entirely around voluntary country pledges – asdifferent as the countries they are coming from – which are still far from adding up toachieving the objectives the agreement defines. In an ensuing article, the same author claims
that the pressure on EU countries to abandon leadership role on sustainable development is
growing [4]. However, no other source of global leadership is emerging that could fill the gap.
Over the last two decades, international negotiations, civil society activism, and private sector
initiatives on their own have not been decisive factors shaping outcomes. EU countries –where Green Parties at times have been able to critically shape policy direction – are the only
actors that have developed the long-term socio-political and economic foundation for acoherent approach to sustainable development. Such structural foundation on the other hand is
missing in the United States, in Russia and in key emerging economies. This means that theEU must continue to lead because without it there will be no coherent political leadership on
global environmental issues.
The above analysis still leaves the question open about the adequacy and coherence of the EU
climate policy goals.
How adequate are the projected EU emission reductions for achieving the goals of theParis agreement?
Even before the 2015 Paris summit, the European Commission proposed in January 2014 a“Policy framework for climate and energy in the period from 2020 to 2030” [5], and the EU
Council adopted in October 2014 the “2030 Climate and Energy Policy Framework” [6]. The
two documents maintain EU´s ambitious role when coping with the challenges of climatechange. They reflect not only the different positions among Member States, but also theEnergy and the Environment (2016) 1-20

3impact of the dramatic developments in the neighbouring Ukraine. As far as the CO₂ emission
target is concerned, the division lines run roughly between Eastern European countries led by
Poland (advocating a less stringent target), the Western and Scandinavian countries, which arein favour of sharp, nationally binding targets, while France is (still) endorsing nuclear energy,
and Germany and Denmark demand additional policies favouring renewable andcorresponding investments in electricity networks [7]. An additional – serious – uncertainty
are the still unknown consequences of Brexit.
The 2030 Climate and Energy Policy Framework may be seen as an intermediate step between
the 2020 package (abbreviated as 20-20-20 targets, presently under implementation), and thevery ambitious European ambitions for reaching in 2050 80% to 95% less CO2 emissions thanin 1990, as presented in the EU 2050 Roadmap [8]. Progress towards the three targets to beattained by 2020 (20% reductions for greenhouse gas emissions reductions, 20% share of
renewable energy; 20% improvements in energy efficiency) may be summarised as follows [5]:xGreenhouse gas emissions in 2012 decreased by 18% relative to emissions in 1990
and are expected to reduce further to 24% lower than in 1990 by 2020.

x

The share of renewables in final energy consumed has increased to 13% in 2012 andis expected to rise further to 21% in 2020.

x

The EU had installed about 44% of the world's renewable electricity (excludinghydro) at the end of 2012.

x

The energy intensity of the EU economy was reduced by 24% between 1995 and2011 whilst the improvement by industry was even 30%.

x

Less successful has been progress in improving energy efficiency [9]: energy savings
will amount to 18-19% in 2020, with one third of this progress due to the lower than
expected growth during the financial crisis.

The political process within the EU leading to the adoption of the 2030 target for renewables
and for the emissions reduction revealed two main dividing lines.
First dividing line: renewables’ target
In the recent years, renewable energy has been a great success world-wide but in some ways
also a disappointment, depending on the point of view. It was a success, because in 2013 it
contributed nearly a half of all newly installed energy production capacity [10]. Its
contribution rose from 7.8% to 8.5% in 2013 alone, corresponding to world-wide investmentsof 214 billion US$. It was a disappointment, because world-wide investments into renewables
decreased in two subsequent years 2012 and 2013. Investments in the EU went down by 44%
to 48 billion $ in 2012 only, whereas in 2013, China invested 56 billion US$, thus becomingworld head runner. Whereas the cost price of solar and wind electricity has been decreasing
sharply since 2009, both sources are still dependent on state subsidies. At the same time, it
should be kept in mind that worldwide annual subsidies for fossil energy are still in the orderof 500 billion US$.
Renewables’ possible contribution to the CO₂ emission reduction has disappointed recently
both at the world and the EU level. At the world level, because renewables’ growth could notcompensate the even larger growth of fossil utilisation in the rapidly growing emerging

4

B. Bošnjaković: Climate change energy security and innovation…

economies. In the EU, the initially spectacular role of renewables has been slowing down forsome very specific reasons that vary from country to country. The German sustainable energy
policy has been confronted with several serious problems since 2012: (1) increasing subsidy
costs of renewable electricity and how to allocate them; (2) consequences of the rapidly
increasing solar and wind contributions for the functioning of the electricity market; (3)increasing GHG emissions from the electricity sector;(4) inadequacy, in both qualitative andquantitative terms, of the present transmission and distribution networks, and of storage
capacities, to cope with the rapid extension of the renewable electricity. The fluctuating andirregular production of solar and wind electricity was causing repeatedly destabilisation ofelectric grids: the incidence of grid perturbations increased by 30% between 2010 and 2013[11]. Several EU Member States like Spain and Italy have been experiencing similar problems
with the subsidised introduction of renewable energy [12]. Recent proposals concerning therevision of the German legislation are not likely to give an answer to the increasing CO₂
emissions. One way out would be a stricter ETS (Emission Trading System) regime at the EU
level. In its present form, with a too low price of less than 10 Euro/t for CO₂ emissions under
the present ETS, there are practically no incentives to switch over from fossil to renewableenergy.
Moreover, a number of EU states like UK and the Netherlands, which exploit and export
natural gas, have in financial respect no strong incentive to adopt nationally binding targets
for renewables. This may explain the 2014 decision by Britain [13] when Prime Minister
Cameron, in response to dependence on Russian gas imports, referred not only to thepossibility of imports from US and Iraq, but also for more European shale gas and nuclear
energy. Poland, with presumably largest shale gas reserves in Europe, is another advocate of
shale gas.
Second dividing line: CO₂ emission reduction target
In 2012, with respect to 1990, GHG emissions in the EU decreased by 18% - partly due to theeconomic restructuring in Eastern Europe and the economic crisis. Being presently
responsible for 11% of the annual global emissions, a further reduction of 40% by 2030
would contribute only 4.5% to the global emissions in 1990 – and relatively even less in viewof the worrying high level of emissions world-wide today. Conservative European politicians
and industry representatives argue that since coping with global warming can be reached only
through global action, Europe should not adopt ambitious targets as long as a global
agreement on binding targets has not been reached (“world would still be getting warmer, but
Europe poorer”). Green and allied politicians, on the contrary, argue that Europe must show
leadership by demonstrating that an ambitious climate policy can deliver green growth andemployment, thus setting an example for the rest of the world. Within the EU, most states andthe European Parliament supported the 40% reduction target. For countries like Denmark,Germany and The Netherlands, this was the minimum. Poland did not agree and finds supportof most countries of Central and Eastern Europe. Finally, two arguments acted in favour of a
40% reduction target: (a) emission reduction of less than 40% would make a target ofemission reduction by 80% or 95% in 2050 even less credible; and (b) reduced availability ofEnergy and the Environment (2016) 1-20

5

Russian gas due to the crisis in the Ukraine, strengthened the advocates of a more rapid
decarbonisation of economy.
The key elements of the 2030 Climate and Energy Policy Framework adopted by the EU
Council on 23 October 2014 are as follows [6].
A binding greenhouse gas 40% reduction target below the 1990 level, to be met throughdomestic measures alone; the reductions in the ETS and non-ETS sectors shall amount to 43%
and 30% by 2030 compared to 2005, respectively.
A well-functioning, reformed Emission Trading System (ETS). The annual reduction in the ‘cap’
on emissions from EU Emission Trading System (ETS) sectors will be increased from 1.74%
now to 2.2% after 2020.
Renewables and energy efficiency. An EU-wide binding target of at least 27% is set for theshare of renewable energy in 2030. It will not be translated into national targets through EU
legislation, thus leaving flexibility for Member States to transform the energy system in a waythat is adapted to national preferences and circumstances. The integration of rising levels ofintermittent renewable energy requires a more interconnected internal energy market andappropriate back up. An indicative target at the EU level of at least 27% is set for improving
energy efficiency in 2030. It will be delivered in a cost-effective manner and it will fully
respect the effectiveness of the ETS-system in contributing to the overall climate goals.This
will be reviewed by 2020, having in mind an EU level of 30%.
The 2030 Climate and Energy Policy Framework moreover emphasises the importance andurgency of (a)Achieving a fully functioning and connected internal energy market;(b) Better
governance by coordinating of national energy policies; and (c) Ensuring energy security by
reducing EU's energy import dependence.
How successful are EU´s climate adaptation policies?
According tot he European Commission, Europe is warming faster than many other parts of
the world, on average 1.3°C higher than in the pre-industrial era, compared with a global
average rise of 0.8°C. Impacts vary across the EU: the Mediterranean basin, mountain areas,
densely populated flood- plains, coastal zones, outermost regions and the Arctic areparticularly vulner- able to climate change impacts. Some extreme weather events haveincreased, with southern and central Europe seeing more frequent heat waves, forest fires anddroughts. Heavier precipitation and flooding is projected in northern and north-eastern
Europe, with a heightened risk of coastal flooding and erosion[14]. One main objective of the
EU Adaptation Strategy is promoting adaptation in key vulnerable sectors through agriculture,
fisheries and cohesion policy, ensuring that Europe’s infrastructure is made more resilient,and encouraging the use of insurance against natural and man-made disasters. Implementation
oft he EU Adaptation Strategy is based on 8 actions, among which 5 seem to be most
relevant: encourage all Member States to adopt comprehensive adaptation strategies;
introduce adaptation in the Covenant of Mayors framework; facilitate the climate-proofing of
the Common Agricultural Policy (CAP), the Cohesion Policy and the Common Fisheries
Policy (CFP); ensuring more resilient infrastructure; promote insurance and other financial
products for resilient investment and business decisions.
By 2012-2013, on the national level — and at the city and regional levels — implementing
adaptation was still at an early stage [15], [16]. Most progress has been reported

6

B. Bošnjaković: Climate change energy security and innovation…

for freshwater management, flood-risk management, and agriculture. Although adaptation
implementation is still at an early stage, adaptation planning work is underway in mostcountries. As of June 2014, 21 EEA member countries have adopted national adaptation
strategies, and a majority oft hem have also developed national implementation plans [17] .
By 2015, urban adaptation has taken off, with 650 European cities participating in European
and global city initiatives [18] .
Climate change as possible cause for the increasing number of migrants and refugees
seeking to enter the EU?
Whereas there is no doubt that there are and will be more climate refugees in the world, themost clear-cut cases have so far been restricted to island states in the Pacific and the Indian
Oceans, which are being increasingly flooded by the rising sea level. The case of migrants
and refugees from North Africa and the Middle East – the main source of displacement to the
EU – is less clear. Of course, climate change was not responsible for the Arab Spring and thewars, terrorism and displacement that followed in its wake. The causes were multiple andinter-related. But perhaps climate change was a malign background presence, nudging thingsin the wrong direction and weighting the dice in favour of disruptive, unpredictable chains ofevents. For this reason, the security community has labelled climate change a 'threat
multiplier'.[19] As such, climate change’s influence on displacement will be difficult todisentangle from the web of other social, economic and environmental factors that shapemigration patterns. It will act at the margin, so most climate-related migration is unlikely tooccur en masse.
Is there a historic responsibility of the EU member states for climate change?
Müller, Höhne and Ellerman [20] consider the politically sensitive issue of differentiating(historic) responsibility for, and not merely (causal) contribution to climate change. Bothconcepts may be used to apply the UNFCCC principle of common but differentiatedresponsibilities. The cumulative sum of a country’s historical emissions is one indicator thattries to capture the contribution a country has made to the climate change problem. In mostcases a country’s historic share of global emissions differs from its current share. For mostindustrialized countries, the historic share is higher, in many cases significantly so. Baumert
et al. [21] discuss various approaches how to assess historic contributions. The outcomes
depend on many assumptions, in particular whether CO₂ from land-use change is taken into
account, and the time period chosen. Proposals that rely on historical emissions prior to 1990
are unlikely to receive widespread support, in part due to data constraints. No official countrylevel data exists prior to 1990. Baumert et al. conclude “that it is unlikely that this concept canform the core of an agreement, or could be assessed in a manner reliable enough to be thebasis for legal obligations”. Leal-Arcas [22] argues that a more effective (and presumably
fairer) way to tackle climate change today is by bringing on board the major GHG emitters,
irrespective of their GDP, and asking them to reduce their GHG emissions in an equitablemanner without ignoring the historic responsibilities on the part of developed countries. Thismeans that, next to the responsibility of Western countries including many EU member states,
the BRICS countries (Brazil, Russia, India, China, and South Africa) are part of the solution

Energy and the Environment (2016) 1-20

7

to climate change mitigation. Climate change will have a significant impact on the BRICS.
Conversely, the expected impact of the BRICS on climate change is considerable.
Could authoritarian or autocratic tendencies in certain countries, especially outside theEU, lead to less stringent climate change policies? There is no general answer to thatquestion, but in many cases the answer is affirmative. On the eve of the G20 summit inHangzhou, the United States and China, the world’s biggest emitters of greenhouse gases,
have announced they will formally ratify the Paris climate change agreement [23]. Donald
Trump, the US Republican candidate for Presidency has been criticised for inonsistentrhetoric, but as far as man-made climate change is concerned, he is consistently disbeliever
and would be world´s only national leader to reject climate science [24]. Putin´s Russia has so
far given mainly lip service to the goals of climate change mitigation efforts [25]. On theother hand, Turkish President Erdogan, Putin´s geopolitical rival (or friend depending on thecircumstances), called for urgent action on climate change in light of its impact on the poor indeveloping countries, which he defined as a moral issue [26]. Among the European politicalparties with authoritarian and anti-EU tendencies, skeptical attitudes towards climate sciencecan be found in particular with Le Pen´s „Front National“, Geert Wilders´ PVV, UKIP in theUK, and the AfD in Germany. Their coming to power would quite probably water down thepresent EU goals and policies with regard to climate change.

Geopolitics of energy supply security
The energy policy of the EU is based on three main pillars: sustainability (with a strong
climate component); security of energy supply; and competitiveness through market
liberalisation. Due to financial and economic pressures, all three pillars are full of
uncertainties. Energy security is additionally threatened by the geopolitical factors and thelack of a coherent external energy policy. Market liberalisation, and thus competitiveness, isunder pressure by protectionism. Environmental sustainability is put in question by related
costs. The three challenges – competitiveness, sustainability and energy security – aremutually partially supporting, but partially contradicting.
With reference to the fundamental principles of the EU (free movement of goods, capital,
services, and people), the EC has been promoting market liberalisation as the basis for theefficiency of the energy sector and the competitivity of the economy as a whole. The energy
sector must conform to the general principles of the free market, in particular to the generalanti-monopoly laws such as those referring to free price formation and prohibition of pricefixing by monopolistic interest groups. In addition, between 1996 and 2003, several directives
and regulations aiming specifically at gas and electricity sectors were adopted, requiring thattransmission grids be be managed independently from production and supply. The aim was tothoroughly transform gas and electricity industries from monopolistic conglomerates into
competitive markets.
There have been dividing lines within the EU between the Commission, Parliament, theMember States and various interest groups with respect to several issues of energy sector
liberalisation. France, and partly Germany, were against dismantling of big (national) energy

8

B. Bošnjaković: Climate change energy security and innovation…

companies; and there was no common will to reduce the generous allocations of industrial
emissions under the ETS (Emission Trading System).
After numerous failed attempts to finalise bilateral energy co-operation agreements with
Russia, the Commission has proposed a tough 'reciprocity clause' for energy relations
with third countries. The move is widely seen to be targeted at Russian state-controlledenergy giant Gazprom. The reciprocity clause was inserted as an apparent response to fears
that ownership unbundling - the separation of integrated energy firms' production assets fromtheir transmission assets - would lead to the indiscriminate acquisition of EU energy grids by
third countries. This “Gazprom clause” was, and still is playing a key role in the response of
the EU to the Ukraine crisis.
Neither of above mentioned instruments was able to give a definitive and effective response
to a number of significant challenges and developments within and beyond the borders of the
EU. These include: (1) the high import dependence of the EU (54% of internal energy
consumption of EU-27 in 2010 is based on imports; with dependence until very recently
increasing); (2) technological improvements of the main competitors (exploration andhorizontal drilling in deep ocean, “fracking” technology for shale gas and oil); (3) new
potential directions of energy supply (new gas and oil pipelines from Central Asia; cheaper
gas in the USA, and thus cheaper coal from the USA; USA on the way to US energy importindependence; plans for the exploration and drilling in the Arctic Ocean); (4) ascent of newenergy producers: Africa, Latin America. All these challenges will remain unanswered unlessthe EU succeeds in adopting a common and coherent external energy policy.
How critical is EU´s energy import dependence?
Over a period of 20 years, import dependence has increased by almost a quarter due to declineof EU production of oil, gas and coal. However, since 2006, the increasing share of
renewables as well as the reduction of overall demand contributed to a stabilisation of importdependency. Oil constitutes at almost 90% one of the largest shares of import dependency,
followed by 66% for gas and 62% for coal. The lowest import dependency of 4% occurs forrenewable energy. Nearly all Member States are heavily dependent as the majority of them
import more than 50% of their energy. Poland and UK have gone from having an energy
surplus to a significant deficit, Denmark has changed from deficit to slight surplus. Based ondata extracted in July 2016, more than half (53.5 %) of the EU-28’s gross inland energy
consumption in 2014 came from imported sources [27]. Of particular relevance for some EU
member states has been their dependence on gas imports from Russia. Development ofmarkets and gas infrastructure (interconnectors, reverse flows and storage) are improving
resilience, but a short term winter supply disruption through Ukraine transit routes may posesignificant challenges to some member states. The Baltic States, Finland, Slovakia andBulgaria were until recently dependent on a single supplier – Russia’s state-owned Gazprom for their entire gas imports (Fig. 1).

Energy and the Environment (2016) 1-20

9Fig. 1: Dependence of EU member states on natural gas supplies from Russia (2014).
Horizontal axis: % of natural gas in the energy mix; vertical axis: % of Russian natural gas in national
natural gas consumption; size of circles: volume of imported Russian natural gas. [28]How vulnerable is the EU with regard to the use of gas/oil as political weapons byexporting/transit countries?
After the collapse of the Soviet Union and its satellite governments in Central and Eastern
Europe, the EU has sought to entangle those energy-rich states (or otherwise ‘energysignificant’, e.g., regarding energy transit) into multilateral regimes – such as those based on
the Energy Charter Treaty (ECT) and the Energy Community (EnC). In the case of the EnC,
the EU is afforded a prominent position in that certain areas of its acquis are inducted into the
EnC’s legal order; the EnC is essentially the realization of original EU external energy policy
ambitions with those states between it and its main energy supplier, namely Russia [29]. A
recent paper [30] analysed the critical energy risks in the OSCE area. Natural gas trade via
pipeline is most closely associated with conflict, followed by electricity trade. Energy flows
crossing multiple borders, jurisdictions, conflict zones, or disputed areas are also a source oftensions as well as rapid changes in energy markets. The security of critical infrastructure,whether from physical or cyber-attac, is a concern for many OSCE countries. The issue of
regulatory fault lines is less understood but more prevalent: this is particularly salient in the
EU and Russia´s common neighbourhood, where neither EU nor Russian law applies or is
porpoerly implemented and enforced.
During the last decade, however, EU has been confronted with a Russia using its energy
exports as a political weapon against its poorer members that were previously under Soviet

10

B. Bošnjaković: Climate change energy security and innovation…

domination. Putin’s Russia attempted “to play off wealthy Western Europe against poorer
Eastern members by offering price flexibility to France and Germany while treating a Poland,a Bulgaria, or an Estonia as if they still fell under the Brezhnev Doctrine. That was the Soviet
Union’s notion of its immediate neighbours’ limited sovereignty, reiterated by President
Dmitri Medvedev after Russian troops entered Georgia in 2008” [31]. In response to thatdevelopment the European Commission opened formal proceedings against Gazprom on 31
August 2012, which resulted in April 2015 in a Statement of Objections to Gazprom alleging
that some of its business practices in Central and Eastern European gas markets constitute anabuse of its dominant market position in breach of EU antitrust rules [32]. Gazprom isallegedly hindering competition in the gas supply markets in eight Member States (Bulgaria,
the Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland and Slovakia) byimplementing an overall abusive strategy in these gas markets, in particular through:territorial restrictions; unfair pricing policy; and by making gas supplies conditional on
obtaining unrelated commitments from wholesalers concerning gas transport infrastructure.
Lithuania claimed almost €1.3 billion compensation from the company at an international
arbitration in Stockholm for allegedly "unfair" gas prices [33].
Russia’s strategic attitudes and means when using energy/gas as economic and political
weapon in the ongoing post-Cold-War confrontation may be characterised as follows.
(a) Assigning high priority to the extension of territorial control, this in contrast to lower
priority, or systemic inability, for innovation.
(b) Striving to cement Gazprom dominance in the EU gas market [34]. On that account,trying to bypass, or even discipline, possible troublemakers (former Soviet republics
like Baltics, Belarus, Ukraine, or former Central Europe satellite states like Czech
Republic, Poland, Slovakia)2; relying upon willing countries like Greece, Hungary,
Serbia; and in case of serious resistance, as in Ukraine, by military intervention.
(c) Increasing foothold in Germany, and Austria, both with excellent record for long-term
energy contracts with Russia, by strengthening their roles as transit countries for otherEU member states [37]. This implies extension and vertical “bundling” of gas
infrastructures owned by Gazprom, including ownership of pipelines from Russia to
Germany and Austria, of critical gas storage on EU territory, as well of pipelines
connecting Germany, and possibly Austria, to other EU member states, if needed bybreaching EU law.
(d) Making use of the weaknesses of the EU, such as: lack of a common and coherent EU
external energy policy; high dependency of some EU member states on gas imports
from Russia; poor or inconsistent implementation of relevant anti-monopoly and“unbundling” EU legislation, even within the EU member states.
Cases illustrating the above contentions are among others: the history and ongoing evolutionof the Nord Stream Pipeline; the failed South Stream Pipeline, and its alternatives; and theassociated political and legal controversies. As a common denominator, Moscow awards
lucrative production and service contracts to major European companies to execute
Gazprom’s pipeline projects in Europe. Such contracts help generate political support within
the EU for Gazprom’s projects, sometimes irrespective of the EU’s energy legislation. A new
chapter in the game concerning the expansion of the Nord Stream pipeline was opened in
2
A Swedish Defence Research Agency study counted over 55 incidents 1991 and 2007, most with “bothpolitical and economic underpinnings” [35], [36].

Energy and the Environment (2016) 1-20

11early September 2015 when Gazprom and its European partners (E.ON, ASF/Wintershall,
OMV, ENGIE and Royal Dutch Shell) signed a shareholders' agreement on the Nord Stream2 gas pipeline project (doubling the present transport capacity) that would bypass Ukraine andbring Europe closer into Moscow's energy orbit. Slovak Prime Minister Robert Fico said on
10 September 2015 that the deal was a "betrayal" that would cost Ukraine and Slovakia a
combined billions of Euros [38]. Slovakia’s and Poland’s presidents, Andrej Kiska andAndrzej Duda, announced on 2 October 2015 that they are against the construction of Nord
Stream 2 [39].
South Stream was planned as a pipeline to transport Russian natural gas through the Black Sea
to Bulgaria and through Serbia, Hungary and Slovenia further to Austria, with links to Croatia
and Macedonia. The project has created controversies, including due to non-compliance with
the EU competition and energy legislation. Three main issues have raised particular concern
in Brussels [40]. First, network ownership “unbundling” requires the separation of energy
supply and energy network provision. Gazprom had 50–51 percent ownership of the jointcompanies that were supposed to construct and own the pipeline. Second, Gazprom was notwilling to allow non-discriminatory access of third parties to the pipeline. Third, an
independent operator, instead of the pipeline owner(s), should have determined the transit
tariffs. On April 17, 2014 the European Parliament adopted a resolution stating that the SouthStream pipeline should not be built and the EU should look for other sources of supply to
reduce dependence on Russian gas [41]. The European Energy Community considered theagreements between Serbia and Gazprom as not in compliance with EU rules on competition[42]. In October 2014, Serbia announced it may have to suspend construction of the SouthStream gas pipeline through its territory, after Bulgaria said it was halting work on its
segment of the pipeline [43]. Russia has initially decided to take the dispute to the World
Trade Organization (WTO), but in December 2014, President Putin announced that the
proposed South Stream pipeline will not go ahead [44].
The demise of the South Stream led to a number of developments and speculations
concerning the supply of gas to Southern and South- Eastern Europe. Italy is increasingly
looking to the development of the Southern Gas Corridor (SGC), which would link gas fields
in Azerbaijan to the Italian/Adriatic region via Georgia, Turkey, Greece and Albania. On theother hand, Russia and Turkey agreed that Turkey’s energy imports from Russia via the Blue
Stream gas pipeline would increase from 16 to 19 billion cubic meters per year. The
agreement had the potential of increasing Turkey’s role as an energy hub in Europe, andignited a debate among energy experts as to whether the proposed Turkish Stream3 pipeline
would undermine hopes of one day constructing a Trans-Caspian pipeline between
Turkmenistan and Azerbaijan [45].
Russia’s geopolitical game has been hitting upon several obstacles. A particularly important
one was the Statement of Objections by the European Commission of April 22, 2015. But
there are several others, reflecting the growing impatience with Russia’s way of using gas
export as a political weapon.
(a) Ukraine’s negotiating position has improved, as its dependence on gas imports from
Russia was reduced. Thanks to EU market liberalization and Central Europe interconnections,
European energy companies are themselves gaining market share by reselling gas of Russian

3

Turkish Stream pipeline to run across the Black Sea from Russkaya CS near Anapa in Russia to Kiyikoy
village in the European part of Turkey, partly along the old corridor of South Stream.

12

B. Bošnjaković: Climate change energy security and innovation…

and other origins in growing volumes to Ukraine. Gazprom’s sales to Ukraine have declined
both in market share and in quantitative terms. [46](b) China business seems still uncertain [47]. Despite handshakes and high-profile events,
signs point to continued tensions in Russia-China energy ties. In 2006, President Putin agreed
to build two gas pipelines to China, one from the east and one from the west, but the twocountries have been at odds ever since over which should be given priority. Moreover, thedevelopments in Europe left China wondering why it should be stuck with a starting price of$350/mcm, when Gazprom was selling gas to Ukraine for much less. Gazprom’s complex
negotiations with China, together with expensive pipeline construction and complex new-fielddevelopment, will delay significant gas flows beyond 2020.
(c) Future role of Turkey as transit country has become extremely uncertain due to serious ups
and downs in its relationship to Rusia, the wars in neighbouring Syria and Iraq, and becauseof ongoing internal instabilities which the country has been undergoing during the lastmonths. These uncertainties are serious and must not be underestimated by the EU policy
makers.
Challenges to EU energy-gas security: disruption scenarios and responses
Civil unrest in Ukraine, disputes with Gazprom over natural gas prices and transit fees have
led to the fear of an interrupted natural gas supply to Ukraine and via Ukrainian transit
pipelines to the EU. In the spring of 2014 the situation seemed more severe comparable to2006 and 2009, but since 2009 both the global and the European natural gas sectors havesignificantly changed in various ways [48]. (a) Since the inauguration of the Nord Stream
pipeline in the late 2011, Russian exports via the Ukraine have diminished from 65% to 50%
of all Russian exports to Europe. (b) EU28 countries have reduced the share of Russian gas
imports from in total 50% in 2001 to 37% in 2012. (c) The EU regulation 994/2010
harmonised national emergency plans and led to expansion of EU interconnectors allowing
for reverse flows. (d) The import capacity of LNG in the EU has been expanded by 15%
between 2009 and 2014. LNG imports could still be increased since utilization rates are low
with only 30% on average in the EU in 2012. (e) While US natural gas imports have been
more than 50% lower in 2013 than in 2009, production has increased by almost 20% due to aboom in shale gas extraction. Some projections expect the USA to become a net exporter ofnatural gas as of 2020. (f) In 2012, natural gas consumption in the EU has been lower by 4%
than in 2009. This was due to the economic crisis and low CO₂ prices.
The EU seems to be better prepared for any disruption of Russian supply, with Russia being
dependent on its main customer. Asian market is an alternative, but in the short run actual
trade flows are limited due to a lack of production and transportation infrastructure.
Despite all progress, the disruption of Russian natural gas exports to Europe may have severe
consequences, in particular for several Eastern European countries. Richter and Holz [48]investigated in May 2014 the European natural gas market position, focusing on alternative
gas suppliers, and analysing the expansion of existing infrastructure. Their results indicatethat the EU LNG import capacity is insufficiently connected to the broader market.
Particularly, cross-border pipeline capacity restrictions prevent higher Spanish LNG imports
used for an efficient distribution across Europe. Similarly, Italy is poorly connected to central

Energy and the Environment (2016) 1-20

13Europe and cannot serve as transit country for African pipeline gas and LNG imports. Hencethe large total EU regasification capacity of 195 bcm cannot be completely used to balance
import needs in all member states.
The Russian-Ukrainian crisis of 2014 has revitalized the European concerns of supply
disruptions of natural gas. Despite being better prepared today, several East European
countries are highly dependent on Russian natural gas. LNG imports play a vital role inreplacing Russian gas, although a large part of the European LNG import capacity is not wellconnected to the broad market. More investments in the intra-European transportation
infrastructure are necessary to diversify the EU imports and balance the internal market4.
These include the connection of the Iberian peninsula and Italy to Central Europe to
distribute the large import potentials of both countries from North Africa and the global LNG
market. Pipeline expansions to reach the Baltics and Finland from Poland are advisable,
whereas investments in the Southern Corridor to bring gas from the Caspian region and the
Middle East via Turkey will depend on the geopolitical developments in that country.

How can the EU decarbonisation policy contribute to reduce energy import dependence?
A radical decarbonisation policy would be the proper approach to both reducing the highenergy import dependence of the EU, and to fulfilling the EU´s ambitions and obligations
with regard to GHG emission reduction. A brief look at Table 1 shows however that both
expectations are not likely to be easily fulfilled. Especially the ambition jump needed to takeplace between 2020 and 2050 seems at present overly optimistic. The 2030 goal for thecontribution of renewables is definitely not ambitious enough, and the path towards 2050 isplastered with uncertainties concerning the development of technology, investments andmarkets. A weak point of the policy is the low level of ambition with regard to energy
savings and energy efficiency. Another significant uncertainty is fed by potential politicalshocks – such as Brexit - and evolving national attitudes with regard to climate change andcorresponding decarbonisation policies in many EU member states. With regard to the future
EU role, the reader should note that the contribution of the EU countries to global emissions
is likely to become small by 2030, and probably negligible, by 2050.

Geopolitics (or geoeconomics?) of innovation and investment
With regard to climate-related and energy-related innovation and investment, the term „geopolitics“ may be a misnomer that could be replaced by „geo-economics“. Still some thoughts
need to be given to these issues as they contribute in a significant way to the global „balanceof power“ in the field of climate change and energy security.
4

Two examples may illustrate this point. Immediately after coming into power in 2010, the Orbán government
advocated a gas pipeline connecting Hungary and Slovakia, which was accomplished on 27 March 2013 thanks
to a subsidy by the EU [49]. Republic of Moldova, having an association agreement with the EU since 2 July
2014, is fully dependent on Russian gas, which comes through Ukraine and separatist territory of Transnistria. In
a tour de force act, Moldova is now being connected with the Romanian gas pipeline system. Its annual capacityof 1 bcm corresponds roughly to Moldova’s annual consumption of gas [50].

14

B. Bošnjaković: Climate change energy security and innovation…

Table1: EU climate change policy goals: indivisible from energy policy
2012

2020

2030

2050

EU EMISSIONSREDUCTION
RELATIVE TO 1990

- 15%

-20%

- 40%

-80% – 95%

RENEWABLESCONTRIBUTION

13%

20%

27%

?

+ 20% (?)

+ 30%

?

~8%

~5% (?)?

ENERGY SAVINGSAND EFFICIENCYCONTRIBUTION EU
TO GLOBALEMISSIONS~10%

In that context, a 2011 report by the International Energy Agency (IEA) has developed amatrix that situates climate change mitigation efforts of countries in the global context
according to the national energy security concerns and proactive measures to harness benefitsof renewable energy technologies [51]. The key point is that deployment of renewables – a
key factor in climate change mitigation efforts - depends critically on two factors: the GDP
and the energy import dependence. With regard to the change of energy import dependence
over time, countries can be grouped into four categories: (a) stable importers that try tocontain or reduce dependence (Germany); (b) former exporters that try not to become
dependent (China); (c) former importers that were successful in becoming independent(Denmark); (d) exporters that are not concerned due to large resources (Russia).
The most recent report by the IEA „World Energy Investment 2016“ [52] makes aninteresting reading. Some of its findings are highlighted below:--

Global energy investment in 2015 amounted to USD 1.8 trillion, down 8% from 2014 due
to a sharp fall in upstream oil and gas investment. China retook the top position in 2015,
largely due to the record level of electricity sector investment. Oil and gas still represent
the largest single category of global energy investement (45%). Investment in theelectricity sector rose to 37% oft he total, driven primarily by the expansion ofrenewables and networks. Structural changes (such as dominance of the services sector inmature economies: EU, Japan, US) reinforced investement in energy efficiency.
Wind, solar and hydropower are reshaping the electricity system. Renewable investment
has remained relatively stable since 2011, but investment supports an accelerated
production expansion due to declining technology costs.

Energy and the Environment (2016) 1-20

-

-

-

-

-

-

-

15

Unit capital costs of supply declined across the energy spectrum, with average cost
reductions in 2015 ranging from 3% in the case of onshore wind to 30% for US shale oiland gas. Projects representing over half of total energy investemnet experienced
significant cost declines, notably solar photovoltaics (PV), upstream oil and gas, andelectricity storage. Some technologies, such as nuclear power, CCS and energy-efficientbuilding renovations, risk falling behind in the future.
Cost reductions explain almost two-thirds of the fall in investment spending. The impactof wind and solar investment on gas-fired generation is far stronger than the competition
to oil in transport from alternative technologies.
Energy efficiency investment increased by 6% in 2015 despite falling energy prices.
Despite lower oil prices, sales of electric cars continue to increase rapidly, driven by
government policies in a growing number of countries.
A major shift in investment towards low-carbon sources of power generation isunderway. Renewables and nuclear capacity coming online in 2015 exceeds the entire
growth of global power demand in that year. The average carbon intensity of power
generation from new capacity worldwide continued to fall, reaching 420 kg of CO2 perMW-hour in 2015. This decline has been a factor in stagnation of global CO2 emissions
over the past two years.
Consumer-led spending under new business models – including distributed solar PV forhouseholds and businesses and corporate buying of renewable power – accounted forover 50 billion of renewable investment, led by the US, EU and Japan. Conventional
power generation investment has essentially come to a halt in the EU, where energy
security concerns are on the rise. Investment in electricity storage is growing but, at USD
10 billion in 2015, remains nowhere near big enough to allay fears of a shortfall in
dispatchable capacity.
The growing role of decentralised renewables production does not eliminate the need forcontinuing investment in the electricity network, given the limited prospects for largescale electricity storage in the medium term. The over USD 260 billion invested inelectricity networks globally in 2015 is a crucial component of energy security.
Energy markets around the world are generally well supplied at present, but investment
trends warn against complaceny about energy security. Investment in inter-regional LNG
chains and major pipelines is falling rapidly, in part a result of geopolitical constrains. In
the electricity sector, wind and solar are now meeting a substantial proportion of thegrowth in demand and annual prodution volumes, but integrating them effectively into
the power system rquires additional investment and changing operational methods. In
many countries including the EU, there is a policy debate about the ability of the current
regulatory institutions to achieve this. Investment in flexible types of electricity
generation, such as gas power, is crawling to a halt in Europe. For systems where variable
renewables account for a large and growing share of the power generation mix,
investment in both electricity storage and smart demand-response solutions will need to
expand substantially.

Globally, energy investment is not yet consistent with the transition to a low-carbon energy
system envisaged in the Paris Agreement reached at the end of 2015. While wind, solar PV
and electric-vehicle investments are broadly on a trajectory consistent with limiting the16

B. Bošnjaković: Climate change energy security and innovation…

increase in global temperature to 20C, investment in other low-carbon technologies is fallingbehind. In several countries, nuclear capacity is ageing with little investment going to
replacement capacity, and renewables are struggling to compensate for reduced nuclear
output. A combination of accelerated technological innovation and an investment framework
aimed at encouraging rapid, large-scale deployment of low-carbon technologiesd will beessential to steer the transformation of the energy system in a timely way in order to jointly
achieve climate and energy security objectives. Emerging experiments with blockchain-based
microgrids may point to one of many innovative ideas for decentralised provision of power toconsumers. [53]Conclusions and outlook
The role of the EU as leading global player in coping with climate change is eroding. This isdue to several factors: political, economic and institutional. Politically, the growing dividing
lines both between the member states and increasing polarisation within the member stateswith regard to climate change policies lead to weak leadership in this matter. Long-term CO₂
emission reduction targets are not supported in a convincing way by short- and medium- term
targets, particularly in the field of renewables contribution, and energy savings and efficiency.
Moreover, due to the rising importance of emerging economies worldwide, the relative
contribution of the EU to the necessary global emission reduction is tending to become
negligible. This obviously cannot but change the nature of dialogue on climate-related
responsibilities, goals and actions among the leading world players and emerging blocks.
Closely interlinked with climate change policy is the energy security situation in the EU. The
specific energy supply security is a strong element of the general security. Both strongly differ
from member state to member state. The border states of the EU have been particularly underpressure of political developments in their neighbourhoods: Russia´s new confrontational
attitudes towards Ukraine and other former Soviet republics, the state failures and (civil) wars
in the Middle East, and North Africa. The deteriorating general security situation leads toconsequences for energy security. A common denominator of the sometimes precarious
energy security is the high dependence of the EU on the import of oil and particulary gas. The„monocultural“ dependence of some EU member states on Russian gas, approaching or
exceeding 90%, is matched only by the still existing far-reaching „monocultural“ dependenceof Russian economy on exports of fossile fuel. Such mutual dependence is interpreted bysome as a guarantee for peaceful cooperation, by others it may be seen as a precursor ofconflicts. Both elements can be seen in the political and legal discussions, manoeuvres andsanctions with regard to the pipelines bringing gas from Russia, or fort hat matter fromCentral Asia, to the EU. The EU seems to be better prepared now than a few years ago for any
disruption of gas supply from the East, partly due to harmonised national emergency plans,
expansion of EU interconnectors, and expanded capacity of LNG. However, it is theaccelerated decarbonisation of the EU and the Russian economies that could make pipeline
politics less confrontational. The EU economy is especially challenged in view of its
decreasing production of oil and gas, and keeping in mind that convential power generation
investment in the EU has essentially come to a halt. The investment in electricity network andstorage is not sufficient yet. What is moreover needed are new institutional, operational andEnergy and the Environment (2016) 1-20

17business models allowing for massive introduction of decentralised renewables in power
production, transport, and heating-cooling.

Literature[1] EU is facing existential crisis, says Jean-Claude Juncker.
https://www.theguardian.com/world/2016/sep/13/jean-claude-juncker-eu-is-facing-existentialcrisis[2] Branko Bošnjaković: Europe between climate change and insecurity: geopolitical aspects.
Pomorski zbornik 2016, Posebno izdanje, 29-62. ISSN 0554-6397[3] Raymond Clémencon: The two sides oft he Paris Climate Agreement: Dismal Failure or
Historic Breakthrough? Journal of Environment & Development, 2016, Vol. 25(1) 3-24.
[4] Raymond Clémencon: Sustainable development, climate politics and EU-leadership: ahistorical-comparative analysis. European Journal of Sustainable Development (2016), 5, 1,
125-144.
[5] European Commission: A policy framework for climate and energy in the period from2020 to 2030. COM(2014) 15 final, Brussels, 22.1.2014. See also European Commission
Press Release: 2030 climate and energy goals for a competitive, secure and low-carbon
economy. http://europa.eu/rapid/press-release_IP-14-54_en.htm[6] 2030 Climate and Energy Policy Framework. European Council, Conclusions 23/24
October 2014. EUCO 169/14 CO EUR 13 CONCL 5.
http://data.consilium.europa.eu/doc/document/ST-169-2014-INIT/en/pdf[7] Jan-Peter Eveleens, Louise van Schaik: De Europese worsteling met het klimaatpakket
voor 2030. Internationale Spectator jaargang 68 nr 7/8., p. 9-13
[8] Roadmap for moving to a low-carbon economy in 2050. 9.07.2014
http://ec.europa.eu/clima/policies/roadmap/index_en.htm[9] European Commission: Energy efficiency and its contribution to energy security and the2030 Framework for climate and energy policy. COM(2014) 520 final, Brussels, 23.7.2014
See also Press Release: European Commission proposes a higher and achievable energy
savings target for 2030. http://europa.eu/rapid/press-release_IP-14-856_en.htm[10] Frankfurt School FS-UNEP Collaborating Centre: Renewable Energy Market ShareClimbs Despite 2013 Dip in Investments.
https://unfccc.int/files/press/releases/application/pdf/gtr_press_release_2.pdf[11] Institute of Energy Research IER: Germany’s Green Energy Destabilizing Electric Grids,
January 23, 2013. http://instituteforenergyresearch.org/analysis/germanys-green-energydestabilizing-electric-grids/[12] Spain and Italy reduce feed-in tariffs. Sun&Wind Energy, 26.06.2014.
http://www.sunwindenergy.com/photovoltaics/spain-and-italy-reduce-feed-tariffs[13] “Britain sets out Europe’s alternatives to Russia”. Reuters, 20 March 2014. The recent
surprise decision by Theresa May to review the first planned nuclear power station for ageneration when she arrived in Downing Street had been regarded as marking a break withearlier enthusiastic courtship of China, and a greater willingness to take on big business. But
after the Chinese ambassador publicly raised concerns about future trading relationships if

18

B. Bošnjaković: Climate change energy security and innovation…

Britain pulled the plug on the deal, May gave the go-ahead. https://www.theguardian.com/uknews/2016/sep/15/theresa-may-accused-backing-down-hinkley-point-c-deal[14] European Commission: The EU strategy on adaptation to climate change, 2013.
http://ec.europa.eu/clima/publications/docs/eu_strategy_en.pdf . See also:
http://ec.europa.eu/clima/policies/adaptation/what/documentation_en.htm[15] EC (2013), Adaptation Strategies for European Cities.
[16] EEA (2012), Urban adaptation to climate change in Europe, EEA Report No 2/2012,
European Environment Agency, Copenhagen, Denmark.
[17] EEA Report No 4/2014. National adaptation policy processes in European countries –2014.
[18] EEA (2016), Urban adaptation to climate change in Europe 2016.EEA Report No
12/2016.
[19] Rob Bailey: Should Europe beconcerned about climate refugees? Chatham House, The
royal Institute of International Affairs, 23 May 2016.
https://www.chathamhouse.org/EXPERT/COMMENT/SHOULD-EUROPE-BECONCERNED-ABOUT-CLIMATE-REFUGEES[20] Benito Müller, Niklas Höhne, Christian Ellermann: Differentiating (historic)
responsibilities for climate change. Climate Policy, Volume 9, Issue 6, 2009[21] Kevin A. Baumert, Timothy Herzog, Jonathan Pershing: Navigating the numbers –Greenhouse gas data and international climate policy. World Resources Institute 2005, 31-33
http://pdf.wri.org/navigating_numbers_chapter6.pdf[22] Rafael Leal-Arcas: The BRICS and Climate Change. International Affairs Forum, pp. 15, 2013[23] Breakthrough as US and China agree to ratify Paris climate deal.
www.theguardian.com/environment/2016/sep/03/breakthrough-us-china-agree-ratify-parisclimate-change-deal[24] Oliver Milman: Donald Trump would be world's only national leader to reject climate
science. www.theguardian.com/us-news/2016/jul/12/donald-trump-climate-change-sciencesierra-club[25] Branko Bošnjaković: Geopolitics of climate change: a review. Thermal Science, Vol. 16,
No. 3, 2012, S. 629-654; see also: Branko Bošnjaković and Iva Mrša Haber. 2015. Climate
Changes and Adaptation Policies in the Baltic and the Adriatic Regions. UTMS Journal of
Economics 6 (1): 21–39.
[26] Turkey´s President Erdogan calls for urgent action on climate change.
http://www.unccd.int/en/mediacenter/MediaNews/Pages/highlightdetail.aspx?HighlightID=417[27] EUROSTAT Statistic Explained. http://ec.europa.eu/eurostat/statisticsexplained/index.php/Energy_production_and_imports[28] European Commission: Communication from the Commission to the European
Parliament and the Council. European Energy Security Strategy. Brussels, 28.5.2014,
COM(2014) 330 final[29] Leal-Arcas, R. and Filis, A. “The Energy Community and the Energy Charter Treaty:Special Legal Regimes, their Systemic Relationship to the EU, and their Dispute Settlement
Arrangements,” Oil, Gas & Energy Law Journal, Vol. 12, Issue 2, pp. 1-42, 2014[30] Indra Øverland, Ellen Scholl, Kirsten Westphal, Katja Yafimava: Energy Security andthe OSCE. SWP Comments 26, May 2016

Energy and the Environment (2016) 1-2019[31] John Vinocur: The EU goes after Gazprom. The New York Times, October 18, 2012.
http://www.nytimes.com/2012/10/19/opinion/the-eu-goes-after-gazprom.html?_r=0[32] European Commission - Press release. Antitrust: Commission sends Statement of
Objections to Gazprom for alleged abuse of dominance on Central and Eastern European gas
supply markets. 22 April 2015. http://europa.eu/rapid/press-release_IP-15-4828_en.htm.
Accessed October 3, 2015.
[33] Stockholm arbitration to hear Lithuania’s claim against Gazprom next year. DELFI by
The Lithuania Tribune. September 25, 2014. http://en.delfi.lt/lithuania/energy/stockholmarbitration-to-hear-lithuanias-claim-against-gazprom-next-year.d?id=65947694. Accessed
October 3, 2015[34] Roman Kilisek: How Gazprom strives to cement its dominance in the European gas
market. Breaking Energy, February 24, 2014. http://breakingenergy.com/2014/02/24/howgazprom-strives-to-cement-its-dominance-in-the-european-gas-market/[35] Bendik Solum Whist: Nord Stream: not just a pipeline, Fridtjof Nansen Institute,
November 2008[36] Robert L. Larsson: Nord Stream, Sweden and Baltic Sea Security. Swedish Defence
Research Agency. ISSN 1650-1942. March 2007[37] Vladimir Socor: Germany in New Role as Transit Country for Russian Gas. Eurasia
Daily Monitor Volume: 11 Issue: 29, February 13, 2014.
[38] Slovak PM calls Nord Stream expansion deal ‘a betrayal’. EurActiv 10 September 2015.
http://www.euractiv.com/sections/energy/slovak-pm-calls-nord-stream-expansion-deal-betrayal-317531[39] Slovakia, Poland against construction of Nord Stream 2 pipeline: presidents. ChinaEurope, 3 October, 2015. http://news.xinhuanet.com/english/2015-10/03/c_134680708.htm[40] Margarita Assenova: Gazprom Agreements on South Stream Breach EU Law; Bulgariaand Serbia Ask EU to Negotiate with Russia. Eurasia Daily Monitor ,Volume: 10 Issue: 220
December 9, 2013.
[41] Joint motion for a resolution. European Parliament 16.4.2014.
http://www.europarl.europa.eu/sides/getDoc.do?pubRef=-//EP//TEXT+MOTION+P7-RC2014-0436+0+DOC+XML+V0//EN[42] EU to Probe Serbia's South Stream Deal. BalkanInsight, 25 April 2014.
http://www.balkaninsight.com/en/article/eu-to-examine-serbia-s-south-stream-deal[43] Radio Free Europ- Radio Liberty: Serbia Says It Will Be Forced To Suspend SouthStream Construction. October 04, 2015. http://www.rferl.org/content/serbia-says-it-will-beforced-to-suspend-south-stream-construction/25415286.html[44] Russia drops South Stream gas pipeline plan. BBC News, 1 December 2014.
http://www.bbc.com/news/world-europe-30283571 Accessed October 4, 2015.
[45] Orhan Gafarli: Russian Energy Proposals for Turkey Could Undermine Southern Gas
Corridor. Eurasia Daily Monitor, Volume: 11, Issue: 225. December 17, 2014.
[46] Vladimir Socor: More Competition, Less Expensive Russian Gas in Ukraine’s Market.
Eurasia Daily Monitor, Volume: 12, Issue: 62, April 3; Issue: 63, April 6; and Issue: 65, April
8, 2015.
[47] Edward C. Chow, Michael Lelyveld: Russia-China Gas Deal and Redeal. Center for
Strategic and International Studies. May 11, 2015. http://csis.org/print/55622[48] Philipp Richter, Franziska Holz: All quiet on the Eastern Front? Disruption scenarios of
Russian natural gas supply to Europe. Discussion Paper 1383, DIW Berlin, May 26, 2014

20

B. Bošnjaković: Climate change energy security and innovation…

[49] László Marácz: Hongaarse parlementsverkiezingen 2014: Orbán mag door met zijn
herstelbeleid. Internationale Spectator, June 2014, Jaargang 68 nr. 6 p. 2-7[50] Rudolf Hermann: Rumänien geht auf mehr Distanz zu Russland. Neue Zürcher Zeitung,
5 August 2014, p. 6[51] Renewable Energy: Policy Considerations for Deploying Renewables. International
Energy Agency 2011, p. 26-30[52] International Energy Agency: „World Energy Investment 2016“. Executive summary.
[53] Blockchain-based microgrid gives power to consumers in New York. New Scientist,
Daily news 2 March 2016. https://www.newscientist.com/article/2079334-blockchain-basedmicrogrid-gives-power-to-consumers-in-new-york/

KLIMATSKE PROMJENE, ENERGETSKA SIGURNOST IINOVACIJE: GEOPOLITIČKI IZAZOVI PRED EU
Sažetak: EU vidi sebe još uvijek kao svjetskog predvodnika pri odgovoru na izazove
klimatskih promjena. Nedavno izbijanje geopolitičkih kriza u susjedstvu – u Ukrajini, na
Bliskom Istoku i u Sjevernoj Africi - ukazuje na sigurnosnu ranjivost Europe, a posebice naranjivost opskrbe energijom kao posljedicom ovisnosti EU o uvozu nafte i plina. Pariški
dogovor o klimi izazov je Europskoj Uniji i na svjetskoj razini, i na razini zemalja članica.
Rad razmatra povezanost i izglede klimatske i energetske politike EU s obzirom na globalnu
odgovornost i sigurnosne interese pojedinih država članica. Etička dimenzija raspravlja se u
smislu pravedne globalne alokacije odgovornosti - između pojedinih regija i država – za
smanjivanje emisija stakleničkih plinova ispod opasnih razina, a i (neizbježive) prilagodbe
posljedicama klimatskih promjena. No istovremeno bi i temeljne vrijednosti svih članica EU
mogle doći u pitanje ukoliko se ne bi jamčila njihova sigurnosna dimenzija. Etički isigurnosni izazovi s kojima je EU suočena, jasno ukazuju na poželjnost ubrzanog uvođenja
nisko-ugljičnog gospodarstva i odgovarajuće infrastrukture, pri čemu obnovljivi izvori ienergetska efikasnost trebaju igrati centralnu ulogu, i to srednje- i dugoročno. Pregled
postojeće literature pokazuje da trajna ovisnost o uvozu nafte i plina, a posebice iz Rusije,
predstavlja ekonomski, politički i okolišni rizik. Rad također ukazuje na globalnu povezanostizmeđu inovacije, investicija i državnih politika, koja je u središtu najnovijeg izvješća
International Energy Agency. Autor daje pregled i kritičko vrednovanje nekih predloženih
odgovora na izazove unutar EU.
Ključne riječi: politika klimatske promjene, energetska sigurnost, EU, Geopolitika

Energy and the Environment (2016) 21-30

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KORIŠTENJU ZEMLJIŠTA I ŠUMARSTVA (LULUCF) U
ISPUNJAVANJU OBVEZA REPUBLIKE HRVATSKE PO OKVIRNOJKONVENCIJI UN-A O PROMJENI KLIME I KYOTSKOM
PROTOKOLU
1LUYDQD)UDQNRYLü0LKHOM1*, Delfa Radoš29ODWND3DOþLü3)RQG]D]DãWLWXRNROLãDLHQHUJHWVNXXþLQNRYLWRVW5DGQLþNDF. 80, 10000 Zagreb,
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Ekonerg ௅ Institut za energetiku i zaštitu okoliša d.o.o., Koranska 5, 10000 Zagreb,
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prate se u pet sektora: Energetici, Industrijskim procesima i uporabi proizvoda,
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ostalo zemljište), kao i za svaku kategoriju zemljišta koja je prenamijenjena u neku drugu a
SULND]DQRL]UDþXQom promjene sadržaja zalihe ugljika u definiranim pohraništima. U radu sedaje osvrt na do sada provedene i nacionalnim sredstvima financirane projekte u sektoru
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3UYRP REYH]XMXüHP UD]GREOMX .3-a (2008. ࣓ 2012. g.), kao i na planirane aktivnosti u
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.OMXþQH ULMHþL Korištenje zemljišta, promjene u korištenju zemljišta i šumarstvo, Inventar
HPLVLMD VWDNOHQLþNLK SOLQRYD QD SRGUXþMX 5HSXEOLNH +UYDWVNH 2NYLUQD NRQYHQFLMD 81-a opromjeni klime, Kyotski protokol
1.

UVOD

Okvirna konvencija Ujedinjenih naroda o promjeni klime (The United Nations Framework
Convention on Climate Change – UNFCCC, Konvencija  PHÿXQDURGQL MH VSRUD]XP ozadržavanju koncentracije VWDNOHQLþNLKSOLQRYDXDWPRVIHULQDUD]LQLNRMDVSUHþDYDQHJDWLYDQ
antropogeni utjecaj na klimatski sustav. Stupila je na snagu 1994. %XGXüL da su odredbe
Konvencije o smanjenju HPLVLMD VWDNOHQLþNLK SOLnova bile nedovoljne, 1997. g. usvojen je

22

N. FrankRYLü0LKHOM'5DGRã93DOþLü =QDþDMVHNWRUD korištenja zemljišta…

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VWDNOHQLþNLK SOLQRYD WLMHNRP RGUHÿHQLK UD]GREOMD. Od stupanja na snagu Protokola 2005. g.,
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sektora: Energetici, Industrijskim procesima i uporabi proizvoda, Poljoprivredi, Korištenju
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,]UDþXQVHWHPHOMi na službenoj metodologiji LYDåHüim YRGLþima IPCC-a.
Sektor LULUCF osobito je važan zato što je jedini sektor u kojemu se bilježe odlivi
VWDNOHQLþNLK SOLQRYD. Prirodne sposobnosti njegovih sastavnica, kao što su npr. biomasa(fitotvar) i tlo, za vezanje ugljika RPRJXüXMX QMHJRYR XNODQMDQMH L] DWPRVIHUH što doprinosiublažavanju klimatskih promjena.
2.

OBVEZE REPULIKE HRVATSKE KAO STRANKE KONVENCIJE I
PROTOKOLA

Republika Hrvatska (RH) postala je stranka Konvencije donošenjem zakona o njezinu
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Priloga I Konvencije ãWR XNOMXþXMH L sve zemlje razvijenog svijeta. Kyotski protokol jeratificiran 27. travnja 2007., a na snagu je u RH stupio 28. kolovoza 2007. Ratifikacijom
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razdoblju za 5% u odnosu na emisije iz bazne, 1990. godine.
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i odlivD VWDNOHQLþNLK SOLQRYD National Inventory Report – NIR) koji nisu pod nadzorom
Montrealskog protokola, SULPMHQMXMXüL usporedive i prihvaüHQHmetodologije. Opseg, format irok podnošenja NIR-a tajništvu Konvencije zadani su odlukama i uputama Konferencije
stranaka. Prilikom izrade NIR-a, države obveznice Konvencije i Protokola moraju osigurati:transparentnost, dosljednost, usporedivost, SRWSXQRVWLWRþQRVWL]UDþXQa emisija/odliva za sve
sektore.
Republika Hrvatska dostavlja Tajništvu Konvencije L]YMHãüDRLQYHQWDUXVWDNOHQLþNLKSOLQRYD
QD SRGUXþMX 5+ RG  2G 2010., L]YMHãüa NIR REXKYDüDMX L GRGDWQH LQIRUPDFLMH NRMH MH
RH dužna dostaviti prema obvezama proizišlima iz Kyotskog protokola. U L]YMHãüima su
informacije te prikazi o emisijama/odlivima VWDNOHQLþNLKSOLQRYDL]ãHVW, odnosno od L]YMHãüDza 2015., pet sektora (Energetika, Industrijski procesi i uporaba proizvoda, Poljoprivreda,
Korištenje zemljišta, promjene u korištenju zemljišta i šumarstvo – LULUCF te Otpad) za
razdoblje od 1990. do n-2 godine, gdje je n godina dostave L]YMHãüa. Emisije i odlivi
VWDNOHQLþNLKSOLQRYDRNRMLPDVHL]YMHãüXMHX1,5-XREXKYDüDMXGLUHNWQHVWDNOHQLþNHSOLQRYH:

Energy and the Environment (2016) 21-30

23CO2, CH4, N2O, HFC, PFC, SF6 i NF3 NDR GRGDWQL X 'UXJRP REYH]XMXüHP UD]GREOMX  i
LQGLUHNWQHVWDNOHQLþNHSOLQRYH: CO, NOx, NMVOC, SO2.
Za provedbu odredaba Kyotskog protokola te sukladno naputcima Odluke 19/CMP.1 (1), RH
je uspostavila, temeljem uredbe (2), 1DFLRQDOQL VXVWDY ]D L]UDþXQ L L]YMHãüLYDQMH o
DQWURSRJHQLP HPLVLMDPD L] L]YRUD L XNODQMDQMD SRPRüX odlivD VWDNOHQLþNLK SOLQRYD
Funkcioniranje sustava osigurava Povjerenstvo ]DPHÿXVHNWRUVNXNRRUGLQDFLMX]DNacionalni
VXVWDY]DSUDüHQMHHPLVLMDVWDNOHQLþNLKSOLQRYDDþLQHJD predstavnici brojnih institucija RH
koje je imenovala Vlada.
2.1

Izvještavanje o odlivima/emisijama u LULUCF sektoru

U sektoru LULUCF potrebno je izvijestiti o odlivima/emisijama unutar zadanih šestNDWHJRULMD ]HPOMLãWD NDNR WR ]DKWLMHYD PHÿXQDURGQR YDåHüa metodologija, propisana uYRGLþima 0HÿXQDrodnog tijela za klimatske promjene (IPCC). Kategorije zemljišta su
VOMHGHüH: šumsko zemljište (Forest Land – FL), zemljište pod usjevima (Cropland – CL),
travnjaci (Grassland – GL), mRþYDUQR ]HPOMLãWH Wetland – WL), nDVHOMHQD SRGUXþMD(Settlements – SL) i ostalo zemljište (Other Land – OL).
Dodatno, za potrebe L]YMHãüD prema Konvenciji, stranke PRUDMX L]UDþXQati emisije/odlive
VWDNOHQLþNLKSOLQRYDLPDMXüLXYLGXGDVHVYDNDQDYHGHQDNDWHJRULMD]HPOMLãWDGRGDWQRGLMHOL
na: zemljište kojem namjena ostaje ista (npr. zemljište pod usjevima koje ostaje zemljište pod
usjevima) i zemljište pretvoreno u drugu kategoriju zemljišta (npr. šumsko zemljište
pretvoreno u naselja). 7DNRÿHU]DKWLMHYDVHGDVHL]UDþXQRSURPMHQLVDGUåDMD]DOLKHXJOMLND
unutar tLK GYLMX SRGMHOD L]UDGL L SUHPD SULSDGDMXüLP SRKUDQLãWLPD XJOMLND XQXWDU VYDNH
kategorije zemljišta: nadzemna biomasa (fitotvar), podzemna biomasa (fitotvar), mrtvo drvo,
listinac, tlo i drvni proizvodi (novo definirano pohranište o kojem se izvješüXMH od 2015.).
3UYR REYH]XMXüH UD]GREOMH .\RWVNRJD SURWRNROD. Ciljevi smanjenja emisije VWDNOHQLþNLKplinova prema Kyotskom protokolu WUHEDMX VH SRVWLüL X GYD REYH]XMXüD UD]GREOMD: Prvo
REYH]XMXüH UD]GREOMH . – 2012. i 'UXJR REYH]XMXüH UD]GREOMH . – 2020. (usvojeno
Dodatkom na Protokol u Dohi 2012.). O nastavku Kyotskoga protokola nakon 2020. stranke
VX RGOXþLYDOH QD .RQIHUHQFLMi u Durbanu 2011., gdje je dogovoren razvoj novog,
PHÿXQDURGQR REYH]XMXüHJ SUDYQRJ DNWa do kraja 2015. godine (3). 1RYL PHÿXQDURGQL
sporazum o globalnom smanjenju emisije VWDNOHQLþNLK SOLQRYD, Pariški sporazum usvojen je
na Konferenciji stranaka u Parizu 2015. godine.
Prema obvezama Protokola, definiranima u odluci Konferencije stranaka koja služi kao
sastanak stranaka Protokola (16/CMP.1), X 3UYRP REYH]XMXüHP UD]GREOMX stranke su bileobvezne u NIR-u izvješüLYDWL RVOMHGHüLPDNWLYQRVWLPD
1. $NWLYQRVWL L] þODQND  3URWRNROD NRMH þLQH pošumljavanje (A), ponovno
pošumljavanje (R) LNUþHQMH (D), (Afforestation, Reforestation, Deforestation – ARD).
Obveza je svih sWUDQDNDGRVWDYLWLL]UDþXQHPLVLMDodlivDWHVRYLPþODQNRPSRYH]DQH
informacije i podatke. U RH nema površina koje su predmetom ponovnog
pošumljavanja.

24

N. FrankRYLü0LKHOM'5DGRã93DOþLü =QDþDMVHNWRUD korištenja zemljišta…

2. $NWLYQRVWL L] þODQND  3URWRNROD NRMH þLQH gospodarenje šumama (Forest
Management – FM), gospodarenje poljoprivrednim zemljištem, gospodarenje
pašnjacima, iVXãLYDQMHLSRQRYQDXVSRVWDYDPRþYDUQLKSRGUXþMHte obnova vegetacije.
8SRJOHGXRYRJþODQNDsWUDQNDPDMHELODRVWDYOMHQDPRJXüQRVWda odaberu jednu, nekoliko,sve ili nijednu RG QDYHGHQLK DNWLYQRVWL R NRMRM üH L]YMHãüLYDWL WLMHNRP 3UYRJ REYH]XMXüHJ
razdoblja. Svaka odabrana aktivnost iz þODQND  RVWDMH REYH]om ]D L]YMHãüLYDQMH WLMHNRPLGXüLK REYH]XMXüLKUD]GREOMD
'RGDWQR R DNWLYQRVWL JRVSRGDUHQMD ãXPDPD VYH VWUDQNH SRVWDMX REYH]QH L]YMHãüLYDWLWHPHOMHPRGOXNH&03WLMHNRP'UXJRJREYH]XMXüHJUD]GREOMD
0HWRGRORJLMDNRMDVHSULPMHQMXMH]DL]YMHãüLYDQMHRSURYHGELREYH]DGHILQLUDQLK3URWRNRORP
ista je kao i za Konvenciju.
Aktivnosti AD-a i FM-D X 5+ SRNODSDMX VH V RGUHÿHQLP NDWHJRULMDPD ]HPOMLãWD SUHPDUNFCCC-XQDQDþLQSULND]DQQDVOLFL

Slika 1. Preklapanje aktivnosti ARD-a i FM-a s kategorijama zemljišta prema UNFCCC-u

Ostvareni odlivi po aktivnostima L] þODQND 3.3 koriste se za ispunjavanje obveza stranaka
REXKYDüHQLK 'RGDWNRP ,, stoga MH WRþQR GHILQLUDQMH SRYUãLQD SRG tim aktivnostima teXWYUÿLYDQMHVQMLPDSRYH]DQLKHPLVLMDodlivDVWDNOHQLþNLKSOLQRYDELORL]QLPQo važno. Odlivi
koje stranke ostvare provedbom aktivnosti iz þODQND  SULPMHQMXMX VH EH] LNDNYRJRJUDQLþHQMD RGQRVQR VYL odlivi koji se ostvare u cijelosti se primjenjuju za ispunjavanjeobveza o smanjenju emisije VWDNOHQLþNLK SOLQRYD QHRYLVQR R WRPH pošumljava li se na
godišnjoj razini oko 1.000 ha (RH) ili 15.000 ha (Irska) (4). Odlivi ostvareni tijekom Prvog
REYH]XMXüHJUD]GREOMDPRJXVHSUHQRVLWLXLGXüD razdoblja za potrebe ispunjavanja obveza osmanjenju emisije u razdobljima nakon 2012. godine.
Dostavom Inicijalnog L]YMHãüa, zahtijevanog odlukom 13/CMP.1 u kolovozu 2008. godine,
RH MHRGDEUDODGDüHL]YMHãüLYDWL o aktivnosti gospodarenja šumama (FM) XQXWDUþODQND

Energy and the Environment (2016) 21-30

25

3URWRNROD X 3UYRP REYH]XMXüHP UD]GREOMX 8 VNORSX LVWRJ L]YMHãüa RH je dostavila i
informacije o odabiru vrijednosti parametara na nacionalnoj razini, kojima se definira šuma(minimalna površina, pokrovnost krošanja i visina stabala). Definirane vrijednosti navedenih
parametara (0,1 ha, LP REYH]XMX5+QDGRVWDYXLQIRUPDFLMDLL]UDþXQHPLVLMDodliva
VWDNOHQLþNLK SOLQRYD ]D ãXPH YLVRNRJ X]JRMQRJ REOLND, QLVNRJ X]JRMQRJ REOLND SDQMDþH  inižeg uzgojnog oblika (makije i šikare).
U pogledu ostvarenog odlivDSRþODQNX3URWRNROD RH, kao ni druge države, nije moglakoristiti ukupan iznos odlivDYHüVDPRMHGDQQMHJRYGLR2GOXNRP&3RH MHRPRJXüHQR
GDSULVSRPHQXWRPREUDþXQXQDJRGLãQMRMUD]LQLLVNRULVWLodliv u iznosu od 0,265 Mt C (oko972 Gg CO2eq). Ako države-stranke Protokola ne ispune sve svoje obveze i ne pridržavaju sepravila o L]YMHãüLYDQMu, PRåH XVOLMHGLWL REXVWDYD L ]DEUDQD WUJRYDQMD HPLVLMDPD VWDNOHQLþNLKplinova.
Problemi RH u ispunjavanju obveza Protokola WLMHNRP3UYRJREYH]XMXüHJUD]GREOMD i razlozi
za pokretanje projekata u sektoru LULUCF. Slijedom Odluke 19/CP.8 iz 2003., RevizijskiVWUXþQL WLP (Expert Review Team – ERT) redovito godišnje provjerava NIR država stranaka
Priloga ,.RQYHQFLMH6YDNHþHWLULJRGLQHRVDPGUåDYDSUROD]LGHWDOMQXSURYMHUXQDFLRQDOQRJL]YMHãüa kroz proces In Country Review. Po pregledu, (57 L]UDÿXMH *RGLãQMH L]YMHãüe opregledu inventara (Annual Review Report – ARR) i po potrebi tzv. Saturday paper. U tim
dokumentima definiraju se svi nedostatci u inventaru države, ali i daju preporuke za njegovo
poboljšanje. Države su obvezne ispuniti zahtjeve ERT-a te kontinuirano raditi na unaprjHÿHQMX
nacionalnog inventara.
Godine 2012. ERT je putem Saturday Paper-a pozvao RH da posveti posebnu pažnju
problemu površina o kojima je izvijestila u kategoriji šumskog zemljišta koje ostaje šumsko iaktivnostima FM-a i AD-a. Iz podataka dostavljenih u NIR-u 2012. bilo je vidljivo dapovršine šuma nisu identificirane u skladu s pravilima Protokola. Ostali nedostatci u
L]YMHãüLYDQMX5+Xsektoru LULUCF bili su definirani u ARR-u 2012. ERT je pozvao RH daprovede analizu površina te emisije/odlive VWDNOHQLþNLKSOLQRYDQDnjima RGJRYDUDMXüHSULMDYL
SRGþODQNRPRGQRVQRþODQNRP3URWRNROD(57MHRVWDYLR+UYDWVNRMPRJXüQRVWGDtu
aktivnost provede tijekom 2013. godine, a da o korekciji površina i s njima povezanim
emisijama/odlivima obvezno izvijesti u svom L]YMHãüu za 2014. Neispunjavanje tih zahtjeva
podrazumijevalo je GD üH (57 primijeniti tzv. adjustement ]D 5+ L GD üH SRGQLMHWL prijavu
Odboru za ispunjavanje obveza (Compliance Committee) Protokola, što bi XNRQDþQLFL moglo
voditi kažnjavanju zbog neispunjavanja obveza ]DEUDQD WUJRYDQMD HPLVLMDPD VWDNOHQLþNLKplinova).
Svojim odgovorom na Saturday Paper RH se obavezala riješiti navedene probleme uzahtijevanom roku. Radi rješavanja problema definiranih u Saturday Paper, ali i ARR-om,
Ministarstvo zaštite okoliša i prirode iniciralo je i provelo dva projekta. Projekti PoboljšanjeL]YMHãüLYDQMD X VHNWRUX korištenja zemljišta, promjena u korištenju zemljišta i šumarstva u
3UYRP REYH]XMXüHP UD]GREOMX .\RWVNRJD SURWRNROD VNUDüHQRJ QD]LYD  /8/8&)   i
1DGRJUDGQMD 1DFLRQDOQRJ VXVWDYD ]D L]YMHãüLYDQMH R HPLVLMDPD VWDNOHQLþNLK SOLQRYD ]Dprovedbu Odluke Europskog SDUODPHQWD L 9LMHüD EU  RG  VYLEQMD  R
SUDYLOLPD REUDþXQDYDQMD HPLVLMD L odlivD VWDNOHQLþNLK SOLQRYD NRML SURL]OD]H L] DNWLYQRVWL
korištenja zemljišta, promjena u korištenju zemljišta i šumarstva i o informacijama koje seodnose na te aktLYQRVWL VNUDüHQRJ QD]LYD /8/8&)  provedeni su 2014. – 2015., a
ILQDQFLUDQL VX VUHGVWYLPD )RQGD ]D ]DãWLWX RNROLãD L HQHUJHWVNX XþLQNRYLWRVW Bili su to prvi

26

N. FrankRYLü0LKHOM'5DGRã93DOþLü =QDþDMVHNWRUD korištenja zemljišta…

SURMHNWL L] SRGUXþMD NOLPDWVNLK SURPMHQD NRML VX u potpunosti financirani nacionalnimsredstvima. 3URMHNWLVXREXKYDüDOLYLãHDNWLYQRVWLRGNRMLKXRYRPUDGXQDYRGLPRVDPRQHNH
U sklopu projekta LULUCF 1 bilo je provedeno nekoliko aktivnosti za potrebe pravilne
identifikacije površina AD-a i FM-a 8 VOXþDMX LGHQWLILNDFLMH SRYUãLQD $'-a, RH je
primijenila tzv. Pristup 3 za identifikaciju šumskih površina kojima gospodare Hrvatske šumed.o.o., a koji podrazumijeva prostorno WRþQR XWYUÿLYDQMH SRYUãLQD NRMH VX ELOH SUHGPHWRP
promjene u korištenju u razdoblju od 1990. godine. AD površine su jedine površine za
identifikaciju kojih je RH uspjela primijeniti najbolji pristup u identifikaciji. Rezultati
provedenog projekta korišteni su za potrebe predaje NIR-a 2014. I]YMHãüe RH je SULKYDüHQRDu ARR 2014 (5) RH je pohvaljena za rješenje problema, a trgovanje emisijama moglo senesmetano odvijati.
'UXJR REYH]XMXüH UD]GREOMH .\RWVNRJD SURWRNROD. 6YH REYH]H L] 3UYRJ REYH]XMXüHJ
razdoblja prema Protokolu po Odluci 2/CMP.7 iz Durbana moraju se ispuniti i u svim
daljnjim vremenskim razdobljima, tj. i nakon 2012 godine. Tijekom zasjedanja u Durbanu
rDGQD VNXSLQD ]D 3URWRNRO GHILQLUDOD MH L QRYD SUDYLOD ]D REUDþXQ odliva ostvarenog
provedbom aktivnosti gospodarenja šumama koji stranke mogu koristiti za potrebe
ispunjavanja obveza smanjenja emisije VWDNOHQLþNLK SOLQRYD X 'UXJRP REYH]XMXüHP
razdoblju.
Za potrebe ispunjavanja obveza u ovom razdoblju, definirana je tzv. referentna razina odliva
za aktivnost gospodarenja šumama (Forest Management Reference Level – FMRL). Emisije iodlivLL]RYHDNWLYQRVWLXVSRUHÿXMXVHQDJRGLãQMRMUD]LQLVRYRPGHILQLUDQRPYULMHGQRãüX]DSRWUHEH REUDþXQDYDQMD FMRL za RH iznosi -6,289 MtCO2eq godišnje. Ako su prijavljeni
odlivLYHüLRG)05/-a, PRJXüHMHNRULVWLWLLGRGDWQHodliveDOLX]RJUDQLþHQMHGDWDMGRGDWQL
iznos ne prelazi 3,5% ukupnog iznosa emisija (bez LULUCF-a) iz bazne 1990. godine
pomnoženoga VEURMHPJRGLQDXREYH]XMXüHPUD]GREOMX Stranke su dužne vršiti tzv. tehnLþNX
korekciju FMRL-a svaki put NDG X QMLKRYRP L]UDþXQX odlivaHPLVLMD GRÿH GR ]QDþDMQLMLK
promjena (npr. prijelaz na višu razinu metodologije). =DKYDOMXMXüL znatnim unaprjHÿHQMima uizvješüLYDQMX u sektoru LULUCF, u sklopu LULUCF 2 provedeQDMHSUYDWHKQLþNDNRUHNFLMDFMRL-a, a prijavljena je u sklopu NIR 2016.
3.

POLITIKA EUROPSKE UNIJE U PROVEDBI KONVENCIJE I PROTOKOLAU RAZDOBLJU DO 2020. GODINE

Na Konferenciji stranaka održanoj u Cancunu 2010., SRVWLJQXWMHNOMXþQLGRJRYRURQDVWDYNX
rada stranaka QD VPDQMHQMX HPLVLMD VWDNOHQLþNLK SOLQRYD L SRPRüL ]HPOMDPD X UD]YRMX SULnjihovoj zaštiti od negativnog utjecaja tih promjena. Sporazumom se pokazuje da klimatske
SURPMHQH ]DKWLMHYDMX L]UDGX GXJRURþQLK VWUDWHJLMD RGUåLYRJ UD]YRMD V FLOMHP RJUDQLþDYDQMD
porasta temperature do maksimalno 20C GRNUDMDVWROMHüDWHVHSRWLþX stranke na pripremu tzv.
nisko-XJOMLþQLK VWUDWHJLMD UD]YRMD Europska unija, kao jedan od najvažnijih partnera.RQYHQFLMHL 3URWRNROD UHGRYLWR SUHQRVLL XJUDÿXMH RGUHGEH tLK PHÿXQDURGQLK VSRUD]XPD X
svoje zakonodavstvo. Tako je još 2008. Europska komisija predložila zakonodavni paket
NRMLP VH RPRJXüDYD SURYHGED W]Y FLOMD -20-20 i integriranog pristupa klimatskoj ienergetskoj politici do 2020. godine. Ciljevi se odnose na:

Energy and the Environment (2016) 21-30

x
x
x

27

VPDQMHQMHHPLVLMDVWDNOHQLþNLKSOLQRYDQDUD]LQL(8-a za najmanje 20% u odnosu na
emisije iz bazne 1990 godine
obavezu da se ostvari 20% udjela energije iz obnovljivih izvora u ukupnoj potrošnji
poboljšanje od 20% na SRGUXþMXHQHUJHWVNHXþLQNRYLWRVWi.

Na sastanku stranaka UNFCCC-a u Dohi 2012. L]UDåHQDMHYHOLND]DEULQXWRVW]ERJ]QDþDMQRJ
MD]D L]PHÿX SUHX]HWLK REYH]D za smanjenje emisija stranaka u razdoblju do 2020. i
SUHGYLÿHQRJ L]RVWDQND UH]XOWDWD QMLKRYD ]ELUQRJ XþLQND X ]DGUåDYDQMX SRUDVWD temperature
ispod 2°C odnosno 1.5°C u odnosu na predindustrijsko razdoblje (6). Zbog toga su razvijenedržave pozvane da preispitaju preuzete obveze za smanjenje HPLVLMD X]LPDMXüL X RE]LU]DNOMXþNH ýHWYUWRJ L]YMHãüD ,3&&-a i naknadne procjene. Tijekom sastanka stranaka KP-a
usvojena je i Izmjena Kyotskoga protokola. Europska unija se Dodatkom 1. Odluke 1/CMP.8
obvezala na 20%-tno smanjenje emisija u razdoblju do 2020. godine.
Do srpnja 2016. Izmjenu iz Dohe, kojom se mijenjaju Dodatak A i Dodatak B Kyotskog
protokola, potvrdilo je 66 stranaka. Da bi Izmjena stupila na snagu, moraju je potvrditi ¾
ukupnog broja stranaka (144 od ukupno 192). Europska unija još nije potvrdila Izmjenu jer je
za to nužno da sve države-þODQLFHSURYHGXSRVWXSDNUDWLILNDFLMHQDQDFLRQDOQRMUD]LQLRH je
jedna od država-þODQLFD(8NRMDMHSURYHODSURFHVUDWLILNDFLMH (7) LRWRPHL]YLMHVWLOD9LMHüH
EU. Do stupanja na snagu, stranke mogu privremeno primjenjivati Izmjenu prema odredbamaþODQaka 20. i 21. KP-a i Odluci 1/CMP.6. Neke stranke sa znatnim udjelom u ukupnim
emisijama najavile su VYRMH SRYODþHQMH RGQRVQR GDOMQMH  QHVXGMHORYDQMH X REYH]DPDVPDQMHQMDHPLVLMDVWDNOHQLþNLKSOLQRYDWLMHNRP'UXJRJREYH]XMXüHJUD]GREOMDProtokola (npr.
Kanada, Ruska Federacija, Japan).
3.1

Obveze u sektoru LULUCF za razdoblje do 2020. godine

Cilj EU za razdoblje do 2020. godine o 20%-WQRPVPDQMHQMXHPLVLMDVWDNOHQLþNLKSOLQRYDX
odnosu na emisije iz bazne 1990. godine postavljen je bez uzimanja u obzir emisija i odliva iz
sektora /8/8&)1HRYLVQRRWRMþLQMHQLFL(XURSVNDXQLMDMHWLMHNRP. usvojila Odluku(EU) br. 529/2013 (8) za taj sektor i propisala obvezu definiranja mjera za]DGUåDYDQMHVPDQMHQMHHPLVLMDLSRYHüDQMH]DGUåDYDQMHodliva u razdoblju do 2020. godine zadržave-þODQLFH Te su mjere definirane za RH L þLQH VDVWDYQL GLR PMHUD L] Nacrta strategijenisko-XJOMLþQRJ UD]YRMa. Prema navedenom propisu, o njihovoj provedbi nužno je izvijestiti(XURSVNXNRPLVLMX X  L  JRGLQL 7DNRÿHURGOXNRPse dodatno obvezuju državeþODQLFHQDL]YMHãüLYDQMH LL]UDþXQHPLVLMDodlivDVWDNOHQLþNLKSOLQRYDNRMi nastaju provedbom
aktivnosti gospodarenja pašnjacima (tzv. Grassland Management – GM) i aktivnosti
gospodarenja poljoprivrednim površinama (tzv. Cropland Management – CM). Države su
REYH]QHWRþQRXWYUGLWLHPLVLMHodlive iz aktivnosti CM-a i GM-a i o njima izvijestiti Komisiju
QDMNDVQLMH GR  RåXMND  JRGLQH 8WYUÿLYDQMH WRþQLK HPLVLMD L] QDYHGHQLK DNWLYQRVWL
podrazumijeva ispunjavanje obveze uspostave sustava na nacionalnoj razini za ovo
L]YMHãüLYDQMH 8 VOXþDMX 5+ to zahtijeva i XVSRVWDYX VXVWDYD ]D SUDüHQMH SRNURYD L XSRUDEH
svih kategorija zemljišta IPCC-a kao i njihove promjene korištenja. Osnovne postavke novoga
sustava definirane su u sklopu projekta LULUCF 2, ali ih je potrebno detaljnije razraditi i
formulirati u obliku projekta radi prijave za financiranje kroz koji od programa EU. Do
predaje L]YMHãüa V SRGDWFLPD L LQIRUPDFLMDPD R NRQDþQR XWYUÿHQLP HPLVLMDPDodlivima iz
aktivnosti CM-a i GM-a u 2022. godini, države-þODQLFH VX REYH]QH, SRþHYãL RG 1,5 .,svake godine dostavljati podatke o QHREYH]XMXüLP emisijama/odlivima iz aktivnosti CM-a i

28

N. FrankRYLü0LKHOM'5DGRã93DOþLü =QDþDMVHNWRUD korištenja zemljišta…

GM-D NRMH VX UH]XOWDW SRGDWDND L LQIRUPDFLMD UDVSRORåLYLK X SRVWRMHüHP VXVWDYX 2G 2016.
JRGLQH þODQLFH VX obvezne dostavljati i posebno L]YMHãüe o poduzetim aktivnostima za
uspostavu sustava za izvješüLYDQMH o emisijama/odlivima iz CM-a i GM-a.
Odlukom (EU) 529/2013 definiraju se L GUYQL SURL]YRGL NDR QRYR SRKUDQLãWH XJOMLND R þLMRM
promjeni zalihe je obvezno izvješüLYDWL. Aktivnostima provedenima unutar projekta LULUCF
2 prikupljeni su podatci i informacije te je L]UDÿHQL]UDþXQSURPMHQH]DOLKHXJOMLNDXRYRPH
pohraništu prvi put za NIR 2015 ,]UDþXQ MH QDSUDYOMHQ, u skladu sa zahtjevima Protokola,posebno za drvne proizvode s FM i AD površina.
8] YHü SRVWRMHüX obvezu izvješüLYDQMD R JRVSRGDUHQMX ãXPDPD SR þODQNX  3URWRNROD WH
neizmijenjenu obvezu izvješüLYDQMD o odlivima/emisijama iz aktivnosti pošumljavanja,
SRQRYQRJSRãXPOMDYDQMDLNUþHQMDãXPDYHüLQDGUåDYDþODQLFDVXRþHQDMHVQRYLPREYH]DPD
izvješüLYDQMD o emisijama/odlivLPD VWDNOHQLþNLK SOLQRYD WLMHNRP 'UXJRJ REYH]XMXüHJ
razdoblja za Europsku komisiju. Da bi RH ispunila te nove obveze, moraju se provesti
SURMHNWLNRMLüHRPRJXüLWL izvješüLYDQMH o emisijama uslijed prirodnih nepogoda, unaprijediti
sustav za izvješüLYDQMH o drvnim proizvodima i unaprijediti izvješüLYDQMHR emisijama uslijedpožara uz primjenu Tier 2 razine IPCC metodologije.
4.

POLITIKA EUROPSKE UNIJE U PROVEDBI KONVENCIJE
35,3$'$-8û,+3523,6$U RAZDOBLJU NAKON 2020.

I

Klimatsko-energetskim paketima EU-a do 2020. i 2030. godine WHGXJRURþQLPFLOMHYLPD(8-apredstavljenima u Plan puta za prijelaz na NRQNXUHQWQRQLVNRXJOMLþno gospodarstvo do 2050.
godine (9) i Energy Roadmap 2050 (10) RGUHÿHQRMHVPDQMHQMHHPLVLMDVWDNOHQLþNLKSOLQRYD
na razini Europske unije za minimalno 20, 40 odnosno 80-95% u razdoblju do 2020., 2030. i JRGLQH X RGQRVX QD HPLVLMH L] ED]QH JRGLQH 6PDQMHQMH VH RGQRVL QD VHNWRUH þLMH VX
HPLVLMHREXKYDüHQHWUJRYDQMHPHPLVLMDPDVWDNOHQLþNLKSOLQRYD (76 LVHNWRUHþLMHVXHPLVLMH
REXKYDüHQH2GOXNRPR]DMHGQLþNRPQDSRUX(ESD). ETS om su XWYUÿHQHNROLþLQHEHVSODWQR
dodijeljeQLKHPLVLMVNLKMHGLQLFDSRVWURMHQMLPDXNOMXþHQLPX(8(76, a ESD-RPVHXWYUÿXMX
godišnje kvote VYDNHGUåDYHþODQLFH]DHPLVLMHXVHNWRULPDNRMLQLVXGLR(76-a.
Postotak smanjenja emisija na razini pojedine države-þODQLFH X SHULRGX GR  JRGLQH
SUHGPHWRP MH QDGROD]HüLK SUHJRYRUD ]D VHNWRUH REXKYDüHQH (6'-RP DOL L NRQDþQRJGRJRYRUD R QDþLQX XNOMXþLYDQMD HPLVLMDodliva iz sektora LULUCF u postizanje ciljeva
Europske unije u smanjenju HPLVLMDVWDNOHQLþNLKSOLQRYDGRJRGLQHZa ovo razdoblje,
VPDQMHQMH HPLVLMD L] VHNWRUD REXKYDüHQLK (76-RP RGUHÿHQR MH QD UD]LQL (XURSVNH XQLMH L
iznosi 43% u odnosu na emisije iz bazne 2005. godine , dRNüHVHNWRULNRMLVXL]YDQVXVWDYDETS-a trebati VPDQMLWLHPLVLMHVWDNOHQLþNLKSOLQRYDGRXRGQRVXQDJRGLQX

4.1

Obveze u sektoru LULUCF u razdoblju nakon 2020. godine

Minimalno smanjenje emisija od 40% do 2030. godine Europska unija MHSODQLUDODQDQDþLQGD
X NRQDþQR REUDþXQDYDQMH XYUVWL L HPLVLMH L odlive iz sektora LULUCF. Europska komisijaUD]PRWULOD MH L VWUXþQR SURFLMHQLOD UDQLMH GHILQLUDQH LQDþLFH u svezi s QDþLQom uvrštavanja
emisija/odliva iz ovoga sektora te je po održanoj raspravi s državama-þODQLFDPD ]DNOMXþLOD
NDNR MH SRWUHEQR UD]PRWULWL L VWUXþQR RFLMHQLWL L QRYH QDþLQH XYUãWDYDQMD odliva/emisija iz

Energy and the Environment (2016) 21-30

29

sektora LULUCF. ,]UDÿHQD je nova ocjena XWMHFDMDSRMHGLQLKLQDþLFD(Impact Assessment) za
uvrštavanje LULUCF-a u postizanje cilja EU o smanjenju emisija nakon 2020. godine te je
L]UDÿHQ i prijedlog nove uredbe kojom se regulira tRSLWDQMH3ULMHGRQRãHQMDNRQDþQLKRGOXND
bit üHproveden postupak usuglašavanja s državama-þODQLFDPD5.

ZAKL-8ý$.

Za postizanje GXJRURþQLK FLOMHYD (8 X VPDQMHQMX HPLVLMD þODQNRP  8UHGEH 
Europskog parlamenta i Europskog vLMHüD (11) propisana je obveza izrade strategija razvoja sniskom razinom ugljikova dioksida za države-þODQLFH 7LMHNRP  JRGLQH 0LQLVWDUVWYR
zaštite okoliša i prirode pokrenulo je proces izrade ove strategije za RH. I]UDÿHQ je nacrt
ovoga dokumenta, a njegovo se XVYDMDQMH RþHNXMH tijekom 2017. godine. Tim strateškim
dokumentom RH definira ciljeve smanjenja emisija VWDNOHQLþNLK SOLQRYD GR  JRGLQH s
pogledom na 2050. godinu X RNYLUX SROLWLþNRJ RNYLUD NRML MH XVYRMLOD (XURSVND XQLMD
6WUDWHJLMRP VX REXKYDüHQL VYL VHNWRUL, a poseban je naglasak stavljen na energetiku,
industriju, promet, poljoprivredu, LULUCF i otpad. Ovaj dokument trebao bi biti polazište za
izradu sektorskih strategija u RH.
Kao i uvijek XVOXþDMXSUREOHPDNRMLVXRGQDFLRQDOQHYDåQRVWL]QDQMHLVYLMHVW UDVSRORåLYLX
svim relevantnim instiWXFLMDPD RRQRPHãWRVHGRJDÿD þLQHRVQRYni preduvjet za definiranje
aktivnosti za rješavanje i ovog, nadasve složenog problema – borbe s klimatskim
SURPMHQDPDâWRYLãHãWRMHSUREOHPVORåHQLMLSRWUHEQRMHYHüH]QDQMHRQMHJRYLPX]URFLPD
ali i posljedicama njegova nepravodobnog rješavanja. Na znanje se potom nastavlja
GXJRURþQD SUHGDQRVW GRQRVLWHOMD RGOXND u definiranju potrebnih okvira djelovanja(organizacijskih, zakonodavnih, institucijskih, financijskih i dr.) za provedbu aktivnosti radi
rješavanja problema. Dobro postavljeni okviri djelovanja iznimno su važni jer svim
]DLQWHUHVLUDQLPD RPRJXüXMX GD GDMX svoj doprinos ublažavanju klimatskih promjena i
RVLJXUDQMXGREURJVWDQMDRNROLãD]DåLYRWEXGXüLKJHQHUDFLMD%H]ta dva osnovna preduvjeta –znanja i dobro postavljenih okvira djelovanja, teško je GRüL GR ]QDþDMQLMLK LVNRUDND L
inicijativa u doprinosu ublažavanja klimatskih promjena.
%ULJD]DRþXYDQMHNOLPHL]GUDYRJRNROLãDQLMH]DGDWDNVDPRQHNLKVNXSLQD QSU]QDQVWYHQLND
ili donositelja odluka), nego i svakog pojedinca. Na državnim institucijama i njihovim
voditeljima je uspostaviti dobar i funkcionalan okvir unutar kojega mogu djelovati svi, jernema opravdanja za zaostajanje u borbi za RþXYDQMH NOLPH i kvalitetna života EXGXüLK
generacija.
LITERATURA[1.]UNFCCC, Konferencija stranaka koji služe kao sastanak stranaka Kyotskoga
protokola, http://unfccc.int/resource/docs/2005/cmp1/eng/08a03.pdf#page=14[2.]8UHGEDRSUDüHQMXHPLVLMDVWDNOHQLþNLKSOLQRYDSROLWLNHLPMHUD]DQMLKRYRVPDQMHQMH
u Republici Hrvatskoj (NN 87/12)[3.]UNFCCC, Konferencija Stranaka, Odluka 1/CP.17,
http://unfccc.int/resource/docs/2011/cop17/eng/09a01.pdf[4.]Council for Forest Research and Development (2014),
http://www.coford.ie/media/coford/content/publications/forestry2030/00504%20Fores
try%202030%20Inserts%20-%2004%20Climate%20Change.pdf[5.]UNFCCC, http://unfccc.int/resource/docs/2015/arr/hrv.pdf

30

N. FrankRYLü0LKHOM'5DGRã93DOþLü =QDþDMVHNWRUD korištenja zemljišta…

[6.]UNFCCC, Konferencija Stranaka, Odluka 1/CP.18,
http://unfccc.int/resource/docs/2012/cop18/eng/08a01.pdf#page=3[7.]=DNRQRSRWYUÿLYDQMX,]PMHQHL]'RKH.\RWVNRJSURWRNROD 11-MU br. 6/15)[8.]2'/8.$EU(8(85236.2*3$5/$0(17$,9,-(û$RGVYLEQMDRSUDYLOLPD]DREUDþXQHPLVLMDLXNODQMDQMDVWDNOHQLþNLKSOLQRYDNRMLQDVWDMXL]
djelatnosti povezanih s korištenjem zemljišta, prenamjenom zemljišta i šumarstvom te
informacijama o mjerama povezanima s tim djelatnostima[9.]COM(2011) 112 final, A Roadmap for moving to a competitive low carbon economy
in 2050, http://eur-lex.europa.eu/legalcontent/EN/TXT/PDF/?uri=CELEX:52011DC0112&from=EN[10.]
COM (2011) 885 final, Energy Roadmap 2050, http://eur-lex.europa.eu/legal
content/EN/TXT/PDF/?uri=CELEX:52011DC0885&from=EN[11.]
85('%$EU(85236.2*3$5/$0(17$,9,-(û$RG
svibnja 2013. o mehaQL]PX]DSUDüHQMHLL]YMHãüLYDQMHRHPLVLMDPDVWDNOHQLþNLKSOLQRYDL]DL]YMHãüLYDQMHRGUXJLPLQIRUPDFLMDPDXYH]LVNOLPDWVNLPSURPMHQDPDQD
nacionalnoj razini i razini Unije te stavljanju izvan snage Odluke br. 280/2004/EZ

THE IMPORTANCE OF THE LAND USE, LAND USE CHANGE AND
FORESTRY (LULUCF) SECTOR FOR FULFILLING THE
OBLIGATIONS OF THE REPUBLIC OF CROATIA UNDER THE UN
FRAMEWORK CONVENTION ON CLIMATE CHANGE AND KYOTO
PROTOCOL
Abstract: The Republic of Croatia, as member of Annex I Parties to the Convention of the UN
Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol (KP), is
required to periodically submit a report on emissions and removals of greenhouse gases
pursuant to the decisions of these international agreements in accordance with prescribed
content, format and submission deadline.
Emissions/removals of greenhouse gases are reported in five sectors: Energy; Industrial
processes and product use; Agriculture; Land use, Land Use Change and Forestry(LULUCF) and Waste. The procedure applied for the estimation of emissions/removals ofgreenhouse gases is the methodology of the Intergovernmental Panel on Climate Change(IPCC). Generally, following this methodology, the emissions are calculated as a product ofmultiplication of the data used to describe the specific activity (e. g. production of mineralraw materials, animal production, forest management, etc.) and corresponding emission
factors.
Removals/emissions of the greenhouse gases in the LULUCF sector are reported for each ofsix default categories of land (forest land, cropland, grasslands, wetlands, settlements andother land) and for each category of land that is converted into another category following
the calculation of the carbon stocks changes in the identified carbon pools.
This paper represents an overview of implemented projects in the LULUCF sector financed
by national funds with the aim to help the fulfilling international obligations of the Republicof Croatia in the First commitment period of the KP (period 2008-2012) and as a reference
for the future activities planned for the period until 2020 and 2030.
Keywords: Land Use, Land Use Change and Forestry, Croatian Greenhouse Gas Inventory,UN Framework Convention on Climate Change, Kyoto Protocol

Energy and the Environment (2016) 31-40

31

POLITIKA PRILAGODBE KLIMATSKIM PROMJENAMA I NJENOFINANCIRANJE 1=YRQLPLUDâYHUNR*UGLü
6YHXþLOLãWHX5LMHFL)DNXOWHW]DPHQDGåPHQWXWXUL]PXLXJRVWLWHOMVWYX
Primorska 42, 51410 Opatija
zgrdic@fthm.hr, tel. 00385/51/294-683
Sažetak: 3URFHV SULODJRGEH SUHWSRVWDYOMD GD VX NOLPDWVNH SURPMHQH QHãWR ãWR VH GRJDÿD LSRNXãDYD LGHQWLILFLUDWLNRUDNHNRML VH PRJX SRGX]HWLNDNRELVHRJUDQLþLOHQMHQHQHSRYROMQH
posljedice i pokušale iskoristiti povoljne prilike. To predstavljD NOMXþQL RGJRYRU ]Dsmanjivanje osjetljivosti na klimatske promjene. Procjenu troškova prilagodbe klimatskih
SURPMHQDPDDQDOL]LUDOHVXUD]OLþLWHinstitucije poput: UNFCC, Svjetske banke, UNDP-a, dr. izanimljivo je da se procjene razlikuju s obzirom na korištenu metodologiju procjena šteta. U
cilju što uspješnije prilagodbe klimatskim promjenama potrebno je da budu dostupna
ILQDQFLMVND VUHGVWYD SRVHELFH VLURPDãQLP ]HPOMDPD EXGXüL GD NOLPDWVNH SURPMHQH QHüHLPDWLMHGQDNXWMHFDMQDVYHGLMHORYHVYLMHWDYHü üHQMH]LQLVLURPDãQLMLGLMHORYLELWLQHIOHNVLELOQL
DSULODJRGEDüHELWLGXJDLWHãND6GUXJHVWUDQHXUD]YLMHQLP]HPOMDPDWURãNRYLSULODJRGEH
QHüH SUHGVWDYOMDWL YHOLNL XGLR X EUXWR GRPDüHP SURL]YRGX L] UD]ORJD ãWR MH X WLP ]HPOMDPD
standard infrastrukture, usluga i izgradnje na visokoj razini. Rješavanje problema
financiranja može se realizirati XNOMXþLYDQMHPSRVORYQLK]DMHGQLFD, države i mnogih fondova
na globalnoj razini, na razini Europske unije, ali i Republike Hrvatske. Cilj rada je istaknuti
financiMVNH SRWUHEH ]D SURMHNWH SULODJRGEH X EXGXüQRVWL QD 6YMHWVNRM UD]LQL L QD UD]LQL
5HSXEOLNH +UYDWVNH 0HWRGRP NRPSDUDFLMH L XVSRUHGQRP DQDOL]RP LVWUDåLW üH VH L]YRULILQDQFLUDQMDSURFHVDSULODJRGEH8UDGXüHVHXNUDWNRREMDVQLWLSRMDPNOLPDWVNLKSURPMHQD
tH SURFHV SULODJRGEH DOL L QDþLQL ILQDQFLUDQMD SURMHNDWD NRML VH RGQRVH QD SULlagodbu
klimatskim promjenama.
.OMXþQHULMHþL: klimatske promjene, politika prilagodbe, financiranje

1. UVOD.OLPDWVNH SURPMHQH VX GXJRWUDMQH SURPMHQH NOLPDWVNLK þLQLWHOMD NRML VH PRJX RþLWRYDWL X
SURPMHQL SURVMHþQLK NOLPDWVNLK HOHPHQDWD SURPMHQL UDVSRGMHOH NOLPDWVNLK GRJDÿDMD V
RE]LURP QD SURVMHþQH YULMHGQRVWL LOL SRMDYL VYH YLãH NUDMQMLK YUHPHQVNLK GRJDÿDMD Dakle,
NOLPDWVNHSURPMHQHüHGMHORYDWLQDSRYHüDQMHUD]LQHPRUDNDUakteristike oluje, temperaturu,NROLþLQXSDGDOLQDLQDGUXJHNOLPDWVNHþLQLWHOMH1DYHGHQHDOLLEURMQHGUXJHSRVOMHGLFHMDVQRXSXüXMXQDPHÿXRYLVQRVWNOLPDWVNLKSURPMHQDLVYHXNXSQRJDOMXGVNRJGMHORYDQMD
3ULODJRGEDNOLPDWVNLPSURPMHQDPDXWMHFDWüHQDpromjene u svim razinama – od lokalne do
QDFLRQDOQH L PHÿXQDURGQH ]DMHGQLFH =DMHGQLFH QD VYLP UD]LQDPD PRUDMX JUDGLWLSULODJRGOMLYRVW XNOMXþXMXüL SULKYDW QRYLK WHKQRORJLMD L SULSUHPDWL VH ]D EXGXüH NOLPDWVNH
stresove [4]. Prilagodbe se pojavljuju kao odgoYRU RGUHÿHQLP NOLPDWVNLP GRJDÿDMLPD L X
kontekstu ostalih socio-ekonomskih promjena. Prvi korak kao odgovor klimatskim
promjenama je promjena ponašanja uzrokovanih klimatskih promjenama. Drugi korak je
1

2YDMUDGMHILQDQFLUDQVUHGVWYLPD6YHXþLOLãWDX5LMHFL]DSURMHNW=381,5,

32=âYHUNR*UGLü Politika prilagodbe klimatskim promjenama i njeno financiranje

pripremanje na posljedice klimatskih promjena kao npr. korištenje sustava navodnjavanja
otpornih na poplave.
2. UTJECAJ KLIMATSKIH PROMJENA
MeteorRORãNLSRGDFLSRWYUÿXMXGDJOREDOQDWHPSHUDWXUD=HPOMHUDVWHVSRþHWNRPsWROMHüD,
a višom stopom od 1976. godine. Mjerenja temperature zraka, koja sežu unatrag pedesetak, ana nekim postajama i više od stotinu godina, pokazuju porast srednje globalne temperaturezraka od 0.3ºC do 0.6ºC za posljednjih 80-100 godina. Srednja globalna površinska
temperatura za 2013. godinu bila je viša za 0.5°C od višegodišnjeg prosjeka 2001-2010. [15].
Osim toga, u mnogim dijelovima SYLMHWD ELOL VX L]UDåHQL NOLPDWVNL HNVWUHPL PHÿX QMLPDUD]DUDMXüHSRSODYHMDNHVXãHVQMHåQHROXMHWRSOLQVNLLKODGQLYDORYL[14]. Sve ovo dovelo je
do posljedica globalnog zatopljenja, a neke od njih su [13]:x 3RGL]DQMHUD]LQHPRUDXVOLMHG]DWRSOMHQMDSRYHüDYDVHLWHPSHUDWXUDPRUDãWRGRYRGL GR SRYHüDQMD QMH]LQH PDVH DOL L ]ERJ WRSOMHQMD OHGD QD SRORYLPD L
ledenjacima na kopnu raste razina mora.
x 3ULODJRÿDYDQMH HNR VXVWDYD WHPSHUDWXUD VH QDJOR SRYHüDYD D XþLQFL QD HNRVXVWDYUHJLRQDOQRVXYUORUD]OLþLWLx 3URPMHQHXYRGQRPVXVWDYXQD=HPOMLVNOLPRPüHVHSURPLMHQLWLLUDVSRGMHOD
RWMHFDQMD YRGD ,QWHQ]LYQLMH SDGDOLQH L YMHURMDWQR YHüD JRGLãQMD NROLþLQDSDGDOLQDL]D]LYDWLüHSRSODYH
x Utjecaji na zdrDYOMHWRSOLMDOMHWDLþHãüLYDORYLYUXüLQHXXPMHUHQLPNOLPDWVNLP
zonama dovoGHGRYHüHJEURMDVPUWQLKVOXþDMHYDDSRMDþDQDRQHþLãüHQMD]UDND
XWMHþX QD ]GUDYOMH 7R GRYRGL GR PLMHQMDQMD UDVSURVWUDQMHQRVWL L XþHVWDORVWL
infektivnih oboljenja.
x 3RMDþDQL HNVWUHPQL GRJDÿDML SRSXW VXãD KODGQRüD ROXMD SRSODYD LWG
SURPMHQRPNOLPHPRJOLELVHSRYHüDWLLþHãüHMDYOMDWL7RüHGRYHVWLGRYHOLNLKšteta na infrastrukturi i gubitku ljudskih života.
1DVXSURW RSüH SULKYDüHQRM WHRULML NRMD VH ED]LUD QD ]DWRSOMHQMX XVOLMHG HPLVLMD VWDNOHQLþNLKplinova u atmosferu, postoje i alternativna objašnjenja. Tako se teorije o promjeni klime
PRJX SRGLMHOLWL QD GYLMH VNXSLQH DVWURQRPVNH L ]HPDOMVNH 7HRUHWLþDUL DVWURQRPVNLK WHRULMDVPDWUDMX GD SURPMHQH 6XQþHYH DNWLYQRVWL RGQosno izmjenjivanje hladnih i toplih razdoblja
dovode do pojave ledenog doba, što se povezuje s promjenama tri astronomska elementa=HPOMLQD SRORåDMD X VYHPLUX SUHFHVLMH W]Y WRþNH HNYLQRFLMD QDJLED =HPOMLQH RVL L
HNVFHQWULþQRVWL =HPOMLQH SXWDQMH SUL JLEDnju oko Sunca [18]. Zemaljske teorije se dijele na
geološkogeografske i atmosferske. Prva skupina povezuje promjene klime u geološkoj
prošlosti s promjenama u obliku, visini i razmještaju kopnenih i vodenih površina s
promjenama morskih struja, ledenog pokURYDLVOLþQR$WPRVIHUVNHWHRULMHSRYH]XMXSURPMHQH
NOLPH V SURPMHQDPD VDVWDYD DWPRVIHUH L QMH]LQH FLUNXODFLMH D QDMYHüH ]QDþHQMH LPDMX RQH
NRMH SURPMHQH NOLPH GRYRGH X YH]X V SURPMHQDPD NROLþLQH DHURVROD LOL &22 u atmosferi.
0HÿXWLP SUHYODGDYDMXüL VWDYRYL ]QDQVWYHQLND RVODQMDQMX VH QD HPLVLMX VWDNOHQLþNLKSOLQRYD
NDR WHPHOMQL X]URN NOLPDWVNLK SURPMHQD 'RND] GD SRVWRML YH]D L]PHÿX SURPMHQH
koncentracije CO2, temperature tla i mora predstavlja istraživanje koje je mjerilo
koncentraciju CO2 iz uzoraka ledene kore Vostok ledenjaka. Temperatura je rekonstruirana na
temelju podataka o glacijacijama te ciklusima flore i faune na zemlji u proteklih 400.000
godina [18]. Usporedba krivulja temperature i koncentracije CO2 vrlo uvjerljivo ukazuje na

Energy and the Environment (2016) 31-40

33

postojanje pove]DQRVWL XJOMLþQRJ GLRNVLGD L WHPSHUDWXUH 8 RNYLUX PHÿXQDURGQRJD
znanstvenog foruma "Intergovernmental Panel on Climate Change", više od 5000
]QDQVWYHQLNDãLURPVYLMHWDELORMHXNOMXþHQRXLVWUDåLYDQMDþRYMHNRYRJDXWMHFDMDQDJOREDOQR
zatopljenje [10]. OpaåDQMDSRWYUÿXMXGDVHNOLPDPLMHQMDL]YDQRNYLUDNRMLVHPRJXSULSLVDWLSULURGQLPYDULMDELOQRVWLPDMHUVXVH]DWRSOMHQMDGRJDÿDODLXSURãORVWLDOLQHWDNYRPMDþLQRPi brzinom. U zadnjih tridesetak godina temperatura je porasla za oko tri puta više nego u
SULMDãQMLP UD]GREOMLPD VOLþQRJ WUDMDQMD ,QWHQ]LWHW SRMDYH L VWUXNWXUD ]DELOMHåHQLK SURPMHQDXSXüXMX QD þRYMHNRYH DNWLYQRVWL NDR QDM]QDþDMQLMHJ X]URþQLND ,DNR UD]PMHUQR PDQML XGLRHPLVLMD VYHJD VWDNOHQLþNLKSOLQRYDQDVWDMHXVOLMHGþRYMHNRYLKDNWLvnosti, taj je postotak
dovoljan da se poremeti prirodna ravnoteža procesa u atmosferi [5] 'DNOH SRYHüDQD
NRQFHQWUDFLMD VWDNOHQLþNLK SOLQRYD X]URNXMH SRYHüDQX DSVRUSFLMX WRSOLQH X DWPRVIHUL ãWRGRYRGL GR SURPMHQD WHPSHUDWXUH ]UDND NROLþLQD RERULQD L RVtalih klimatoloških elemenata[22]. 9HüLQDVWUXþQMDNDNRMLL]XþDYDMXNOLPDWVNHSURPMHQHVODåXVHGDVHSRYHüDQMHJOREDOQH
VUHGQMHWHPSHUDWXUHSRYUãLQH=HPOMHPRåHRþHNLYDWLVOMHGHüLKQHNROLNRVWRWLQDJRGLQDDNRVH
HPLVLMH VWDNOHQLþNLK SOLQRYD X]URNRYDQH ljudskim aktivnostima, ne smanje i ne kontroliraju[5].
3. POLITIKA PRILAGODBE KLIMATSKIM PROMJENAMA
6WDNOHQLþNL SOLQRYL RVWDMX X DWPRVIHUL GXJR QDNRQ ãWR VX ELOL HPLWLUDQL .DG EL L HPLVLMH X
ovom trenutku prestale još bi uvijek dolazilo do nekog stupnja zagrijavanja. S obzirom da
YHüLQD PHÿXQDURGQLK VSRUD]XPD NRML VX QDVWDOL NDNR EL VH MDVQR RJUDQLþLOD HPLVLMD
VWDNOHQLþNLK SOLQRYD GRVDG QLMH ELOD XVSMHãQD pa WUHED SULKYDWLWL NDNR MH RGUHÿHQD NROLþLQDzagrijavanja neizbježna te kako treba napraviti pripreme za izazove koje ono donosi [20].
Zemlja je u ovom trenutku toplija za 0.7°C u odnosu na 1900. godinu, a ako se npr. sve
HPLVLMH VWRSLUDMX GDQDV =HPOMD üH VH X LGXüHP GHVHWOMHüX ]DJULMDWL ]D GDOMQMLK -1ºC [19].
Definicija prilagodbe klimatskim promjenama može glasiti: adaptacija prirodnog ili ljudskog
VLVWHPD QD VDGDãQMH LOL RþHNLYDQH NOLPDWVNH SURPMHQH D PRWLYLUDQD MH HNRQRPVNLPVRFLMDOQLPLOLRNROLãQLPþLQLWHOMLPD[3]. 3ULODJRGEDQRYLPNOLPDWVNLPXYMHWLPDXEXGXüQRVWLbi mogla biti vrlo skupa, a njen cilj je smanjiti osjetljivost i negativne efekte klimatskih
promjena.
'DNOHSULODJRGEDMHSUDNWLþDQQDþLQQDYLNDYDQMDQDWUHQXWQHNOLPDWVNHSURPMHQHLHNVWUHPQH
GRJDÿDMHNDRLSULODJRGEDQDGXJRWUDMQLMHNOLPDWVNHSURPMHQH Prilagodba može djelovati na
dvije razine [19]:x Izgradnjom kapaciteta za prilagodbu – kreiranjem informacija i uvjeta
UHJXODWRUQLK LQVWLWXFLRQDOQLK L XSUDYOMDþNLK  NRML VX SRWUHEQL ]D SRWSRUX VDPRP
procesu prilagodbe. Mjere za izgradnju kapaciteta prilagodbe mogu biti od
razumijevDQMD SRWHQFLMDOQRJ XWMHFDMD NOLPDWVNLK SURPMHQD L PRJXüQRVWL SULODJRGEH
GR NUHLUDQMD WRþQR RGUHÿHQLK DNFLMD L DNXPXOLUDQMD L]YRUD SRWUHEQLK ]D
implementaciju.
x Aktiviranje akcija prilagodbe – þLQMHQMHUD]OLþLWLKNRUDNDNRMLüHSRPRüLVPDQMHQMX
osjetljivostL NOLPDWVNRP UL]LNX LOL LVNRULãWDYDQMX PRJXüQRVWL 7R VH þLQL X] SRPRü
QSU LQYHVWLUDQMD X IL]LþNX LQIUDVWUXNWXUX NRMD ãWLWL RG VSHFLMDOQLK NOLPDWVNLK UL]LNDSRSXWSRSODYDVXãDLVOLþQR
Koristi se prilagodbe u kratkom i dugom roku, a povezane su s odrHÿHQRP PMHURPIOHNVLELOQRVWL QD PRJXüQRVW SULODJRGEH 8 NUDWNRP URNX RGJRYRU QD NOLPDWVNH SURPMHQH MH
RJUDQLþHQILNVQLPþLQLRFLPD SRSXWIL]LþNHLQIUDVWUXNWXUH WDNRGDVXPRJXüQRVWLRJUDQLþHQH34=âYHUNR*UGLü Politika prilagodbe klimatskim promjenama i njeno financiranje

7DNR üH VH QSU YHOLNH LQYHVWLFLMH X L]JUDGQMX LQIUDVWUXNWXUH za navodnjavanje dešavati u
GXJRPYUHPHQVNRPSHULRGX8NROLNRNOLPDWVNHSURPMHQHSRYHüDMXVYRMLQWHQ]LWHWSODQLUDQD
LQIUDVWUXNWXUD PRåH SRVWDWL ]DVWDUMHOD ãWR üH ]DKWLMHYDWL GRGDWQH WURãNRYH ]D QMHQX
modernizaciju.
0QRJR RGOXND üH VH DXWRPDWVNL SULKYDWLti i to predstavlja važnu konstataciju za ekonomsko
promišljanje politike prilagodbe. Cilj prilagodbe je smanjiti osjetljivost na klimatske
promjene i varijabilnost, ali i smanjiti negativne utjecaje klimatskih promjena. Ne postoji
jednostavna procedura koMD EL XNOMXþLOD Srilagodbu klimatskim promjenama, ali potrebno jeXþLQLWLVOMHGHüH [2]:1. Ohrabrivanje sudionika procesa - YLWDOQLDVSHNWXGHWHUPLQLUDQMXEXGXüHJXVSMHKDSURFHVDSULODJRGEHMHXNOMXþLYDQMHXSURFHVOMXGLNRMLPRJXQDSUDYLWLQHNHSURPMHQH
TLOMXGLPRUDMXELWLL]UD]OLþLWLKVHNWRUDNDNRELEROMHSURPRYLUDOLGRQRãHQMHRGOXND
kroz transparentan proces koji kreira povjerenje i smisao za proces prilagodbe.
Zainteresirane ljude predstavljaju: a) Predstavnici vladinih odijela, regionalnih ilokalnih državnih tijela, te b) Predstavnici privatnog sektora i nevladinihorganizacija.
2. Definiranje problema – VOMHGHüL NRUDN MH UD]XPLMHYDQMH NDNR NOLPDWVNH SURPMHQH
mogu utjecati na regiju i koji su rizici X EXGXüQRVWL Razumijevanje klimatskih
promjena glavni je korak u definiranju problema. Sintetiziranje informacija od
SRVWRMHüLK QDFLRQDOQLK L UHJLRQDOQLK NOLPDWVNLK RUJDQL]DFLMD PRJX RVLJXUDWL
UD]XPLMHYDQMH ãWR üH EXGXüQRVW GRQLMHWL ,] UD]ORJD ãWR VH WXUL]PX QLMH SULGDYDOD
velika važnost u prošlim istraåLYDQMLPDSRWUHEQRMHRGUHGLWLUL]LNHVNRMLPDüHVHRQ
susresti, odnosno definirati problem.
3. Kapacitet prihvata i ocjena - NDSDFLWHWSULKYDWDXSXüXMHQDPRJXüQRVWVLVWHPDGD
prilagodi svoje ponašanje novim klimatskim uvjetima. Ovaj se kapacitet ne možePMHULWL GLUHNWQRYHüVRFLMDOQLPREUD]RYQLP LQVWLWXFLRQDOQLP þLQLWHOMLPD NRMLPRJXRGUHÿLYDWLNDSDFLWHWSULODJRGEH2GUHÿLYDQMHNDSDFLWHWDSULKYDWD]DKWLMHYDGHILQLUDQMH
WNRVHSULODJRÿDYDLãWRVHSULODJRÿDYD
4. Identificiranje opcija prilagodbe – proces LGHQWLILNDFLMH WUHED ]DSRþHWL V
identificiranjem trenutnih strategija prilagodbe i politika u cilju rješavanja sadašnjih
klimatskih rizika. Nakon analiziranja trenutnog stanja potrebno je identificirati opcije
SULODJRGEHEXGXüQRVWL
5. Procjena opcija prilagodbe – u cilju procjene koja je najbolja opcija prilagodbe zaRGUHÿHQR SRGUXþMH SRWUHEQR MH VYH LGHQWLILFLUDQH RSFLMH SULODJRGEH RFLMHQLWL SR
VOMHGHüLP NULWHULMLPD QHWR GRELW YULMHPH SRYUDWD GLVWULEXFLMD SRYUDWD YODGLQD
politika, troškovi, okolišni utjecaji, sposobnost implementacije i socio-ekonomske tetehnološke barijere. Poželjno je i da se sami kriteriji rangiraju iz razloga što neki
LPDMXYHüXDQHNLPDQMXYDåQRVW]DRGUHÿHQRSRGUXþMH
6. Implementacija prilagodbe – L]DEUDQDRSFLMDXWRþNLSHWPRUD biti implementirana.
U cilju implementacije poželjno je izraditi Strateški plan koji naglašava akcije
XNOMXþHQLK VXGLRQLND 3ODQ L]JUDGQMH NDSDFLWHWD L WUHQLQJD 3RVORYQL SODQ NRMLSUHGYLÿDWURãNRYHLSULKRGH3ODQNRPXQLNDFLMH3ODQRGUåLYRVWLL3ODQPRQitoringa
opcije prilagodbe.
7. Monitoring i procjena prilagodbe – Prilagodba klimatskim promjenama
SUHGVWDYOMD GXJRURþQL LQYHVWLFLMVNL SODQ OMXGVNLK L ILQDQFLMVNLK UHVXUVD 8 FLOMXRVLJXUDQMD RSWLPDOQH UHDOL]DFLMH LQYHVWLFLMH NOMXþQL NRUDN MH RVLJXUDQMH SURcjene
efikasnosti implementiranog procesa prilagodbe.

Energy and the Environment (2016) 31-40

35

2YLKVHGDPNRUDNDSRWUHEQRMHSURPDWUDWLNDRFLNOLþQLNUXJXNRMHPVHNRUDFLSRQDYOMDMXNo,
sposobnost prilagodbe klimatskim promjenama ovisi o podsketorima, destinacijama iRGUHÿHQLPSRVORYLPDXQXWDUWXULVWLþNHLQGXVWULMH
4.

FINANCIRANJE PRILAGODBE KLIMATSKIM PROMJENAMA

8NOMXþLYDQMH LOL LQWHJULUDQMH SULODJRGEH NOLPDWVNLP SURPMHQDPD X SURFes planiranja
QHRSKRGQDMHVWUDWHJLMD]DRGUåLYLGXJRURþQLUD]YRM8WMHFDMLNOLPDWVNLKSURPMHQDQHGHãDYDMX
VHVDPRQHNLPDYHüXWMHFDMLXMHGQRPVHNWRUXPRJXQHJDWLYQRLOLSR]LWLYQRXWMHFDWLQDGUXJHVHNWRUH8PQRJLP]HPOMDPDXUD]YRMXSRVWRMHWHãNRüHXLntegriranju koncepata prilagodbe unacionalnu politiku zbog: nedostatka kapaciteta za planiranje, monitoringa i procjena; maleNROLþLQH UDVSRORåLYLK SRGDWDND R SULODJRGEL L PDQMDN PHKDQL]PD ]D GLMHOMHQH SRVWRMHüLK
podataka i upravljanje njima, limitirane sYMHVQRVWLRYDåQRVWLSURFHVDSULODJRGEHL]PHÿXOMXGL
koji bi je trebali provesti ali i stanovništva [15]. Dakle, u proces prilagodbe moraju biti
XNOMXþHQLVYLGLRQLFLXGUXãWYX, QRXVWYDUQRVWLPDQMDNNRRSHUDFLMHL]PHÿXUD]QLKPLQLVWDUVWYD
naglašen je kao glavna barijera procesa prilagodbe. Da bi se to prevladalo, ministarstva,
lokalni nositelji vlasti, lokalne i nacionalne razvojne agencije trebaju biti informirane o
UHOHYDQWQLP]DNOMXþFLPDRGUHÿHQLKSURFHVDSULODJRGEH.DRSRPRüSURFHVXSULODJRGEHMDYOMD
VH ]QDþDMDQ EURM DNFLMD NRMH PRJX SULSRPRüL XNOMXþHQMX SURFHVD SULODJRGEH X SROLWLNXXNOMXþXMXüLDNFLMHQDORNDOQRMQDFLRQDOQRMLUHJLRQDOQRMUD]LQL2VLPUD]QLKDNFLMDSRVWRMHL
efikasni alati koji služe razvoju i izgradnji kapaciteta za prilagodbu i ukOMXþLYDQMH u politiku
na svim razinama.
Razvijene zemlje (zemlje Anexa II skupine) uložile su u multilateralne i bilateralne projekte u
FLOMXSULODJRGEHXJRGLQL]QDþDMQHL]QRVHQRYDFDãWRSULND]XMHLVOLMHGHüDWDEOLFDTABLICA 1: Doprinos razvijenih zemalja u razne projekte prilagodbe u 2012. godini- u mil USD $ZemljaAustralia
Austrija
Belgija
KanadaDanskaEU
FinskaFrancuska
1MHPDþND
*UþNDIslandIrska
ItalijaJapan
Luksemburg
Nizozemska
Novi Zeland
Norveška
PortugalŠpanjolskaŠvedska

Multilateralni projekti
45,46
2,57
0,49
114,27
6,23
132,39160,67
5,99
1,41
1,59
0
46,01

Bilateralni projekti
36,8
16,49
9,07
83,11
237,3315,97
3.267,04
730,95
0,07
0,74
0,2
15,52
3.226,18
14,2
110,22
20,86
46,79
18,53
192,73
34,19

UKUPNO
82,26
19,06
0,49
123,3483,11
237,3322,2
3.399,43
891,62
0,07
0,74
0,2
21,51
3.226,18
15,61
111,81
20,86
46,79
18,53
192,7380,2

36Švicarska=âYHUNR*UGLü Politika prilagodbe klimatskim promjenama i njeno financiranje

2,11

80,65

82,76

Velika Britanija
148,6260,37
408,97SAD
324,791.496,61
1.821,4
Ukupno992,589.914,62
10.907,2
Izvor: Getting to $100 billion: Climate finance scenarios and projections to 2020, World Resources Institute,
Working paper, May, 2015., p. 15

U financiranju prilagodbe trebati üH VH dodatno angažirati razvijene zemlje koje moraju
podupULMHWLSRþHWQHWURãNRYHSURFHVDSULODJRGEHLSRPRüLGUXJLP]HPOMDPDXVDPRPSURFHVX
prilagodbe. Infrastruktura koju je potrebno mijenjati proteže se od raznih odvodnih sistema,FHVWD åHOMH]QLFD YRGRYRGD L ]GUDYVWYD 0HÿX RVWDOLPD X SURMHNWH SULODJRGEH Xlagale su iUD]QHLQVWLWXFLMHSRSXW(XURSVNHEDQNH]DREQRYXLUD]YRM$IULþNHUD]YRMQHEDQNH(XURSVNH
investicijske banke i sl., a iznose financiranja ovih projekata u 2012. godLQLSULND]XMHVOLMHGHüL
graf.

GRAF 1: Financiranje procesa prilagodbe u 2012. godini od strane raznih organizacija u
mln USA $2NYLU]DUD]XPLMHYDQMHQDþLQDQDNRMLVHSULODJRGEDPRåHSRYH]DWLVDUDQMLYRãüXXþLQMHQMHQD
WHPHOMXSURMHNWDSULODJRGEHQDWHPHOMXNRMLVHMHLGHQWLILFLUDORþHWLULID]e, što prikazuje i
VOLMHGHüLJUDIEnergy and the Environment (2016) 31-40

37

GRAF 2: )D]HUD]YRMDLSULODJRGEHSRYH]DQHVDPRJXüLPL]YRULPDILQDQFLUDQMD
Vezano uz ovaj okvir, metoda tradicionalnog financiranja razvoja bolja je za projekte koje seodnose na osjetljivost prilagodbe, dok se metoda novo i dodatno financiranje može odnositi
na projekte koje se vezuju uz utjecaje prilagodbe.
,DNR VH SRVOMHGLFH NOLPDWVNLK SURPMHQD QH PRJX VD VLJXUQRãüX XWYUGLWL VFHQDULML EXGXüHJ
utjecaja mogu biti dovoljni da bi se odredila strategija planiranja financiranja prilagodbe. U
QHNLP VOXþDMHYLPD WURãNRYQR MH HILNDVQLMH LPSOHPHQWLUDWL PMHUH SULODJRGEH YHü VDGD L WR ]DGXJRURþQX LQIUDVWUXNWXUX 7URãNRYL SULODJRGEH X UD]YLMHQLP ]HPOMDPD EDUHP X VOMHGHüLKQHNROLNRGHVHWOMHüDQHüHSUHGVWDYOMDWLYHOLNLXGLRXEUXWRGRPDüHPSURL]YRGXL]UD]ORJDãWR
je u tim zemljama standard infrastrukture, usluga i izgradnje na visokoj razini [17]. U]HPOMDPDXUD]YRMXLVLURPDãQLP]HPOMDPDVLWXDFLMDüHELWLREUQXWDDVOLMHGHüLJUDI prikazuje
SURFMHQXWURãNRYDUD]OLþLWLKDJHQFLMDL]DUD]OLþLWHJRGLQH

GRAF 3: Procjena troškova prilagodbe u zemljama u razvoju sukladno raznim
autorima u razdoblju od 2015-2050. u mlrd USA $/po godini38=âYHUNR*UGLü Politika prilagodbe klimatskim promjenama i njeno financiranje

5D]OLND SURFLMHQMHQLK WURãNRYD SULODJRGEH SURL]OD]L L] GUXJDþLMHJ NRULãWHQMD PHWRGRORJLMH
procjene šteta. Bilo bi nužno da se u ILQDQFLUDQMHRYLKWURãNRYDVDãWRYHüLPL]QRVLPDXNOMXþHrazvijene zemlje
Ambiciozan plan prilagodbe koji je postavljen na temelju SRYHüDQMa temperature od max. 2°C
od strane UNFCCC konferencije u Copenhagenu, Cancunu, Durbanu i Parisu zahtjeva]QDþDMQRVPDQMHQMHHPisije ne saPRXUD]YLMHQLPYHüLX]HPOMDPDXUD]YRMX7URãNRYLWDNYLKVPDQMHQMD UDVWL üH WH üH LQGXVWULMDOL]LUDQH ]Hmlje morati pokriti sve inkrementalne (dodatne
troškove). 3UHPD QHNLP SUHGYLÿDQMLPD XNROLNR VH ]DJDÿHQMH RGUåL QD UD]LQL  SSP  &22
ukupni troškovi u zemljama u razvoju iznositi je 220 mlrd USD do 2020 JRGLQL GRN üH
inkrementalni troškovi iznositi 125 mlrd USD $ [11]. Kao što se može primijetiti razlika
L]PHÿXRVQRYQLKLLQNUHPHQWDOQLKWURãNRYDQLMHWDNRYHOLND$IULþNH]HPOMHLVND]XMXQDMYHüH
troškove u usporedbi s ostalim zemljama, sa maksimalnih oko 2,5% troškova u ukupnom
EUXWR GRPDüHP SURL]YRGX 3ODQLUDQL RVQRYQL WURãNRYL X RVWDOLP ]HPOMDPD GDOHNR VX LVSRG
2,5% BDP-a, a inkrementalni troškovi dosežu jedva 1% BDP-a.
8 FLOMX SRVWL]DQMD HILNDVQRVWL X DORFLUDQMX VUHGVWDYD ]D SULODJRGEX SRWUHEQR MH XþLQLWL
komparaciju neto dobiti za sve projekte. 7URãNRYL XþLQMHQL ]D SULODJRGEu klimatskim
SURPMHQDPD SROXþLW üH RGUHÿHQH UH]XOWDWH 6 HNRQRPVNRJ stajališta oni se definiraju kao
UD]OLND L]PHÿX WURãNRYD NOLPDWVNLK RãWHüHQMD NRML VX QDVWDOL VD L bez poduzetih mjera
prilagodbe [16]. %XGXüL WURãNRYL PRJX VH JOHGDWL L X VYMHWOX PRJXüQRVWL NRMH üH VH X
EXGXüQRVWLSUXåDWL
Osim razvijenih zemalja, kao fiQDQFLMHUL SULODJRGEH PRJX VH SRMDYLWL UD]QH PHÿXQDURGQH
DJHQFLMHSULYDWQLVHNWRULNXüDQVWYDJGMHVHYHOLNL]QDþDMGDMHPHÿXQDURGQLPDJHQFLMDPDL]
razloga što vlade zemalja posebice srednje razvijenih, ali i onih s niskim dohotkom, maloulažu u prilagodbu.

5. =$./-8ý$.
Klimatske promjene su dugotrajne promjene NOLPDWVNLK þLQLWHOMD D RGUDåDYDMX VH NUR]
SURPMHQH SURVMHþQLK NOLPDWVNLK HOHPHQDWD UDVSRGMHOH NOLPDWVNLK GRJDÿDMD V RE]LURP QD
SURVMHþQH YUijednosti i pojave krajnjih vrePHQVNLK GRJDÿDMD One se oþLWXMX X SRGL]DQMX
UD]LQH PRUD X SRYHüDQMX WHPSHUDWXUD QD ]GUDYOMH OMXGL WH X HNVWUHPQLP NOLPDWVNLPGRJDÿDMLPD 'D EL VH XEODåLOH QHåHOMHQH NOLPDWVNH SURPMHQH QXåQH VX SULODJRGEH RYLP
promjenama.
Politika prilagodbe klimatskim promjenama koristi se uz pRPRü L]JUDGQMH kapaciteta za
prilagodbu i raznim akcijama prilagodbe prvenstveno u cilju smanjivanja negativnih utjecaja
klimatskih promjena. Da bi se ova politika mogla SURYHVWL QXåQH VX DNWLYQRVWL NRMH üHpoduzeti razne institucije, država, ali i samo stanovništvo. Da bi se mogle provesti aktivnosti
i mjere za prilagodbu klimatskim promjenama nužno je izgraditi i utvrditi sistem financiranja.
Ovaj se VLVWHP WUHED RVORQLWL QD RGUHÿLYDQMH IDNWRUD NRML XWMHþX QD UDQMLYRVW L]JUDdnju
kapaciteta prilagodbe, upravljanje klimatskim rizicima i suprotstavljanje klimatskim
promjenama. Razvijene zemlje uložile su u razne projekte prilagodbe oko 10,9 mlrd USD u
2012. gRGLQL=QDþDMQLMHL]QRVe u ulaganja ostvarile su Francuska (3,4 mlrd USD) i Japan (2,2
mlrd USD). Planom priODJRGEH X] SRYHüDQMH WHPSHUDWXUH RG PDNVLPDOQR & X  uodnosu na 1990. u 6YLMHWXüHUD]YLMHQH]HPOMHXORåLWLPOUG86'RVQRvnih troškova te 120
mlrd USA dodatnih troškova. Planirani troškovi (izuzev AfrLþNLK ]HPalja) iznose manje od
2,5% BDP-a, a dodatni do 1% BDP-a. Osim razvijenih zemalja u financiranju prilagodbe
WUHEDMXVHXNOMXþLWLUD]QHPHÿXQDURGQHDJHQFLMHSULYDWQLVHNWRULNXüDQVWYD8]WDNDYSULVWXSEnergy and the Environment (2016) 31-40

39

PRJXüD VX ]QDþDMQD XODJDQMD X SURYHGEL SULODJRGEH klimatskim promjenama u Svijetu, teizbjegavanje negativnih posljedica klimatskih promjena.
LITERATURA[1.]Assessing the Costs of Adaptation to Climate Change, A review of the UNFCCC another recent estimates, Imperial College, London, August 2009.
[2.]Climate Change Adaptation and Mitigation in the Tourism Sector, Frameworks, Tools
and Practices, UNEP, University of Oxford, 2008.
[3.]Climate Change and Tourism: Responding to Global Challenges, World Tourism
Organization and United Nations Environment Programme, 2008.
[4.]Climate Change: Impacts, Vulnerabilities and Adaptation in Developing Countries,
United Nations Framework Convention on Climate Change, Germany, 2007.
[5.]ýUQMDU 0 Ekonomika i politika zaštite okoliša (NRQRPVNL IDNXOWHW 6YHXþLOLãWD X
Rijeci, Glosa, Rijeka, 2002.
[6.]Dobra klima za promjene, Klimatske promjene i njihove posljedice na društvo igospodarstvo u Hrvatskoj ,]YMHãüH R GUXãWYHQRP UD]YRMX +UYDWVND 81'3 =DJUHE
2008.
[7.]Getting to $100 billion: Climate finance scenarios and projections to 2020, World
Resources Institute, Working paper, May, 2015.
[8.]http://www.grida.no/climate/ipcc_tar/wg1/067.htm#231[9.]http://www.mzopu.hr/doc/ozstr10.pdf[10.]
Is the recent warming unusual?, Climate Change 2001: The Scientific Basis,
IPCC,
[11.]
Jakob, M., Steckel, J.C., Flashsland, C., Baumstark, L.; Climate finance fordeveloping country mitigation: blessing or curse, Climate and Development, 2015.,
Vol. 7., No. 1, p. 1-15
[12.]Klimatske promjene- efekt staklenika, MZOPUG[13.]
Müller, H.; Turizam i ekologija, Masmedia, Zagreb, 2004.
[14.]
3UDüHQMe i ocjena klime u 2009. godini, 2010.
[15.]
3UDüHQMHLRFMHQDNOLPHXJRGLQL 2014.
[16.]
Remling, El, Persson, A., Who is adaptation for? Vulnerability and adaptation
benefits in proposals approved by the UNFCC Adapation Fund, Climate andDevelopment, 7:1, p. 16-34[17.]
Setterhwaite, D., Huq, S., Pelling, M., Reid, H., Lankao, R.; Adapting to
Climate Change in Urban Areas, Human Settlements Discussion Paper Series,
International Institute for Environment and Development, London, 2007.
[18.]
6LMHUNRYLü 0 3DQGåLü . Efekt staklenika i njegov utjecaj na klimatske
promjene, Pomorski zbornik, Knjiga 29/1991., Rijeka, 1991.
[19.]
Stern, N.; The Economics of Climate Change, The Stern Review, Cambridge
University Press, Cambridge, 2006.
[20.]Šimac, Z., Vitale, K.; Procjena ranjivosti od klimatskih promjena, Hrvatski
Crveni križ, Zagreb, 2012.
[21.]
The Cost of Climate Adaptation, www.wri.org[22.]8þLQDNVWDNOHQLND,MZOPUG,
http://kenny2.globalnet.hr/klima.mzopu.hr/default.aspx?id=43.
[23.]Wall, G.; 7XULVWLþND LQGXVWULMD 1MHQD UDQMLYRVW L SULODJRGOMLYRVW SURPMHQH
klime, Acta turistica, Vol.18, Br. 2, 2006.

40=âYHUNR*UGLü Politika prilagodbe klimatskim promjenama i njeno financiranje

CLIMATE CHANGE ADAPTATION POLICY AND ITS FINANCING
Abstract: The process of climate change adjustment is based on the assumption that climatechange is something real and happening; it tries to identify the steps that can be taken inorder to mitigate its adverse effects and take advantage of the opportunities it offers. This
represents the key response in the effort to reduce vulnerability to climate change. The costsof adaptation to climate change have been analysed and assessed by various institutions, suchas UNFCC, the World Bank, UNDP etc. Interestingly, the estimates differ with respect to thedifferent methodologies used in the assessment. In order to successfully adapt to climatechange, constant financial resources need to be available. This is especially the case for poor
countries, since climate change will not have an equal impact on all parts of the world; thepoorer countries will be more inflexible and adaptation will be long and difficult. On theother hand, in developed countries, the costs of adaptation to climate change will represent
only a small share of gross domestic product, due to the higher standards of the existing
infrastructure, services and construction. Solving the problem of financing can be achieved byincluding the business community, the government, and various funds at the global level, theEuropean Union level, as well as at the level of Croatia. The aim of this paper is highlighting
the financial needs for adaptation measures in the future, both at the global and Croatianlevel. The sources of financing the climate change adaptation process are examined using themethods of comparison and comparative analysis. This paper briefly explains the concept ofclimate change and the adaptation process, as well as the ways of financing the projects
related to climate change adaptation.
Key words: climate change, adaptation policy, financing

Energy and the Environment (2016) 41-48

41

OIL AND GAS INDUSTRY AND CHALLENGES FROM CLIMATECHANGE REGULATIONS
Domagoj Vulin1, 'DULD.DUDVDOLKRYLü6HGODU2/XFLMD-XNLü3
1

Faculty of Mining, Geology and Petroleum Engineering, Pierottijeva 6, Zagreb, tel.:
003851 55 35 846, domagoj.vulin@rgn.hr

2Faculty of Mining, Geology and Petroleum Engineering Pierottijeva 6, Zagreb, tel.:
003851 55 35 829, daria.karasalihovic-sedlar@rgn.hr

3Faculty of Mining, Geology and Petroleum Engineering, Pierottijeva 6, Zagreb, tel.:
003851 5535 838, lucija.jukic@rgn.hr

Abstract: Oil companies are facing the problem of allowed carbon dioxide emissions becauseof high-energy consumption or gas flaring. Green (or greener) technology, in the case of oil
and gas companies became one of the key parts of their business strategy, often by comprising(or by equalizing) energy sustainability with sustainability of a business. There are three maincategories of air pollutants in upstream and downstream activities: fuel combustion, fugitive
emissions and carbon dioxide separated at natural gas processing plants. In refineries,
boilers in which fuels are oxidized, in order to generate heat for internal separate use, aremajor contributors to CO2 emission from fuel combustion. Fugitive emissions are mostly
related to emissions of methane during oil production (flaring, leakage at seals in flanges,
valves etc. or depressurizing releases during blow down in pressure vessels or oil production
wells). Gas processing plants in Croatia are producing significant amount of CO2 which after
purification could be used for Enhanced Oil Recovery (EOR). In order to review the options
for CO2 emission reduction during upstream (and part of mid-stream) operations it should beconsidered that burning 1 m3 of diesel will result in about 2.5 tonnes of CO2 and that flaringof 1 m3 of gas (at standard conditions) generates around 2 kg of CO2. Possible strategy that
oil and gas companies can use to deal with challenges from climate change regulations wasanalyzed in this work. Additionally, results of case study of CO2 emissions for a different gas
composition burned at flaring system in Croatia, and amounts of CO2 at gas processing
plants that could be reduced were analyzed. Also, economic analysis with net present value ofdifferent technological investments was conducted.
Keywords: CO2 emission, gas flaring, pressure depletion, net present value

1. INTRODUCTION – SOURCES OF CO2
Among the largest CO2 sources in upstream part of oil and gas production process are natural
gas processing facilities and flares. In Croatia oil is produced from 34 fields, condensate is
primarily produced from eight gas-condensate fields, while natural gas is produced from 23

42'9XOLQ'.DUDVDOLKRYLü6HGODU/-XNLü: Oil and gas industry…

gas fields. Almost all perspective locations for oil production are in northern part of Croatia,
i.e. Sava and Drava Depression. Domestic hydrocarbon production can cover more than 60 %of the domestic demand. The largest CO2 point source from upstream activities is in Molve,
where gas and condensate are processed for further transportation [1]. At oil production
fields, there is prominent aspect of gas flaring as one of factors that are not contributing theimage of oil and gas industry as environmentally-friendly.

1.1. CO2 emissions and mitigation possibilities
Mitigation of greenhouse gas emissions can be achieved during upstream activities by (1)efficient gas separation from oil, (2) using natural gas for energy demand near hydrocarbon
production facility (3) using natural gas for injection back to an oil reservoir to improve oil
mobility i.e. for Enhanced Oil Recovery (EOR).
In this work focus was given to gas flaring near hydrocarbon production facilities. Natural gas
processing plant Molve and ethane facility near Dugo Selo produce more than 6 500 t/year of
CO2 by flaring. This flaring has not been considered for this work, as flaring is not constantthrough the year, i.e. the flares at these facilities are used for periodic burning of gas whensome part of facilities works near blow-out pressure.
Large quantities of CO2 might be stored into regional aquifers in Croatia, which are marked
on figure 1 [2].

Figure 1 Regional deep saline aquifers in Croatia [2]The most recent assessment of aquifer storage capacity is published in Vulin et al. (2012) [3],estimating almost 1000 Mt of CO2 that could be stored in Sava Central aquifer during thewhole period of injection. Such estimated amounts indicate that all CO2 produced in Croatia

Energy and the Environment (2016) 41-48

43(including all CO2 from oil and gas production activities) can be injected and permanently
stored into geological formations. However, such projects demand extensive research andinvestment into pilot project(s), and CO2 storage to aquifers considers large CO2 point
sources. In other words, if CO2 capture at power plants and heating plants in Croatia will not
be the option, storage capacity of one regional aquifer would be oversized for CO2 that could
be captured in Croatia. On the other side, hydrodynamic properties of aquifer (e.g.
permeability distribution, wettability, pore size distribution), thermodynamic and geochemical
process of CO2-brine-rock interaction and techno-economical aspects of CO2 storage toaquifers might change interpretation of CO2 storage capacity, which also contributes to thefact that storage in such formations should be comprehensively studied and that thetechnology will not be available at least for several years at specific site in Croatia.
In this work the study of typical oil reservoir was conducted in terms of:--

Oil production decline through lifetime of a reservoir;
Constant pressure decrease during oil production and consequently different oil
and gas composition during separation at pressures below saturation (bubble point)pressure;
Gas composition at different separation conditions at the surface;
CO2 production by flaring the gas separated from different production andseparation pressure-temperature (p-T) conditions;
Economic parameters related to possible reduction of CO2 emission.

2. LABORATORY ANALYSIS OF FLUID FROM OIL FIELD
Assumption that gas separation from oil in an oil reservoir can be simulated in laboratory bydifferential liberation experiment proved to be good [4], [5]. In reservoir, when pressure
decreases below saturation pressure, gas phase appears and gas liberation occurs until the endof production from a reservoir. During gas liberation, different molecules evaporate from oil.
Oil and gas composition at each pressure below saturation pressure can be determined only bygas chromatography analysis of liberated gas in DL test (oil composition can be thencalculated by material balance) or by cubic equation of state (EOS) which has to be tuned (tobe proven as accurate) to simulate experiments conducted in the laboratory.
Gas to oil volumetric ratio, and compositions of oil and gas phase from DL experiment(performed at reservoir temperature) were input for further calculation of gas separation fromproduction well to surface conditions (flash process).
For simulation of PVT (pressure-volume-temperature) experiments cubic equation of state isused together with vapor-liquid equilibria calculation (VLE). The approach of tuning EOS
parameters includes a large number of iterations and numerical solutions, so it was convenient
to use PVTi simulation software [6]. When accurate EOS for observed oil composition isavailable, input parameters for further calculation are production decline (changes of oil
produced) and pressure decrease. These parameters are needed to calculate CO2 emitted at
different (separation) conditions at the surface.

44'9XOLQ'.DUDVDOLKRYLü6HGODU/-XNLü: Oil and gas industry…

3. CALCULATION RESULTS
In order to predict future oil production, a typical oil production of a relatively old and small
field was taken and decline curve analysis was applied for this case. The main assumption isthat the trend of a curve in the past will be present in the future and this assumption can bemade considering well—known production history. Exponential decline was selected basedon the production history behavior, with annual decline rate of 15 %. Equation used for
production forecast [7]:‫ݍ‬௢ = ‫ݍ‬௢௜ ή ݁ ି஽ή௧(1)

where:
qo – oil production, m3/yqoi – initial oil production, m3/y
D – decline rate 1/yeart – time, year
Gas production is calculated on the basis of a constant gas-oil-ratio which had been measured
in the history of this field.
Another parameter needed for CO2 emission calculation is reservoir pressure, which can be
estimated if reservoir drive mechanism is known. Figure 2 shows a typical oil recovery(Np/N)-pressure (p) diagram for the case of an oil reservoir throughout the reservoir lifetime.
In the beginning of the production, elastic drive mechanism (above bubble point) is present,
and in some later time, solution drive mechanism and/or gas cap mechanism start to dominate.
Although pressure curve would differ in case of water flooding and in case of a great gas cap,
for purpose of this research, this typical pressure curve shape can be applied and pressure canbe correlated for a specific case. First period (top left) on this curve can be approximated witha 3rd order polynomial since gas cap influence in minimal. Rest of the production period canbe approximated with a 2nd order polynomial since pressure and production data are available.

Figure 2 Change of reservoir pressure with increasing oil recovery

Energy and the Environment (2016) 41-48

45

After the reservoir pressure is determined, flare gas composition can be simulated. Since thecomposition depends on the exit pressure, two different compositions are obtained, one forseparation at 7 bar, which represents separator, and one for separation at 1 bar. This way
emitted amounts of CO2 with and without separator can be compared.
First step is to determine carbon content of individual hydrocarbon compound on a masspercent basis:‫ܥݓ‬஼೔ =

ெ಴ ή௫
ெ೔

(2)

where:
wCCi - carbon content of (hydrocarbon) component i (mass part of unit)
MC - molecular weight of carbon (MC=12 g/mol)x - stoichiometric coefficient for carbon (number of carbon atoms in a molecule)
Mj - molecular weight of component
For plus fraction, stoichiometric coefficient (x) is determined by finding an alkane with thesimilar molecular weight.
Carbon content of the mixture can be calculated using next equation:‫ܥ‬௖ = σ௡௜ୀଵ(‫ݓ‬௜ ή ‫ܥݓ‬௖௜ )(3)

where:
Cc – carbon content of the mixture (mass part of unit)
wi – weight fraction of component i
The amount of CO2 produced by flaring can be calculated with:‫ܧ‬஼ைଶ = ܸ ή ‫ܥ‬௖ ή

ெ಴ೀమ
ெ಴

ή σ௡௜ୀଵ ‫ܯ‬௜ ή ‫ݖ‬௜(4)where:
V – (flaring) gas volume, m3
MCO2 – molecular weight of carbon dioxidezi – molar fraction of component i
Finally, for given case, oil and gas production, reservoir pressure and CO2 emissions were
calculated and results are in table 1.

46'9XOLQ'.DUDVDOLKRYLü6HGODU/-XNLü: Oil and gas industry…

Table 1 Results of CO2 emission calculation

2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026

Np

Gp

2152
1852
1594
1372
1181
1016
875
753
648
558
480

538 000
463 000
398 500
343 000
295 250254 000
218 750
188 250
162 000
139 500
120 000

CO2 emission
pressure,bar
sa separatorom bez separatora80
30 87843 94180
26 57337 81580
22 87132 54760
19 83029 31360
17 07025 23260
14 68521 70760
12 64718 69460
10 88416 08860
9 366
13 84560
8 065
11 92260
6 938
10 255

4. INVESTMENT CALCULATIONIn this paper, two possible investment options were analysed with economic feasibility ofseparator installation. General goal of the analysis was to indicate investment possibilities ofthe separator introduction into the production system on hydrocarbon field production plant.
The purpose of the project was to define decrease of the CO2 emissions and to calculate
economic return of separator investment. The project defined the possible scenarios as thefirst - business as usual (without separator) and the second - do something else (withseparator). The both analysed scenarios have the same technological prerequisite. Since bothscenarios have the certain impact on the environment due to the CO2 emissions - external
impact (ecological output), impact of the project on climate and vice versa have been
analysed. For the total expenditures prediction investment costs, project management,
documentation and the OPEX have been taken into account. The discount rate of 7.5 % has
been taken as relevant for the whole petroleum industry operating in production ofhydrocarbons in Croatia. In cash flow the current CO2 emissions prices of 4.15 EUR per CO2
units have been taken for production period until the technical limit of production due to thepressure drop [8]. Also amortization have been calculated for the capital investment. Since
project does not generate revenues, it was analysed from the negative expenditures point ofview. Direct expenditures of production were analysed (material, personnel, maintenance)with presumption of financing from investors capital only (revenues, bank credit). Economic
analysis has given the discounted sum of all costs through production period as analysed time
horizon. All indicators were discounted. As a result, net present value - NPV was calculated
as a sum of all present values of the project in the analysed time.
The economic analysis showed that the NPV was positive for the total investment startingfrom 15 % of emissions over emissions cap value. The financial internal rate of return – IRR,
value that shows the rate according to which NPV is equal to 0 in analysed time frame, wascalculated (Figure 3).

Energy and the Environment (2016) 41-48

47

20,00%
15,00%

IRR, %

10,00%
5,00%
0,00%-5,00%

0

0,05

0,1

0,15

0,2

0,25

-10,00%-15,00%over emission cap, %Figure 3. Internal rate of return – production with separator

The IRR was above discount rate for the investment up to 14,5% of emissions over emissions
cap value. Below that, IRR was below discount rate. Therefore, the project was analysed ascommercially acceptable for wide range of emissions over the emission cap starting from
14.5%.

5. CONCLUSION
The specific goal of the project was to define net benefits resulting from the capital
investment into separator for decreasing CO2 emissions. In the primary phase, the initialphysic indicators of the project like production quantities of natural gas, pressure, quantities
of CO2 emissions through production time have been calculated. In the second phase,
economic indicators have been calculated. These indicators could help measure the impact ofthe project (revenue, costs, NPV, IRR) which could influence to socio-economic variables(e.g. new working places, increase of GDP or total decrease of GHG emissions). The further
investigation could include more data and could give total feasibility of the project byanalysing costs and benefits not only for the investor, but also other socio-economic costs andbenefits including the complete socio-economic context of the project. This would probably
give the size of the increase of the benefits for the society. Local area was defined as targetedarea, although the analysed area could be of much wider geographic context due to the factthat global emissions decrease is not directly related to specific area. For the detailed costbenefit analysis, it would be necessary to quantify all the positive and negative direct andindirect impacts of the investment. Due to localized scope of the project, indirect impacts
were excluded from this analysis.
The results of techno-economic analysis could be used as possible business strategy option for
dealing with climate change challenges in the petroleum industry. The results showed that
small changes in technological production flow like separator introduction could be net
positive and applicable at the different hydrocarbon production facilities.

48'9XOLQ'.DUDVDOLKRYLü6HGODU/-XNLü: Oil and gas industry…

References:[1] Ministry of Economy and Ministry of Construction and Physical Planning, 2013. Second
National Energy Efficiency Action Plan for the Period until the End Of 2013[2] EU Geocapacity, 2009. Assessing European capacity for geological storage of carbon
dioxide. Technical reports, FP-518318: EU Geocapacity, 2007. Storage Capacities. WP2.3
D12; 2009.
[3] Vulin, D., Kurevija, T. and Kolenkovic, I., 2012. The effect of mechanical rock properties
on CO 2 storage capacity, Energy, 45(1), pp.512-518.
[4] Standing, M.B.: Volumetric and Phase Behavior of Oil Field Hydrocarbon Systems, Millet
Print Inc., Dallas (1977) 81.
[5] McCain, W.D. Jr.: The Properties of Petroleum Fluids, second edition, PennWell, Tulsa(1990) 283.
[6] Schlumberger, 2015 Eclipse Software - Acknowledgement to Schlumberger foropportunity to use software for scientific purposes[7] Arps, J. J.: Analysis of Decline Curves, Trans. AIME 160, pp. 228-247[8] Belektron Carbon Newsleter (2016): EUA Dec 16 – current CO2 unit prices(http://www.belektron.eu/hr/)

NAFTNA I PLINSKA INDUSTRIJA I IZAZOVI KOJE POSTAVLJAJUPROPISI O KLIMATSKIM PROMJENAMA
1DIWQH NRPSDQLMH VH VXRþDYDMX V SUREOHPRP GRSXãWHQLK HPLVLMD &22 koje se javljaju kao
posljedica intenzivne potrošnje energije ili spaljivanja plina na baklji. Zelena (zelenija)
WHKQLNDMHXVOXþDMXQDIWQLKi plinskih kompanija SRVWDODNOMXþQLPGLMHORPSRVORYQHVWUDWHJLMH
JGMH MH þHVWR HQHUJHWVND RGUåLYRVW VDGUåDQD X RGUåLYRVWL GMHODWQRVWL Tri su glavne skupineL]YRUD ]DJDÿLYDþD]UDNDX³XSVWUHDP´L³GRZQVWUHDP´DNWLYQRVWLPDVDJRULMHYDQMHJRULYDHPLVLMHRGRG]UDþLYDQMDugljikovog dioksida odvojenog u postrojenjima za obradu prirodnog
plina. U rafinerijama, bojleri u kojima goriva oksidiraju i stvaraju toplinu za internu
potrošnju predstavljaju glavni izvor CO2 od izgaranja goriva. (PLVLMH RG RG]UDþLYDQMD VH
uglavnom odnose na emisije metana tijekom pridobivanja nafte (spaljivanje na baklji, curenje
QDEUWYDPDYHQWLOLPDLVOLþQR). Postrojenja za obradu prirodnog plina u Hrvatskoj proizvode]QDþDMQX NROLþLQX &22 %XGXüL GD VH UDGL R SURþLãüHQRP &22, može se upotrijebiti za
XWLVNLYDQMH X OHåLãWD X VNORSX WHUFLMDUQLK PHWRGD SRYHüDQMD LVFUSND HQJO (25 – Enhanced
Oil Recovery). Kako bi VH GDR SUHJOHG PRJXüQRVWL ]D VPDQMHQMH HPLVLMD &22 tijekom“upstream” (i dijela “mid-stream) aktivnosti, treba naglasiti kako spaljivanje 1 m3 dizela
rezultira s oko 2,5 tone CO2, dok spaljivanje 1 m3 prirodnog plina (pri standardnim uvjetima)
proizvodi 2 kg CO2. U radu su analizirane strategije koje naftne i plinske kompanije mogu
primijeniti kako bi se nosile s izazovima koje donose propisi o klimatskim promjenama. Osim
WRJD SULND]DQL VX UH]XOWDWL VWXGLMH VOXþDMD X NRMRM VX SURXþDYDQH HPLVLMH &22 ]D UD]OLþLWHsastave plLQD VSDOMHQRJ QD EDNOMDPD WH PRJXüQRVWL VPDQMHQMD NROLþLQH HPLVLMD &22 u
postrojenjima za obradu prirodnog plina primjerice prilikom ugradnje separatora.
.OMXþQHULMHþLemisija CO2, izgaranje plina, pad tlaka

Energy and the Environment (2016) 49-58

49

TWO YEARS (2013 – 2015) OF FINE AEROSOL MONITORING IN
RIJEKA, CROATIA
0ýDUJRQMD1, T. ,YRãHYLü2,2UOLü1
Department of Physics, University of Rijeka, Radmile 0DWHMþLü+5-51000 Rijeka,
Tel: +385 51584623; +385 51584620, E-mail: mcargonja@uniri.hr, ivo.orlic@uniri.hr
2
Education and Teacher Training Agency, Trpimirova Street 6, HR-51000 Rijeka, Tel:
+385 51317690, E-mail: tatjana.ivosevic@azoo.hr
1

Abstract: In the city of Rijeka, Croatia, two-year aerosol pollution monitoring campaign wasrecently completed. During period from August 2013 to September 2015, 345 samples of fine
fraction of aerosols were collected on stretched Teflon filters. All samples were analyzed by
X-ray Fluorescence (XRF) technique and concentrations of 19 elements from Si to Pb were
determined. Concentrations of black carbon were determined by Laser Integrated Plate
Method.
Concentrations of elements were compared with weather conditions such as wind speed anddirection, precipitation and relative humidity and with city activities such as traffic andindustrial activities.
The results were statistically evaluated by means of Positive Matrix Factorization (PMF).
Several anthropogenic sources were found such as secondary sulfates, industry, road trafficand smoke. The resulting annual average PM2.5 concentrations for years 2013, 2014 and GR QRW H[FHHG DQQXDO OLPLW YDOXH RI  ȝJ P-3, which is defined by the EU Directive
2008/50/EC.
Keywords: Rijeka, aerosols, PM2.5, XRF, meteorological conditions, traffic, industry
1. INTRODUCTION
Fine fraction (PM2.5) of aerosols makes atmospheric particles with aerodynamic diameter
below 2.5 ȝP Because of its small size, these particles easily enter human respiratory systemand even blood system, carrying potentially harmful substances. It has been proved that thisparticulate matter has very serious effect on human health during a long term exposure [1,2].
Besides human health, it reduces visibility and affects cloud formation, Earth’s radiativebalance and climate. In urban and industrial area this fraction is mostly of anthropogenic
origin such as industry, power plants, road traffic and ship emission, but approximately 10%
comes from natural sources such as sea spray and soil dust [3].
The City of Rijeka (latitude 45°21’N, longitude 14°26’E) is the largest Croatian port and thethird Croatian city by size with 130 000 inhabitants. Sampling site was surrounded withseveral possible pollution sources: harbour (cargo traffic of about 10 Mt/year), road and railtransport, shipyard (the biggest one in Croatia), oil refinery, oil powered thermal plant (320MW; cancelled 2015) and coal powered thermal plant Plomin. There are also one oil powered
thermal plant and oil refinery in Trieste, about 60 km away from Rijeka (Figure 1).
During the two years sampling period (from August 2013 to October 2015) 345 daily aerosol
samples were collected at the Port of Rijeka. The samples were analyzed by X-ray
Fluorescence (XRF) technique at the Laboratory for Elemental Micro-Analysis (LEMA),
Department of Physics, University of Rijeka to obtain concentrations of 19 elements from50

M. ýDUJRQMD7,YRãHYLü,2UOLü Two years of fine aerosol monitoring …

silicon to lead. Additionally, black carbon (BC) concentrations were determined by Laser
Integrated Plate Method (LIPM) at LEMA. The results were statistically evaluated using
positive matrix factorization (PMF) to identify the contributions of major sources ofparticulate matter.
The influences of meteorological conditions and daily traffic density on PM2.5 concentrations
were also studied. PM2.5 concentrations showed good correlations with meteorologicalparameters, as well with the traffic density.

Figure 1 Location of the sampling site. Labels: TPP - thermal power plant and OR - oil
refinery
2. EXPERIMENTAL
The sampling site was situated at the Port of Rijeka, with the sampler inlet 3 m above the sea
level, 2 m above the ground level and 30 m away from two busy roads and main bus terminal.
The sampling was performed from August 6th 2013 to October 1st 2015. In total, 345 daily
samples were collected.
Particulate matter was collected on stretched Teflon filters (PALL Corporation R2P1025,
GLDPHWHURIPPȝPSRUHVL]H XVLQJDF\FORQHVDPSOHUEDVHGRQ$1672¶V $XVWUDOLDQ
Nuclear Science and Technology Organisation) fine aerosol sampling unit. Average flow rate
was (22.5 ± 3) l/min to obtain the cut-RIIVL]HRIȝP
Two techniques were used for aerosol analysis at LEMA: XRF and LIPM. By XRF wereobtained concentrations of 19 elements (Si, P, S, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu,
Zn, Br, Sr and Pb). Excitation was performed by a rhodium X-ray tube under 50 kV and 1
mA. The beam was collimated to a diameter of 2 mm and perpendicular to the sample. X-rays
were measured with a silicon drift detector which was positioned at 45° in respect to theincoming beam [4]. The spectra were analyzed with the AXIL (Analysis of X-ray spectra by
Iterative Least squares) computer code [5].
By LIPM were obtained concentrations of black carbon [6]. For that purpose, laser beam of
633 nm of wavelength was used assuming a mass absorption coefficient of 7.02 m2 g-1.
The total PM2.5 mass was determined gravimetrically by Mettler Toledo MX5 microbalance(uncertainty ±  ȝJ UHDGDELOLW\  ȝJ UHSHDWDELOLW\  ȝJ  XQGHU WKH ODERUDWRU\ FRQGLWLRQV
(temperature 22°C, relative humidity 50%). The measurements were performed at the
ANSTO.
Meteorological conditions were measured at the main meteorological station in Rijeka, which
is situated about 1.5 km north from the air sampler unit. Daily dominant wind direction, daily

Energy and the Environment (2016) 49-58

51

averages of wind speed, temperature and relative humidity and daily values of precipitation
were used. All meteorological data was obtained by the National Meteorological andHydrological Service.
Backward trajectories were plotted with National Oceanic and Atmospheric Administration’s(NOAA) HYSPLIT atmospheric transport and dispersion modeling system [7] for eachsampling day at 00:00, 06:00, 12:00, 18:00 and 24:00 h and then clustered to seven clusters.
Traffic density was measured by the Road Authority of Rijeka at two busy roads about 30 m
away from the aerosol sampler (15 detectors). For this purpose, only two detectors wererunning through the whole sampling period, so we present only data obtained by those 2
detectors.
3. RESULTS
The results of averages (Avg), standard deviations (SD) and maxima (Max) of concentrationsof elements from Si to Pb, PM2.5 and BC and corresponding minimum detection limits (MDL)
are shown in Table 1. The MDLs for elements from Ca to Br are below 1 ng/m3.
Table 1 Average concentrations, standard deviations, maxima and minimum detection limits
for PM2.5, BC and elements from Si to Pb. All values are given in μg/m3
Element
Si
P
S
Cl
K
Ca
Sc
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Br
Sr
Pb
BC
PM2.5

Avg
0.059
0.0062
0.663
0.046
0.154
0.081
0.000450.00310.00290.000780.00370.075
0.000220.001430.00370.01170.00230.00110.0062
3.439
20.663SD
0.145
0.0085
0.485
0.127
0.242
0.086
0.000710.00440.00410.000640.00910.059
0.00055
0.00156
0.00930.01030.00180.0052
0.023
1.267
7.743

Max
1.35
0.093
2.975
1.445
2.983
0.64
0.00450.038
0.039
0.00570.153
0.394
0.00750.0114
0.151
0.106
0.019
0.075
0.423
8.75
51.47

MDL
0.02090.006140.00376
0.00255
0.001330.001020.00088
0.00080.000750.000690.000630.00058
0.000540.00060.000640.000690.00088
0.00080.00149
0.36
1Calculated average of PM2.5 concentration for the whole sampling period was 20.6 μg/m3.
Annual average concentrations of PM2.5 for the sampling years 2013, 2014 and 2015 were52

M. ýDUJRQMD7,YRãHYLü,2UOLü Two years of fine aerosol monitoring …

23.3 μg/m3, 18.2 μg/m3 and 21.4 μg/m3, respectively. These calculated annual values did notexceed recommended PM2.5 DQQXDOOLPLWYDOXHIURP(8'LUHFWLYH(& ȝJP3).
60
50
c/ǋg m-3

40
30
20
10
0



1.1-2

2.1-3
v/m s-1

3.1-4>4

Figure 2 PM2.5 concentrations for different wind speeds

Figure 3 Polar plots for elemental concentrations for each wind direction and absolute
frequency of wind directions
Figure 2 shows changes of PM2.5 concentrations depending on the changes of daily averagewind speed. These concentrations decreased with the increase of wind speed to wind speed ofEnergy and the Environment (2016) 49-58

53

4 m/s because stronger winds bring more clean air. For wind speeds higher than 4 m/s,
concentrations showed higher median because the strongest winds brought air pollution fromthe further sources.
Figure 3 represents polar plots for black carbon and some elemental concentrations dependingon the wind direction and absolute frequency of wind directions. It should be noted that there
were no days of NW and WNW prevailing wind directions during the sampling period.
Elements such as S, K, V, Ni, Cu, Zn and Pb were mostly coming from NNW direction.
Sulfur, vanadium and nickel dominantly come from industry, potassium from biomass (wood)burning, and copper and zinc from road traffic [8].
Elements such as Si, Ca, Ti and Fe came from the same prevailing wind direction, ESE,
because they are typical crustal elements. Chlorine came from southern winds which were
blowing across the Adriatic Sea and brought sea spray. Chlorine is the main constituent of sea
spray. Black carbon has several sources [3] and as we expected, it had several prevailing winddirections.
Although NE was the prevailing direction for the whole sampling period (bora wind), it was
not dominant direction for any element. That means that this wind didn’t bring significant
pollution, but brought fresh air.
Backward trajectories were plotted with the HYSPLIT program. Five trajectories of 72 h were
simulated per each day (at 00:00, 06:00, 12:00, 18:00 and 24:00 h). After removing 44
trajectories, 1546 trajectories were joined to 7 clusters. Figure 4 shows mean trajectories of
those 7 clusters, along with their relative contributions.

Figure 4 Mean trajectories for 7 clusters
Box-whisker plots for Cl and S concentrations for each cluster are shown on Figure 5.
Concentrations of Cl are the most connected to clusters 4, 5 and 6. All of those clusters comeacross the sea surfaces.
Concentrations of S are the highest for clusters 2, 3 and 5. Cluster 2 (34% of observations) isthe most frequent and includes trajectories circulating through the near surroundings of thesampling site. These trajectories are connected to the calm weather periods when pollution
accumulates in the atmosphere. Cluster 3 (15%) brought pollution from Eastern Europe.

54

M. ýDUJRQMD7,YRãHYLü,2UOLü Two years of fine aerosol monitoring …

Cluster 5 (10%) represents trajectories that arrive across the Adriatic Sea, but also across SE
side of Rijeka, so they brought pollution from the oil refinery (Fig. 1).
Cl

S
3

0,8

2,5
0,6

c/ǋg m-3

2

0,4

1,5

1
0,2
0,5

0

0

Cluster 7

Cluster 6

Cluster 5

Cluster 4

Cluster 3

Cluster 2

Cluster 1

Full period

Cluster 7

Cluster 6

Cluster 5

Cluster 4

Cluster 3

Cluster 2

Cluster 1

Full period

Figure 5 Box-whisker plots of Cl and S concentrations for full period and different clustersa)

PM 2.5

100

b)

Cl

PM 2.5100Cl
1

c/ǋg m-3

c/ǋg m-3

1

10
0,01

1

0,0001

10

0,01

1

0,0001RH/%

90-10060-89<6090-10060-89

PMPrecipitation

No precipitation

Precipitation

No precipitation

RH/%

Figure 6 Box-whisker plots for PM2.5 and Cl concentrations for: a) days without and with
precipitation; b) different relative humidity
Figure 6 a) shows PM2.5 and Cl concentrations for days without and with precipitation. The
difference between those two regimes is not so obvious. Generally, rainfall removes some ofthe particles from the atmosphere. Concentrations of Cl, on contrary, are somewhat higher
during days with precipitation because Cl comes from air masses coming from the sea.
Figure 6 b) represents PM2.5 and Cl concentrations for different relative humidity. Although
PM2.5 concentrations didn’t show significant change with increase of relative humidity, Cl
concentrations clearly increased with relative humidity.

Energy and the Environment (2016) 49-58

55

PM 2.560
50

8c/ǋg m-3

40

6

30

4

20
0

0
20000-30000

Cr

Mn

0,05
0,04

0,003

0,5

10000-20000

Number of vehicles

0,004

0,6

<10000<10000Ca

20000-30000

210000-20000

10

Number of vehicles

0,7

BC

10

c/ǋg m-3

0,03

0,4

0,002

0,3
0,2
0,1

20000-30000

10000-20000<100000,025

Number of vehicles
Cu

c/ǋg m-3

0,08

0,015

0,2

0,06

0,01

0,1

0

20000-30000

10000-20000

Number of vehicles

20000-30000

010000-20000

0,02<1000020000-30000

10000-20000<10000

Number of vehicles

0,04

0,005

<100000

Number of vehicles
Zn

0,1

0,02

0,3

0,12

20000-30000

010000-20000

020000-30000

10000-20000<10000

Number of vehicles
Fe

0,4

0,01

<10000

0

0,02

0,001

Number of vehicles

Figure 7 Box-whisker plots of Ca, Cr, Mn, Fe, Cu and Zn concentrations for different
numbers of vehicles
Impact of traffic density on particulate matter has also been analyzed. As a measure of traffic
density, number of vehicles counted by 2 detectors was chosen. There were actually 15
detectors on this road, but due to some technical problems only these 2 were running properly
through the whole sampling period.

56

M. ýDUJRQMD7,YRãHYLü,2UOLü Two years of fine aerosol monitoring …

Figure 7 shows concentrations of PM2.5, BC, Ca, Cr, Mn, Fe, Cu and Zn for different numbersof vehicles. Concentrations of PM2.5 showed an increase with the increase of the number ofvehicles.
Concentrations of Ca, Cr, Mn, Fe, Cu, Zn, and BC show very similar pattern. These elements
are known to be good markers of traffic pollution. For example, Fe is an indicator of engine
wear, Cu indicates breaks wear and Zn indicates tire wear [3].
All measured concentrations, errors and minimum detection limits were used for statisticalanalysis by means of positive matrix factorization (PMF) [9] to obtain major pollution
sources. Seven major sources were found along with their relative contributions. Those
sources are listed in Table 2. The dominant sources were vehicles and biomass burning fordomestic heating. Secondary sulfates and heavy oil combustion were coming from industry,
such as oil refinery [10]. Source named “industry iron” was coming from the local shipyard.
Fireworks were present just during some special events like the New Year celebration,
victories of local football club, Fiumanka (one of the largest regattas on the Adriatic Sea),
Rijeka summer evening, etc.
Table 2 Pollution sources and their relative contributions to the total concentrations of PM2.5
obtained by PMF
SourceVehiclesBiomass burning
Secondary sulfates
Heavy oil combustion
Industry ironRoad dust
Fireworks

Relative contribution/%
37
28
16
8
5
5
1

4. CONCLUSION
Two years air monitoring on composition of fine aerosols was performed in Rijeka from
August 2013 to October 2015. In total, 345 PM2.5 daily samples were collected and analyzed
by XRF and LIPM techniques. Concentrations of 19 elements from Si to Pb and black carbon
were obtained.
It has been found that PM2.5 concentrations generally decreased with the increase of the windspeed up to 4 m/s. For higher wind speed, concentrations of PM2.5 were higher because
stronger winds brought air pollution from further sources. Precipitation generally decreased
PM2.5 concentrations and high relative humidity increased it, but Cl concentrations showed
the opposite behavior. However, wind had much stronger influence on PM2.5 pollution.
Higher traffic density caused higher concentrations of PM2.5, Ca, Cr, Mn, Fe, Cu and Zn.
These elements are tracers of road traffic.
Statistical results show seven major sources of pollution, along with their relative
contributions: vehicles (37%), biomass burning (28%), secondary sulfates (16%), heavy oil
combustion (8%), industry iron (5%), road dust (5%) and fireworks (1%).

Energy and the Environment (2016) 49-58

57

ACKNOWLEDGEMENTS
The authors are grateful to Mr. V. Mezak from the Port of Rijeka Authority, Mr. D. Frka and0V$7RPOMDQRYLüIURPWKH5RDG$XWKRULW\5LMHND0U'0OLQHNIURPWKH1DWLRQDODQG
Meteorological Service and the NOAA Air Resources Laboratory (ARL) for the provision of
the HYSPLIT transport and dispersion model.
REFERENCES[1] Pope, C.A.III., Dockery, D.W.: Health effects of fine particulate air pollution: Lines thatconnect, Journal of the Air and Waste Management Association, 56 (2006) 709-742[2] Sarnat, J.A., Marmur, A., Klein, M., Kim, E., Russell, A.G., Sarnat, S.E., Mulholland,
J.A., Hopke, P.K., Tolbert, P.E.: Fine Particle Sources and Cardiorespiratory Morbidity:
An Application of Chemical Mass Balance and Factor Analytical Source-Apportionment
Methods, Environmental Health Perspectives, 116 (2008) 4, 459-466[3] ,YRãHYLü7., 2UOLü,%RJGDQRYLü 5DGRYLü,: Long term fine aerosol analysis by XRF
and PIXE techniques in the city of Rijeka, Croatia, Nuclear Instruments and Methods inPhysics Research B, 363 (2015) 119-123[4] ,YRãHYLü 7 0DQGLü / 9DUDãDQHF 0 2UOLü , Fine aerosol pollution in Rijeka,
Energy and the Environment, 23, Opatija, 2012, 31-39[5] Van Espen, P., Janssens, K., Nobels, J.: AXIL-PC, software for the analysis of complex Xray spectra, Chemometrics and Intelligent Laboratory Systems, 1 (1986) 109–114[6] Taha, G., Box, G. P., Cohen, D. D., Stelcer, E.: Black Carbon Measurement using Laser
Integrating Plate Method, Aerosol Science and Technology, 41 (2007) 266-276[7] Stein, A.F., Draxler, R.R, Rolph, G.D., Stunder, B.J.B., Cohen, M.D., Ngan, F.: NOAA's
HYSPLIT atmospheric transport and dispersion modeling system, Bulletin of theAmerican Meteorological Society, 96 (2015) 2059-2077[8] Cohen, D.D., Crawford, J., Stelcer, E., Bac, V.T.: Characterisation and source
apportionment of fine particulate sources at Hanoi from 2001 to 2008, Atmospheric
Environment, 44 (2010) 320-328[9] Paatero, P., Tapper, U.: Positive Matrix Factorization: a non-negative factor model with
optimal utilization of error estimates of data values, Environmetrics, 5 (1994) 111 – 126[10] Moreno, T., Querol, X., Alastuey, A., de la Rosa, J., de la Campa, A.M.S., Minguillon,
M., Pandolfi, M., Gonzales-Castanedo, Y., Monfort, E., Gibbons, W.: Variations in
vanadium, nickel and lanthanoid element concentrations in urban air, Science of the
Total Environment, 408 (2010) 4569-4579

58

M. ýDUJRQMD7,YRãHYLü,2UOLü Two years of fine aerosol monitoring …

DVIJE GODINE (2013 – 2015) ANALIZE FINE FRAKCIJE AEROSOLAU RIJECISažetak: U ovom radu prikazana je analiza RQHþLãüHQMD OHEGHüLP þHVWLFDPDXJUDGX Rijeci.
Tijekom razdoblja od kolovoza 2013. do listopada 2015. Godine prikupljeno je 345 uzoraka
fine frakcije aerosol na tankim teflonskim filtrima. Svi uzorci su analizirani tehnikom
fluorescencije X-]UDND þLPH su RGUHÿHQH koncentracije 19 elemenata od silicija do olova.
Koncentracije crnog ugljika RGUHÿHQH su apsorpcijskom metodom.
Dobivene elementne koncentracije XVSRUHÿHQH su s meteorološkim uvjetima kao što su brzina
i smjer vjetra, oborine i relativna vlažnost zraka i gradskim aktivnostima poput intenziteta
dnevnog prometa i industrijskih djelatnosti.
Rezultati su VWDWLVWLþNL REUDÿHQL NRULVWHüL pozitivnu PDWULþQX IDNWRUL]DFLMX 30)  2GUHÿHQRje nekoliko antropogenih izvora RQHþLãüHQMD kao što su sekundarni sulfati, industrija, cestovni
promet i izgaranje biomase. Dobivene godišnje srednje vrijednosti koncentracija PM2.5
frakcije za godine 2013., 2014. i 2015. ne premašuju SUHSRUXþHQX godišnju JUDQLþQX
YULMHGQRVWRGȝJP-3 u direktivi Europske komisije 2008/50/EC.
.OMXþQH ULMHþL Rijeka, aerosoli, PM2.5 frakcija, XRF, meteorološki uvjeti, promet, industrija

Energy and the Environment (2016) 59-68

59

COMPARISON OF BOILERS FOR TREATED
AND UNTREATED WASTE
Martin Janda1), Tomáš Dlouhý1), Paolo Blecich2)%HUQDUG)UDQNRYLü2)
1)

Czech Technical University in Prague, Zikova 1903/4, 16636 Praha 6, Czech Republic
Faculty of Engineering, University of Rijeka, Vukovarska 58, 51000 Rijeka, Croatia
E-mail: jandis.j@gmail.com, tomas.dlouhy@fs.cvut.cz, pblecich@riteh.hr,
bernardf@riteh.hr

2)

Abstract: This paper presents the design and comparison of two boilers with the same steam
output, but with different quality of incoming fuel. The first steam boiler is fed by low quality
municipal waste without any treatment, which has a lower calorific value of 9.2 MJ/kg. In
contrast to the first fuel, the second fuel is a sorted municipal waste with a lower calorificvalue of 16.3 MJ/kg. For the sizing of boilers, the same methodology of calculation is used,which ensures the comparability of these projects. The comparison includes the analysis of
the fuel quantity supplied to the boilers, the size of the boilers and the combustion conditions.
Keywords: municipal waste, sorted waste, waste incinerator, steam boiler, lower calorificvalue, pretreatment of waste

1. INTRODUCTION
With a growing population, people are closely connected to problems that deserve ourattention and a search for their solution. One of these problems is the accumulation ofmunicipal waste in landfills. Waste storage can lead to leaking of the liquid portion of waste
into the ground and contamination of underground waters. It can also be considered a waste of
useful material, since it includes precious materials such as metal. The smell and appearanceof the landfills can also be problematic, since they are often situated near human settlements.
There are several solutions which lead to a reduction in the amount of waste, or which utilize
waste as a fuel or intermediate product. The most basic way of dealing with municipal waste
is through recycling, which can be done by producers (recycling of paper, plastics, metal,
glass and bio waste), or in a factory as preparation of waste for utilization. The efficiency ofrecycling mainly depends on people and the financial motivation they receive for the return ofwaste. The other way of reducing the amount of waste is upcycling, which means reusing it.
The waste utilization is starting to be much more popular mainly in developed countries,
where it is considered as a fuel more than as a waste. The most common principles of waste
utilization include: incineration, gasification and inorganic fermentation. Each of thesetechniques has its advantages and disadvantages and therefore their area of suitableutilization. This work is focused only on incineration, which is still the leader in theprocessing of the waste.
During incineration the municipal waste is used as a fuel that provides enough energy forwarming water up, evaporating it and getting it up to the desirable parameters for driving thesteam turbine and hence producing electricity.

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M. Janda, T. DORXK\3%OHFLFK%)UDQNRYLü Comparison of Boilers...

With the combustion of waste are, however, connected problems including the diversity ofmaterial, moisture, or a higher content of chlorine. The composition of waste is also different
in different parts of the country or particularly abroad. This can be changed, for example, byreinforcing new consumer habits, a willingness to recycle or through waste legislation. In any
case, the composition of the material and its lower calorific value are essential in the design ofthe boiler.
These problems can be partly or totally eliminated by pre-treatment of the fuel, where the fuelcan be drained and the useless parts of the waste separated. This however requiresconsiderable investment and higher operating costs, which leads to the decision of whether it
would be more profitable to combust fuel with or without pre-treatment.
This work is dedicated to the design of boilers, which are supplied with different types ofwaste. The main goal of the work is the calculation and comparison of the incoming mass
flow, combustion conditions and size of the boilers with the same output performance [1].

2. CHARACTERISTICS OF FUEL AND INCINERATOR
There exists no definition of the term refuse derived fuel (RDF), which might be due to thefact that in each state there are different legislative definitions of sorted waste and its
composition. “Refuse”, however, is the common name for municipal waste and the term RDF
is usually connected with sorted municipal or industrial waste with high level of lower
calorific value. In the following table is listed the elemental composition of RDF that is usedin this work [2].
Table 1. Elemental composition of refuse derived fuel [2]moisture C
H
Composition of waste [%]25.08 36.06 5.27
Lower calorific value

N

S

O

A

0.66

0.86 16.44 15.61

16.263 MJ/kg

Municipal solid waste (MSW) consists of everyday items that are discarded by people. It
generally has a lower level of lower calorific value and a higher content of moisture and ash.
In the following table are listed the elemental compositions of municipal solid waste that areused in this work.
Table 2. Elemental composition of municipal solid waste
moisture C
H
Composition of waste [%]30
26.48 2.52
Lower calorific value

N

S

0.84

0.42 11.76

9.2 MJ/kg

The parameters for the design of the incinerator are listed in table 3.

O

A
28

Energy and the Environment (2016) 59-68

61

Table 3. Parameters of incinerator
Steam flow
Steam Temperature
Pressure
Enthalpy of superheated steam
Water supply temperature
Enthalpy of supply water

43 t/h400 °C
4.3 MPa
3209.1 kJ/kg
105 °C
440.2 kJ/kg

3. DESIGN PROCEDURE
The design procedure for a new boiler can be outlined in the following points:
x

x
x
x
x

x

Draft concept as a design of combustion chamber, number of boiler strokes, types andorder of all heat transfer surfaces, option of approximate inlet and outlet temperaturesof working medium, option of temperature regulators – number and location, fluegases outlet temperature, incoming combustion air inlet temperature and quantity;
Estimation of air suction in the combustion chamber and boiler strokes (profile ofequilibrium ratio) and estimation of pressure in the boiler;
Stoichiometric calculations – calculation of volumetric and heat characteristic of fluegas. Creating of I-t diagram describing the relationship between temperature andenthalpy of flue gas with a certain quantity of air;Calculation of heat losses and creation of heat balance of the boiler, calculation of fuelconsumption;
Calculation of the main outline dimensions of the combustion chamber, which are
given by requirements to complete the combustion process and cooling down of theflue gas below the softening temperature of ash. Calculation of released heat in the
combustion chamber, the uncooled temperature flame and the heat trapped in the
combustion chamber;
Detailed calculations and designing of all surfaces in other strokes – the calculation ofrest of vaporizer, superheaters and economizer.

4. CONCEPT OF BOILERS
The concept of boilers is based on the existing solution as well as consultations with thesupervisor of the work. The concepts are as follows:xxx

Incineration takes place on a grade with a slope of 30 °C. The grade is moving in the
opposite direction of the flue gas.
The lower part of the boiler is covered by lining, which should have helped to protect
the walls against corrosion and regulate the amount of heat that is transferring fromflue gas to the working medium. In the part just above the grade, the lining also helps
to dry the fuel.
The volume of the combustion chamber is great in order to assure a slow speed of theflue gas and therefore also enough time for the completion of the combustion process
in the combustion chamber (the flue gas has to remain in the combustion chamber for
least 2 s).

62

M. Janda, T. DORXK\3%OHFLFK%)UDQNRYLü Comparison of Boilers...

x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x

The width of the boiler is the same for all strokes and it is equal to 4 m.
In the lower part of the combustion chamber just above the grade is the cross-section
narrowed to achieve better motion of the flue gas.
The boiler consists of four vertical strokes. The first three are made up of themembrane wall. The forth one just from sheet.
The vaporizer tubes have an inner diameter equal to 50 mm and a pitch of 80 mm.
In the case of a boiler for combusting municipal solid waste, combustion air warms up
to 150 °C in a steam air heater.
In the case of a boiler for combusting refuse derived fuel, the air does not warm up.
The temperature of the inlet air is considered to be at 25 °C.
The equilibrium ratio is equal to 1.7.
The equilibrium ratio at the end of boiler is considered to be 1.85 (due to suction of
the air from the surrounding area).
The steam generator operates on the principle of natural circulation with one cylinder.
From the cylinder a boiler blowdown of 1% of steam flow is taken away.
At the end of the combustion chamber there is the flue gas grid.
The second stroke is empty due to the high temperature of the flue gas and the risk of
clogging the heat transfer surface.
In the beginning and at the end of third stroke are the flue gas grids.
In the third stroke are situated two superheaters that are running in counterflow.
Between the superheaters is situated the regulator of steam temperature – an injector
with a flow of 3% of the steam flow.
The second superheater is divided into two parts and it is the first superheater in thegeneration of steam.
In the fourth stroke is situated the economizer.
The outlet temperature of flue gases from the boiler is 180 °C, to minimize the risk ofchlorine corrosion.

5. GEOMETRY OF INCINERATORSThe geometry of the incinerator for municipal solid waste fully corresponds to the concept
described in the previous chapter. According to the sketch shown in Figure 1, one canvisualize the size of the boiler and the height of the flue gas grid. Moreover, it is also apparent
that the area is covered by lining (all the heat transfer surfaces from the bottom up until 5 m
above the narrow part).
Figure 2 shows the geometry of the incinerator combusting refuse derived fuel. It is apparent
that an incinerator combusting fuel with a higher level of lower calorific value can be smaller
while achieving the same output performance. From this picture it is obvious that this boiler islower, the first and the second strokes are narrower (have the same width) and due to theregulation of the heat transferring to the working medium in combustion chamber, the level oflining chosen is higher. It was also possible and advantageous to design the flue gas grid to be
shorter, since there is a smaller quantity of flue gas.

Energy and the Environment (2016) 59-68

Figure 1. Geometry of incinerator for municipal solid waste (MSW)

Figure 2. Geometry of incinerator for refuse derived fuel (RDF)

63

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M. Janda, T. DORXK\3%OHFLFK%)UDQNRYLü Comparison of Boilers...

6. CALCULATIONS
6.1. Volumetric flow rates and I-t chart
Volumetric flow rates and the I-t chart for the flue gases are the most important outputs ofstoichiometric calculations. The volumetric flow rates of flue gases, listed in Table 4,
influence the speed of flue gases in the boiler, while the I-t chart is used for calculation of theflue gases enthalpy which depends on the temperature and equilibrium ratio. The volumetricflow rate of primary incoming air is 17.74 m3/s for the MSW incinerator and 16.52 m3/s for
the RDF incinerator. Combustion of fuels with larger calorific values ensures smaller
volumetric flow rates and higher enthalpy that allows for the design of boilers with smaller
cross-sections. This is especially advantageous in the case of flue gas grids or superheaters.
Table 4. Volumetric flow rate of flue gas
Equilibrium ratio
MSW [m3/s]
RDF [m3/s]
1.7

20.07718.214

1.75
1.775
1.8
1.85

20.59820.85921.12021.642

18.69918.94219.18519.671Figure 3. I-t chart for flue gases from municipal solid waste

Figure 4. I-t chart for flue gases from refuse derived fuel

Energy and the Environment (2016) 59-68

65

6.2. Basic heat balance of boilers
The main purpose of the basic heat balance of boilers is to determine the efficiency and fuelconsumption of the boiler in order to achieve the required parameters. The reduced calorificvalue summarizes the heat fluxes per fuel unit fed to the boiler. It expresses the heat input of
the boiler needed to calculate the overall boiler efficiency and is determined from theequation:ܳ୧,୰ୣୢ = ܳ୧୰ + ‫ܫ‬ୱ୦ + ܳୟ୦(1)

In equation (1), ܳ୧୰ the lower calorific value, ‫ܫ‬ୱ୦ is the fuel sensible enthalpy at 20 °C and ܳୟ୦is additional heat flux from the combustion air. In the case of refuse fuel combustion, the inlet
air temperature is equal to the ambient temperature and it is not included in the equation.
The boiler efficiency can be determined indirectly from the total heat losses in the boiler.
However, heat losses cannot be calculated precisely, but rather for the greater part they haveto be estimated or deducted from charts. The total heat loss consists of the below-mentioned
shares, as also reported in Table 5:x stack gas heat losses (the largest heat losses)
x combustion heat losses (caused by unburned fuel - carbon in bottom ash and flyingash)
x radiation heat losses
x sensible heat losses from bottom ash
The boiler performance, i.e. the total heat output, is calculated from the following equation:(2)ܳ୴ = ‫ܯ‬ୱୱ ή (݅ୱୱ െ ݅୵ୱ ) + ‫ܯ‬ୠ ή (݅ୡ୵ െ ݅୵ୱ )In equation (2), ‫ܯ‬ୱୱ is the mass flow of superheated steam, ݅ୱୱ its enthalpy, ݅୵ୱ is the watersupply enthalpy, ‫ܯ‬ୠ is the blowdown mass flow and ݅ୡ୵ is the enthalpy of water in thecylinder. The slight difference in the heat outputs in Table 5 is caused by a small difference inthe enthalpy of blowdown water. The fuel mass flow rate to the boiler is calculated from:‫ܯ‬௣௔௟ =ܳv(3)

ܳi,red Kb

Table 5. Results from the basic heat balance of boilers
MSW
Calorific value
Sensible enthalpy
Additional heat
Reduced calorific value
Total loss
Efficiency
Total heated output of the boiler
Mass of incoming fuel

9200
40.96
753.1
9994
0.221
77.9
33112
4.253

RDF
kJ/kg
kJ/kg
kJ/kg
kJ/kg
%
kW
Kg/s

16263
37.9
16301
0.1594
84.05
33113
2.417

kJ/kg
kJ/kg
kJ/kg
kJ/kg
%
kW
Kg/s

66

M. Janda, T. DORXK\3%OHFLFK%)UDQNRYLü Comparison of Boilers...

6.3. Performance of heat transfer surfaces and temperatures of flue gas
The flue gases temperature at the combustion chamber outlet is determined from the *XUYLþ
relationship [3] which is based on four similar characteristics for the combustion chamber:xx
xx

uncooled flame temperature – theoretical adiabatic combustion temperature
Boltzmann number – similarity criterion for calculations of boilers
coefficient M – coefficient for adjusting of temperatures in the combustion chamber
degree of blackness of the combustion chamber – expresses the radiation properties

The charts in Figure 5 and 6 show the flue gases temperatures in the boilers while expressing
the relationship between the temperature and the performance of heat transfer surfaces. The
performance of the heat transfer surfaces is given in Table 6. In the case of RDF, thetemperature in the combustion chamber is higher and the flue gases cool down more rapidly.
This is caused by higher enthalpy and smaller flow rate of flue gases. The difference between
the design outlet temperature of flue gases and the calculated values is caused by inaccuracyof methodology.

Figure 5. P-t chart for MSW

Energy and the Environment (2016) 59-68

67

Figure 6. P-t chart of RDF

Table 6. Performance of heat transfer surfaces
Heat transfer surfaces
Combustion chamber
1. flue gas grid2. stroke
2. flue gas grid2. superheater
Parallel surface of vaporizer
1. superheater
Parallel surface of vaporizer
Reversing chamber
3. flue gas grid
Economizer
Total transferred heat

MSW [kW]
9182
1329
6626
687
2525
532
3419
265
426
247
7879
33117

RDF [kW]
9642
1263
6156
754
2520
550
3206
260
464
261
8053
33129

7. CONCLUSION
This work showed that in order to correctly design the boiler, the calculations should be basedon the type of fuel since the fuel calorific value and its composition play a role in every aspectof the boiler. Therefore, it is necessary to decide before the calculations if the waste will bewith or without treatment. The investment costs and the process costs are the factors that for
the largest part affect the decision about the type of fuel.
Although this work does not analyse waste from the same area, it can be concluded that thebetter quality of the treated waste is not just by coincidence. This type of fuel has a smaller
amount of moisture, sulphur and ash which are the most unwanted elements in the fuel.
Therefore, it can be expected that a process with this type of fuel will run more smoothly andwith lower process costs (mainly post-treatment). On the other hand, the investment costs in
incinerators running on pretreated waste will be significantly higher. A thorough economic

68

M. Janda, T. DORXK\3%OHFLFK%)UDQNRYLü Comparison of Boilers...

analysis is necessary to better understand the advantages and drawbacks of each of the twoboilers as well as the differences between them.
It can be said, however, that the technical characteristics are better in the case of the boiler
running on treated fuel. For the same output, this boiler is generally smaller and needs lessfuel, achieves higher efficiency while the costs of service and maintenance are lower due tothe better fuel quality and composition.
BIBLIOGRAPHY[1] M. Janda: Comparison of boilers for treated and untreated waste, master thesis, (inCzech), Czech Technical University in Prague, Prague, 2016.
[2] M. Fejfuša: Steam boiler for incineration of 40 t/h of refuse derived waste, (in Czech),
Brno University of Technology, Brno, 2014.
[3] T. Dlouhý: Calculation of boilers and combustion heat exchangers, (in Czech), Czech
Technical University in Prague, Prague, 1999.

86325('%$.27/29$=$2%5$Ĉ(1,I 1(2%5$Ĉ(1,273$'

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Energy and the Environment (2016) 69-74

69

SAMOODRŽIVOST U POSTUPANJU S OTPADOM 1,-(02*8û(BEZ ISKORIŠTAVANJA ENERGETSKOG POTENCIJALA OSTATKA
OTPADA – POSEBNO NE NA OTOCIMA
9LNWRU6LPRQþLþ
Vikos, MLKDQRYLüHYD2EDOD6LVDN-257, viktor.simoncic@gmail.com
0DULR0LOLþLü
VeleXþLOLãWH X5LMHFL*DOGRYDþNDE6LVDN, 098/989-3679,
mario.milicic.1993@gmail.com
Sažetak: Novim Planom gospodarenja otpadom za period 2016. – 2022. se dodatno
zanemaruje iskorištavanje energetskog potencijala ostatka otpada 7DNRÿHU s obzirom na
inzistiranju na odvojenom sakupljanju na izvoru dovodi se u pitanje ispunjavanje ciljeva iz
Strategije niskoXJOMLþQRJ UD]YRMD 5HSXEOLNH +UYDWVNH 3RVHEDQ SUREOHP SUHGVWDYOMDW üH
ispunjavanje obaveza na otocima. U radu se daje prijedlog kako s novo razvijenom
WHKQRORJLMRP NRMD RPRJXüXMH L]GYDMDQMHVRUWLUDQMH NRULVQLK GLMHORYD RWSDGD L] PMHãRYLWRJ
LLOL QD L]YRUX RGYRMHQR VDNXSOMHQRJ RWSDGD QD ILQDQFLMVNL SULKYDWOMLY QDþLQ PRåH ULMHãLWLproblem postupanja s otpadom na otocima.
.OMXþQHULMHþLotpad, gospodarenje otpadom, energetsko iskorištavanje, otoci, tehnologija
32672-(û(67$1-(,VSXQMDYDQMHREDYH]DL]SULVWXSQRJXJRYRUDL]PHÿX5HSXEOLNH+UYDWVNHL(XURSske unije jeizuzetno zahtjevno, a obaveze se ne ispunjavaju sa željenim tempom. Odlaže se 400 000 tonabiorazgradivog komunalnog otpada više nego što bi se smjelo do konca 2016. godine i dobrih
800 000 tona više mješovitog komunalnog otpada no što smo se obavezali da üHPRRGODJDWLdo 2017. godine.
Raspolažemo tek sa 50-ak reciklažnih centara, od kojih samo par ima sortirnice. Trenutno je u
funkciji samo nekih 15-ak postrojenja za biološku obradu. Inzistira se na odvojenom
sakupljanju otpada na izvoru, što je uvjetno prihvatljiv koncept, ali uz uvjet da nakon
izdvajDQMD QD L]YRUX VOLMHGH RGJRYDUDMXüH VRUWLUQLFH L LQGXVWULMD NRMD PRåH SULKYDWLWL
prikupljene sirovine, a ne da (dio) na izvoru sakupljenog otpada završava na deponijama.
'YD]DYUãHQDåXSDQLMVNDFHQWUD]DJRVSRGDUHQMHVRWSDGRP0DULãüLQDL.DãWMXQNDRLnovi
SODQLUDQL %LOMDQH'RQMH3LãNRUQLFD%LNDUDF/HþHYLFD …) temelje se na tehnologiji koja je
SULPMHUHQD VDPR ]D REUDGX RVWDWND RWSDGD SUL þHPX MH MHGDQ RG JODYQLK ÄSURL]YRGD³
alternativno gorivo – RDF (Refuse Derived Fuel).
U raspravi je novi prijedlog novog Plana gospodarenja otpadom za period 2016 – 2022.
1DåDORVW 3ODQ JRWRYR GD LVNOMXþXMH HQHUJHWVNR LVNRULãWDYDQMH RVWDWND RWSDGD ,DNR VH SODQQDþHOQRWHPHOML QD QRYRM SDUDGLJPL ÄFLUNXODUQRJ JRVSRGDUVWYD³ L]EMHJDYDQMHP HQHUJHWVNRJ
iskorištavanja ostatka približava se konceptu „nula otpada“ (eng. „zero waste“) koja se u
cijelosti temelji samo na materijalnom iskorištavanju otpadaãWR3ODQþLQLQHUHDOQLP.

70

96LPRQþLþ: 6DPRRGUåLYRVWXSRVWXSDQMXVRWSDGRPQLMHPRJXüHEH]LVNRULãWDYDQMD«

2. KAMO IDE EU?
U EU sDPR X ãHVW GUåDYD XNLQXWR MH RGODJDQMH þLPH VX VH NROLþLQH komunalnog otpada
smanjile s 90 % na manje od 5 % u posljednjih 20 godina, dok su stope recikliranja uRGUHÿHQLP UHJLMDPD GRVHJOH   1R X GUXJLP VH GUåDYDPD þODQLFDPD QD RGODJDOLãWD
odvozi više od 90 % otpada, dok se reciklira manje od 5 %. (1)Slika 1. Prikaz stope recikliranja, kompostiranja, spaljivanja i odlaganja otpada u Europi
8QDWRþ RYDNYRP VWDQMX ]DFUWDYDMX VH MRã SXQR ]DKWMHYQLML FLOMHYL JOHGH VPDQMHQMD QDVWDQND
stupnja iskoristivosti LVSUMHþDYDQMDRGODJDQMDRWSDGDEnergy and the Environment (2016) 69-74

71

Slika 2. 3ULND]NOMXþQLKHOHmenata revidiranog prijedloga o otpadu
Ako bi u Hrvatskoj željeli riješiti problem kao X1MHPDþNRM, da više ništa ne odlažemo, onda
EL PRUDOL LPDWL X] QDMUD]OLþLWLMH SULYUHGQH JUDQH L FLMHOL QL] UD]OLþLWLK SRVWURMHQMD Samo sa
stajališta razlike u broju stanovnika 20 puta manje. Nijemci su 1971. zatvorili nekih 50 000
divljih odlagališta. Danas imaju 167 spalionica otpada, za koje im, nakon što je došlo zadnjih
JRGLQDXSURPMHQLVPMHUDNPDWHULMDOQRPLVNRULãWDYDQMXþDNQHGRVWDMHotpada. Sad bi mogli
SURüL V PDQMLP EURMHP DOL SULMH  – 40 godina nisu mogli. Imaju 705 „waste to energy“
postrojenja, 2462 postrojenja za biološku obradu, 1094 sortirnica, 1331 postrojenja za
UD]JUDGQMX ELMHOH WHKQLNH  SRVWURMHQMD ]D þLãüHQMH ]HPOMLãWD L MRã SUHNR WUL WLVXüH UD]QLKpostrojenja za obradu otpada.
3. MOŽE LI BEZ ENERGETSKOG ISKORIŠTAVANJA OSTATKA OTPADA?
,]EMHJDYDQMH RGODJDQMD MRã GXJR QHüH ELWL PRJXüD DNR XRSüH  EH] LVNRULãWDYDQMD RVWDWND
otpada, koji nema drugu tržišnu i ekonomsku vrijednost, osim kao zamjenskog goriva!
U otpadu je do nekih 40 % ostatka koji se može koristiti kao zamjensko gorivo. Uz grubi
RGQRV HQHUJHWVNH YULMHGQRVWL ]DPMHQVNR JRULYR  NRQYHQFLRQDOQR JRULYR       ]QDþL GD
postoji potencijal od nekih 200 000 tona godišnje konvencionalnog goriva.
*RULYLGLRRVWDWNDWUHEDUMHãDYDWLDNRMHPRJXüHSUHNRMDYQLKVLVWHPD jer privatni sektor možei uvjetovati visoke cijene ako ne postoje druga rješenja. U Sloveniji i Hrvatskoj se
preuzimanje RDF-DQDSODüXMHDQSU6UELMLVHSODüD
-DYQL VLVWHPH PRåH ]QDþLWL 9HOLNDH FHQWUDOQDH 7( –TO u kontinentalnom dijelu: Zagreb,možda Osijek, .... Na otocima bi se problem mogao rješavati korištenjem RDF goriva uturizmu i poljoprivredi (staklenici).

72

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6WUDWHJLMLQLVNRXJOMLþQRJUD]YRMD5HSXEOLNH+UYDWVNHkako doprinos gospodarenja otpadom u
XNXSQLPHPLVLMDPDVWDNOHQLþNLKSOLQRYDXL]QRVXRGWUeba smanjiti na 0.5 %, dodatno
SRWYUÿXMXQXånost preispitivanja novog Plana gospodarenja otpadom.

4. KAKO NA OTOCIMA?
Ciljne vrijednosti koje preuzimamo iz EU kao da se odnose samo velika ekonomski i
infrastrukturno zaokružeQD L JXVWR QDVHOMHQD SRGUXþMD 1R SRVWRMH L SRGUXþMD QLVNHQDVHOMHQRVWL LQIUDVWUXNWXUQH RWHåDQH SRYH]DQRVWL NDR ãWR VX QD SULPMHU RWRFL SD þDN L QL]REDOQLK QDVHOMD 8] WR QD RWRFLPD JUDGRYL VX þHVWR RVWDOL X JDEDULWLPD VUHGQMH YMHNRYQLKgradova, tako dDXQMLPDSRVWRMLFLMHOLQL]SURVWRUQLKRJUDQLþHQMD]DSRVWDYOMDQMHYHüHJEURMD
posuda za odvojeno sakupljanje otpada i potrebnih postrojenja.
+UYDWVND LPD UHODWLYQR PDOX JXVWRüX QDVHOMHQRVWL RG QHNLK  VWDQRYQLNDNP2. Na Malti je
JXVWRüD VOLþQD RQRM X Zagrebu preko 1200 stanovnika/km2. U Belgiji je 387, NizozemskojDX1MHPDþNRMåLYLRNRVWDQRYQLNDNP28/LþNR– senjskoj županiji samo 12.
3RORYLFDJUDÿDQD+UYDWVNHåLYLXYHüLKJUDGRYDQDQHNLKNP2, a druga polovica na
53.000 km2 sa JXVWRüRPQDVHOMHQRVWLRGVDPRVWDQRYQLNDNP2.
QDVHOMDRGþHJDEH]VWDQRYQLNDUD]YUVWDQLVXXDGPLQLVWUDWLYQHMHGLQLFH JUDGDLRSüLQD'YLMHWUHüLQHQDVHOMDLPDSRSXODFLMXPDQMXRGVWDQRYQLND (2)Otoci su posebno izloženi visokim troškovima postupanja s komunalnim otpadom. 3RVWRMHüL
sistem postupanja s komunalnim otpadom na otocima je ekonomski upitan zbog prostornih
RJUDQLþHQMDQHGRVWDWNDSULYUHGHNRMDPRåHSURFHVXLUDWLGLRRWpada, kadrova, infrastrukture...
1D YHüLQL RWRND SRVWXSDQMH V NRPXQDOQLP RWSDGRP VH UMHãDYD QD NODVLþDQNRQ]HUYDWLYDQQDþLQkao i na kopnu. U planu je prijevoz otpada na zbrinjavanje na kopno. Zbog troškova tomože biti velika prepreka daljnjeg razvoja, a mogao bi biti i mRJXüL L]D]RY L NDR PRJXüH
rješenje razvojnih problema.
Danas postoje tehnološka rješenja koja bi se mogla prilagoditi potrebama takvih sredina naQDþLQ GD VH komunalni otpad iskoristi kao resurs razvoja. Uspostavomodrživosti/samodostatnosti u rješavanju problema osigurala bi se dodatna radna mjesta,
SRVWLJOL HNRQRPVNL XþLQFL SURGDMRP VLURYLQD L GRELOD SRWUHEQD HQHUJLMD ]D SURãLUHQMH
djelatnosti u zimskim mjesecima.
Važno je da se naþLQSULNXSOMDQMDLREUDGHVRUWLUDQMDNRPXQDOQRJRWSDGDSULODJRGLWDNRGDVHL]GYRMH VYH NRULVQH VLURYLQH XNOMXþXMXüL L ELRUD]JUDGLYL RWSDG L RVWDWDN JRULYRJ GLMHOD NDRnamjensko gorivo.
Da treba prestati robovati centraliziranom sistemu regionalnih – županijskih centara pokazano
je na primjeru postupanja s otpadom, na prLPMHUX RWRND .RUþXOH. Napravljena je analiza
UD]OLþLWLK NRQFHSDWD 7YUWND ÄGUJLVFKFRQVXOW³ 1MHPþDND , od kojih je najskuplji odvoz nažupanijski centar, a QDMSULKYDWOMLYLML RQDM V PRJXüQRãüX REUDGH RWSDGD XNOMXþXMXüL L
iskorištavanje energetskog potencijala.

Energy and the Environment (2016) 69-74

73

Slika 3. Prikaz UD]OLþLWLKNRQFHSDWDSRVWXSDQMDVRWSDGRP.OMXþ WDNYRM PRJXüQRVWL GDMH QRYD WHKQRORJLMD UD]YUVWDYDQMD RWSDGD NRMD RPRJXüXMH
izdvajanje svih korisnih dijelova RWSDGD L] PMHãRYLWRJ RWSDGD =ERJ PRJXüQRVWL VXãHQMD
dobiva se i relativno energetski bogato zamjensko gorivo koje se može iskoristiti u malimenergetskim postrojenjima kapaciteta 0.5 – 4 t/sat; ekvivalent 2 kg RDF = 1 kg ugljena/lož
ulja: staklenici zimi, grijanje hotela, bazena itd.
Tehnologija je u cijelosti u duhu zakona EU. Naime, Odluka Komisije 2011/753/EU o
XVSRVWDYLSUDYLODLPHWRGDL]UDþXQD]DSURYMHUXSRãWLYDQMDFLOMHYDL]þODQND  'LUHNWLYH(= (XURSVNRJ SDUODPHQWD L 9LMHüD 6/ / 310, 25.11.2011.) RPRJXüXMH GD VH
izdvajanje onih dijelova korisnog otpada iz miješanog otpada, koji se usmjeravaju na daljnju
oporabu smatra jednakim odvojeno sakupljenim na izvoru.
MBO - Tehnologija TEHNIX, Donji Kraljevac, se koristi za izdvajanje korisnih sirovina iz
mješovitog i za sortiranje na izvoru izdvojenog otpada.

74

96LPRQþLþ: 6DPRRGUåLYRVWXSRVWXSDQMXVRWSDGRPQLMHPRJXüHEH]LVNRULãWDYDQMD«

Slika 4. Shematski prikaz MBO – Tehnologije TEHNIXSUSTAINABILITY IN WASTE MANAGEMENT IS NOT POSSIBLEWITHOUT EXPLOITATION OF THE ENERGY POTENTIAL REST OF
WASTE - ESPECIALLY NOT ON THE ISLANDS
Abstract: The new Waste Management Plan for the period 2016th - 2022nd further ignores the
exploitation of the energy potential rest of waste. Also, due to the insistence on separate
collection at source leads to the non-fulfillment of the goals from the Low-emission
Development Strategy. The special problem will be the fulfillment of obligations on theislands. The paper gives a proposal how with the newly developed technology, which allows
seclusion/sorting of useful parts from mixed waste and/or on the source of separately
collected waste which can on the financial acceptable way solve the problem of waste
management on the islands.
Keywords: waste, waste management, energy exploitation, islands, technology

Energy and the Environment (2016) 75-80

75

ENERGY POTENTIAL FROM MUNICIPAL SOLID WASTE IN SOUTH
EAST EUROPE

0DULQ0LOHWLü- Energy institute Hrvoje Požar, Savska cesta 163, Zagreb, Croatia
Tel: +385 99 5326271; Fax: +385 (0)1 6040-599; email: mmiletic@eihp.hr
9LNWRU'UDJLþHYLü– Faculty of engineering Rijeka, Vukovarska 58, Rijeka, Croatia
Tel: + 385 98 336859; email: viktor.dragicevic@riteh.hr, vdragice55@gmail.com

Summary: Desktop study on energy potentials from municipal solid waste (MSW) in Southeast Europe was carried out resulting in broad conclusion that large, (still) untapped
potentials for energy recovery of MSW exist in the region. Geographically and economicallydiversified, each assessed country has its own specific waste streams and management
systems as well as potential recovery options for selected waste streams. As elsewhere, wasteenergy recovery in the analysed countries is largely dependent on policy, economic
environment and social support. While there are countries with more advanced waste
management systems (Slovenia, Croatia), most of the countries are still at the beginning, withlow levels of collections and separation levels, and/or quantity limits. Although current
situation poses a high risk for implementation of waste to energy schemes in those countries,
it is also an opportunity to consider. Approximation of the whole region to EU standards,
adoption of Waste Framework Directive and Circular Economy Strategy obligations andtargets, and launch of first waste to energy projects will offer positive signals of market
creation with good perspective to grow in the coming years.
Keywords: municipal solid waste, energy potential, Southeast Europe.
INTRODUCTION
Waste management is a challenge throughout the Southeast Europe region with waste
management showing considerable disparities between the neighbouring countries. The
municipal solid waste management issue is a broad but complex subject especially wheninvestigated at country level. In general for the Southeast Europe countries waste generationis characterized by lower waste levels than the EU28 but with rapidly rising per capita levels
and overall poorly coordinated waste management mechanisms with limited recycling
structures and a heavy reliance on (often uncontrolled) landfills. At present, the main waste
disposal methods include sanitary landfill, with very low rate of composting and negligible
incineration, etc. Sanitary landfill technology is mature and cheap, but it has several
shortcomings as it occupy plenty of land resource [1], and might cause the secondary
pollution to soil and underground water. As a result, this method has been limited gradually
by EU legislation. At the same time, waste to energy (WTE) methods such as incineration andgasification are the two primary WTE technologies that have been used successfully
throughout the world [2, 3].
A key point of the EU policy objectives are stated in the Waste Framework Directive (WFD)(2008/98) and more recently additional objectives are foreseen in the Circular Economy

76

00LOHWLü9'UDJLþHYLü: Energy potential from municipal solid…

Package. The obligation of member states and candidate countries is to implement waste
management plans and foresee waste reduction and resource efficiency measures covering thewhole cycle: from production and consumption to waste management and the market forsecondary raw materials. A baseline point is the knowledge of waste structure and quantities
in order to develope reliable and realistic waste management plans implementing best
technological solution.
In this paper we used publicly available data on municipal solid waste quantities andcomposition to calculate the available energy potential.
ENERGY POTENTIAL IN SELECTED SOUTH EAST EUROPE COUNTRIES
Bosnia and Herzegovina
The composition of municipal waste collected and disposed in Bosnia and Herzegovina islargely unknown, and there is no systematic follow-up and monitoring of the waste
composition. There are some studies covering local situations, which can be used to roughly
determine the average composition of waste. Table 1 shows the composition of the waste for
WKHUHJLRQRI%LKDü
Table 1 Composition of collected municipal waste for the region of Bihac.
Plastic

Paper

Glass

13,2%

10,2%

8%

Waste
wood
5,4%

Textile4,6%

Rubberwaste
1,4%

Organic
waste
31,6%

Metal
0,7%

Construction
waste
5,7%

Hazardous
waste
1,3%

Other
17,9%

Source: 0LQLVWDUVWYR]DJUDÿHQMHSURVWRUQRXUHÿHQMHL]DãWLWXRNROLQH)HGHUDFLMD%RVQHL+HUFHJRYLQH Pregled
osnovnih podataka o otpadu i aktivnosti u procesu upravljanja otpadom u unsko-sanskom Kantonu – regiji%LKDü. 2013.

Above percentages of waste composition were used as reference for the calculation of thetheoretical energy potential of waste at the state level.
According to official data [4] in 2013 in Bosnia and Herzegovina have been collected
1,191,267 tonnes of waste. Of the above amount was detracted the inert waste (metals, glass,etc.) and the waste which must be separately collected according to EU directives andtherefore in the long-term will not be available for energy recovery. Therefore it is obtained
an amount of 833.887 tons of municipal waste collected on an annual basis that cantheoretically be used to produce energy. Using as a value for the energy content of waste 11,5
MJ/kg [5] it is obtained a value of 9,59x106 GJ/year as a theoretical total energy potential of
mixed municipal waste collected in Bosnia and Herzegovina annually.
Montenegro
The Study on the assessment of needs for the revision of the Strategic Master Plan for Waste
Management in Montenegro and recommendations for the organization of waste management
activities in the period up to year 2030 [6] are reporting evaluation on the waste to energy
capacities in Montenegro. It is reported that the current amount of waste fractions suitable forthermal treatment is equal to thermal power of 30 MW. If the available heat were used forelectricity generation, it would mean a power plant of 10 MW. However, it is foreseen thatwaste thermal treatment plant will be operational only after the year 2025. The projection isthat in the year 2020 an amount of 50.000-60.000 tonnes of RDF would be available withenergy content sufficient to be used as a fuel in a thermal treatment plant of 10MWel power.
The annual electricity production should amount to 70GWh.

Energy and the Environment (2016) 75-80

77

Above data are in contrast with the data presented in the White Book – Montenegro Energy
Development Strategy until 2030 [7]. In that document an amount of 197 GWh of electricity
from waste is reported as an actual value and the projection for the year 2030 is 280 GWh/y.
However, the same Strategy states that the incineration of 100.000 tons of waste per year in
the short and medium term is unsustainable in Montenegro given the cost of the plant inaddition to the cost of collection and transport. That statement is supported by theconsideration that technology of waste incineration plant is favourable for treatment of larger
quantities of waste i.e. above 100.000 t/year (Schneider et al., 2010) [8]. By increasing thecapacity of the plant, the cost of incineration per ton of MSW is falling while the energy
efficiency of the treatment is growing.
Croatia
In the period from 2015 to 2030, the Waste management plan of Croatia [9] foresees 530,000
tons as an annual average combustion fraction of waste, which corresponds to approximately
6,1x106 GJ/y of energy. Above-mentioned combustion fraction corresponds to 30% of thetotal amount of produced waste and to 50% of the waste treated at the waste treatment
facilities. It should be taken into account that the share of the waste combustion fractions andits quality depends on the processing technology. According to literature [10], of the total
quantity of waste treated at mechanical-biological treatment plant an average range of 40-60%
is the waste fractions processed into fuel. Therefore the implemented waste treatment
technologies will be key in ensuring the required quality fuel to be used by plants for energy
waste treatment.
SerbiaUntil recently waste management in Serbia was based only on collection and waste disposal at
not strictly sanitary landfills, but often on small open dumps. In order to change existing
practice the main goals of waste management in Serbia are increase in selection andseparation of recyclables, especially of packaging waste, and disposal of remaining waste at
sanitary (regional) landfills. According to the Agency for Environmental Protection [11]annually in Serbia is collected about 2,5 million tons of municipal solid waste. Theoreticalvalue of the energy potential of municipal solid waste in Serbia determines its combustible
fraction with an average energy value of about 11,5MJ/kg. In the structure of municipal waste
the combustible fraction amounts to 65% to 70% of waste materials, therefore the energy
potential of municipal waste in Serbia theoretically can reach 20,1x106 GJ/year if the waste isthermally treated. Of this the potential of the biodegradable biodegradable fraction isestimated at 11,7x106 GJ/year.
Slovenia
The foreseen waste to energy capacity of the Republic of Slovenia is presented in the Waste
Program and Waste prevention program of Republic Slovenia [12]. To achieve theenvironmental targets set by the Directive 2008/98 /EC the Program has set out two scenarios:- Scenario of minimum amount of preparation for re-use and recycling of municipal waste(hereinafter: the scenario I), and- Scenario for ambitious preparing for re-use and recycling of municipal waste (hereinafterreferred to as Scenario II), (by 2030 to provide 65 per cent recycling of municipal waste, 75
per cent recycling of packaging waste, not more than 10 per cent of all waste is landfilled
regardless of the amount).
Estimated average annual thermal power generated by thermal treatment of municipal solid
waste (MSW), according to the scenario I for 2020 is estimated at 55,02 MW.

78

00LOHWLü9'UDJLþHYLü: Energy potential from municipal solid…

Scenario II gives slightly less average annual thermal power, namely 47,88 MW.
The Table 2 below represents the estimated amounts of waste available for thermal treatment
in 2020 by both Scenarios as a total and sub-divided by region.
Table 2 Slovenia - estimated waste amounts by region
RegionGorenjska
GoriškaObalno-Kraško
Primorskonotranjska
Jugovzhodna
Slovenia
Spodnjeposavska
Osrednjeslovenska
Zasavska
Savinjska
Koroška
Podravska
Pomurska
Total

Thermal treatment of waste
2020 Scenario I
2020 Scenario II
(t/y)
(t/y)
6.427
5.511
5.558
4.766
6.631
5.686
2.448
2.099
6.048

5.186

3.057
19.448
2.004
8.380
3.048
11.3294.213
78.631

2.622
16.711
1.718
7.185
2.613
9.714
3.613
67.425

KosovoWaste management is a complex industry in Kosovo, encompassing a series of public andprivate actors at the municipal and national level. Waste is generally collected at designatedcollection points by regional waste companies, and dumped into landfills without any type ofsorting, organisation, or further processing. Government and ministerial strategies dealing
with waste management are in existence, and are being implemented, albeit slowly. Data on
waste production are reporting 335kg of waste per capita in 2011-2012 [13] corresponding to582.900 tons annually of municipal solid waste. However it should be emphasized that dataon collected waste are inaccurate. Considering the combustible fraction as 65% to 70% of
waste materials we can obtain the theoretical energy potential of MSW to amount at 6,7x106
GJ/y.
Albania
There are still significant structural flaws in the Albanian waste management system. Waste
management and use for energy services in Albania is at a low level. Both waste collection
and disposal are in need of considerable improvement. Illegal landfills and trash in the streets
are common in both rural and urban settings in Albania. Systems for the collection ofmunicipal solid waste are provided in most cities and towns, but not in rural
areas. Very little recycling of waste is undertaken.
As reported above for Kosovo, also in Albania is very difficult to present reliable figures on
the available amount of municipal solid waste and its possibility to be used as fuel.
The annual production of municipal solid waste in Albania amounts approximately to 1,1
million tonnes [14]. Considering the combustible fraction as 65% to 70% of available wastematerials it can be obtained that theoretical energy potential of MSW amounts to 8,9x106
GJ/y.

Energy and the Environment (2016) 75-80

79

CONCLUSION
The results shown here are showing the possibility to implement energy recovery in waste
management systems of South east Europe countries and can provide an estimate of thepotential energy production from the waste sector to be , for instance, benchmarked with otheroptions when setting energy strategies.

Figure 1. Energy potential divided by countries in SE Europe
Total estimated energy potential of MSW that can be used for energy production in Southeast
Europe (excl. Slovenia) is 8,9x106 GJ/y.
REFERENCES[1] Dong, C., Jin, B., & Li, D. (2003). Predicting the heating value of MSW with a feed
forward neural network. Waste Management, 23(2), 103-106[2] Liu, Y., & Liu, Y. (2005). Novel incineration technology integrated with drying,pyrolysis, gasification, and combustion of MSW and ashes vitrification. Environmental
science & technology, 39(10), 3855-3863.
[3] Albores P., Petridis K. and Dey P.K. 2016. Analysing efficiency of Waste to Energy
Systems: Using Data Envelopment Analysis in Municipal Solid Waste Management. Procedia
Environmental Sciences, 35, 265 – 278[4] Agencija za statistiku Bosne I Hercegovine. Saopštenje. Javni odvoz i odlaganje
komunalnog otpada. 2014.
[5] Economopoulos, A.P. 2009. Technoeconomic aspects of alternative municipal solid
wastes treatment methods. Waste Management, 30(4): 707-15[6] ERICO Velenje, Institut za ekološka istraživanja d.o.o. 2011. Study on the assessment ofneeds for the revision of the Strategic Master Plan for Waste Management in Montenegro andrecommendations for the organization of waste management activities in the period up to2030. Available at: http\\www.gov.me/ResourceManager/FileDownload.aspx?rId=108569...2[09.09.2015][7] Ministry for economic development of Montenegro. 2014. Energy development strategyof Montenegro by 2030 – White book. Ed. Ministry for Economic Development, Podgorica[8] Schneider, D. R., Loncar, D., Bogdan, Z. 2010. Cost Analysis of Waste-to-Energy Plant.
Strojarstvo 52 (3) 369-378

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00LOHWLü9'UDJLþHYLü: Energy potential from municipal solid…

[9] Ministry of Environmental and Nature Protection. 2015. Waste management plan republicof Croatia 2015-2021. Draft.
Available:
http://www.mzoip.hr/doc/nacrt_plana_gospodarenja_otpadom_republike_hrvatske_za_razdob
lje_2015-2021.pdf[10] C. Montejo, C. Costa, P. Ramos, M. del Carmen Marquez. 2011. Analysis andcomparison of municipal solid waste and reject fraction as fuels for incineration plants,
Applied Thermal Engineering, doi: 10.1016/j.applthermaleng.2011.03.041[11] $JHQFLMD]D]DãWLWXåLYRWQHVUHGLQH7HPDWVNRSRGUXþMHRWSDG
Available:
http://www.sepa.gov.rs/index.php?menu=20170&id=20004&akcija=showAll[12] Government Republic of Slovenia. 2015. Waste Program and Waste prevention programof Republic Slovenia. Available:
http://www.mop.gov.si/fileadmin/mop.gov.si/pageuploads/osnutki/program_ravnanja_z_odpa
dki.pdf[13] European Environmental Agency. 2015. SOER 2015 — The European environment —state and outlook 2015 / Countries and regions / Kosovo.
Available:
http://www.eea.europa.eu/soer-2015/countries/kosovo[14] European Environmental Agency. 2013. Municipal waste management in Albania.
Available:
http://www.eea.europa.eu/publications/managing-municipal-solid-waste/albania-municipalwaste-management

ENERGETSKI POTENCIJAL KOMUNALNOG KRUTOG OTPADA U-8*2,672ý12-(8523,
Sažetak ,VWUDåLYDQMH R HQHUJHWVNRP SRWHQFLMDOX NRPXQDOQRJ NUXWRJ RWSDGD X -XJRLVWRþQRMEuropi rezultiralo MH ]DNOMXþNRP GD SRVWRML YHOLN MRã XYLMHN  QHLVNRULãWHQL SRWHQFLMDO ]Denergetsku oporabu navedene vrste otpada u regiji. Svaka analizirana država ima svoje
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odabrane tokove otpada. Energetska oporaba komunalnog otpada u analiziranim zemljama u
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Iako postoje zemlje s naprednijim sustavom gospodarenja otpadom (Slovenija, Hrvatska),YHüLQD ]HPDOMD MRã XYLMHN QLMH XYHOD PRGHUQH VXVWDYH JRVSRGDUHQMD RWSDGRP WH VX SULVXWQH
niske razine prikupljanja i odvajanja. Iako trenutna situacija predstavlja visok rizik zaXYRÿHQMH WHKQRORãNL QDSUHGQLK L ]DKWMHYQLK VXVWDYD ]D HQHUJHWVNX RSRUDEX otpada u tim]HPOMDPDWRWDNRÿHUSUXåDLSULOLNX]DUD]YRMLSREROMãDQMHWUHQXWQHVLWXDFLMH3ULEOLåDYDQMH
cijele regije prema standardima EU, usvajanje obveza i ciljeva navedenih u Okvirnoj direktivi
o otpadu i Strategiji cirkularne ekonomije, kao i pokretanje projekata energetske oporabe
RWSDGD RGDVODWL üH SR]LWLYQH VLJQDOH R VWYDUDQMX WUåLãWD X] GREUX SHUVSHNWLYX ]D UDVW X
narednim godinama.
.OMXþQHULMHþL NRPXQDOQLNUXWLRWSDGHQHUJHWVNLSRWHQFLMDOMXJRLVWRþQD(XURSDEnergy and the Environment (2016) 81-88

81

PREVENTION OF OZONE LAYER DEPLETIONUSING CLOUD SEEDING
Anant Wadhwa1), Anshu Kumar2), Sona Awasthi3)
1)

CEO, Anant Enterprises, Chandigarh, India; TH Brandenburg,
Brandenburg an der Havel, Germany, +49-17683364469, dj.anant@gmail.com
2)
Managing Director, Anant Enterprises, Chandigarh, India,+91-9814301541, ctc.chd@gmail.com
3)
TH Brandenburg, Brandenburg an der Havel, Germany,+49-17683325808, sonaawasthi@yahoo.co.in
Abstract: The main aim of this project is to provide a solution for prevention of ozone layer
depletion using the cloud seeding technology in which we reduce the surface area required
for the harmful CFCs to build up and react with the ozone layer causing global damage towildlife and human life. These chemicals are banned and further usage of such compounds isforbidden by law. Montreal Protocol was designed to reduce and eventually ban the
consumption and production of substances that pose a serious threat to the Ozone Layer andthereby on the human existence itself. The paper deals about various aspects of Montreal
Protocol, the steps already taken for the prevention and the innovative method of cloudseeding which would help achieving our targets before the stipulated time and therefore
preventing the environment as we know it. The method of cloud seeding has been used sincealmost half a century now to create artificial rains for crops growing areas with relative low
precipitation. The technique used to create artificial clouds for raining can also be
antithetically used for dispersing the clouds that provide an adsorption surface for thechemical compounds in winters in the region of South Pole, which in turn get split intomolecules from sun’s UV-rays and furthermore react with the Ozone molecules andeventually destroying it.
Keywords: Ozone Layer Depletion, ODS, Refrigerants, HVAC, Environmental Protection,
Montreal Protocol
1.

INTRODUCTION

Ozone depletion describes two distinct but related phenomena observed since the late 1970s: a
steady decline of about 4% in the total amount of ozone in Earth's stratosphere (the ozone
layer), and a much larger springtime decrease in stratospheric ozone around Earth's Polar
Regions. The latter phenomenon is referred to as the ozone hole.
The details of polar ozone hole formation differ from that of mid-latitude thinning but themost important process in both is catalytic destruction of ozone by atomic halogens. The main
source of these halogen atoms in the stratosphere is photo dissociation of man-madehalocarbon refrigerants, solvents, propellants, and foam-blowing agents (CFCs, HCFCs,
freons, halons). These compounds are transported into the stratosphere by winds after being
emitted at the surface. Both types of ozone depletion were observed to increase as emissionsof halocarbons increased.

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A. Wadhwa, A. Kumar, S. Awasthi: Prevention of ozone layer depletion using cloud...

CFCs and other contributory substances are referred to as ozone-depleting substances (ODS).
The ozone layer prevents most harmful UVB wavelengths (280–315 nm) of ultraviolet light(UV light) from passing through the Earth's atmosphere and therefore observed and projected
decreases in ozone generated worldwide concern. It is suspected that a variety of biologicalconsequences such as increases in sunburn, skin cancer, cataracts, damage to plants, andreduction of plankton populations in the ocean's photic zone may result from the increased
UV exposure due to ozone depletion. Although the process of reaction of Ozone with theabove mentioned chemical compounds occurs naturally, the introduction of large amount ofman-made chemicals of such nature has led to an accelerated rate of ozone layer depletion andthereby causing a ozone hole and eventually a significant interest of the sceintists forprotection and prevention of same.
2.

OZONE CYCLE – BASICS AND DAMAGE

Three allotropes of oxygen are involved in the ozone-oxygen cycle: oxygen atoms (O oratomic oxygen), oxygen gas (O2 or diatomic oxygen), and ozone gas (O3 or triatomic oxygen).
Ozone is formed in the stratosphere when oxygen molecules photo dissociate after in taking
an ultraviolet photon whose wavelength is shorter than 240 nm. This converts a single O2 into
two atomic oxygen radicals. The atomic oxygen radicals then combine with separate O2
molecules to create two O3 molecules. These ozone molecules absorb UV light between 310
and 200 nm, following which ozone splits into a molecule of O2 and an oxygen atom. The
oxygen atom then joins up with an oxygen molecule to regenerate ozone. This is a continuing
process that terminates when an oxygen atom "recombines" with an ozone molecule to maketwo O2 molecules.
2O3 R]RQH ĺ22 (oxygen)(1)

The overall amount of ozone in the stratosphere is determined by a balance between
photochemical production and recombination.
Ozone can be destroyed by a number of free radical catalysts, the most important of which are
the hydroxyl radical (OH·), nitric oxide radical (NO·), chlorine atom (Cl·) and bromine atom(Br·). The dot is a common notation to indicate that all of these species have an unpaired
electron and are thus extremely reactive. All of these have both natural and man-madesources; at the present time, most of the OH· and NO· in the stratosphere is of natural origin,but human activity has dramatically increased the levels of chlorine and bromine. Theseelements are found in certain stable organic compounds, especially chlorofluorocarbons(CFCs), which may find their way to the stratosphere without being destroyed in the
troposphere due to their low reactivity. Once in the stratosphere, the Cl and Br atoms areliberated from the parent compounds by the action of ultraviolet light, e.g.
CFCl3 + eleFWURPDJQHWLFUDGLDWLRQĺ&Oāā&)&O2(2)

Energy and the Environment (2016) 81-88

83

The Cl and Br atoms can then destroy ozone
molecules through a variety of catalytic cycles.
In the simplest example of such a cycle, achlorine atom reacts with an ozone molecule,taking an oxygen atom with it (forming ClO)
and leaving a normal oxygen molecule. The
chlorine monoxide (i.e., the ClO) can reactwith a second molecule of ozone (i.e., O3) toyield another chlorine atom and two moleculesof oxygen. The chemical shorthand for thesegas-phase reactions is:
x Cl· + O3 ĺ &O2  22: The chlorine
atom changes an ozone molecule to ordinary oxygen
x ClO + O3 ĺ&Oā22: The ClO from the previous reaction destroys a second ozone
molecule and recreates the original chlorine atom, which can repeat the first reaction
and continue to destroy ozone.
3.

CLOUD SEEDING – BASICS

Figure 1 Natural Ozone formation in
Environment

Cloud seeding, a form of weather modification, is the attempt to change the amount or type ofprecipitation that falls from clouds, bydispersing substances into the air that serve as
cloud condensation or ice nuclei, which alter
the microphysical processes within the cloud.
The usual intent is to increase precipitation(rain or snow), but hail and fog suppression are
also widely practiced in airports.
The most common chemicals used for cloudseeding include silver iodide, potassium iodide
and dry ice (solid carbon dioxide). Liquid
propane, which expands into a gas, has also
been used. This can produce ice crystals at
higher temperatures than silver iodide. After
promising research, the use of hygroscopic
materials, such as table salt, is becoming more
popular. Cloud seeding to increase snowfall
takes place when temperatures within the
FORXGV DUH EHWZHHQ  DQG í ) í DQG
í20 °C). Introduction of a substance such as
silver iodide, which has a crystalline structure
similar to that of ice, will induce freezing
nucleation.

Figure 2 Cloud Seeding Practice for Cloud
Dispersion and Artificial Rain

84

A. Wadhwa, A. Kumar, S. Awasthi: Prevention of ozone layer depletion using cloud...

Cloud seeding chemicals may be dispersed by aircraft or by dispersion devices located on the
ground (generators or canisters fired from anti-aircraft guns or rockets). For release byaircraft, silver iodide flares are ignited and dispersed as an aircraft flies through the inflow ofa cloud. When released by devices on the ground, the fine particles are carried downwind andupward by air currents after release.
4.

FORMATION OF OZONE HOLE – WHY SOUTH POLE

The presence of the Ozone Hole is usually observed in the South Pole and this is a doubt thatneeds to be cleared before understanding the usage of Cloud Seeding Technology. In order for
rapid ozone destruction to happen, clouds (known as PSCs, Polar Stratospheric Clouds or
Nacreous Clouds) have to form in the ozone layer. In these clouds surface chemistry takes
place. This converts chlorine or bromine (from CFCs and other ozone depleting chemicals)
into an active form, so that when there is sunlight, ozone is rapidly destroyed. Without theclouds, there is little or no ozone destruction. Only during the Antarctic winter does theatmosphere get cold enough for these clouds to form widely through the center of the ozone
layer. Elsewhere the atmosphere is just too warm and no clouds form. The northern andsouthern hemispheres have different 'weather' in the ozone layer, and the net result is that thetemperature of the Arctic ozone layer during winter is normally some ten degrees warmer
than that of the Antarctic. This means that such clouds are rare, but sometimes the 'weather' iscolder than normal and they do form. Under these circumstances significant ozone depletion
can take place over the Arctic, but it is usually for a much shorter period of time and covers asmaller area than in the Antarctic.
5.

LINK BETWEEN CLOUD SEEDING AND DEPLETION PREVENTION

The PSCs (Polar Stratospheric Clouds) essentially provide a surface for the harmful CFCs andother such chemicals used in the Refrigeration industry to react with the Ozone molecules
present in the stratosphere in the presence of Sun’s UV (Ultra-violet) rays. They play the roleof an adsorbent. It means that the clouds do not play rolein any chemical reaction that is happening instead
provide a surface for the reaction to happen.
The process of seeding could be easily understood by
the following graphic description.
CFC Molecule

Figure 3 shows a not to scale drawn image of the Figure 3 Presence of CFC Molecules
presence of CFC and other such molecules on the PSC
on the surface of PSCs
surface. Since the surface area and volume of suchclouds is relatively high, they act as a humongous adsorbent. In order to reduce the above
mentioned area and volume, we introduce chemical compounds (salts) like Potassium Iodide,Silver Iodide or just the normal table salt (NaCl), efficiency of which is still questionable.
These compounds react with the water particles and ice crystals present in the clouds andincrease their density and hence disperse the clouds by precipitating them in the form of
rainfall or snowfall depending on the atmospheric conditions.

Energy and the Environment (2016) 81-88

85

Figure 4 Introduction of seeding agents over the PSCs

Figure 5 Significant Reduction in Cloud Volume and hence less surface area for the CFCs toreact on
It is easily observable and measurable that after the cloud seeding has been performed on thespecific cloud groups having the highest density, the surface area and the volume of suchclouds drastically, the CFC molecules are set free from the surface and concentration of suchmolecules also decreases exponentially. The process of ozone depletion depends greatly on
the concentration of ODS (Ozone Depleting Substances). Once the concentration is reduced
vastly, almost to the similar level of the natural occurring of the chemical reactions between
ozone and CFCs, it is safe to say that harmful effects of ozone depletion and ozone hole also
reduce by a significant measure.

86

A. Wadhwa, A. Kumar, S. Awasthi: Prevention of ozone layer depletion using cloud...

6. IMPACT OF CLOUD SEEDING CHEMICALSWith an NFPA 704 health hazard rating of 2, silver iodide can cause temporary incapacitationor possible residual injury to humans and mammals with intense or continued but not chronic
exposure. However, there have been several detailed ecological studies that showed negligible
environmental and health impacts. The toxicity of silver and silver compounds (from silver
iodide) was shown to be of low order in some studies. These findings likely result from theminute amounts of silver generated by cloud seeding, which are about 1% of industry
emissions into the atmosphere in many parts of the world, or individual exposure from tooth
fillings.
Accumulations in the soil, vegetation, and surface runoff have not been large enough tomeasure above natural background. A 1995 environmental assessment in the Sierra Nevada ofCalifornia and a 2004 independent panel of experts in Australia confirmed these earlier
findings.
Since silver iodide and not elemental silver is the cloud seeding material, the claims ofnegative environmental impact are disputed by peer-reviewed research as summarized by theinternational Weather Modification Association.
Apart from that usage of Sodium Chloride (NaCl) also reduces the environmental and healthimpact, if any, to a more feasible standard. The financial, economic and logistical issues to thesame still remain unanswered.
CONCLUSION
From the discussion above it is safe to conclude that the usage of cloud seeding technology is
feasible in terms of achieving our targets of similar environmental conditions of 1930s as set
by Montreal Protocol. A study from the Montreal Protocol states that following the roadmap
of reduced ODS usage may lead to better environmental conditions by the end of year 2070,
which is still more than half a century away. By using cloud seeding technologies, it would besafe to say that achieving the target of 2070 can be reduced to a span of 10-15 years or evenmore, depending on the efficiency of application.
Although the project seems pretty easy in theory and on paper, the actual impact assessment
can only be done once financial and technical support is provided from various institutions
and organizations. It may take a time frame of about 1-2 years before the project is actuallyrealized and ready for actual on field deployment, but the first step needs to be taken by thetheoretical approach, knowledge creation and distribution among the groups of people thatthink alike with the approach of a better sustainable environment for the generations to come.
Furthermore, individuals, parties, concerns and organizations need to understand the severityof the problem and start taking a few steps forward by reducing the consumption and overallbanning of ODS (Ozone Depleting Substances) and GWP (Global Warming Potential)
chemicals as soon as financially and economically feasible, move towards better refrigerants
and chemicals and last but not the least innovative methods and projects like this to curb the
problem from the root rather than waiting for the science & technology to develop for asustainable alternative.

Energy and the Environment (2016) 81-88

87

REFERENCES[1] "Adjustments to the Montreal Protocol". United Nations Environment Programme Ozone
Secretariat.
[2] "The Ozone Hole-The Montreal Protocol on Substances that Deplete the Ozone Layer".
Theozonehole.com. 16 September 1987.
[3] “Environmental Politics Climate Change and Knowledge Politics”, Reiner Grundmann,Vol. 16, No. 3, 414–432, June 2007
[4] Creating a real change for the environment. Secretariat of the Multilateral Fund for the
Implementation of the Montreal Protocol. 2007.
[5] "Evidence for the effectiveness of the Montreal Protocol to protect the ozone layer".
http://www.atmos-chem-phys.org. Retrieved 2010
[6] Christner BC, Morris CE, Foreman CM, Cai R, Sands DC (2008). "Ubiquity of biological
ice nucleators in snowfall". SCIENCE 319 (5867): 1214
[7] American Society of Civil Engineers, www.asce.org[8] Weather Modification Association, www.weathermodification.org[9] World Meteorological Organization – http://www.ametsoc.org/policy/wxmod98.html[10] Harris, Edward R., 1981: Sierra Cooperative Pilot Project - Environmental Assessment
and Finding of No Significant Impact. U.S. Department of the Interior, Bureau of
Reclamation, Denver, CO, 208 pp.
[11] Howell, Wallace E., 1977: Environmental Impacts of Precipitation Management: Results
and Inferences from Project Skywater. Bull. American Meteorological Society, 58, 488–501[12] Web link:
http://web.archive.org/web/20080306070626/http://www.nmt.edu/about/history/storms/chap3.htm[13] ³$*,BWR[LFLW\SGIƎ:HDWKHU0RGLILFDWLRQ$VVRFLDWLRQ
[14] "Homepage of the Society for cloud seeding Rosenheim (in German)". Retrieved 16
April 2013

88

A. Wadhwa, A. Kumar, S. Awasthi: Prevention of ozone layer depletion using cloud...

635-(ý$9$1-( 2â7(û(1-$ OZONSKOG 2027$ý$
KORIŠTENJEM TEHNOLOGIJE ZASIJAVANJA OBLAKASažetak: Cilj ovRJ SURMHNWD MH SUXåLWL UMHãHQMH ]D SUHYHQFLMX RãWHüHQMD R]RQVNRJ RPRWDþD
SRPRüX]DVLMDYDQMDREODNDWHKQRORJLMRPNRMRPELVHVPDQMLODpovršina akumulacije štetnih
CFC spojeva koji reagiraju s ozonskim RPRWDþHP X]URNXMXüL SULWRP RãWHüHQMD QD globalni
biljni i životinjski svijet, kao i na ljudske živote. Ove kemijski spojevi su zabranjeni i daljnje
korištenje CFC-a zabranjeno je zakonom. Montrealski sporazum dogovoren je s ciljem
smanjenja i na posljetku zabrane proizvodnje i potrošnje tvari koje predstavljaju ozbiljnu
SULMHWQMXR]RQVNRPRPRWDþXLVDPRPOMXGVNRPåLYRWX2YDMVHUDGEDYLUD]OLþLWLP aspektima
0RQWUHDOVNRJVSRUD]XPDSRGX]HWLPPMHUDPD]DSUHYHQFLMXRãWHüHQMDR]RQVNRJRPRWDþDNDR
i inovativnom metodom zasijavanja oblaka koje mogu SRPRüLkod ostvarivanja dogovorenih
FLOMHYDSULMHSRVWDYOMHQRJURNDLNRGRþXYDQMDRNROLãD. Tehnologija zasijavanja oblaka koristi
VH YHü JRWRYR SROD VWROMHüD kod stvaranja umjetnih kiša za potrebe usjeva u SRGUXþMima s
UHODWLYQRPDORPNROLþLQRP oborina. Tehnologija koja se koristi za stvaranje umjetnih kišnih
REODND PRåH VH WDNRÿHU NRULVWLWL L QD VXSURWDQ QDþLQ ]D UDVSUãLYDQMH REODND NRML SUXåDMXpotrebnu površinu akumulacije štetnim kemijskim spojevima tijekom zimskog razdoblja naJužnom polu, a koji bi reagirali sDVXQþHYLP89]UDþHQMHPVWYDUDMXüLSULWRPãWHWQHPROHNXOH
koje uništavaju molekule ozona.
.OMXþQHULMHþL RãWHüHQMHR]RQVNRJRPRWDþDãWHWQHWYDUL 2'6 UDGQHWYDUL+9$&VXVWDYL
zaštita okoliša, Montrealski sporazum

Energy and the Environment (2016) 89-98

89

DESIGN OF A NETWORK OF PYROLYSIS UNITS WITH A CENTRALGASIFICATION PLANT FOR THERMOCHEMICAL CONVERSIONOF DISPERSED WASTE BIOMASS

Juma Haydary, ďXGRYtW-HOHPHVQNê, Jozef Markoš, Jozef Dudaš
Institute of Chemical and Environmental Engineering. Slovak University of Technology
in Bratislava, Radlinského 9, 812 37 Bratislava, Tel.: ++421 2 59325252, E- mail:juma.haydary@stuba.sk

Abstract: One of the challenges of using biomass as a source of renewable energy is its
dispersion over the land. Collection and transportation of biomass waste to a central energy
generation plant can significantly increase the process cost and cause additional
environmental load. One of the solutions offered is a network of small pyrolysis units incombination with a central gasification plant. Small pyrolysis units dramatically reduce thevolume of waste and concentrate the waste energy content into pyrolysis products which aretransported to the central gasification plant. Pyrolysis products collected from all pyrolysis
units are gasified and produced gas is used in combined heat and power generation.
This works deals with computer design and simulation of such a system including all pyrolysis
units and the central gasification plant. As input waste, biomass flow real data from a real
region of Slovakia were used. A site of six pyrolysis units was proposed based on realpotential of the location which was 38.5 t/hr in total. Material characteristic data andpyrolysis yields were measured in laboratory and/or obtained from literature. Simulated
pyrolysis units produced 25.71 t/hr of bio-oil and 6.69 t/hr of bio-char. Bio-oil and bio-charwere mixed into a bio-slurry and gasified in an entrained flow gasifier. Produced gas wasused in a combined heat and power plant. The model enabled material and energy balance of
all units, phase and chemical equilibrium calculations and parametric sensitivity analysis ofunits.
Keywords: Pyrolysis, gasification, biomass, waste, modelling

1. INTRODUCTION
Biomass is considered one of the most important sources of renewable energy. Different
origins of biomass such as vegetal, animal and municipal are known. From the view point ofenergy application, two types of biomass are distinguished; the first type is the biomass grown
for this purpose, and the second type is the waste biomass. Waste biomass can be divided into
the following groups:
ࡃ wood and wood waste from forestry and wood processing industry,

90

J. Haydary, L. Yelemesnky, J. Markoš, J. Dusaš: Design of a network of …

ࡃ

waste from agriculture and landscape maintenance (maize and cereal straw, rapestraw, hay, the remains of vineyards and orchards),
ࡃ
waste from livestock,ࡃorganic waste from food industry.
The first two classes of waste biomass are formed mainly of lignocellulosic materials; themajor components of their structure are cellulose, hemi-cellulose and lignin. These groups ofwaste biomass represent a huge potential of renewable energy, however, they are notconcentrated in a single location but dispersed over large areas. Due to low bulk density ofthese materials (40-60 kg/m3 for straw, 70-120 kg/m3 for compressed straw, 160-250 kg/m3
for wood chips, 50-80 kg/m3 for hay, 150-250 kg/m3 for compressed hay [1]), the cost of raw
material collection and transportation to the plant can crucially affect the process economy.
Lower heating value of waste lignocellulosic biomass is between 15 and 20 MJ/Kg [2].
Assuming a 20 MW power plant with the electricity efficiency of 30%, more than 350 tons ofbiomass per day are required. In case of using straw, around 4000 m3 of this raw material per
day has to be transported to the plant. This amount of waste biomass is usually not available
in an area close to the plant; therefore, the raw material has to be transported from far
distances, which extremely affects the economy of the process.
One of the solutions offered [3] is a network of small pyrolysis units in combination with acentral gasification plant. Small pyrolysis units dramatically reduce the volume of waste andconcentrate the waste energy content into pyrolysis products which are transported with much
lower cost to the central gasification plant. Pyrolysis products collected from all pyrolysis
units are gasified and produced gas is used in combined heat and power generation.
This works deals with computer design and simulation of such a system including all
pyrolysis units and the central gasification plant. In this work, the economy of this solution is
not compared with the economy of a conventional biomass gasification plant, but the aim is tocompute the material and energy balance of individual units of this system as well as its
global material and energy balance.
2. MATERIALS AND METHODS
The subject of this study was agricultural waste biomass produced in a real region in
Slovakia. The selected region in Figure 1 has an area of around 3800 km2 and the distance
between the outermost points is around 120 km. It is a region with highly developed
agriculture and related industry. Based on the statistics of the Slovak republic in this region,
more than 7.5x104 ton/year of agricultural waste from the cultivation of wheat, barley andcorn are produced; 60 % of this waste is usually returned back to the land and 40% (around7.5x104 ton/year) is available for energy applications. Details on the availability of different
agricultural waste in sub-regions of the studied region are presented in Table 1. A network ofsix pyrolysis units was proposed to be located in positions shown in Figure 1. The amount andtype of biomass waste to be processed in individual units is shown in the right column ofTable 1.
Proximate and elemental composition of biomass waste was derived from [4][5][6] and it isshown in Table 2. Moisture of biomass was assumed to be reduced to 10 wt.% before entering
the pyrolysis reactor.

Energy and the Environment (2016) 89-98

91

Aspen Plus simulation was used to design all pyrolysis units as well as the central gasification
plant. Figure 2 shows the scheme of a pyrolysis unit in Aspen Plus. The pyrolysis reactor wasmodelled using the RYIELD model, where yields of char, oil and gas are calculated using
correlations based on experimental data.

Figure 1: Selected region of pyrolysis units location

Individual biomass types, bio-char and bio-oil were defined as nonconventional components
characterized by proximate composition, elemental composition and particle size distribution.
Based on the literature sources [6] [7] and other published works, the maximum yield of oil
was achieved at a temperature of around 500 oC; thus, this temperature was used as thetemperature of the pyrolysis reactor and the yields corresponding to this temperature as yieldsof pyrolysis products. Gas pyrolysis yield was combusted to cover the heat requirement of thepyrolysis reactor. Oil fraction was assumed to be mixed with ground char fraction to a slurry
to enable its pumping and transportation by tankers. However, mixing of pyrolysis products tobio-slurry is optional; the alternative to this method is separate transportation of solid andliquid products.

Table 1: Available waste biomass in selected region
Sub-region

Dunajská streda

Type ofbiomass

Waste
ton/yearFor energy applications

wheat

53525.621410.2(ton/year)

barley22210.4

8884.1corn

153131.4

61252.6

92

J. Haydary, L. Yelemesnky, J. Markoš, J. Dusaš: Design of a network of …

TrnavaHlohovec3LHãĢDQ\

Galanta

Senicawheat

41117.6

16447

barley170019.6

68007.8

corn

49008.1

19603.2

wood

13214

13214

wheat

13857.2

5542.9barley4479.31791.7

corn

10704.1

4281.6wheat

21911.4

8764.5barley13492.95397.2

corn

33163.6

13265.4

wheat

29404

11761.6

barley12885.95154.4corn

63127.6

25251
5431.7wheat

13579.4

barley7022

2808.8corn

27743.2

11097.3

753597.3

309367

Total

Table 2: Proximate and elemental composition of biomass
Waste source

Moisture

VM*

FC*

ASH*

C

H

N

S

O**

wheat
barley
corn
wood

10
10
10
10

79.92
85.00
81.92
85.89

15.18
8.10
16.00
13.15

4.90
6.90
2.08
0.96

42.80
49.70
50.88
52.70

5.44
6.90
5.26
5.34

0.6
1.00
0.74
0.50

0.00
0.70
0.19
0.00

46.26
34.80
40.85
40.50

*dry basis** calculated to 100%
The central gasification plant consisted of an entrained flow gasifier, gas cleaning system,
Rankin cycle for power generation and a heat energy utilization system. The Aspen Plusflowsheet of the gasification plant is shown in Figure 3. The equilibrium model was assumed
for gasification reactor.

Energy and the Environment (2016) 89-98

93

Figure 2: Pyrolysis process flow diagram

Figure 3: Central gasification plant process flowsheet

The equilibrium constant was calculated at constant temperature and pressure using the standard state
Gibbs energy, ' r G

K a298e298

 ' r G 298
RT

:

(1)

94

J. Haydary, L. Yelemesnky, J. Markoš, J. Dusaš: Design of a network of …

where Ka298 is the equilibrium constant at 298 K, ǻrG298 the standard Gibbs energy [J.mol-1], R the gas
constant (R = 8,314 J.mol-1K-1), and T is the temperature [K].
Fugacity coefficients were assumed to be equal to 1 in this work. Standard Gibbs energy of reaction
was calculated based on the standard reaction enthalpy, ǻrH298 [J.mol-1], and the standard reaction
entropy, ǻrS298 [J.mol-1K-1] as:' r G 298

' r H 298  T' r S 298(2)

Values of ǻrH298 and ǻrS298 were calculated using the standard reaction enthalpy and the entropy offormation. For more detail on the equilibrium model see [8].

3. RESULTS AND DISCUSSION
The simulation scheme shown in Figure 2 was applied to simulate each of the six pyrolysis units. The
difference was in the amount and composition of biomass waste. In total, 38.46 t/hr of biomass waste
are processed in all pyrolysis units. The moisture content of dried biomass was 10 wt.% due to its
reduction in a dryer before entering the pyrolysis reactor. Total flow of oil, char and gas was 25.71,
6.59 and 6.16 t/hr, respectively. The gas fraction contained mainly CO2, CO, CH4, H2 and C2-C5hydrocarbons; it was combusted and the released energy was used to heat the pyrolysis reactor.
However, flue gases after heating the pyrolysis reactor still contain a lot of heat energy. The remaining
energy of flue gases was used in the process of biomass drying. Material balance details of eachpyrolysis unit are presented in Tale 3.

Table 3: Material balance details of pyrolysis units
Component / location
Biomass (t/hr)
Bio-oil (t/hr)
Pyro-gases
Bio-char (t/hr)
Gas composition(kg/hr)
CO2
CO
CH4
H2
ETHANEPROPANE
N-BUTANE
I-BUTANEPENTANE

Dunajskástreda
11.44
8.04
1.46
1.94

TrnavaHlohovec3LHãĢDQ\

Galanta

Senica

Total

14.45
9.63
2.39
2.43

1.45
0.88
0.29
0.28

3.43
2.21
0.62
0.6

5.27
3.41
0.95
0.91

2.42
1.54
0.45
0.43

38.46
25.71
6.16
6.59

1417
580
276
46
345
253
133
67
83

1058
433
206
34
258
189
100
50
62

128
53
25
4
31
23
12
6
8

275
112
53
9
67
49
26
13
16

421
172
82
14
102
75
40
20
25

199
82
39
6
49
36
19
9
12

3499
1431
682
114
852
625
329
165
204

Energy and the Environment (2016) 89-98

95

In this work, the oil and char fractions were assumed to be mixed to a bio-slurry. Table 4shows the proximate and elemental composition of bio-slurry containing around 20 wt% ofchar and 80 wt.% of oil.
Table 4: Proximate and elemental composition of bio-slurry
Comp.
SlurryMoisture
18.82

VM*
84.63

FC*
11.7

ASH*
3.67

C
58.71

H
5.38

N
0.79

S
0.02

O**
31.42

The bio-slurry was used as the feed to the central gasification plant. An entrained flow reactor
at atmospheric pressure was considered in this study. Assumptions made in the equilibrium
model are satisfactorily met in this reactor type. A total mass flow of 32300 kg/hr, whichcorresponds with the total bio-slurry produced in all pyrolysis plants, was used.

Volume fraction

Two different processes of bio-slurry gasification were studied: Gasification using air as thegasification agent, and gasification using pure oxygen. Figure 4 shows the composition of
produced gas at different mass flows of air (content of N2 is not shown). The conversion iscompleted when an air mass flow of around 65 t/hr is achieved. This value represents an air tofeed mass flow ratio of around 2 and at this value of air mass flow, the content of CO is at its
maximum, the content of H2 is quite high and the content of CO2 is at its minimum, thereactor temperature of 1130oC was applied. Because of the high content of nitrogen, theproduced gas has the relatively low heating value of 4-5 MJ/Nm3. Table 5 shows details on
the gasification reactor mass balance.

Air (kg/hr)
Figure 4: Composition of producerd gas using air as the gasification agent (content of N2 is not shown)96

J. Haydary, L. Yelemesnky, J. Markoš, J. Dusaš: Design of a network of …

Table 5: Mass balance of the gasification reactor when air is used as thegasification agent
SLURRY
25
1,1
32300

Air
100
30
88386

SYNGAS
1130
1,01325
119724ASH
1130
1,01325
963

0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
25710
6160

0.0
0.0
0.0
0.0
0.0
67799.7
20586.7
0.0
0.0
0.0
0.0
0.0

1109.825529.7
16297.88774.30.0
68007.2
0.0
0.0
5.3
0.2
0.0
0.0

0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0

Volume fraction

Temperature [°C]
Pressure [bar]Mass flow [kg/h]Component mass flow [kg/h]
H2
CO
CO2
H 2O
SO2
N2
O2
CH4
H2S
NH3
Bio-oil
Bio-charO2 (kg/hr)

Figure 5: Composition of produced gas using oxygen as the gasification agent

To increase the heating value of produced gas, pure oxygen or oxygen enriched with air canbe used as the oxidizing agent. However, this solution requires additional cost for an oxygen
plant. Figure 5 shows the composition of produced gas at different mass flows of oxygen. The
conversion is completed when an oxygen mass flow of around 15 t/hr is reached. This value
represents an oxygen to feed mas flow ratio of around 0.46; at this value of oxygen to mass
flow ratio, again the content of CO is at is maximum (around 46 mol.%), and the content of
CO2 is at its minimum (10 mol.%), and the hydrogen content is 32 mol.%. The reactor

Energy and the Environment (2016) 89-98

97

temperature was maintained at 1130oC and the gas heating value is around 10 MJ/Nm3.
Details on the process mass balance are presented in Table 6.

Table 5: Mass balance of the gasification reactor when oxygen is used as the gasification agent

Temperature [°C]
Pressure [bar]Mass flow [kg/h]Component mass flow [kg/h]
H2
CO
CO2
H 2O
SO2
N2
O2
CH4
H 2S
NH3
Bio-oil
Bio-char

SLURRY25
1.1
32300-46.07
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
24176.08124.0

O2
100
30
15440
0.26
0.0
0.0
0.0
0.0
0.0
0.0
15440.0
0.0
0.0
0.0
0.0
0.0

SYNGAS
1130
1.0132546778-45.91
1449.029826.3
9546.95743.7
0.0
207.7
0.0
0.1
5.3
0.0
0.0
0.0

ASH
1130
1.01325
963
0.09
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0

Using the three steam cycles shown in Figure 3, more than 27,5 MW of electricity and 125
MW of heat can be produced. These numbers correspond with the 90 % total efficiency of
combined heat and power system and with the 17.5 % electricity efficiency.

4. CONCLUSION
A network of pyrolysis units significantly reduces the volume of waste biomass and enables
easy transportation of waste to a central gasification and power generation plant. Computer
aided conceptual design of pyrolysis units and the gasification plant proved the suitability ofsuch a system in a real region of Slovakia. A network of six pyrolysis units processed 38.5
t/hr of biomass to produce 25.71 t/hr of bio-oil, 6.69 t/hr of bio-char, and gases to be used asenergy source in the pyrolysis process. The pyrolysis product can be used in a central
gasification combined heat and power plant to generate 27,7 MW electricity and 125 MW.
Optimal air to feed mass ratio in the gasification reactor was 2, and in case of using oxygen as
the oxidizing agent, the optimal O2 to feed mass ratio was 0.47.
Acknowledgement
This work was supported by the Slovak Research and Development Agency under the contract
No. APVV-15-0148

98

J. Haydary, L. Yelemesnky, J. Markoš, J. Dusaš: Design of a network of …

REFERENCES

[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]

http://www.sila-nadrze.cz/objemove-hmotnosti.html, available July 20, 2016
Biomass Energy Data Book – 2011 – http://cta.ornl.gov/bedb, available July 20, 2016
Briggwater A.V., pyrolysis and gasification of biomass and waste, CPL Press, UK,2003
Mullen, C. A., et al. "Analysis and comparison of bio-oil produced by fast pyrolysis
from three barley biomass/byproduct streams." Energy & Fuels 24.1 (2009): 699706.
Mullen, C. A., et al. "Bio-oil and bio-char production from corn cobs and stover by
fast pyrolysis." Biomass and bioenergy 34.1 (2010): 67-74.
Greenhalf, C. E., et al. "A comparative study of straw, perennial grasses andhardwoods in terms of fast pyrolysis products." Fuel 108 (2013): 216-230.
Paenpong, Chaturong, and Adisak Pattiya. "Effect of pyrolysis and moving-bed
granular filter temperatures on the yield and properties of bio-oil from fast pyrolysis ofbiomass." Journal of Analytical and Applied Pyrolysis 119 (2016): 40-51.
Haydary, J. "Gasification of Refuse-derived Fuel (RDF)." GeoScience Engineering
62.1 (2016): 37-44.

OBLIKOVANJE MREŽE 3,52/,7,ý.,+-(',1,&A SA SREDIŠNJIM
POSTROJENJEM ZA UPLINJAVANJE ZA TERMOKEMIJSKUPRETVORBU RASPRŠENE OTPADNE BIOMASESažetak: Jedan od izazova korištenja biomase kao izvora obnovljive energije je rapršenost
izvora sirovine. Sakupljanje i prijevoz biomase do središnjeg postrojenja za proizvodnju
HQHUJLMHPRåH]QDþDMQRSRYHüDWLWURãNRYHSURFHVDLX]URNRYDWLGRGDWQRRSWHUHüHQMHQDRNROLã3RQXÿHQRUMHãHQMHRYRJSUREOHPDMHPUHåDPDOLKSLUROLWLþNLKMHGLQLFDXNRPELQDFLMLV
FHQWUDOQLPSOLQLILNDFLMVNLPSRJRQLPD0DOHSLUROLWLþNHMHGLQLFHGUDVWLþQRVPDQMXMXYROXPHQ
otpada i koncentrirDMXVDGUåDMSLUROLWLþNLKVLURYLQDNRMLVHWUDQVSRUWLUDMXGRVUHGLãQMHJSRVWURMHQMD]DUDSVOLQMDYDQMH3URL]YRGLSLUROL]HSULNXSOMHQLL]VYLKSLUROLWLþNLKMHGLQLFD
rasplinjavaju se i proizvedeni plin se koristi u kombi postrojenjima za proizvodnju toplinske i
HOHNWULþQHHQHUJLMH2YDMUDGSULND]XMHUDþXQDOQLGL]DMQLVLPXODFLMXWDNYRJVXVWDYDXNOMXþXMXüLVYHSLUROLWLþNHMHGLQLFHLVUHGLãQMHSRVWURMHQMH]DUDVSOLQMDYDQMH.DRXOD]QLSRGDFLNRULãWHQLVXVWYDUQLSRGDFLL]UHJLMHX6ORYDþNRM2SWLPDOQRãHVWSLUROLWLþNLKMHGLQLFD
je predloženo na temelju stvarnog potencijala promatrane lokacije koje iznosi 38,9 t/h.
.DUDNWHULVWLþQLSRGDFLPDWHULMDODLSLUROLWLþNRJSRWHQFLMDODVXL]PMHUHQLXODERUDWRULMXLLOL
GRELYHQLL]OLWHUDWXUH6LPXOLUDQLSLUROLWLþNHMHGLQLFe proizvode 24,8 t/h bio-ulja i 8,12 t/h biopepela. Bio-ulje i bio-pepeo se potom miješaju u bio-VPMHVXLUDVSOLQMDYDMXXSURWRþQRPUDVSOLQMDþX3URL]YHGHQLSOLQMHNRULãWHQXNRPELQLUDQRPSRVWURMHQMX]DSURL]YRGQMXWRSOLQVNH
LHOHNWULþQHHQHUJLMH3ULND]DQLPRGHORPRJXüDYDPDWHULMDOQXLHQHUJHWVNXELODQFXVYLKMHGLQLFDSURUDþXQID]QLKLNHPLMVNLKUDYQRWHåDL]UDþXQNROLþLQHLVDVWDYDVYLKWRNRYD
materijala i parametarske analize osjetljivosti.
.OMXþQHULMHþL: Piroliza, uplinjavanje, biomasa, otpad, modeliranje.

Energy and the Environment (2016) 99-110

99

THE TRANSITION TOWARDS DECARBONIZATION: A LEGAL AND
POLICY EXPLORATION OF THE EUROPEAN UNION
Rafael Leal-Arcas
Queen Mary University of London, r.leal-arcas@qmul.ac.uk

Abstract: Decarbonization is the final and visionary goal of European Union (EU) energy
policy. The EU has traditionally conveyed the dashing resolution to lead the strife against
climate change. In that sense, the EU shelters the hope that its example will whet otherregions around the globe to follow suit. This paper argues that such a grandiose aspiration
could cause a new industrial revolution based on vanguard clean and low-carbon
technologies that may boost the EU’s recovery from the economic crisis and launch the vital
conversion to a more sustainable energy system. To that end, the EU has set itself the ultimate
objective of reducing greenhouse gas emissions to a towering 80-95% below 1990 levels by
2050. This decarbonization aim will come at a cost, similar to a hotel analogy: a five-star
hotel is much better, but more expensive, than a one-star hotel. By conceptual analogy,
renewable energy is a much better, but more expensive, option to generate energy than coal.
The paper concludes that the potential for solar energy is phenomenal and that the greatest
result of investing in low-carbon technologies will be to become increasingly energy
independent. So there is hope and great business opportunities.
Keywords: decarbonization, Paris Agreement on Climate Change, EU emissions trading
scheme1.

INTRODUCTION

Combating climate change is one of the 17 sustainable development goals. 1 Climate change isa long-term problem with immediate consequences. When the UN Framework Convention on
Climate Change (UNFCCC) was created in 1992, two thirds of global GHG emissions camefrom the so-called Annex I countries. 2 The situation then was as follows: one group (i.e.,Annex I countries) was expected to solve the problem of climate change; the other group (i.e.,
non-Annex I countries) was waiting to see whether the problem would be solved. Today, thetop-10 GHG emitters include five Annex I countries and five non-Annex I countries. 3 These
facts show that the geopolitics of climate change has shifted in that the approach to deal withclimate change mitigation is via burden-sharing and a declaration of intention to mitigate
climate change supported by an effective monitoring system. Given these facts, one could
argue that it is too late to be a pessimist. 4 The International Energy Agency (IEA) Ministerial1

https://sustainabledevelopment.un.org/?menu=1300.
The term ‘Annex I countries’ refers to developed countries and countries that are undergoing the process oftransition to a market economy. Article 3 of the Kyoto Protocol to the 1992 UNFCCC places the responsibilityof reducing GHG emissions only with Annex I countries.
3
IEA, “CO2 emissions from fuel combustion: Highlights,” 2014, p. 9.
4
For analysis and critique of the UNFCCC architecture, see R. Leal-Arcas “The BRICS and Climate Change,”
International Affairs Forum, pp. 1-5, 2013; R. Leal-Arcas “Climate Change Mitigation from the Bottom Up:
Using Preferential Trade Agreements to Promote Climate Change Mitigation,” Carbon and Climate Law Rev,
2

100

R. Leal – Arcas: The Transition Towards Decarbonization…

statement of November 2015 confirms the gradual commitment of many countries to a lowcarbon energy system. 5
Decarbonization is the final and visionary goal of EU energy policy. The EU has traditionallyconveyed the dashing resolution to lead the strife against climate change. 6 In that sense, theEU shelters the hope that its example will whet other regions around the globe to follow suit. 7
Such a grandiose aspiration will entail a new industrial revolution based on vanguard clean
and low-carbon technologies which should presumably boost Europe’s recovery from theeconomic crisis and launch the vital conversion to a more sustainable energy system. 8 To that
end, the EU has set itself the ultimate objective of reducing GHG emissions to a towering 8095% below 1990 levels by 2050. 9 This decarbonization aim will come at a cost, similar to a
hotel analogy: a five-star hotel is much better, but more expensive, than a one-star hotel. By
conceptual analogy, renewable energy is a much better, but more expensive, option to
generate energy than coal. 10
The path towards decarbonization has already been chronologically delineated by theEuropean Commission through the 2020 Package, 11 the 2030 Framework 12 and the 2050
Vol. 7(1), pp. 34-42, 2013; R. Leal-Arcas “Unilateral Trade-related Climate Change Measures,” The Journal ofWorld Investment and Trade, Vol. 13, No. 6, pp. 875-927, 2012; R. Leal-Arcas “Kyoto and the COPs: Lessons
Learned and Looking Ahead,” Hague Yearbook of International Law, Vol. 23, pp. 17-90, 2010; R. Leal-Arcas“Top-down versus Bottom-up Approaches for Climate Change Negotiations: An Analysis,” The IUP Journal of
Governance and Public Policy, Vol. 6, No. 4, pp. 7-52, December 2011; R. Leal-Arcas “Alternative Architecture
for Climate Change: Major Economies” European Journal of Legal Studies, Vol. 4, Issue 1, pp. 25-56, 2011.
5
IEA, “IEA Ministerial Statement on Energy and Climate Change,”
http://www.iea.org/media/news/2015/press/IEA_Ministerial_Statement_on_Energy_and_Climate_Change.pdf.
6
As of May 2015, Norway, a non-EU country, had proposed the withdrawal of billions of dollars of investments
out of coal in order to help decarbonize the economy. It is hoped that the EU (and other parts of the world) will
follow suit. See Crouch, D. and Clark, P. “Norway oil fund plans to withdraw from coal-burning utilities,”
Financial Times, 27 May 2015, available at http://www.ft.com/intl/cms/s/0/bc336430-04b8-11e5-adaf00144feabdc0.html?ftcamp=crm/email/2015528/nbe/WorldNews/product#axzz3bJwtbM00.
7
There is still much to be done, according to the IEA, to decarbonize the energy sector. See IEA, “Track theenergy transition: Where we are, how we got here, and where we need to be,” OECD/IEA, 2015, available athttps://www.iea.org/publications/freepublications/publication/COP21EnergyTransition_DataBrief_08December.
pdf.
8Andoura, S. and Vinois, J.-A. “From the European Energy Community to the Energy Union: A Policy proposal
for the short and the long term” Notre Europe, p. 26, 2015.
9
European Commission, “Roadmap for moving to a low carbon economy in 2050,” http://eurlex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A52011DC0112.
10
For analyses of renewable energy in the EU context, see Marjan Peeters and Thomas Schomerus (eds.),
Renewable Energy Law in the EU (Edward Elgar 2014); A. Johnston, ‘The impact of the new EU Commission
guidelines on State aid for environmental protection and energy on the promotion of renewable energies,’ in T.
Sveen (ed.) EU Renewable Energy Law: Legal challenges and new perspectives (Scandinavian Institute of
Maritime Law, Marius Nr. 446, 2014); H. Bjørnebye, Investing in EU Energy Security: Exploring the Regulatory
Approach to Tomorrow's Electricity Production (Kluwer Law International 2010).
11

The 2020 climate and energy package aims to 1) reduce GHG emissions by 20% from the 1990 levels, withbinding national targets; 2) increase the share of EU energy consumption produced from renewable sources to20%, with binding national targets; and 3) increase energy efficiency to save 20% of EU energy consumption,with non-binding national objectives, all by 2020. See http://ec.europa.eu/clima/policies/package/index_en.htm.
The 2020 climate and energy Package does not address the energy efficiency target directly. This is done
through the 2011 energy efficiency plan and the energy efficiency Directive 2012/27/EU of 25 October 2012.
12
The 2030 Framework for climate and energy policies sets 1) a binding EU target of at least 40% cut in GHG
emissions below the 1990 level, with binding national objectives; 2) a binding EU target of at least 27% in
renewable energy, but non-binding national objectives; and 3) an indicative energy efficiency target of at least
27%,
with
non-binding
national
objectives,
all
by
2030.
See

Energy and the Environment (2016) 99-110

101

Roadmap. The objectives charted by the 2020 Package have so far been a success story in that
not only have they prompted the EU to significantly curb GHG emissions, enhance energy
efficiency, and foster the use of renewables, but they have also sustained the employment of
more than 4.2 million people in various eco-industries 13 and constituted a key driver behindthe 45% growth of the European economy in real terms since 1990. 14 The Union is well on
track, not only to hit its 2020 emissions and renewable targets, but to surpass them fairly
easily, whilst it should come close to its efficiency goal. 15 The great expectations arising fromthis triumphant climate and energy package have been strongly tempered by the growing
uncertainties spawned by the new 2030 Framework for climate and energy policies, which
will be analyzed in the next section.
Table 1 below compares the three decarbonization deadlines (2020, 2030, and 2050) against
the three indicators (GHG emissions reduction, energy efficiency, and renewable energy).

Table 1: EU decarbonization targets
Indicator/ Period
GHG emissions
reduction2020 Package
20% below 1990
levels2030 Framework
40% below 1990
levelsEnergy efficiency

20% improvementcompared with abusiness-as-usual
scenario
20% renewable
share of overall
energy consumption

27% improvementcompared with abusiness as-usualscenario 16
27% renewable
share of overall
energy consumption

Renewable energy

2050 Roadmap
80-95% below
1990 levels

http://ec.europa.eu/clima/policies/2030/index_en.htm and the Conclusions of the European Council of 24
October 2014 (at pp. 4-5), available at
http://www.consilium.europa.eu/uedocs/cms_data/docs/pressdata/en/ec/145397.pdf.
13
Eurostat, “Environmental goods and services sector”<http://epp.eurostat.ec.europa.eu/statistics_explained/index.php/Environmental_goods_and_services_sector>.
14
Communication from the Commission to the European Parliament, the Council, the European Economic andSocial Committee and the Committee of the Regions: a policy framework for climate and energy in the period
from 2020 to 2030, p. 2, COM(2014) 15 final (22 January 2014).
15
Ibid.
16
The European Council endorsed an indicative target of 27% improvement in energy efficiency to be reviewed
in 2020, having in mind a 30% target. See European Commission, “2030 framework for climate and energy
policies” <http://ec.europa.eu/clima/policies/2030/index_en.htm>.

102

R. Leal – Arcas: The Transition Towards Decarbonization…

Therefore, regarding the reduction of GHG emissions, the 2030 Framework is more ambitious
than the 2020 Package. The energy efficiency target under the 2030 Framework is moredaring (27%) in comparison with the 20% advocated under the 2020 Package. Nonetheless, it
is arguably more flexible in that, not only do national objectives continue to be non-binding,but even the EU target has become “indicative,” whereas, under the 2020 Package, it wasbinding at the EU level. As for the renewable energy target, it is more assertive under the2030 Framework (27%) in comparison with the 20% advocated under the 2020 Package. Thatsaid, it is looser in that, although the EU target remains binding, the national objectives haveregressed to become merely voluntary, whereas, under the 2020 Package, they were binding.
This paper discusses first the link between decarbonization and industrial competitiveness. It
then provides an analysis of the Paris Agreement on Climate Change. It concludes with someclean energy options as a possible way forward in the fight against climate change.

2.

A BALANCE BETWEEN DECARBONIZATION AND INDUSTRIALCOMPETITIVENESS 17

A new global climate regime resulted from the Conference of the Parties (COP)-21 inDecember 2015 in Paris. The road to Paris was marked by a shift from global efforts todomestic actions on climate change mitigation, as well as a move from commitments tocontributions to carbon emissions reduction. 18 It is argued that the new regime is moving
towards a voluntary national pledge and review system, which deviates from the EU’s desire
for a fully, and not partially, legally binding climate agreement, bringing the Paris deal closer
to the US’s and China’s vision of soft global governance for climate change. This puts a bigquestion mark on whether and how a soft regime could potentially achieve an atmospheric
CO2 concentration below 450 parts per million in order to limit global warming to 2 degrees
Celsius. Moreover, the International Energy Agency argues that, to keep global warming
below 2 degrees Celsius, fossil fuels would need to fall to 60% of the energy mix by 2040. 19
The EU-28 is the world’s third largest emitter of CO2 (the first two being China and the US,
respectively), accounting for around 10 per cent of total global carbon emissions. 20 Brussels
has historically been in favor of a new multilateral binding agreement, which was at least
temporarily vetoed in the COP-15 21 in Copenhagen in 2009. The EU has traditionally been
17
This section draws largely from Leal-Arcas, R. and Carafa, L. “Road to Paris COP21: Towards Soft Global
Governance for Climate Change?” Renewable Energy Law and Policy Review, Vol. 5(2), pp. 130-135, 2014.
18
See a report by Marianne Fay et al., “Decarbonizing Development: Three Steps to a Zero-carbon Future,” The
World Bank, 2015 (arguing that the actions necessary to make the transition to zero net emissions are affordable
if governments start today, but it warns that the costs will grow if action is delayed). The report lays out threesteps countries can follow to reduce net emissions of greenhouse gases to zero and stabilize climate change: Planfor the end goal, not just the short-term; get prices right as part of a broad policy package that triggers changes ininvestment and behavior; and smooth the transition for those most affected.
19
See “Oil companies and climate change: Nodding donkeys,” The Economist 14-20 November 2015, pp. 71-72,
at 71 (citing the IEA).
20
According to the latest Global Carbon Project data, the EU28 produced 3613 MtCO2 in 2013. Available at
http://www.globalcarbonatlas.org/?q=en/emissions.
21
The Conference of the Parties (COP) is the supreme body of the UN Framework Convention on Climate
Change. It comprises all the 170-plus states that have ratified the Convention. It held its first session (COP-1) in
Berlin in 1995 and meets on a yearly basis unless the Parties decide otherwise. The COP’s role is to promote andreview the implementation of the Convention. It periodically reviews existing commitments in light of theConvention’s objective, new scientific findings, and the effectiveness of national climate change programs. The

Energy and the Environment (2016) 99-110103

leading international climate policy efforts ‘by example’, i.e., through the creation of
innovative climate-energy legislation including a domestic emissions trading scheme as wellas binding 2020 targets for emissions reduction, renewable energy and energy efficiency.
In recent years, the impetus for addressing climate issues has diminished and EU decisionmakers have shifted their focus towards more short-term pressing problems, such as rising
unemployment and the Eurozone’s daunting challenges. The policy conditions that enabled
the agreement on the EU climate-energy legislative package at the end of 2008 are no longer
the same.
On 23 October 2014, EU leaders agreed upon new climate-energy targets for 2030:x

one fully binding target of 40% reduction of GHG emissions below 1990 levels. 22 The
emissions reduction target will be broken down to individual EU member states basedon their GDP per capita. This will be coupled with a structural reform of the European
carbon market.

xa weaker target of 27% renewable-energy share in the EU’s energy mix, which will
not be binding at a national level. 23 This means that member states will decide how tomeet their emissions reduction targets – for instance by opting to install additional
renewable-energy capacity, building carbon-free nuclear power plants or developing
more efficient coal-fired power plants. However, the renewable-energy target isbinding at an EU-wide level. The Juncker Commission will have to come up withconcrete policy proposals in order to clarify how such an EU-wide binding target for
renewables may work.

xa non-binding, optional target of a 27% increase in energy efficiency. A few months
ago, the European Commission had called for an efficiency goal of 30%. That waswatered down to 27%, although it could be raised to 30% by a review in 2020. 24

This agreement is very much in line with the one-binding target proposal tabled by theEuropean Commission back in January 2014. 25 But it deviates substantively from the vote of
the former European Parliament in favor of three binding targets: a 40% cut in GHG
emissions, at least 30% renewable-energy share, and a 40% improvement in energy
efficiency. 26
The key question is whether the European Council’s one-binding-target plan is appropriate
and for what purpose. The answer to this question varies according to two main benchmarks:
politics and policy.
When we take politics as a benchmark, the European Council agreement may represent a wise
move on the part of EU leaders in the light of the Paris COP-21. The Union went to Paris with
COP can adopt new commitments through amendments and protocols. In December 1997, at its third session(COP-3), it adopted the Kyoto Protocol, containing stronger emissions-related commitments for developed
countries in the post-2000 period.
22
European Council, “Conclusions on 2030 Climate and Energy Policy Framework,” EUCO 169/14, Brussels,
24 October 2014.
23
Idem.
24
Idem.
25
European Commission (2014), Communication: A policy framework for climate and energy in the period from2020 to 2030, Brussels, COM/2014/015 final.
26
European Parliament (2014), Resolution of 5 February 2014 on a 2030 framework for climate and energy
policies, Brussels, 2013/2135(INI).

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the world’s most ambitious climate targets for 2030. At a domestic level, however, the targets
will be translated into concrete policies only after the Paris summit. A final legislative
package (under co-decision rule) was initially expected for July 2015 - just in time for theParis COP-21 summit. From the outcome of the European Council, it seems clear that EU
leaders prefer to move on the legislative process only after December 2015. On the one hand,
this may give the EU a chance to concentrate on climate diplomacy efforts with China and the
US. On the other hand, arriving in Paris with just targets on paper was a risky strategy for the
EU. A good legislative proposal by the European Commission could have been a mid-way
solution.
When we take policy as a benchmark, it is a different story. If the EU’s climate policy priority
is to pursue the internationally-agreed target to limit atmospheric warming to below 2°C, a
40% cut in carbon emissions by 2030 is far from adequate – as Tyndall Centre for Climate
Change Research Deputy Director Kevin Anderson argues. 27 In an open letter to former
European Commission President Barroso, Anderson explained that “for the EU to honor its
2°C commitment the Commission must find the courage to pursue an equitable and sciencebased 2030 decarbonization target of around 80%. Anything less and the EU will renege on
its 2°C commitments and, as the Commission rightly notes, bequeath to future generations alegacy of devastating impacts”. 28
In contrast, if the EU’s climate policy priority is to guide European economies towards
sustainable growth 29 without unduly compromising industrial competitiveness, a 40% cut in
GHG emissions by 2030 is more than sufficient – as new evidence shows. 30
Brussels’s official position is that the 2-degree Celsius target is the goal for the EU 2030
decarbonization target. It maintains that the 40% target is in line with evidence of theIntergovernmental Panel on Climate Change, as it puts Brussels right on track to meet the
EU’s 2050 goal of cutting emissions by 80%-95%. 31
Within the former European Commission, a one-binding-target plan appeared to be already alow common denominator. Throughout 2014, difficult internal discussions singled out eight
different Commissioners as well as former President Barroso. Former Energy Commissioner
Günter Oettinger defended a weaker 35% target. 32 His main argument was that the EU is on
track to cut GHG emissions by 20% by 2020 mostly thanks to the economic crisis and theclosure of outdated plants in Eastern Europe. 33 As these low-hanging fruits are gone, every
percentage cut will get more difficult in the future.

27
http://kevinanderson.info/blog/wp-content/uploads/2013/12/Letter-pdf-to-President-Barroso-on-2030decarbonisation-Dec-2013.pdf
28
Ibid.
29
Beyond the EU scope, see the 2014 report by The New Climate Economy, “Better Growth, Better Climate,”
available at http://2014.newclimateeconomy.report/misc/downloads/.
30
Carraro, C. Tavoni, M. Longden, T. and Marangoni, G. (2014), ‘The Optimal Energy Mix in Power
Generation and the Contribution from Natural Gas in Reducing Carbon Emissions to 2030 and Beyond’, The
Harvard Project on Climate Agreements, Discussion Paper 14-63.
31
European Commission (2011), “A Roadmap for moving to a competitive low carbon economy in 2050,”
Brussels, COM(2011) 112 final.
32
EurActiv, “Oettinger rallies opposition to 2030 CO2 target,” 5 February 2014, available at
http://www.euractiv.com/energy/oettinger-rallies-opposition-203-news-533084.
33
Ibid.

Energy and the Environment (2016) 99-110

3.

105

THE PARIS AGREEMENT ON CLIMATE CHANGE

On 12 December 2015, a new climate change agreement of legally binding nature 34 wasreached after an intensive round of climate talks that took place in Paris in the context of the
UNFCCC. Both developed and developing countries committed to control their GHG
emissions. 35 In fact, before the conference started, more than 180 countries had submitted
pledges 36 to cut or curb their carbon emissions. 37 In addition, since countries alone cannot
solve the climate-change problem, for the first time in a COP there was the engagement of
thousands of mayors, governors, CEOs and billionaires committed to a clean energy future.
The key elements of this major deal may be summarized as follows:
x

x

x
x

x

The Agreement aims to keep the global average temperatures “well below 2 °C above
pre-industrial levels” 38 and also to “pursue efforts to limit the temperature increase to
1.5 °C above pre-industrial levels, recognizing that this would significantly reduce therisks and impacts of climate change;” 39
Parties participate in so-called intended nationally determined contributions 40 – i.e.,
pledges setting out how they plan to limit their GHG emissions during the 2020s. The
text expressly mentions that parties “shall pursue domestic mitigation measures, withthe aim of achieving the objectives of such contributions.” 41 It should be made clearthat countries will now be expected, but not compelled, to honor the individual
pledges made. This new approach makes the Paris Agreement a historic deal;
The Agreement provides that all countries have to improve their GHG emissions cutsin the future, improving their plans every five years. 42 Presumably, this process should
become easier with time as low-carbon energy becomes cheaper;
The Agreement also requires that “developed” nations (as defined by the UNFCCC)
continue to help developing countries with the costs of going green and the costs ofcoping with the effects of climate change, mobilizing $100bn a year of public andprivate finance; 43 andThe text sets out plans for a new transparency framework to see whether countries are
actually carrying out their pledges, in order to hold them accountable and inform thestocktake. The first global stocktake will be in 2023, and then “every five years
thereafter unless otherwise decided by the Conference of the Parties.” 44

Moreover, the Paris Agreement may be considered as soft law in that there is no disputesettlement mechanism. The central compliance mechanism is described in Article 15:
34

Article 20, Paris Agreement, Draft decision -/CP.21.
For an analysis of the role of major developing contries in climate change before the COP-21, see R. LealArcas “The BRICS and Climate Change,” International Affairs Forum, pp. 1-5, 2013.
36
For a summary of intended nationally determined contributions submitted to the UNFCCC, see
https://www.c2es.org/international/2015-agreement/indcs.
37
This new approach is so transformative that even Saudi Arabia, an oil empire, is committed to climate change
mitigation. Freedman, A. “For the first time, Saudi Arabia, oil empire, commits to fixing climate change,”
Mashable, 10 November 2015, http://mashable.com/2015/11/10/saudi-arabia-oil-gas/#6vgojhPj5ZqQ.
38
Article 2.1(a), Paris Agreement, Draft decision -/CP.21.
39
Idem.
40
Article 4.2, Paris Agreement, Draft decision -/CP.21.
41
Idem.
42
Article 4.9, Paris Agreement, Draft decision -/CP.21.
43
Paris Agreement, Draft decision -/CP.21, paras. 54 and 115.
44
Article 14, Paris Agreement, Draft decision -/CP.21.
35

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R. Leal – Arcas: The Transition Towards Decarbonization…

“A mechanism to facilitate implementation of and promote compliance with the45
provisions of this Agreement is hereby established.”“The mechanism […] shall consist of a committee that shall be expert-based andfacilitative in nature and function in a manner that is transparent, non-adversarial andnon-punitive. The committee shall pay particular attention to the respective national
46
capabilities and circumstances of Parties.”

The only way to pressure parties is an obligation on them, under Article 13.7, to provide thefollowing information: (a) “A national inventory report of anthropogenic emissions bysources and removals by sinks of greenhouse gases;” and (b) “Information necessary to trackprogress made in implementing and achieving its nationally determined contribution.” This
information will undergo a “technical expert review.”47 The Paris Agreement explains in
Article 13.12 the technical expert review as follows:“The technical expert review under this paragraph shall consist of a consideration of theParty’s support provided, as relevant, and its implementation and achievement of its
nationally determined contribution. The review shall also identify areas of improvement
for the Party, and include a review of the consistency of the information with themodalities, procedures and guidelines referred to in paragraph 13 of this Article, taking
into account the flexibility accorded to the Party under paragraph 2 of this Article. The
review shall pay particular attention to the respective national capabilities andcircumstances of developing country Parties.”

All of this shows that the Paris Agreement is far from offering a dispute settlement
mechanism similar to that of the WTO or other multilateral treaties.
Furthermore, in accordance with Article 21, the Paris Agreement will not enter into force until
at least 55 parties to the UNFCCC, accounting for 55 per cent of global GHG emissions, have
ratified it.
The Paris Agreement is relevant because it finalizes the paradigm shift from the binary world
created by the Kyoto Protocol (which makes a rigid distinction between Annex I and nonAnnex I countries) to the more harmonious common global framework that started to emerge
in the Copenhagen Accord. 48 Much has been discussed about the fact that the Kyoto Protocol
was doomed to fail from the very beginning precisely because it failed to foresee that many
non-Annex I countries were on their way to becoming major GHG emitters, either in absoluteor per capita terms, and yet are not legally bound by the Kyoto Protocol to reduce their GHG
emissions. 49 As the COP-21 was approaching, interesting developments happened that may
have contributed to its final success: in November 2014, President Obama of the US andPresident Xi of China met in Beijing and agreed to commit to climate change mitigation;

45

Article 15.1, Paris Agreement, Draft decision -/CP.21.
Article 15.2, Paris Agreement, Draft decision -/CP.21 (emphasis added).
47
Article 13.11, Paris Agreement, Draft decision -/CP.21.d
48
See Leal-Arcas, R. Climate Change and International Trade, Edward Elgar, 2013, chapter 4.
49
For instance, China is, since the late 2000s, the major GHG emitter in the world. Qatar, Brunei, and Singapore
are among the richest countries in the world per capita, and yet are treated as developing countries for the
purposes of the annexes in the UNFCCC and the Kyoto Protocol. For an analysis and critique of the Kyoto
Protocol, see Leal-Arcas, R. Climate Change and International Trade, Edward Elgar, 2013, chapters 5 and 6.
46

Energy and the Environment (2016) 99-110

107

Pope Francis spoke openly and passionately about the importance of mitigating climatechange. 50
From an EU perspective, the Paris COP-21 was a key test-case for the Juncker European
Commission. Clearly, the EU needed to get the US, China and other emerging economies onboard. The EU’s climate strategy posed a big question mark for the Paris global climate deal:
sprint now and maintain atmospheric warming to below 2 degrees Celsius? Or keep economic
competitiveness and sprint later? The new climate-energy targets for 2030 seek to strike abalance between a credible decarbonization policy and a sustained industrial competitiveness.
Such a start-now-and-sprint-later approach certainly had an impact on the COP-21. Theinternational community knows very well that countries cannot expect the whole world tostop emitting GHGs, given how important fossil fuels are today to the way our economies
work. 51 Yet, it needed an effective agreement on climate change mitigation, in which theinternational community would agree on the following: (1) subsidies for fossil fuels will needto eventually disappear; 52 (2) countries will reduce their carbon emissions at their own paceand in their own way; and (3) countries will measure their performance on carbon emissions
reduction.
Now that the Paris Agreement makes reference to limiting the temperature increase to 1.5 °C
above pre-industrial levels, the EU’s 2050 roadmap would need to be re-visited and adapt inaccordance with this more ambitious goal than was the case before the pre-Paris Agreement.
Here is the chance for the EU to lead in sustainable energy and for the rest of the world tofollow.

4. CONCLUSION
A promising advancement is the European Energy Union’s commitment to phase out
environmentally harmful subsidies altogether. Continuing to fund fossil fuels within Europe
would be counterproductive, not only in the light of the EU’s ambitious energy and climate
goals, 53 but also in that it would delay the arrival of new technologies. Therefore, redirecting
these subsidies to support low-carbon technologies and digital energy innovation represents asensible change of course.
Beyond the EU context, there is a new initiative of visionary billionaires determined toprovide energy that is reliable, affordable and carbon-less. The initiative is called“Breakthrough Energy Coalition.” 54 The European Energy Union could and should join
forces with this coalition that is currently working with a growing group of visionary
countries towards joint research to make sure that this project becomes a reality. Another way
to help mitigate climate change is through energy storage, which offers many benefits such as
reduced costs and increased profits. Moreover, yet another initiative called Mission

50

Pope Francis, Praise Be to You – Laudato Si’: On Care for Our Common Home, Ignatius Press, 2015.
“Hopelessness and determination,” The Economist, 19 December 2015, pp. 16-18, at 16.
52
See the Fossil-Fuel Subsidy Reform Communique, in which eight countries (known as the Friends of Fossil
Fuel Subsidy Reform) are calling for the phase-out of subsidies to fossil fuels. Available at
http://www.iisd.org/sites/default/files/publications/FFSR_Communique_17_4_2015.pdf.
53
The leaders of the G7 (Canada, US, UK, France, Italy, Germany, and Japan) have the ambition to phase out
fossil fuel emissions in the 21st century. See Clark, P. and Wagstyl, S. “G7 leaders agree to phase out fossil
fuels,” Financial Times, 8 June 2015.
54
To access their principles, see http://www.breakthroughenergycoalition.com/en/index.html.
51

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R. Leal – Arcas: The Transition Towards Decarbonization…

Innovation 55 brings together a group of 20 countries 56 that aim to reinvigorate and accelerateclean energy innovation throughout the world to make clean energy affordable for all. The
European Energy Union should also join forces with this initiative. 57
What needs to be done now that we have the Paris Agreement on Climate Change? Privateinternational law will be important in renewable energy. Moreover, funding from emerging
markets will be crucial. Furthermore, more international cooperation will be necessary: there
is now more funding tan even ($100 billion/year from 2020), but the details are not there yet.
In that sense, the Paris Agreement was an agreement to agree. In addition, the implementationof the Paris Agreement will be crucial: the focus of Paris Agreement was on the so-called
intended nationally determined contributions, where countries need to increase their ambitions
and review them every five years.
On clean energy, there are reasons to be optimistic because the options for the future areabundant. Wind turbines and solar panels are proliferating across Europe, India, 58 China andthe US, albeit they are barely restraining CO2 emissions. Wind power projects on a massive
scale are underway in the North Sea and so are projects to bring solar energy produced in the
Saharan desert to southern Europe. 59 An increasing number of developing countries isinvesting in renewable energy out of their own initiative, not because they are legally boundto do so. There are positive examples of countries that have climate change laws in place (onGHG emissions reduction) even if they are not a party to the UNFCCC (e.g., Taiwan) or an
Annex I country (e.g., Mexico).
More R&D spending on energy technologies would be necessary to decarbonize the economy.
Solar energy could become cheaper thanks to new materials and assembly technologies. 60 The
potential of solar energy is phenomenal: solar energy today is only 0.3% of global energy.
Yet, one hour of sun can generate energy for the whole Earth for an entire year; 61 or put it
differently, in 14.5 seconds, the sun emits enough energy to power the Earth for an entire
day. We could power the entire world if we covered less than 3 per cent of the Sahara Desert
with solar panels. 62 The whole of Europe could be powered if we covered 0.3% of the Sahara
Desert with solar collectors. 63 Countries will need better ways of storing and trading
renewable energy via large mega-grids. Geoengineering could be further developed to55

http://mission-innovation.net/.
http://mission-innovation.net/countries/.
57
Efforts to do so on the part of the EU and other OECD partners are already visible. See European
Commission, “The EU and other OECD partners agree on trade measures supporting cleaner energy,” 18
November 2015, available at http://trade.ec.europa.eu/doclib/press/index.cfm?id=1401.
58
See for instance Sivaram, V. et al., “Research for the Sun: How India’s Audacious Solar Ambitions Could
Make or Break its Climate Commitments,” Stanford Steyer-Taylor Center for Energy Policy and Finance,
available at https://www-cdn.law.stanford.edu/wp-content/uploads/2015/12/Reach-for-the-Sun-High-ResolutionVersion.pdf.
59
Morocco is currently building one of the largest solar plants in the world and hopes to export power to Europe
in the future. See “Nuclear power in the Middle East: Wasting energy,” The Economist, 28 November 2015, p.
57.
60“Clear thinking needed,” The Economist, 28 November 2015, pp. 13-14.
61“Solar Frontiers,” The Economist, http://films.economist.com/.
62
See Zakaria, F. “The GPS Road Map for Powering America,” CNN, Aired on 21 October 2012, available at
http://transcripts.cnn.com/TRANSCRIPTS/1210/21/cp.01.html.
63
Smith, D. “Solar Collectors Covering 0.3 Percent of the Sahara Could Power all of Europe,” Popular Science,
22 June 2009, available at http://www.popsci.com/environment/article/2009-06/solar-collectors-covering-03sahara-could-power-all-europe.
56

Energy and the Environment (2016) 99-110

109

mitigate climate change. 64 The greatest result of investing in low-carbon technologies will be
to become increasingly energy independent. So there is hope and great business opportunities.

64
Leal-Arcas, R. and Filis-Yeloghotis, A. “Geoengineering a Future for Humankind: Some Technical andEthical Considerations,” Carbon and Climate Law Rev, Vol. 6(2), pp. 128-148, 2012.

110

R. Leal – Arcas: The Transition Towards Decarbonization…

TRANZICIJA PREMA DEKARBONIZACIJI: ISTRAŽIVANJEPRAVNOG I ZAKONODAVNOG OKVIRA EUROPSKE UNIJE
Sažetak: dekarbonizacija je krajnji i vizionarski cilj energetske politike Europske Unije (EU).
(8 MH WUDGLFLRQDOQR GRQRVLOD þYUVWH RGOXNH X SUHJRYRULPD R NOLPDWVNLP SURPMHQDPD6XNODGQRWRPH(8VHQDGDüHSRVOXåLWLNDRSULPMHUNRMHJüHVOLMHGLWLLGUXJHUHJLMHVYLMHWD
2YDM VH þODQDN EDYL UDVSUDYRP GD RYDNR VYHREXKYDWDQ SODQ PRåH X]URNRYDWL QRYXLQGXVWULMVNX UHYROXFLMX NRMD EL VH WHPHOMLOD QD þLVWLP L QLVNRXJOMLþQLP WHKQRORJLMDPD NRMH EL
mogle ubrzati ekonomski oporavaN(8LRPRJXüLWLSUHOD]DNQDRGUåLYHHQHUJHWVNHVXVWDYH,]
WRJ VL MH UD]ORJD (8 SRVWDYLOD NUDMQML FLOM VPDQMHQMD HPLVLMH VWDNOHQLþNLK SOLQRYD ]D YLVRNLK
80-95% ispod razina iz 1990. godine, do 2050. godine. Ovaj dekarbonizacijski cilj nosiRGUHÿHQHWURãNRYHSDVHKRWHOLMHUVNLPUMHþQLNRPPRåHUHüLGDMHKRWHOVSHW]YMH]GLFDSXQR
bolji, ali i skuplji od hotela s jednom zvjezdicom. Prema tome, obnovljivi izvori energije su
SXQR EROML DOL L VNXSOML RG NRULãWHQMD XJOMHQD ýODQDN ]DNOMXþXMH GD MH SRWHQFLMDO VXQþHYH
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.OMXþQH ULMHþL dekarbonizacija, Pariški sporazum o klimatskim promjenama, EU sustav
WUJRYDQMDHPLVLMDPD]UDþQLSURPHWWUDQVSRUW

2. KONFERENCIJA

Energy and the Environment (2016) 111-122

111

BIOMASS BASED CHP PRODUCTION WITH STIRLING ENGINE
Bálint KatonaBsc, BUTE, Dep. of Energy Engineering, 1111 Budapest, Muegyetem rkp. 3.,
katona94@gmail.com
Tamás Lazamechanical engineer, +36-1-463-1762, laza@energia.bme.hu
Abstract: Using of renewable energy sources is becoming increasingly important, because
fossil fuels are dwindling continuously and occur unequally around the Earth. To replacefossil fuels, using of biomass is an advantageous solution and it even has got a huge potential.
The most effective way to gain energy from it is produce heat and power at the same time.
There are several methods to produce these two kinds of energy together and one of these is
the combined heat and power production with Stirling engine, which is less common andresearched than the other ones. The aim of this paper is to explore and estimate the forestry
waste of a Hungarian subregion and suffice the heat and power demands of a small village
located in it using a Stirling engine as the part of the technology.
Keywords: Small-scale CHP, Stirling engine, biomass, residential district heating

1

INTRODUCTION

Of all the renewable energy sources biomass is prominent and plentiful [1]. As theseenergy sources are coming into view, they redound the diversification of the power
generation. Small-scale CHP systems are offering a grate solution in this subject, because
they can save 20-28% primary energy compared to produce heat and power separately [2]. In
this paper, a Hungarian village near Kaposvár and the surroundings of it will be analyzed.
There can be find large forestry areas and the forestry waste of them could be used for energy
production. The most obvious utilization of them is direct combustion with a Stirling engine.
In case of internal combustion engine or gas turbine biomass must be turned into biogas
which is a complicated process and steam turbines are not cost effectives in this size. With the
produced heat the heat demand of the chosen village would be sufficed by a district heating
system. The demand would be specified previously. The electricity, which is a by-product of
the technology, may cover a significant part of the electricity demand of the village. Due tothe properties of the engine, the system can operate with other kind of fuels, like biomass
from agriculture, therefore it can be used in other regions with different vegetation. Another
Hungarian subregion (Pápa) has been examined previously from the side of biogas basedenergy supply by agricultural by-products [3]. Now we skip the conversion of biomass into
biogas and the starting materials are also different.

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B. Katona,T. Laza: Biomass Based CHP Production with…

TECHNOLOGICAL OVERVIEW

2.1 The Stirling engine
In the last decades the Stirling engine has been the subject of great researches, although thefirst one was built in 1818. The reason of development is that the engine can utilize therenewable energy sources with good efficiency. On the other hand, this is the only usefultechnology for solid biomass fueled small-scale CHP production in this size. The working
gas, which circulates in an internal, closed cycle can be air, hydrogen or helium and none ofthese are toxic. The mean pressure of them is much smaller than in case of conventional
prime movers, therefore it is safer. It is an external combustion engine, thus it can operatewith almost any kind of external heat sources, included solid, liquid, gaseous materials, waste
heat, geothermic, chemical, nuclear and solar energy. Because of this, the combustion is more
perfect, continuous and results less CO, NOx, soot, etc. Environmentally this means a great
advantage.
The main parts of the appliance are the pistons, displacer and the heat exchangers: theheater, regenerator and cooler. There are four phases of the ideal Stirling cycle:
x The working gas is compressed to higher pressure by the work piston. The
compression takes place at the constant lower temperature TC. The cooler power
thus exits the cycle from the colder space. Heat is rejected and work is supplied(between points 1 and 2).
x The displacer piston displaces the gas from the colder space to the hotter space. The
gas is heated to the higher temperature TE in the regenerator (between 2 and 3). The
heating takes place at a constant volume since the work piston is not moving.
isx The gas is expanded at the constant temperature TE and thus the heater power
imported to the cycle (between 3 and 4). The work piston moves down. Heat is
supplied and work produced.
x The gas is displaced (by displacer) to the colder space through the regenerator andtemperature TC (between 4 and 1). The cooling process takes place at a constantvolume, because the work piston is not moving. The gas is cooled and heat is stored
into the regenerator [4].
The area defined by the cycle on the p-V diagram represents the work done. The rate of it
and the input heat means the theoretical efficiency. In this case it equals to the Carnot
efficiency [4]. 3 main types of the engines can be distinguished by operation: Į ȕ DQG Ȗ
Compared to the Ȗ W\SH WKH Į W\SH GRHV QRW FRQWDLQ GLVSODFHU DQG LQ WKH ȕ W\SH WKH ZRUN
piston and the displacer are placed in the same cylinder.

Energy and the Environment (2016) 111-122

113

Fig.1. The ideal (continuous line) and the real Stirling cycle (dashed line)in the Stirling engine [4]In case of solid biomass combustion in Stirling engines, the biggest problem is the foulingof the hot side heat exchanger, because it reduces the heat transfer surface. It is caused by theash generated during the combustion. The problem becomes significant above 1200 °C in caseof wood firing, since this is the melting point of the ash. If energy grass is used, this value islower, 640 °C [5]. The solution is the proper shaping and cleaning of the combustion
chamber. In result of an Austrian cleaning system development, the electric efficiency of theengine increased from 20% to 27% and the overall electric efficiency of the CHP plant from
9,2% to 13% [6]. Further researches and developments are required in connection with theengines, which will result more reliable, more efficient and cheaper units in the near future[7].

2.2 Biomass CHP plant
The main goal of the small-scale CHP plants regardless of the type of the prime mover is
to suffice the heat demands. The electricity is only a secondary product, therefore it is not thebasic of the sizing. Generally, the electricity production of small-scale CHP plants is around15-100 kWe [1]. The smaller micro CHP plants are producing 1-3 kWe power and5-15 kWth heat [2]. Figure 2 shows the schematic of a biomass based CHP plant operatingwith Stirling engine. The combustion is realized in a two stage design to achieve low NOx
emission. The temperature of the flue gas is about 950 °C before it goes through the hot heatexchanger, which is typically between 750 °C and 790 °C. Then it gets to the air pre-heaterand the economizer. At the end of the process, the temperature of the flue gas is 120-150 °C
and the cooling water is heated up to 55-75 °C depending of the cooling circuit [6]. This is thewater used for district heating and the heat consumer is the village itself. The produced poweris also used up by the village, but the system cannot follow the changes of the electricity
demands.

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B. Katona,T. Laza: Biomass Based CHP Production with…

Fig. 2. The applied CHP plant [6]If there is economical possibility, it is worth to suit a thermal energy storage into thesystem, which could store a large quantity of thermal energy for a couple of hours. The heat
demands of the houses would be equalized and it would mean steady operation of the engines.
A CHP unit with an appropriately sized thermal storage system can cover the overall thermalenergy demand while saving 15-45% of primary energy [8]. Considering the electrical energy,
the economic viability of the system can be increased significantly. The sizing andoptimization are complex problems and done with different software. Results of several
researches of smaller systems can be find in Ref. [8].

3INTRODUCING CSERÉNFA AND THE REGION

The reason behind choosing this subregion of Hungary for our work was that we wanted toutilize biomass in forestry regions. The area is located in the east side of Somogy County as it
can be seen in Fig. 3. The village is between two cities, Kaposvár and Dombóvár, 15 km fromthe capital of the county. It can be easily approached from main roads and forestry roads,
which is important because of the fuel transportation. The area ratio of the forests in Somogy
County is among the greatest in the country, 32% of it is covered by them [9]. Around
Cserénfa this number is even bigger, 56%. This is considerably higher than the national
average. Our aim was to choose a small township, thus there are 84 houses in the village,
which lies on 1775 ha and the number of the residents is 219. None of the residential houses
are connected to the sewer system, so the sewage drainage is solved by individual systems
everywhere. Regarding to the residential houses, they are all one-storey, old buildings, only
10 of them was built in the last 25 years [10].

Energy and the Environment (2016) 111-122

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Fig. 3. The location of the village

The power consumption of the settlement can be called average compared to other similar
villages, it was 200 MWh in the last years in average. However, the natural gas consumption
is less than the national average. This is because in 2014 58 from 84 houses had natural gas
heating [10]. In the rest of the houses probably there was wood heating. Because of this theheat demand of the village cannot be estimated with sufficient accuracy using these data, so
another method was used. Figure 4 shows the natural gas and electricity consumption of thevillage in the last decade. The diagram represents only the residential houses, since they are to
be sufficed. According to the diagram there was no big change in the last few years, but
compared to 2005 a great decrease can be seen. This is likely the effect of the financial crisis
in 2008, and the continuous population decline. The notable vacillation of the gas
consumption is due to the changing of gas prices and average winter temperatures which
determine the heat demands.

Fig. 4. Energy consumption of the village [10]

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B. Katona,T. Laza: Biomass Based CHP Production with…

HEAT DEMAND AND WOOD POTENTIAL

4.1 Heat demand of the village
Average data was used to calculate the heat demand. It is known that the average floor areaof the houses is 95 m2. From the viewpoint of insulation, the houses are quite underdeveloped.
65% of them was built before 1970 and 45% of them even before 1960 [10]. According to a
furnace sales company’s sizing data, in case of badly insulated houses the heat output demand
per airspace is 60 W/m3 [11]. Thus the estimated required heat using equation (1) is
1,25 MWth.
(1)
where: C
Ahousehnhousethe heat output demand per airspace [W/ m3]
average floor area of one house [m2]average inner height [2,6 m]
number of residential houses [-].

This value could be decreased to 1 MWth by an 8 cm thick insulation, but the current state
was taken into consideration. The hot water output demand was calculated according to theaverage hot water consumption per capita, using Ref. [12]. The required hot water output is
210 kWth. Stirling engines operate with better efficiency when their temperature andperformance is higher [6]. Thus 1 MWth thermal output Stirling engines are planned tooperate in all with high load, which is 70% of the maximum heat demand. The remaining heatis supplied on the coldest days by a simple 350 kWth furnace, approximately for 350 hours,
because cumulatively the third of the hot water output is used in sizing [12]. The fuel of thefurnace is also wood, but this part of the system would not produce electricity in this period.
In heat demand calculation
specific heat demand indicator was used. The heating
period lasts from October 15 to April 15, which means 4368 hours. It is usually influenced by
the weather. Based on equation (2), the heat demand is 10,8 TJ/a. The hot water demand is
added to this, which is 6,6 TJ/a according to equation (3).

(2)(3)
where:
ĲH
qh
ĲHW

heat output demand [MW]heating time [s]specific heat demand indicator [-]hot water output demand[MW]hot water using time [s].

So the overall heat demand of the village is 10,8+6,6=17,4 TJ/a, which is planned to satisfy
with the biomass potential and the appliances. It has to be mentioned, that it is an upper limit,
there are smaller values in practice because of the heating and money saving habits. The
estimated heat demand of the village from natural gas consumption is 13,8 TJ/a.

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4.2 Wood potential of the subregion
The fuel of the different CHP systems including Stirling engines can be quite varied.
Cserénfa and its subregion are forest-rich areas, which clearly leads to use forestry waste forenergy production. In case of direct combustion of wood in Stirling engine the preparation is
simpler and needs less energy than gasification, so the potential is examined from this point ofview [13]. Specifying the available biomass potential first we focused on the quantity of thewood, then the heating value and at last the moisture content of it. Economically it is not
worth to transport biomass fuel from further than 20 km. Therefore, we collected the forestry
areas in a circle with 15 km radius around the village sorted by tree species according to amap made by the National Forestry Directorate. In Somogy the forestry areas are 171 837 ha,which means 37 989 thousand m3 live wood stock (2013 data, [9]). The forestry areas in thechosen subregion are 39 703 ha altogether. As there is equal living wood quantity on eachhectare with similar type of forests, the estimated living wood stock of the subregion is8777 thousand m3. 2,06% of the trees is the gross logging capacity in Somogy, namely
181 thousand m3 wood in the subregion. Table 1 shows the area, the volume, the heating
value and the density of the different tree species.
Table 1.
Main properties of the typical tree species [14]Area [ha]Volume [m3]
LHV [MJ/kg]
Density [kg/m3]
Oak
8631
39300
18,2
730
Beech
6905
31440
18,1
720
Turkey oak
1439
6550
18,1
765
Locust tree
12659
57650
17,5
790
Other leafy
10070
45860
~17,5
~600
Many parts of the cut tree can be used for energy purposes. First of all, the logging residue
can be utilized, which is the difference of the gross and the net logging capacity. This means
branches, twigs, and bark at the place of the logging. According to a forestry company’s
information in Somogy, the logging company collects the waste-like wood with hand or
machines, and after 2-6 month of drying, they chop up and sell it. The quantity of it in
Hungary was 14% of the gross logged capacity in 2011 [15]. After drying, the heating valueof the logging residue is almost equal to the firewood, however before drying it is slightly lessthan the moist firewood’s. The next option is firewood. In Hungary the quantity of it waslarger than the industrial wood’s quantity in the past few years. In 2011 it was 49% of thegross logging capacity [15]. Thirdly the timber industry’s by-products can be utilized. These
are usually sawdust and pieces of wood, which can be the 20% of the industrial wood [16].
The sawdust can be mixed with firewood and burned directly or pellets, briquettes can bemade out of it. The average ratio of different products of wood processing is shown in Fig. 6.

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B. Katona,T. Laza: Biomass Based CHP Production with…

Fig. 5. Products of wood processing [16]The freshly cut wood contains 45-50% moisture. This means half of the air-dry wood’s
heating value, which has 8-15% moisture content. 10% moisture content surplus can result-2 MJ/kg reduction in heating value [5]. The wood must be dried in the open air for 2 years
before burning. The aim is to achieve 10-15% moisture content, which is worth to fuel with.
In Table 1 the heating values belong to absolute dry wood. The moisture content of wood is a
top priority, the drying and steady supply of dry wood must be ensured. From combustion
technological reasons it has to be mentioned, that the absolute dry wood’s organic material iscellulose, the inorganic substances of it are potassium, phosphorus and the compounds of lime
and iron. The wood consists of 51% carbon, 42% oxygen, 6,3% hydrogen, 0,1% nitrogen,0,3% ash, 0,3% other [5].
During the drying unlike the mass of the wood, the volume of it practically does notchange. Hence we collected the average density of the tree species in air-dry state to get themass of the usable wood after drying. Then we reduced all the heating values by 2 MJ/kg to
get the air-dry state. At the other leafy trees, we counted with the average value of soft woods.
After this, we got the actually usable biomass potential. As a result, the total gross logging
capacity around 15 km of the village is 129 thousand tons, whereof the logging residue is
18 thousand tons, the firewood is 63 thousand tons and the timber industrial by-product is
11 thousand tons. After multiplying them with the heating values, the energy content of themare 286 TJ, 1001 TJ and 174 TJ. These values are an order of magnitude higher than the heat
demand of the village (17,4 TJ/a).

5

USE OF THE SMALL-SCALE CHP SYSTEMAs the numbers show, the wood biomass potential in the subregion’s forests can plentifully
suffice the heat demands. Our primary aim is to utilize the by-products of course, so logging
residues and timber industrial by-products would be used. The clean, dry wood from thetimber industry is a suitable raw material of pellets and briquettes, which has excellent
combustion technological properties [5,17]. The village is placed near to Kaposvár, so it could
use the by-products of many wood companies. However, this is an energy-intensive andexpensive process, thus it could be worth if a briquetting plant would be established nearby.

Energy and the Environment (2016) 111-122

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The residues generated by logging are sold to the people, or to smaller plants as fuel by theforestries. Although only the logging residue would be enough to suffice the heat demand of
the village, it must not be forgotten that there are 24 more municipalities, including the capitalof the county. These towns and villages could also claim the wood as fuel or industrial raw
material. Therefore, we decreased the size of the area and according to our calculations it
would be enough to collect the logging residues from a circle around the village with a radiusof 4,5 km. To supply the village continuously, the quantity of warehoused wood should bespecified. Using equation (4), the needed quantity of wood is 360 m3/h, with average heating
value and 79% thermal efficiency [18]. In the non-heating season this value is 60 m3/h. Thesewood volumes must be ensured to suffice the maximum heat demands at any time.

(4)
where:
ȘthLwvolume of the wood [m3/h]
maximum heat demand [MW]thermal efficiency of the plant [-]heating value of the wood [MJ/m3]

Owing to the German, Austrian, and Danish researches in the recent years, many bigger
CHP plants based on Stirling engines have been tested and become available with various
performances [6,13,17,19]. One of the biggest plants operates with chopped wood. It is basedon an 8 cylinder Stirling engine and besides 475 kWth heat it can produce 75 kWe power from640 kWth fuel [18]. This means 11,7% electrical efficiency at peak load, which is not differ
significantly in case of partial load after reaching the steady state [20]. The efficiency valuesof this engine was used in calculations. If we calculate with peak utilization, the heating
operates for 3111 hours and the hot water supply for 8760 hours. So the annual electricalenergy production of the plant is 2,75 TJ, i.e. 764 MWh. It is almost four times more than theresidential demand. The production however does not follow the electricity demands. In caseof peak periods with high power demand or low heating demand periods electricity must be
imported from the national grid. If the produced electricity is more than the actual demand, it
can be used for public buildings, public lighting or it can be sold to the grid. The income fromthe selling is heavily dependent on the actual production period’s feed-in tariff.

6 CONCLUSION
In this paper we examined the energy aspects of a Hungarian village. Our aim was tosuffice the energy demands with a district heating system based on CHP production. The
plant is supposed to operate with Stirling engine, which offers the most favorable solution inthis size in case of solid biomass fuel. First we specified the electricity, heat demand and the
maximum thermal output demand in the village. Then we sized up the biomass potential of
the surroundings. Because of the dominance of the forests in the region, it was evident torealize wood based energy production. Therefore, we collected the by-products of woodprocessing, which are worth to use for energy purposes, and the energy content of them. We

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B. Katona,T. Laza: Biomass Based CHP Production with…

discovered that it is enough to collect the logging residues from a few kilometers around thevillage to suffice the heat demands. This provides enough electric energy to the village,
except in the peak periods. The system is also able to operate with agricultural residues, so it
can be applied in other type regions. The paper revealed that there are huge potentials inbiomass as a renewable energy source in Hungary. Regions in other countries with similar
natural circumstances should also consider that in the future these CO2 neutral sources should
be an even bigger part of the energy mix.

7

REFERENCES[1]

Dong L, Liu H, Riffat S: Development of small-scale and micro-scale biomass-fuelled
CHP systems –A literature review, Applied Thermal Engineering 2009, 29:2119–2126[2]

Gróf Gy: Micro-CHP technologies and potentials, HEEP 2015, Pécs, 27-29 May 2015[3]

Ihász R, Laza T: Determining the biogas potential of agricultural by-products in a
Hungarian subregion, WIREs Energy Environ, 2016. doi: 10.1002/wene .219

[4]Kuosa M, Kaikko J, Koskelainen L: The impact of heat exchanger fouling on the
optimum operation and maintenance of the Stirling engine, Applied ThermalEngineering 2007, 27:1671–1676[5]

Bíró B: Biomassza hasznosítás. Digitális Tankönyvtár, 2012.
http://www.tankonyvtar.hu/hu/tartalom/tamop412A/20100017_11_biomassza/index.html (accessed: 2016.07.29.)[6]

Marinitsch G, Biedermann F, Carlsen H, Bovin JK, Schöch M, Obernberger I:
Development of a hot gas heat exchanger and a cleaningsystem for a 35kWel hermetic
four cylinder Stirling engine for solid biomass fuels, http://www.bios-bioenergy.at(accessed: 2016.07.19)[7]Thombare DG, Verma SK: Technological development in the Stirlingcycle engines,
Renewable and Sustainable Energy Reviews 2008, 12:1–38[8]

Murugan S, Horák B: A review of micro combined heat and power systems forresidential applications, Renewableand Sustainable Energy Reviews 2016, 64:144–162[9]

Vajda Gy, Kassai L, Lakatos I, Pári A, Valentovics É, Varga É: Területi statisztikaiévkönyv, 2013, KSH, Budapest, 2014[10] telir.hu. 7HOHSOpVLDGDWJ\ĦMWĘ, https://www.teir.hu/rqdist/main?rq_app=teldata(accessed: 2016.07.21.)[11] tibo.hu. 6]NVpJHVIĦWĘWHOMHVtWPpQ\, http://www.tibo.hu/hogyan-valasszunkfutokeszuleket (accessed: 2016.07.28.)[12] Egri I, Gyurcsovics L, Magyar Z, Szikra Cs, Viczai J: Komplex tervezési segédlet, 2016.
03.24.

Energy and the Environment (2016) 111-122

121[13] Cardozo E, Erlich C, Malmquist A, Alejo L: Integration of a wood pellet burner and a
Stirling engine to produce residential heat and power, Applied Thermal Engineering
2014, 73:671-680[14] Tóth P, Bulla M, Nagy G: Energetika, Digitális Tankönyvtár, 2011.
http://www.tankonyvtar.hu/hu/tartalom/tamop425/0021_Energetika/adatok.html(accessed: 2016.07.29.)[15] Molnár S: A bruttó-nettó fakitermelés és az apadék változása az elmúlt 20 évben,FATÁJ-Online, 2013.03.07. http://www.fataj.hu/2013/03/071/201303071_brutto-nettofakitermeles-es-az-apadek.php (accessed: 2016.07.25.)[16] Ádám B: Energiaellátás, alternatív energiaforrások hasznosítása, Digitális
Tankönyvtár, 2011, http://www.tankonyvtar.hu/hu/tartalom/tamop412A/20100019_Energiaellatas_alternativ_energiaforrasok_hasznositasa/ch07s05.html (accessed:
2016.07.29.)[17] Damirchi H, Najafi G, Alizadehnia S, Ghobadian B, Yusaf T, Mamat R: Design,
Fabrication and Evaluation of Gamma-Type Stirling Engine to Produce Electricity
from Biomass for the micro-CHP system, Energy Procedia 2015, 75:137–143[18] Biedermann F, Carlsen H, Obernberger I, Schöch M: Small-scale CHP Plant based on
75 kWel Hermetic Eight Cylinder Stirling Engine for Biomass Fuels – Development,
Technology and Operating Experiences, 2nd World Conference and Exhibition on
Biomass for Energy, Industry and Climate Protection, May 2004, Rome, Italy, pp.17221725, ETA-Florence (Ed.)[19] García D, González MA, Prieto JI, Herrero S, López S, Mesonero I, Villasante C:
Characterization of the power and efficiency of Stirling engine subsystems, Applied
Energy 2014, 121:51–63[20] Cacabelos A, Eguía P, Míguez JL, Rey G, Arce ME: Development of an improved
dynamic model of a Stirling engine and a performance analysis of a cogeneration plant,
Applied Thermal Engineering 2014, 73:608-621

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B. Katona,T. Laza: Biomass Based CHP Production with…

KOGENERACIJA NA BAZI BIOMASE SA STIRLINGOVIM
MOTOROM
Sažetak: Korištenje obnovljivih izvora energije postaje sve važnija tema uslijed smanjenja
SULURGQLK]DOLKDIRVLOQLKL]YRUDHQHUJLMHNRMLVHWDNRÿHUQDOD]HLQHUDYQRPMHUQRQD=HPOML6D
VWDMDOLãWD HQHUJHWVNH XþLQNRYLWRVWL QDMSRYROMQLMH MH UMHãHQMH ]D SURLzvodnju toplinske i
HOHNWULþQH HQHUJLMH X LVWR YULMHPH W]Y NRJHQHUDFLMD 3RVWRML QHNROLNR QDþLQD ]D SURL]YRGQMXRYLKGYLMXYUVWDHQHUJLMH]DMHGQRDMHGDQRGQMLKMHSRPRüX6WLUOLQJPRWRUDNRMLMHUMHÿHX
primjeni i slabije istražen od ostalih vrsta motora. Velika prednost Stirling motora u odnosu
na druga rješenja je da može proizvesti kombiniranu toplinu i energiju iz gotovo bilo koje
YUVWH L]YRUD HQHUJLMH XNOMXþXMXüL REQRYOMLYH 6WRJD MH ORNDOQR GRVWXSQD ELRPDVD SRYROMQL
energent kao gorivo za motor. 8VNODÿLYDQMH VD ]DNRQVNLP UHJXODFLMDPD HPLVLMD SRPRüX
posebno razvijenog ložišta u ovakvom sustavu je pojednostavnjeno, jer vanjsko izgaranje jesavršeniji proces nego unutarnje izgaranjem u tradicionalnim benzinskim ili dizel motorima.
U ovom radu ispitaQD VX SRGUXþMD X MXåQRM 0DÿDUVNRM ]D NRULãWHQMH RYDNYRJ VXVWDYD 2YRSRGUXþMH VH QDOD]L X RNUXJX 6RPRJ\ NRMH MH EUHåXOMNDVWR L XJODYQRP SUHNULYHQR ãXPDPD
Raspoloživa biomasa ovdje nastaje uslijed šumarstva i drvne industrije koja se nalazi oko 30
km od odabranog mjesta. Stoga je važan cilj istražiti izvore biomase te drvnu industriju u
SURPDWUDQRMUHJLML1DVHOMHNRMHDQDOL]LUDPRXQDãLPL]UDþXQLPDMHSURVMHþQHYHOLþLQHPDORVHOR X RYRM UHJLML V RNR VWR NXüD 3UYL FLOM MH RGUHGLWL SRWUHEQX NROLþLQX WRSOLne i zadovoljiti
potrebu za toplinom promatranog naselja. U tu svrhu malo kogeneracijsko postrojenje treba
ELWL GL]DMQLUDQR 2VLP SRWUHEQH WRSOLQH PRåHPR SURL]YHVWL L HOHNWULþQX HQHUJLMX VD 6WLUOLQJPRWRURP X VXVWDYX 2YDM VXVWDY MH WDNRÿHU VSRMHQ L QD HOHNWULþQX PUHåX þLPH PRåHPR
VPDQMLWLHOHNWULþQHWURãNRYHQDVHOMD.OMXþQH ULMHþL: Mala kogeneracijska postrojenja, Stirling motor, Obnovljivi izvori energije,
Stambeno daljinsko grijanje

Energy and the Environment (2016) 123-134

123

BIOGAS FACILITIES AS A CARBON SINKS WITH THE PRODUCTION OF
NEW MATERIALS WITH LOW CARBON FOOTPRINT'LQNRĈXUÿHYLü
Energy institute Hrvoje Požar, Savska 163, Zagreb, 01/6326-145, ddurdevic@eihp.hr
Abstract: Process of anaerobic digestion (AD) produces biogas as a renewable fuel which
has many advantages - not only before fossil fuels, but also before other renewable sources
because of its possibility of storage and as a supstitute for natural gas. Except its possibility
for reducing greenhouse gas emissions through replacement of energy from fossil fuels, theprocess laso produces a product called digestate, which presents a large problem in a biogas
production facility. With the use of digestate, it is possible to solve that problem and produce
a valuable raw material for various industries (such as construction, biotechnology andenergy industry). This paper presents the use of digestate in said industries, which leads toreduce of burden on environment with the use of digestate, i.a. the reduction of CO2 emissions
with the storage in a cellulosic material.
Key words: anaerobic digestion, digestate, industry, biogas
1. INTRODUCTION
The process of anaerobic digestion (AD) produces two products: biogas – a renewable fuelfrom biomass, and digestate – the fermented remain of organic matter. AD is aimed towards
production of biogas as a main source of income, while digestate is mostly cosidered as a byproduct.
Digestate is rich with macro- (N, P, K) and micro- (Se, Cu, …) nutrients, water and carbon
that are contained in undigested organic matter which makes 3-5% of total volume. Each of
the components in digestate has a developed market, but together they make a high value
fertiliser with unstable nutrient ratio, high costs of application and storage.
Phosphorus (P) is the eleventh represented element in Earth's core and the only element in the
15th group of periodic table that does not exist in nature in free form. It is one of the essential
elements that is important for growth and development of all living organisms. Currently
there are dissipation and losses in every aspect of P lifespan and the major way of loss
includes erosion and soil washing, but also ineffective use of fertiliser, biodegradable waste
and municipal wastewater. Sustainable use of P has become the subject of numerous
researches.
Phosphate ore is the primary source of P that is used for yield increase of crops and animal
growth, and thus for the maintaining of the growing human population. Known sites ofphosphate ores are located and concentrated in only couple of states, from which only Finland
is in European Union (produces small amounts). Almost two thirds of known reserves ofphosphate ore are located in western Africa, precisely Morocco and Western Sahara (Science
Communication Unit, 2013).
Present testings have shown that there are certain amounts of remained P in digestate
produced by process of AD, in organic and inorganic form and in amounts that can potentiallybe too high to release them in the environment. That is the reason why current researches are124

D. ĈXUÿHYLü: Biogas Facilities as a Carbon Sinks with …

aimed at recovery of P from digestate in industrially usable form. As phosphate in digestate isbound to solid particles, it has to be transferred to solution with chemical processes.
Undigested part of organic matter in digestate is lignocellulosic mass which is made ofcellulose (40-50%), hemicelullose (25-30%) and lignin (15-20%). Becuase of the presence of
celullose and hemicellulose in the material, the wall of lignocellulosic fibers is not subjected
to microbiological degradation.
Digestate that is low-enriched by chemical processes can be used in various ways: as a raw
material for combustion process which produces energy, material for bioplastics production ormaterial for construction industry (e.g. production of insulation material). In last two ways,
digestate is used as a carbon sink (Houghton, 2002; Cailleau, Braissant, & Verrecchia, 2004),
which prevents emission of carbon dixide (CO2) in the atmosphere from cogeneration processthat uses biogas produced during AD. Thereby, the cycle in a biogas facility is closed, every
waste stream is used and carbon footprint of the facility is reduced.
2. BIOGAS FACILITY
The general concept of facility that produces and uses biogas affects energy production andthusly heat production. Facility concept affects the different options of reuse of waste heatfrom cogeneration units. They can be characterized by next parameters (Rutz, Mergner, &Janssen, 2012):
x Main goal: Production of energy (electrical and thermal), waste treatment, injectionof biomethane in natural gas network, energy storage, load control, nutrient productionand enrichment
x Facility size: Facility size range start at 1-2 kW for utilization of house waste and up
to large facilities that produce several megawatts of energyx Technology: Dry / wet digestion, batch / continuous digestionx Business model: Agricultural, industrial, household, wastewater treatmen, biogas
facilities with waste treatment
x Type of raw material: Energy crops, agricultural waste and remains, food waste,industrial waste, sewage sludge
Main goal of biogas facilities in Europe is currently the production of renewable energy,
especially electrial energy. Namely, the emphasis in planning is on electrical energy
production (guaranteed tariff) which is the reason that efficient use of thermal energy isoverlooked.
In order to increase the efficiency of facility for production and use of biogas, the main goal
should be greater use of primary energy contained in biogas. Energy efficiency of biogas
facility is achieved by different measures, such as utilization of waste heat from cogeneration
units in the frame of some purposeful concept of heat reuse or by enriching of biogas tobiomethane (quality of natural gas > 95% methane) – which can be injected in natural gas
network. Second important goal is the ability of biogas cogenerations to stabilize electricity
network in a way of storaging energy and contribute to active load management in some sortof smart-grid. (Rutz, i dr., 2011). Several decades ago, during the starting phase of biogas
market in Germany, the main goals were recycling and enrichment of nutrients in agriculture
in organic cultivation systems.
The average size of typical biogas facility in Germany and most of other European countries
is around 450kWel. However, size of biogas facilities range from 1-2 kW (3-4 m3 of digester)for use of household waste, which are frequently used in many developing countries, tosofisticated facilities that have several megawatts for production of biogas. The size of theEnergy and the Environment (2016) 123-134

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facility affects the amount and availability of thermal energy production which is mostly used
for digester heating.
Technology type affects the amount of necessary heat, since temperature level and insulation
are different. Continuous supply of thermal energy is usually required for all biogas facilities.
Seasonal environment temperature largely affects the thermal energy supply. Good digester
insulation is a prerequisite za efficient and stable process. Operation of biogas facility is
usually integrated in existing activities of the facility.
Business model affects the main goals of biogas facility and also on potential possibilities ofthermal energy utilization. Facilities that use raw material from agriculture for biogas
production usually use the thermal energy for heating cattle accomodation, drying of woodremains, house heating; in wastewater treatment facilities it is used for sanitation,
hygienisation and cleaning; in industrial facilites the usual use is for process purposes.
As will be indicated below, type of raw material affects the biogas composition, and thuslyon the quantity and quality of available thermal energy.
3. PROCESS OF ANAEROBIC DIGESTION
Biogas is produced in the process of AD. It is a biochemical process in which different typesof anerobic microorganisms (bacterias) degrade complex organic matter (biomass) into lesscomplex organic compounds, without the presence of oxygen. Process of AD is present inmany natural environments such as marine sediment, bovine stomachs or in peatlands. The
same process occurs in biogas facilities where incoming organic material, i.e. raw material or
supstrate, is anaerobically digested on two main products: biogas and digestate.
Appropriate raw material for AD process comprise a wide range of biomass, but it is desirable
that they are easily degradable. This includes various fats, oilsm sugars and starch. Cellulose
is also easily degradable, while lignin (an important part of wood) is hardly degradable by AD(Lukehurst, Frost, & Saedi, 2010).
Typical raw material for biogas facilities can be both plant and animal origin (Rutz, Mergner,& Janssen, 2012):
x Animal excrement (manure, slurry, solid manure)x Agricultural remains and by-productsx Organic waste from food processing industry
x Organic waste from biotechnology industry (e.g. pulp and paper, pharmaceuticalproducts)x Organic fraction of municipal solid waste
x Waste that occurs during preparation and consumation of food in cateringx Seawge sludge from wastewater treatmenr facility
x Energy crops (e.g. corn, sugar beet, grass)Type of raw material affects the Ad process and the final composition of produced biogas.
Biogas usually consists of methane (CH4, 40-80%) and carbon dioxide (CO2, 15-45%) andsmaller amounts of hydrogen sulfide (H2S), ammonium (NH3), nitrogen (N2), and othercompounds. It is also usually saturated with water vapour (H2O).
Besides raw material, other factors affect on biogas composition, such as digestion systemconstruction, digester temperature, retention time and organic matter uptake.
Biogas composition is an important characteristic that affects biogas combustion incogeneration unit, and thusly on composition and temperature of exhaust gases. This affects

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D. ĈXUÿHYLü: Biogas Facilities as a Carbon Sinks with …

the amount and quality of thermal energy produced, that can be used in framework of a
specific heat utilization concept.
Futhermore, digester temperature which enables bacteria to quickly degrade material also
determines the concept of biogas facility. A part of heat energy from cogeneration unit isusually used for digester heating. They are usually divided according to following
temperature levels (Rutz, Mergner, & Janssen, 2012): psychrophilic (below 25°C), mesophilic(25°C – 45°C) and thermophilic (45°C – 70°C).
Digester temperature directly affects the concept of thermal energy utilization because if thedigester is cold, it is necessary to bring more thermal energy for its heating and that gives lessenergy available for other purposes. On the other side, biogas yield increases, accordingly totemperature increase. That is way it is necessary to define a temperature optimum. Several
factors affect the temperature selection: used material, facility construction, wanted retention
time, degradation speed and selected heat utilization concept. For biogas facility operator,
stability of AD process usually presents the most important factor during the selection oftemperature level.
3.1. BIOGAS
Biogas is a flammable mixture of gases, whose composition is described in Table 1. It ismostly composed of CH4 and CO2, and it is produced by anaerobic degradation of organic
matter. The composition of biogas depends on type of bacteria and raw material used during
the process of degradation. If a raw material consists of carbohydrates, such as glucose andsimilar simple sugars and high-molecular polymers, such as cellulose and hemicellulose, theproduction of methane will be low. However, if the amount of fats is high, then the methane
production will also be high (Jorgensen, 2009).
Table 1. Biogas composition (Jorgensen, 2009)
Gas
Methane (CH4)
Carbon dioxide (CO2)
Hydrogen sulfate (H2S)
Hydrogen (H2)Ammonium (NH3)
Carbon monoxide (CO)
Nitrogen (N2)
Oxygen (O2)%55 – 70
30 – 45
1–2
In traces
In traces
In traces

Biogas is produced from organic waste, i.e. excrement mixed with plant waste. A cubic meterof biogas matches the amount of around 0.6 kg fuel oil by energy value 0DMGDQGåLü .
As opposed to composting or combustion, by turning biomass to biogas, mineral substancessuch as nitrogen, phosphorus and potassium remain completely preserved in digestate.
The main purpose of biogas production in most of European facilities is its use incogeneration. Before combustion, biogas is dried and usually cleaned because for most gas
engines there are prescribed maximum amounts of hydrogen sulfide, halogenatedhydrocarbons and siloxane. Efficiency of a engine based on cogeneration unit amounts up to
90%, from which the engine produces around 35% of electrical and 65% of thermal energy.
Most facilities require smaller fraction of generated thermal energy (20-40%) for digester
heating system and larger part (60-80%) is considered as „waste“ heat that is usually not usedin other purposes. This heat could potentially be used for production of additional electricalenergy, e.g. in Stirling engines, organic Rankine cycle (ORC) and in Clausius-Rankine cycle

Energy and the Environment (2016) 123-134

127(CRC) or in other purposes, such as heating, drying and cooling (Rutz, Mergner, & Janssen,2012).
Cogeneration on biogas
Cogeneration or combined heat and power (CHP) represents a concept of simultaneous
production of electrical and thermal energy. Cogeneration is applicable anywhere where thereis need for electrical, thermal and/or cooling energy (in cas of trigeneration – production of
three different types of energy) (Andrassy, i dr., 2010). Cogeneration enables:
x More efficient use of fuel energy compared to separate production of thermal andelectrical energy
x CO2 emission reduction
x Production on consumption location, which leads to reduction of transportation anddistribution losses andx Safer and more flexible energy supply.
All cogeneration system, if properly sized, save fuel energy because of the fact that they are
more efficient than separate electrical and thermal energy production systems. Beside more
efficient production, cogeneration plants reduce the consumption of primary energy because
they are usually located near the final consumer which reduces or completely avoids losses intransportation and distribution of electrical and thermal energy. Example of an cogeneration
on biogas is shown on Figure 1.

Figure 1. Scheme of a biogas cogeneration
Calise et al. (2015) made an investigation on technical and economical feasibility ofcogeneration facility powered by biogas. Obtained results show that cogeneration facility on
biogas is tehnically and financially feasible and that it is a potential replacement for facilities
powered by fossil fuels, especially because it was about a small facility with power of 330
kWel on a small farm (Calise, Cremonesi, & Vastogirardi, 2015). The solution solves thefarms requirement for electrical and thermal energy which can be used for, e.g. heating thestables during winter period.

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D. ĈXUÿHYLü: Biogas Facilities as a Carbon Sinks with …

3.2. DIGESTATEAD proces produces biogas and a very wet residue called digestate, which is a mixture ofpartially degraded organic matter, microbiological mass and inorganic compounds. Direct
application of digestate as an agricultural fertiliser currently is considered as a cheap solution
for the problem of its landfilling and recovery of mineral and organic compounds that are init. During AD, unstable compounds in digestate are degraded and the remaining organic
compounds make it harder and more stable (Grigatti, Girolamo, Chincarini, & Ciavatta, 2011;
Schievano, Adani, Tambone, D’Imporzano, & Scaglia, 2009).
Digestate has a high nutrient content, such as nitrogen, phosphorus and potassium, whichmake it an excellent fertiliser for agricultural areas. Digestate also contains other materials
which are important for plant growth, such as calcium, sulfur, magnesium and other elements
in traces.
However, digestate content highly depends on type and composition of the raw material thatis used for AD. An example of digestate composition produced from food waste is given in
Table 2. Such digestate is convenient for use as a fertiliser on agricultural fields (AD, 2016).
Table 2. Example of a digestate from waste food composition (AD, 2016)
Parameter
Concentration Function by plant growth
8.4
Soil acidity regulationpH
5.19 % m/m
Soil structure
Dry matter
6000 mg/kg
Stem, branch and leaf growth
Total nitrogen (N)Stem, branch and leaf growth
Nitrogen in form of 4766 mg/kg
ammonium (NH-4N)
466 mg/kg
Seed germination and early development
Total phosphorus (P)2309 mg/kg
Flower and fruit development
Total potassium (K)71.2 mg/kg
Regulates uptake of other elements
Total magnesium (Mg)
268 mg/kg
Production of chlorophyll and amino acids
Total sulfur (S)Palatability of grasses
Water Soluble Sodium (Na) 1430 mg/kg
15.2 mg/kg
Chlorophyll production
Manganese (Mn)
2.36 mg/kg
Grain formation and development
Copper (Cu)8.84 mg/kg
Enzyme systems
Zink (Zn)0.347 mg/kg
Nitrate metabolism
Molybdenum (Mo)0.219 mg/kg
Pine production in animals
Cobalt (Co)
4. UTILIZATION OF DIGESTATE PRODUCED DURING AD PROCESS
Some digestates cannot be used as a agricultural fertilisers and need to be taken care of inanother way. These are limited by Nitrates Directive. Nitrates Directive is a popular name forCouncil Directive 91/676/EEC of 12 December 1991 concerning the protection of waters
against pollution caused by nitrates from agricultural sources (91/676/EEZ, 1991). This
document determines obligations of EU member states concerning protection and supervision
measures for protection of the environment from nitrates pollution that need to be applied on
agrucultural properties.
The purpose of adoption of the Nitrates Directive is in protection and prevention of further
excessive nitrate pollution of groundwater and drinking water, which is mostly caused byagricultural origin nitrates, ergo because of inappropriate and excessive use of manure as
fertiliser. That is the reason why it is necessary to find other ways of digestate utilization inorder to avoid its excessive landfilling.

Energy and the Environment (2016) 123-134

129

4.1.COMBUSTION OF DIGESTATE PELLETS
Combustion of biomass in its natural form is the easiest way of energy utilization. It can beused as a fuel in open furnaces, furnaces for room heating and stoves for food preparation.
Pressed briquettes can be made out of biomass that are convenient for larger furnaces andboiler rooms for steam production that can be used for room heating and technologicalprocesses and electrical energy production (Požar, 1992).
Dried digestate in form of pellets has shown to be a great alternative for energy production.
Kratzeisen et al. (2010) conducted a research on digestate pellets combustibility and theydetected the value of 15-16 MJ/kg, which is in range with pinewood with bark (Kratzeisen,6WDUþHYLü0DUWLQRY0DXUHU 0XOOHU .
This research shows great potential of digestate use as a fuel for combustion, but beforehand
drying is necessary because digestate obtained with AD process contains large amounts ofwater – up to 80% (Drosg, Fuchs, Saedi, Madsen, & Linke, 2015). Drying can be achieved byusing thermal energy obtained in cogeneration plant powered by biogas which is a way to use
thermal energy that would usually be released in the atmosphere.
4.2.MATERIAL FOR BIOPLASTICS PRODUCTION
Consequence of using crude oil as a raw material in almost every industry has led to its
drastical reduction in volume supplies in the world. One of the most important derivative of
crude oil is plastic which is used for production of packaging, pipes, glues, insulation andmany other products. However, no matter how important plastic is, it is shown that it is one of
the largest problem in th world considering waste.
Technical research center VTT in Finland has developed a method which can significantly
improve the quality of plastic packaging that is bio-based. New generation of bioplastic
packaging is not only more ecological but also has some advantages compared to traditional
plastic packaging. Plastic packaging industry is moving towards products that are completely
bio-based.
Amount of crude oil which is annually used for plastic production is around 5% of total world
crude oil consumption. Around 40% of all plastic is used for packaging purposes, which
presents a large pressure on packaging industry to reduce its dependence on crude oil. Using
renewable natural resources in industry, dependence on crude oil is reduced, as are CO2
emissions. However, transfer to bio-based economy requires not only products that areecological but also that are competitive considering the quality.
There are different materials for production of bioplastics but most known is PHA(polyhydroxyalkanoate). It is a simple structured macromolecule synthesized using gram
positive and gram negative bacterias, in conditions with phosphorus, magnesium and nitrogendefficiency and with carbon redundance (Madison & Huisman, 1999). Because of this,digestate is a perfect raw material for bioplastic production, especially in combination withnutrient recovery system that impoverishes digestate from phosphorus, magnesium andnitrogen.
Bacterias produce such polyesthers in order to preserve energy and carbon the same way as
glucose is kept as gycogen in people or starch in plants. PHA, which is synthesized by many
microorganisms, can be produced biotechnologically in large amounts, from renewable
supstrates, using fermentation and can be extracted from biomass after production by simple
physical and chemical processes.

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D. ĈXUÿHYLü: Biogas Facilities as a Carbon Sinks with …

PHA polymers are widely recognized as a great material for replacement of traditional plastic
that is made from fossil fuels. Their mechanical characteristics are very good, can beprocessed by melting, they have a good ultimate tensile strenght, high transparency and great
biodegradability (Fradinho, Domingos, Carvalho, Oehmen, & Reis, 2013).
However, they have a high production cost, limited functionality, are not compatible withconventional processing methods and are susceptible to thermal degradation (Kaur & Roy,2015).
The price of bioplastic made from PHA ranges between 2 and 3 dollars per kilogram.
Nevertheless, this price is still high compared to the price of polypropilene which is under 1
dollar per kilogram, despite the rise of crude oil. It should be emphasized that not ten years
ago (in 1988), the price of PHA was ten times higher than today and in 1980 the price waseven 600 times higher. Today, 60% of biopolymer production is situated in Europe. Despite
the high price, biopolymers have an unavoidable application in medicine because PHA i
biocompatible (e.g. controlled release of medicine at the exact precise place of activity,
surgical seams – degradable threads). A broad application is possible in product packaging,
and a production of fishing nets from biopolymers also started äLYNRYLü .
4.3.NUTRIENTS RECOVERY
Digestate after AD process still contains a lot of nutrients that are possible to for extraction
with specific chemical processes. Most important of these nutrients are P and N, as it waspreviously stated. One way for recovery of nutrients is a reactor process where nonrenewable
macro-nutrient (P) is extracted with N in form of struvite (struvite crystallization process).
Struvit or magnesium ammonium phosphate is a commercial fertiliser, with listed quality anda current price of 400 €/t.
In reactor, phosphorus (PO43-) and nitrogen (NH4-) ions from digestate are brought in contact
with magnesium (Mg) and create magnesium ammonium phosphate (MgNH4PO4), i.e.
struvite, according to following equation:
Mg2+ + NH4+ + HPO42- + 6 H22ĺ0J1+4PO4 x 6 H20 + H+ (Çelen & Türker, 2001).
Process is aimed towards maximum struvite crystallization in order to keep as much as
possible nonrenewable P in nutrient cycle. For maximum reaction of struvite crystallization, it
is necessary to add Mg in order to achieve theoretical ratio of constituents Mg2+:PO43:NH4+=1:1:1 (Çelen & Türker, 2001; Lin, J.Gan, Rajendran, Reis, & Hu, 2015) and regulate
pH value in mildly alkaline range (Cerrillo, Palatsi, Comas, Vicensc, & Bonmatía, 2014) inorder to avoid binding of present calcium with phosphate ions in digestate and sedimentationof calcium phosphate instead of struvite. With named factors, mixing is also required. Mg isadded in form of magnesium chloride (MgCl2) because its better solubility in water, lesser
influence on Ph value of reaction mixture compared to Mg(OH)2 and better contact with otherions which leads to better struvite crystallization (Lin, J.Gan, Rajendran, Reis, & Hu, 2015).
NaOH addition is essential in order to contain constant value of pH of the solution which
partially leads to degradation of lignocellulosic mass, i.e. lignin that is soluble in alkaline
environment.
After crystallization, struvite is sedimented on the bottom and can be separated by filtration or
centrifuge (Lee, Oh, Yang, & Yoon, 2015; Yilmazel & Demirer, 2011). After struvite
separation, impoverished digestate is separated on solid and liquid fraction with a separator
where solid fraction can be used in other purposes.
It is possible to extract up to 90% of P and 50% of N contained in digestate with the describedmethod. Struvite needs to be pasteurized and for that process waste heat from cogeneration

Energy and the Environment (2016) 123-134131

canbe used. Impoverished digestate has lesser odor emission because of separated ammonium
ions (that cause bad odors (Saedi, i dr., 2008)) through struvite crystallization.
Depending on the input balance of nutrients and efficacy of struvite crystallization, it isexpected that the liquid fraction can be used as liquid for fertigation because it contains
smaller amount of nutrients that are useful as a fertiliser. If necessary, amount of N can beadditionally reduced with a process of N stripping.
4.4.DEVELOPMENT OF THERMAL-INSULATION MATERIAL
According to global activities for climate change mitigation, construction industry is turning
towards new materials that would have lesser carbon footprint and also replace the demand
for renewable aggregates according to goals of Strategy for using raw materials. Advantagesof using cellulosic insulation material instead of fiberglass have already been identified andCellulose Insulation Manufacturers Association has established a web page in order to inform
potential users about characteristics of such material. Cellulosic insulation is already on themarket and has formal quality characteristics.
Production of celullosic insulation from digestate has and advantage from environmental
viewpoint because it represents carbon sink that is also a pretreatment in the insulation
process. The disadvantage is in the small amounts per facility (around 4 000 tonne/year for 1
MWel) in order to put such type of insulation on construction industry market. The solution
for this disadvantage is in setting the biogas facility as a center for production of local
insulation material that will be used for improvement of energy efficiency of buildings nearby
in a way that it will be used as it is produced, with minimum storage. Namely, when increasein energy efficiency of buildings project is in implementation, the procedure is gradual:
building by building. It is presumed that it is possible to match the production of local
insulation material for external envelope of the building with implementation dynamic. This
would result in large savings of greenhouse gas emissions and, through production of similar
insulation material and transport costs, reduced demand for energy for heating and cooling,with engagement of local resources: wokr force and materials.
Solid fraction of impoverished digestate contains around 50% of undigested lignocellulosic
mass (partially degraded lignin and hemicellulose) which would have application inconstruction industry. Under influence of pressure and temperature, lignin acts as a binder
which makes the produced material (impoverished digestate) „bonded“.
By adding CO2 and NaOH in solid fraction of impoverished digestate, natrium hydrogencarbonate occurs, i.e. soda (NaHCO3) occurs according to the following equation:
Na+(aq) + OH-(aq) + CO2(g) ĺNaHCO3(s) (Kolbah, 1986)
CO2 is brought to the mixture from gases that are produced from biogas combustion incogeneration plant. Biogas is a gas mixture that consists mostly from CH4 and CO2 (Saedi, idr., 2008) and during the combustion, only CH4 reacts. CO2 that does not react comes out of
the facility in form of exhaust gas.
With CO2 utilization in reactor for material production that will be used in constructionindustry, carbon sink is created (Cailleau, Braissant, & Verrecchia, 2004) through storage ofCO2 from exhaust gases and replacement of greenhouse gas emissions during the productionof traditional construction material. Apart from the fact that newly established material has anegative carbon footprint, construction material from cellulose is usually treated with soda asa fire protection which a characteristic as a insulation material is reached.

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D. ĈXUÿHYLü: Biogas Facilities as a Carbon Sinks with …

5. CONCLUSION
The main goal of listed methods in this paper is the increase of economic and technicalefficiency of biogas facility. This goal will be partially achieved through the process ofphosphorus extraction in form of struvite and degradation of hemicellulose in order toincrease the efficacy of input material, which is comercially justified since its market value isaround 400€/t. This paper presents several proved solutions from various industrial sectors in
a new way which increases the efficiency of biogas facility operation and utility of all its
products: biogas, digestate and CO2. Each of these processes has a limited economical
justification on its own and the hypothesis is that it will realise by symbiosis of the mentioned
processes. Mentioned processes and methods will contribute to global efforts for mitigation ofclimate change and transfer towards low-carbon economy on several research areas, fromwhich are most significant:x Energy industry: more efficient replacement of fossil fuels through better efficiencyof biogas facility
x Construction industry: development of new insulation material with low carbon
footprint
x Biotechnology industry (bioplastics): development of new materials which havelesser impact on the environment
x Environment protection: CO2 storage in cellulosic material
According to global activities for climate change mitigation, construction industry is turning
towards new materials which would have lesser carbon footprint, but also replace the demand
for nonrenewable aggregates (Commission, 2011). The goal is to position the material instandard use by reconstruction of existent buildings with simple construction concepts (family
houses, buildings for industry and agriculture) which make 60% of building fund. Application
by agriculture buildings has a goal to reduce unfavourable influence from the environment naheat comfort and with that accomplish the assumption for production increase. By apartmentbuildings the goal is to offer a cost favourable material, locally produced and appropriate for a
simple implementation. Before digestat, i.e. undigested cellulosic fibers is adapted toinsulation marterial, nonrenewable phosphorus and nitrogen will be removed in struvite formin order to keep these nutrients in natural nutrient cycle. During the mentioned process, alkali
is used that is required for merging CO2 with natrium. From this point of view, struvite
crystallization can also be considered as a pretreatment for the production of insulationmaterial.
New products, such as biodegradable plastics reduce the harmful contribution of traditional
plastic production in more ways than one – less crude oil is spent (whose amounts reduce, and
it is a nonrenewable material) and greenhouse gas emissions are reduced – during material
production but also during its degradation in the environment. Thereby it reduces the harmful
effect on the environment.
The unique contribution of suggested methods is a local solution for global efforts of keeping
the temperature below 2°C by 2100, according to motto „act locally, think globally“.
Observing a biogas facility as a micro-circular economy whose products (energy frombiogas), intermediate products (biogas) and by-products (CO2, digestat) can achieve positivechanges in local economy and increase the life standard of rural community through creationof demand for new and different work force and business activities (production of insulationmaterial, bioplastics and struvite, trade and installation of insulation material). Positivechanges can also remove the NIMBY (Not In My Back Yard) effect, if there is such, because
benefits from biogas facilities are transferred from opertor to local community. So far there
were no attempts to make a symbiosis of mentioned processes, and it is expected that overall

Energy and the Environment (2016) 123-134

133

and potential local, national and global social, economical and environmental effects will beconsiderable.

LITERATURE[1.]$QGUDVV\ 0 %DOHQ , %RUDV , 'RYLü ' %RUNRYLü ä /HQL . /RQþDU '3DYNRYLü % 6ROGR 9 6XþLü % L âYDLü 6 3ULUXþQLN ]D HQHUJHWsko certificiranje
zgrada, Tiskara Zelina, Zelina, 2010.
[2.]Cailleau G., Braissant O. i Verrecchia E. P.: Biomineralization in plants as a longterm carbon sink, Naturwissenschaften, 91 (2004.) 4, 191-194[3.]Calise F., Cremonesi C., i Vastogirardi G. D.: Technical and economic analysis of acogeneration plant fueled by biogas produced from livestock biomass, Energy
Procedia, 82 (2015), 666-673[4.]Çelen I., i Türker M.: Recovery of Ammonia as Struvite from Anaerobic Digester
Effluents. Environmental Technology, 22 (2001.) 11, 1263-1272[5.]Cerrillo M., Palatsi J., Comas J., Vicensc J., i Bonmatía A.: Struvite precipitation as atechnology to be integrated in a manure anaerobic digestion treatment plant –removal efficiency, crystal characterization and agricultural assessment. Journal ofChemical Technology and Biotechnology, 90 (2015.) 6, 1135-1143[6.]'LUHNWLYD 9LMHüD RG  SURVLQFD  R ]DãWLWL YRGD RG RQHþLãüHQMD
uzrokovanog nitratima iz poljoprivrednih izvora, 91/676/EEZ, 1991.
[7.]Drosg B., Fuchs W., Saedi T. A. Madsen M., i Linke B.: Nutrient Recovery by Biogas
Digestate Processing, IEA Bioenergy, 2015.
[8.]Fradinho J., Domingos J., Carvalho G., Oehmen A., i Reis M.: Polyhydroxyalkanoates
production by a mixed photosynthetic consortium of bacteria and algae, Bioresource
Technology, 132 (2013), 146-153[9.]Grigatti M., Girolamo G.D., Chincarini R., i Ciavatta C.: Potential nitrogenmineralization, plant utilization efficiency and soil CO2 emissions following theaddition of anaerobic digested slurries, Biomass Bioenergy, 35 (2011.) 11, 4619-4629[10.]Houghton R.A.: Terrestrial carbon sinks–uncertain explanations, Biologist, 49(2002.) 4, 155-160[11.]
Jorgensen P.J.: Biogas - green energy, Digisource Danmark, Aarhus, 2009.
[12.]
Kaur G., i Roy I.: Strategies for Large-scale Production of
Polyhydroxyalkanoates, Chemical and Biochemical Engineering, 29 (2015.) 2, 157172[13.]
Kolbah D.: 3ULUXþQLN]DNHPLþDUH Kemija u industriji, Zagreb, 1986.
[14.].UDW]HLVHQ06WDUþHYLü10DUWLQRY00DXUHU&L0XOOHU-Applicabilityof biogas digestate as solid fuel, Fuel, 89 (2010.) 9, 2544-2548[15.]
Langage AD, Digestate 'RKYDüHQR L] /DQJDJH $' (23. May 2016).:
http://www.langagead.com/digestate.html[16.]
Lee E., Oh M., Yang S., i Yoon T.: Struvite Crystallization of Anaerobic
Digestive Fluid of Swine Manure Containing Highly Concentrated Nitrogen, AsianAustralasian Journal of Animal Sciences, 28 (2015.) 7, 1053-1060[17.]
Lin H., Gan J., Rajendran A., Reis C.E., i Hu B.: Phosphorus Removal andRecovery from Digestate after Biogas Production (u knjizi Biofuels - Status andPerspectives), Intech, 2015., str. 517-546[18.]
Lukehurst C.T., Frost P., i Saedi T.E.: Utilisation of digestate from biogas
plants as biofertiliser, IEA Bioenergy, 2010.

134

D. ĈXUÿHYLü: Biogas Facilities as a Carbon Sinks with …

[19.]
Madison L.L., i Huisman G.W.: Metabolic Engineering of Poly(3Hydroxyalkanoates): From DNA to Plastic, Microbiology and molecular biology
reviews, 62 (1999.) 1, 21-53[20.]
0DMGDQGåLü L.: Obnovljivi izvori energije, Graphis, Zagreb, 2008.
[21.]
Požar H.: Osnove energetike 1, Školska knjiga, Zagreb, 1992
[22.]
Rutz D., Janssen R., Hoffstede U., Beil M., +DKQ + .XOLãLü % -XULü ä
Kruhek M., Ribic B., Haider P., Gostomska A., Nogueira M.A., Martins A.S., MartinsM., doCéu Albuquerque M., Dzene I., Niklass M., Gubernatorova I., Schinnerl D.,
Ruszel M. i Pawlak P.: Organic Waste for Biogas Production in Urban Areas, 19.
europska konferencija i izložba o biomasi, VP3.4.27, Berlin, 2011., 2125-2131[23.]
Rutz D., Mergner R., i Janssen R.: Održivo korištenje toplinske energije izbioplinskih postrojenja, WIP Renewable Energies, München, 2012.
[24.]
Saedi T.A., Rutz D., Prassl H., Kottner M., Finsterwalder T., Volk S., i Janssen
R.: 3ULUXþQLN]DELRSOLQ Intelligent Energy Europe, 2008.
[25.]
Schievano U.A., Adani F., Tambone F., D’Imporzano G., i Scaglia B.:
Anaerobic digestion: opportunities for agriculture and environment, Regione
Lombardia Publisher, Milano, 2009.
[26.]
Science Communication Unit: Science for Environment Policy In-depth
Report: Sustainable Phosphorus Use, European Commission DG Environment,
Bristol, 2013.
[27.]
Yilmazel Y., i Demirer G.: Removal and recovery of nutrients as struvite fromanaerobic digestion residues of poultry manure, Environmental Technology, 32(2011.) 7-8, 783-794.
[28.]äLYNRYLü G.: Zašto trebamo "zelenu" plastiku?, +59$76.( â80( þDVRSLVza popularizaciju šumarstva, 151 (2009.), 16-19

BIOPLINSKA POSTROJENJA KAO MJESTO PONORA
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Sažetak: Procesom anaerobne digetije (AD) dolazi do stvaranja bioplina koji je obnovljivo
gorivo koje ima brojne prednosti pred fosilnim gorivima, ali i ostalim obnovljivim izvorima
HQHUJLMH]ERJPRJXüQRVWLVNODGLãWHQMDWHMH]DPMHQD]DSULURGQLSOLQ2VLPãWRSULGRQRVLsmanjenju emisija staNOHQLþNLKSOLQRYDNUR]]DPMHQXHQHUJLMHIRVLOQLKJRULYDGROD]LGR
stvaranja proizvoda koji naziva digestat, koji predstvalja veliki problem bioplinskom
SRVWURMHQMX1MHJRYLPLVNRULãWDYDQMHPMHPRJXüHULMHãLWLWDMSUREOHPWHVWYURLWLYULMHGQX
sirovinu za ra]OLþLWHLQGXVWULMH SRSXWUJDÿHYLQVNHLQGXVWULMHLQGXVWULMHELRWHKQRORJLMHLR
HQHUJHWLNH 8RYRPUDGXVXRSLVDQLQDþLQLXSRWUHEHGLJHVWDWDXQDYHGHQLPLQGXVWULMDPDãWRGRYRGLGRVPDQMHQMDRSWHUHüHQMDQDRNROLãXSRWUHERPLVWRJPHÿXRVWDOLPLVPDQMHQMHP
emisija CO2 pohranom u celuloznom materijalu.
.OMXþQHULMHþLanaerobna digestija, digestat, insdustrija, bioplin

Energy and the Environment (2016) 135-146

135

A MECHANISTICALLY BASED REAL-TIME CAPABLE SYSTEMLEVEL MODEL OF PEM FUEL CELLS*UHJRU7DYþDUDQGTomaž Katrašnik*8QLYHUVLW\RI/MXEOMDQD)DFXOW\RI0HFKDQLFDO(QJLQHHULQJ$ãNHUþHYD6,-1000
Ljubljana, Slovenia, +386 1 4771 305, tomaz.katrasnik@fs.uni-lj.si
Abstract: Preferred way to tackle the requirements on shorter product development cycles
and reduced development cost is the virtual product development. This also includes systemlevel models that are applied in the early development stages for exploration of the design
space and for the system design as well as in the later validation and calibration phases
including HiL applications. Application of the same model in the early and the later
development stages cuts development costs and time, however developing a simulation model
meeting the above addressed objectives imposes a considerable challenge.
The core principle of the presented innovative fuel cell system level modelling approach istaking 1D numerical model for pipe gas-flow and superimposing onto it a 2D analytic
solution for concentration and velocity distribution in the plane perpendicular to the gas-flow
together giving a 3D information on species concentration in the fuel cell. The 2D solution isdevised on a jigsaw puzzle of multiple coupled domains enabling the modelling of parallel
straight channel fuel cells. Electrochemical and other nonlinear phenomena are fully coupled
to the species transport framework and solved within a single matrix. This 1D+2D approachgives the model its name: Hybrid 3D Analytic-Numerical (HAN).
The comparative evaluation shows very good agreement between the HAN-RT (Real-Time)
results and the results of a leading 3D CFD tool for modelling fuel cells, which proves that
HAN-RT achieves high fidelity results at very short computational times. It can thus becharacterised as a promising mechanistically based real-time capable system level modelling
approach of PEM fuel cells.
Keywords: Fuel cell; Modelling; System level; Real-time capable
1. INTRODUCTION
System level simulations are recently gaining on significant importance. This is driven by
the frontloading in the development process and by the increasing complexity of thepowertrains and power plants. Not surprisingly, the application of such system level
simulations also to the development process of fuel cell dynamic systems is recently quickly
gaining on importance.
System level simulations aim at modelling the whole system by means of multi-domain
simulations, where different domains correspond to different system’s components as forexample shown in Figure 1 for a fuel-cell electric vehicle (FCEV). In order to support tasks inearly stages of development a system level component model must feature high level ofpredictiveness and generality, meaning that it is capable of modelling not only a single
specific component but a wider range of components of the same type. These predictivenessand generality enable, on one hand, virtual development of the whole system already before
any physical prototypes of the component or its performance data are available and, on theother hand, gives guide lines for component development on the basis of the simulated
component-system interaction. These features are crucial for efficiently exploring the huge

136*7DYþDU..DWUDãQLN Mehanistically based real time capable system…

design space of modern powertrains and power plants being characterized by large
complexity of these system and wide variety of component technologies and ratings as well as
control strategies.
It is very desired, if system level models also feature short computational times. Amongothers there are two distinct applications of system level models where short computationaltimes are of great importance:- application in early stages of development where the optimisation of a dynamic system
inherently requires performing a large number of simulations to cover various operational
scenarios and- application as plant models in the validation and calibration stages of development in theoffice off-line and in the online HiL (hardware-in-the-loop) environments.
In HiL environments it is mandatory that models strictly fulfil the real-time constraints [1].

Figure 1

Schematics of the multi-domain system level FCEV powertrain model including
fuel cell stack and Balance of the plant domain as well as Thermal system,
Powertrain/Vehicle and Control domain.

It is also very beneficial from the workload point of view and from the plant model
consistency point of view when the same model can be used in the early design stages ofdevelopment and in the validation and calibration stages of development.
The so called reduced dimensionality models in their broader sense, i.e. any modelthat does not address all three dimensions equally, are a typically answer to the need for abalance between computational speed and accuracy of results. Common reduced
dimensionality models are the 2D models (e.g [2], the 2D model in [3]) and the so called
1D+1D models (e.g. [4]), which are a simplification of the 2D models (models where only themost dominant physical phenomena - e.g. mass transport via bulk gas flow in channel - areaddressed in the dimension that runs along direction of gas flow). The 2D modelling approachleads to certain systematic discrepancies that are sometimes compensated by means ofEnergy and the Environment (2016) 135-146

137

correction parameters yielding the pseudo 3D modelling approach (e.g. [5,6] and Sherwood
number adjusted 2D model in [3]). An alternative to this pseudo 3D approach is the so called
2D+1D approach (as found in [3]) where the physical phenomena are fully addressed in theplane perpendicular to the gas flow and, analogously to 1D+1D approach, only the dominantphysical phenomena are addressed in the direction of the gas flow.
The pseudo 3D and 2D+1D models aim to take into account all three dimensions
whilst achieving considerably shorter computational times than 3D CFD simulations.
However, with the exception of [5], they still cannot achieve computational times comparable
to the 1D models due to their inherent numerical nature. Owing to its analytic nature the quasi
3D model found in [5] features computational times comparable to the 1D models. However[5] offers an approximate analytic solution for direct liquid fuel cells that is only valid whenconstant velocity along channels is assumed.
$UWLFOHV RI 7DYþDU DQG .DWUDãQLk [7-9] propose a Hybrid 3D Analytic Numericalapproach to modelling species transport (HAN) in a PEM fuel cell as a way to obtain resultswith full 3D resolution whilst achieving short computational times. The principles of HAN
modelling in [7-9] are presented on a straight channel co-flow and counter-flow fuel cell andits core principle can be summarized as: A hybrid 3D model constructed by taking a 1D
numerical model for the gas-flow along the channel with a superimposed 2D analytic solution
for the plane perpendicular to the gas-flow. The additional computational load introduced by
the calculation of the 2D analytic solution was shown to be of the same order of magnitude as
the computational load of the base 1D calculation proving this hybrid 3D approach to becomputationally efficient. The HAN modelling approach has been comparatively evaluatedagainst CFD simulation results [7-9] and also against experimental measurements [10].
Although the HAN modelling approach is characterized by a very good ratio between
computational times on one side and model resolution and its accuracy on the other, the HAN
models presented in [7-9] are not real-time capable, which is the cost of their high spatial
resolution. Therefore a computationally optimized HAN modelling approach denoted HANRT (Real-Time) was developed to comply with the real-time constraints imposed by the HiL
applications [11]. HAN-RT is based on the optimized modelling framework that efficiently
combines sufficient level of model complexity and short computational times. Although
HAN-RT gives results on species distribution with lower resolution compared to the HAN
models found in [7-9], it still captures the essential 3D geometrical characteristics of themodelled fuel cell leading to high fidelity of the results relevant for system level simulation(i.e. the net electric current, power, fuel utilisation...)Furthermore the HAN-RT model features interfaces that enable its integration in anarbitrary FC system topology by connecting it to the components for balance of plant
including cooling system and other electric components as presented in Figure 1. This allows
for modelling a broad range of mobile and stationary applications in virtual representation ofreal operating conditions making it a system level model that is also suitable for optimizationof the entire system including its control.
This paper present a consistent and in-depth benchmarking of a HAN-RT that is
implemented in the commercial multi-domain system level tool AVL CruiseM to a wellestablished very detailed 3D CFD modelling tool for simulating fuel cells AVL FIRETM [12].
Results clearly indicate that HAN-RT is capable of well predicting U-I curve and moreoverthat it predict very accurately spatially resolved parameters despite computational times thatare shorter for several orders of magnitude.

138*7DYþDU..DWUDãQLN Mehanistically based real time capable system…

2. THEORTETICAL BACKGROUNDThis section outlines the main idea behind the HAN modelling approach and summarises
the main equations specific to HAN and HAN-RT in particular. For a detailed andcomprehensive mathematical formulation of the HAN modelling approach and the model
limitations the reader is kindly referred to references [7,9,11].
The modelled fuel cell is a straight hydrogen-air type PEM fuel cell (FC) with its
geometry taken from a laboratory test fuel cell operated in both co- and counter-flow
configurations. The fuel cell topology and geometry are illustrated in Figure 2a distinguishing
the following sub-elements: the cathode feed part comprising cathode channels and cathodegas diffusion layer (GDL); a thin catalyst layer for oxygen reduction; a hydrated proton
exchange membrane; a thin catalyst layer for hydrogen oxidation; anode feed part comprising
anode channels and anode gas diffusion layer (GDL).

Figure 2 Fuel cell geometry schematically broken-down onto elementary units for HAN
computation. The blue regions represent the membrane and the spottedtranslucent the GDLs; the green surfaces represent the rib symmetry plane andthe yellowish surfaces the symmetry plane between two ribs. (a) A five-rib parallel
channel co- or counter-flow fuel cell geometry. (b) Representative unit with one
slice (red) indicated. (c) Slice as a sliced-out section of the representative unit. (d)Slice split onto computational domains.
The modelled fuel cell is made of a number of equal parallel symmetrical ribs where ahalf of one such rib is indicated between the green and the yellow symmetry planes in Figure
2a. Since the two halves of one rib are mirror images and since all ribs are identical the fuelcell is a multiplication of one half of rib i.e. the so defined half of one rib is the representative
unit of the fuel cell.
As depicted in Figure 2b and 2c, the representative unit is sliced along the direction of
the channel flow into a number of thin slices. Within each slice only the variation of variablesin the plane perpendicular to the channel gas flow is addressed. This effectively makes a slice
a 2D object. A slice has three parts: a cathode feed part, a membrane electrode assembly(MEA) part and an anode feed part. As discernible form Figure 2d, the three parts are further
divided onto seven computational domains: each feed part is divided into one channel domain
and two GDL domains (GDL#1, GDL#2 as depicted in Figure 3) while the whole MEA partis contained within its MEA domain. The so defined computational domains, depicted in
Figure 2 as shallow rectangular cuboids, share the 2D nature of a slice and are thus, in termsof mathematical modelling, simple rectangles.

Energy and the Environment (2016) 135-146

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Obtaining 2D analytical solutions for slices and coupling them to one another via theperpendicular numerically resolved 1D gas flow gives this approach the name “hybrid 3D
analytic-numerical”. The HAN model thus gives full 3D information on species concentration
distribution.

Figure 3 Detailed schematic of feed part comprising three computational domains. The“Source” arrow represents the convective species inflow from the channel domainof the previous upstream slice and the “Sink” arrow represents the species
outflow into the channel domain of the next downstream slice. The blue arrows
represent the molar fluxes of species traversing the borders between domains. The
ribbed purple surface represents the catalyst layer, i.e. the MEA/GDL interface.
The basis of HAN modelling approach is solving the steady state diffusion eq. [7-9]:(1)
is the 3D nabla operator,
the diffusion
where represents the 3D species fluxes,
coefficient the species concentrations and the 3D gas velocity. Placing the feed part into
the coordinate system defined in Figure 3 the 2D nabla operator (the 3D nabla should not
be confused with its 2D version ), the 2D Laplace operator , the 2D velocity and theare defined in the crossvelocity component along the direction of channel gas flow
sectional plane as:(2)
Rewriting eq. (1) using the 2D+1D notation and neglecting the term

(i.e. taking into

account the assumption of no diffusive transport along the coordinate) reads:

140*7DYþDU..DWUDãQLN Mehanistically based real time capable system…

(3)
Approximating the termin eq. (3) as:(4)

yields after some algebraic manipulation [7,9](5)where the fact that and are constant in the relevant channel domain is taken into accountmaking eq. (5) linear with respect to and .
The core of the HAN’s numerical treatment of the gas flow in the channel is the finite:
difference approximation for the derivative(6)is the depth of the slice withanddenoting the values of
wherecoordinate at the points where species flow enters and exits the channel domain respectively
as indicated in Figure 3. Using approximation (6) in eq. (5) yields:(7)
Eq. (7) can be interpreted as a simple species transport equation on a 2D plane with a source
and a sink term: the source term being(i.e. the species inflow contribution)and the sink term being(i.e. the species outflow contribution). This

interpretation enables the species transport along the coordinate and in thewithin a channel domain, treated with a single 2D differential equation:plane to be,(8)

The source term
and the sink term
are schematically represented by the two yellow
arrows in Figure 3.
The velocity of gas is in GDL is assumed to have zero component along coordinate,. Thus, eq. (7) in GDL is simplified to:i.e.
(9)are the effective diffusion coefficients in GDL.
The core principle of HAN modelling approach is obtaining a general analytic solutionof the 2D diffusion problem in each of the seven computational domain types (Figure 2d)[7,9]. This is done by finding the domain specific eigen functions (also called harmonics) oftheoperator. For each domain the specific solution comes in the form of a specific linear
combination of its eigen functions, i.e. a 2D type Fourier series. In the channel domain these
read:
where

(10)
and in the GDL domains(11)Energy and the Environment (2016) 135-146

141

where
and represent either
or
and
or
(in Figure 3) depending on therelevant domain. Finding the specific solution for the species concentration in the whole
representative unit thus means finding all Fourier coefficients in the linear combinations ofeigen functions of the seven computational domains in every slice. These Fourier coefficientsare defined when coupling domains to one another.
Any feasible calculation takes into account a finite number of elements in the Fourier
series in eqns. (10) and (11). An increasing number of terms taken into account, on one hand,increase result accuracy, and on the other hand, increase the computational load and lengthen
the computational times.
The smallest number of terms taken into account in the channel domain that still leads
to satisfactory results is used in the HAN-RT model [11]:(12)
The physical significance of the three terms in eq. (12) is easily discerned from distinguishing
the two parts of a solution of the diffusion equation (1) or (8), which are the particular integral
and the homogeneous solution. The term
represents a particular integral in whichpart is the quasi steady solution for the concentration profile of the diffusion problem
thewith a boundary condition of fixed species flux (in the case of the channel domain this is theflux of species exchanged between the channel and GDL). The term
is ahomogeneous solution and is responsible for the transient behaviour of species concentrationin the gas stream on its way along the channel.
In the GDL domains there is only the quasi steady profile since no source or sinkterms are present, which simplifies the concentration profile to:(13)
Additionally, since the calculation of the current density distribution needs only the catalyst
surface species concentration distribution (and not the overall species concentration
distribution in the fuel cell) the HAN-RT model avoids calculating all Fourier coefficients inthe species concentration distribution series expansion in a domain (eqns. (12) and (13)). To
calculate the catalyst surface concentration of the reactant, which governs the electrochemical
reaction kinetics on the catalyst, the relationship between the average catalyst surface
concentration, the average species fluxes across the catalyst, the average concentrations ofspecies in the channel domain and the 1st order term (i.e.
in equation (12)) in the channel
domain is used:(14)

where represents the species flux across the catalyst layer,
andthe average
species concentration at the catalyst surface in the GDL#1 and GDL#2 domains respectively,
the average species concentration in the channel domain,
the 1st order termin the channel domain (in equation (13)) and the superfixes and pertain to the reactant
and the product species respectively. The constant tensors
andare derived from thelinear relationships between concentration differences and species fluxes and depend solely
on the channel and GDL geometry.

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3. RESULTS
The modelled laboratory experimental fuel cell was a parallel channel counter-flow fuelcell geometry as schematically depicted in Figure 2 operating under dry conditions, i.e.: noliquid water in channels and GDL-s. The fuel cells geometrical properties are summarised in[7,9]. Due to space limitations simulation results of the fuel cell stack calculated with bothmodelling tools are compared only in this paper. Therefore, and to enhance clarity ofcomparisons of the results are shown for isothermal operating conditions to expose features ofthe fuel cell stack models. 3D CFD mesh was composed of 4320 volume elements, whereas
HAN-RT features numerical resolution of 10 elements, i.e. slices, in the z-direction, i.e. 1D,
combined with the analytic solution (eqns. (12-14)) in the perpendicular 2D plane.

UV

0.90

CFD
HAN RT

0.85
0.80
0.75
0.70
0.65
0

2000

4000

6000

i A m2

Figure 4 Comparative plot of the simulated polarisation curves
The most indicative simulation result of the fuel cell is the polarisation curve shown in
Figure 4. It is important to note that for both tools, results were calculated with constant set ofmodel parameters over the entire range. It is discernible from the figure that results of thecomputationally optimised HAN-RT agree very well with the results of the high resolution
and high accuracy CFD modelling tool. The average current density that is plotted inpolarisation curve is an integral value and does not reveal how well the model predicts the
distribution of current density and species concentration within the fuel cell.
Therefore, spatially resolved results are also analysed to further confirm predictiveness
HAN-RT. As shown in Figure 3, at each representative unit, i.e. position along channel – z
coordinate, the HAN-RT model distinguishes average values under (cathode) channel (0 < y <w1 in Figure 3) and average values under rib (w1 < y < w1+w2 in Figure 3). For easiercomparison the detailed CFD results are also gathered and averaged to give corresponding“under channel” and “under rib” values and plotted alongside the HAN-RT results in Figure
5.
Results in Figure 5 are plotted for the following operating conditions: voltage 0.8 V,
temperature 80°C, pressure 1 bar, relative humidity of the feed gas on the anode side approx.
0.5 and on the cathode a side approx. 0.3. Anode inlet is in all graphs in Figure 5 on the leftside.
Figure 5 shows spatially distributed key physical quantities in a fuel cell. Comparison of
the results reveals HAN-RT’s capability to resolve these parameters with high fidelity. In
addition, these results clearly indicate that multidimensional treatment is required foradequate modelling of the phenomena in fuel cells, which is mainly imposed by the complex
and non-unidirectional species transport.

Energy and the Environment (2016) 135-146

143

a)

b)

c)

d)

Figure 5 Plots of distribution of values of various variables over cathode catalyst surface andin the cathode channel of the representative unit at 0.8 V. The surface underchannel and surface under rib are distinguished. The z-axis runs along thechannel gas flow direction with the anode inlet at the left side. Blue colour
denotes catalyst surface under the channel and red colour indicates catalyst
surface under the rib. Larger coarser dots indicate results of the HAN-RT andsmaller denser dots indicate results of the 3D CFD simulation tool.
In addition, to comparing the results of the models it is important to compare their
computational speeds. Due to different computational nature of both modelling tools, it is notpossible to directly compare the computational times. The computational time for the 3D CFD
gives the time required for calculating a converged steady state operational point, while thecomputational time reported for HAN-RT corresponds to the time needed for calculation of asingle time-step in a simulation of a transient operation as it is designed for transient
simulations. The 3D CFD thus requires approx. 2400 s for 5000 iterations required to obtain asteady-state solution. HAN-RT requires 0.33 ms for a single time step, which is internallyalso characterised by solver iterations imposed by solving a DAE system. It can thus beconcluded that HAN-RT can be used for HiL applications at frequencies above 1kHz stillleaving ample CPU margin for other system level components.
4. CONCLUSIONSThe comparative HAN-RT versus CFD plots have demonstrated HAN’s ability toadequately simulate the integral and spatially distributed key physical quantities in a fuel cell.
These results validate the HAN-RT’s hybrid 2D analytic + 1D numerical approach tomodelling the fundamental fuel cell governing mechanism, i.e.: the diffusive and convective
transport of species.

144*7DYþDU..DWUDãQLN Mehanistically based real time capable system…

Furthermore, innovative 1D numerical approach coupled with an analytic 2D model for
species transport yield computational times characteristic for 1D models and simultaneously
provides results with 3D resolution while relying on the first principles. The model thus
features a high level of predictiveness and real-time capability making it suitable both for the
early and for the later development stages including HiL applications. Overall, HAN-RT
proves to be accurate and computationally efficient and as such a very promising fuel cell
model for system level simulations.
LITERATURE[1].
Pfau, R.U. and Schaden, T. Real-Time Simulation of Extended Vehicle Drivetrain
Dynamics. Multibody Dynamics. Computational Methods in Applied Sciences, Springer 2011,
23, 195-214.
[2]
Ee, Sher Lin and Birgersson, Erik. Two-Dimensional Approximate Analytical
Solutions for the Direct Liquid Fuel Cell. J. Electrochem. Soc. 10, 2011, Vol. 158, 8122481234.
[3]
Kim, Gwang-Soo, et al. Reduced-dimensional models for straight-channel proton
exchange membrane fuel cells. J. Power Sources. 10, 2010, Vol. 195, 3240-3249.
[4]
Esmaili, Q., Ranjbar, A. A. and Abdollahzadeh, M. Numerical Simulation of a Direct
Methanol Fuel Cell through a 1D+1D Approach. International J. Green Energy. 2, 2013, Vol.
10, 190-204.
[5]Ling, Chun Yu, Ee, Sher Lin and Birgersson, Erik. Three-dimensional approximate
analytical solutions for direct liquid fuel cells. Electrochimica Acta. 30, 2013, Vol. 109, 305315.
[6]
Chang, Paul, et al. Reduced dimensional computational models of polymer electrolyte
membrane fuel cell stacks. J. Computational Physics. 2, 2007, Vol. 223, 797-821.
[7]7DYþDU*UHJRUDQG.DWUDãQLN7RPDåAn Innovative Hybrid 3D Analytic-Numerical
Approach for System Level Modelling of PEM Fuel Cells. Energies. 10, 2013, Vol. 6, 54265485.
[8]7DYþDU*UHJRUDQG.DWUDãQLk, Tomaž. A computationally efficient hybrid 3D analyticnumerical approach for modelling species transport in a proton exchange membrane fuelcell. J. Power Sources. 2013, Vol. 236, 321-340.
[9]7DYþDU*UHJRUDQG.DWUDãQLN7RPDåAn Innovative Hybrid 3D Analytic-numerical
Model for Air Breathing Parallel Channel Counter-flow PEM Fuel Cells. Acta Chim. Slov.
2014, Vol. 61, 308–315.
[10] 7DYþDU*UHJRUAnalytic-numerical 3D model for treatment of species transportphenomena in fuel cells. Doctoral Thesis. University of Ljubljana, March 2014.
[11]. 7DYþDU*UHJRUDQG.DWUDãQLN7RPDå. A computationally efficient hybrid 3D
analytic-numerical approach for system level modelling of PEM fuel cells. 5th European
PEFC & H2 Forum 2015, 30 June - 3 July 2015, Lucerne, Switzerland: proceedings,(European fuel cell forum, 19) Chapter-05_EFCF-2015-Sessions-A08-A11-A12-A14 (f. 168177)[12]. AVL FIRETM v2014 manual: Electrification/Hybridization

Energy and the Environment (2016) 135-146

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neophodni. Primjena istog modela u ranim i kasnijim fazama razvoja smanjuje troškove
razvoja i vrijeme, no razvoj simulacijskog modela koji udovoljava gore navedenim ciljevima
QDPHüH]QDþDMDQL]D]RY
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SRGDWDNRNRQFHQWUDFLMLWYDULXJRULYQRMüHOLMLX'. 2D rješenje je osmišljeno kao slagalica
RG YLãH VSRMHQLK GRPHQD RPRJXüDYDMXüL PRGHOLUDQMH JRULYQLK üHOLMD V SDUDOHOQLP UDYQLP
kanalima. Elektrokemijske i druge nelinearne pojave u potpunosti su povezane s transportom
spoja i riješene su unutar jedne matrice. Ovaj 1D + 2D pristup daje modelu njegovo ime:
+LEULGQL'$QDOLWLþNR-1XPHULþNL +$1 PRGHO.RPSDUDWLYQD SURFMHQD SRND]XMH YUOR GREUR VODJDQMH L]PHÿX UH]XOWDWD +$1 PRGHOD L
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146*7DYþDU..DWUDãQLN Mehanistically based real time capable system…

Energy and the Environment (2016) 147-156

147

COMPUTATIONAL FLUID DYNAMICS MODEL OF HIGHPERFORMANCE PROTON EXCHANGE MEMBRANE FUEL CELLWITHOUT EXTERNAL HUMIDIFICATION
Željko Penga, Frano Barbir)DFXOW\RIHOHFWULFDOHQJLQHHULQJPHFKDQLFDOHQJLQHHULQJDQGQDYDODUFKLWHFWXUH5XÿHUD%RãNRYLüD21000 Split, Croatia, +385 (21) 305-958, zpenga@fesb.hr
Abstract: Proton exchange membrane fuel cell (PEMFC) performance depends on the amount ofwater present inside the ionomer membrane, since the protonic conductivity of the membrane is
proportional to the membrane water content. The mass balance of electro-chemical reactions
inside an operating cell shows that sufficient amount of water is generated during PEMFC
operation inside the cathode catalyst layer to keep the membrane well hydrated, without the needfor external humidification. However, most of the commercially available PEMFC stacks use
external humidification units on a regular basis. The usage of external humidification results inhigher specific volume of the stack, higher complexity and maintenance requirements, narrow
operating range and consequently higher system costs, hindering the potential of PEMFCs inreplacing the internal combustion engine in automotive applications. High performance
operation without the need for external humidification presented in this work is based, andproven experimentally, on establishing a non-uniform temperature flow field for PEMFC. This
novel concept demonstrates numerous advantages over the common approach where isothermal
temperature field is considered, without compromising the performance, while the flooding of
the channels and gas-diffusion layers is reduced, and at the same time enables high performance
operation for a wide range of operating parameters. The non-uniform temperature field required
for such operation is determined using the Mollier h-Z chart, by calculating the generated
amount of water per channel length and determining the required temperature profile which will
result in close to 100% relative humidity along the entire flow field. The developed 3D
computational fluid dynamics model takes into consideration different physical processes inside
an operating cell and shows very good agreement with the experimental results from previous
studies [1,2] for different operating parameters.
Keywords: Self-humidified PEMFC, Computational fluid dynamics, Non-uniform temperature
field
1. INTRODUCTION
Proton exchange membrane fuel cell stacks are a promising solution for replacing the internal
combustion engines in automotive applications. Most of the automotive companies aredeveloping, or have already developed a vehicle powered by PEMFCs. The World Green Car
Award in 2016 is awarded to Toyota Mirai, which employs a high-end PEMFC stack of 370
single cells [3]. However, the main drawbacks of commercial fuel cell stack application, besides
limited commercial availability of hydrogen refueling stations at the moment, are the price andcomplexity of the fuel cell system. Such system can be seen in Fig. 1., and the objective of thispaper is development of a fuel cell system without external humidifiers or hydrogen recirculation
pump. Once such operation is attained, the initial price of the system could be reduced by 3040% and the system complexity would be significantly reduced.

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Figure 1. Commercial PEMFC system components: 1 – mass flow controller; 2 – external
humidifier; 3 – insulation and line heating from humidifier unit to the cell; 4 – PEMFC; 5 –insulation of hydrogen recirculation loop; 6 – hydrogen recirculation pump; 7 – deionized watertank and temperature control; 8 – deionized water circulation pump; 9 – heat exchanger.
The performance of the fuel cell is highly dependent on the water content of the ionomer
membrane. This is due to the fact that high membrane protonic conductivity can be achieved
only if the membrane is saturated with water. If the membrane water content is low, it results inhigher ohmic losses, i.e. lower operating electric potential for a fixed operating electrical current.
The commercial systems solve this problem by employing external humidifiers.
The external humidifiers saturate the reactant gases with water vapor at a certain temperature,
which is usually kept at a value close to the operating temperature of the cell. The reactants enter
the cell at high relative humidity and the membrane is well hydrated from the anode and cathodeside. Consequently, the membrane water content is high, as well as the operating electric
potential. But, since the fuel cell produces water during the operation, the generated water inside
the cell is unable to evaporate because the reactants are already saturated with water vapor.
The result of excess liquid water generation inside the cell causes blockage of the pores of thegas-diffusion layers. Since the reactants are unable to pass through liquid water, the result is
reduced electrochemically active surface area of the membrane. If the operating current density
is high, more water is being generated, and the blockage of the reactant channels can occur. Thisphenomenon is called flooding of the cell. The result of flooding is a catastrophic decrease in
PEMFC performance and must be avoided during the operation at all times.
The potential of flooding occurrence is the main reason for the design of reactant channels withgreater cross-sections, and the requirement for limiting the cell operation only for a certain range
of operating electrical currents. Greater cross-sections of the channels result in higher material
costs of the stack, higher specific weight and lower specific power of the stack.
Since the operating cell produces water and heat during the electrochemical reactions ofhydrogen and oxygen on the triple-phase boundaries inside the cathode catalyst layer, and thegenerated water is sufficient to humidify the reactants and keep the membrane water content
high, there should be no need for external humidification. The mentioned concept is already
implemented to a limited extent commercially [3], although it requires a hydrogen recirculation

Energy and the Environment (2016) 147-156

149

pump to establish high relative humidity along the entire flow field. The requirement of thehydrogen recirculation pump in such commercial systems is necessary because the operating
temperature of the cell in [3] is kept quite uniform, even though a slight temperature gradient ofca. 5 K is observed.
The novelty of this work is in establishing a non-uniform temperature flow field for an operatingcell by means of control of the mass flow rate of the coolant liquid. In this way, both heat andwater generated during the operation of the cell are being used. The result is a high performancefuel cell, without the requirement for external humidification or hydrogen recirculation pump,which will consequently result in a very simple, robust and low-cost PEMFC system.
2. METHODOLOGY
In order to study different physical processes inside an operating cell, a steady-state CFD
PEMFC model has been developed in a previous study [1]. The CFD model was calibrated andvalidated with experimental data from Tolj et al. [2] with very good agreement of every
parameter being measured. However, the previous study was developed for a segmented single
cell where the temperature of each segment was controlled by Peltier thermo-elements. Thisapproach had limited practicality, and the goal of this work is in establishing a required
temperature profile with mass-flow rate control of the coolant liquid – deionized water.
2.1. Domains
Geometry of the CFD model is implemented from single cell geometry from work of Tolj et al.
[2], with added coolant channels. The cross section of the fuel cell domains is shown in Fig. 2.
The complete geometry represents the cross section shown in Fig. 2 extruded in length of 200
mm.

Figure 2. Numerical domains, cross-section view: 1 – bipolar plate/end plate; 2 – reactant
channel; 3 – coolant channel; 4 – gas-diffusion layer; 5 – catalyst layer; 6 – proton exchange
membrane.
2.2. Mesh
In order to enable study of different physical processes inside PEMFC, a grid dependency study
was carried out for various mesh configurations by varying mesh type and number of finite
volumes. Since the geometry is quite simple, and has large difference in scale size (edge lengthspan from 10 Pm – catalyst layer thickness, to 0.2 m – axial length of PEMFC), it was mostconvenient to use a structured hexahedral mesh, i.e. Cartesian grid. The total number of finite
volumes was 320,000. The cross section of the channels was divided into four sub-divisions,while the gas-diffusion layers, catalysts and the membrane were divided into four sub-divisions
along their thickness.

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3. GOVERNING EQUATIONS AND BOUNDARY CONDITIONS
Numerical calculations were carried out using ANSYS Fluent 16.2 PEM Fuel Cell Module. The
operating parameters used in the setup are shown in Table 1. The parameters used for the model
calibration were open-circuit voltage of 0.91 V, implemented from work of Tolj et al. [2], andthe cathode reference current density, calibration was carried out for the operating current
density of 500 mAcm-2. The resulting value for cathode reference current density used during thesimulations was 0.0155 Am-2. The remaining material parameters are kept on the default values
in PEM Fuel Cell Module, since further data was not available from the experiments.
Table 1. Operating parameters
Parameter
ValuesCathode stream abs. pressure
1.01325 bar
Anode stream abs. pressure
1.01325 bar
Cathode stream inlet temperature
30°C
Anode stream inlet temperature
25°C
Coolant inlet temperature
30°C
Fuel cell temperature
60°C
orinducedRelative humidity of cathode stream 75%
inlet
Relative humidity of anode stream dry
inlet
Current density
500 mA/cm2
Stoichiometry, cathode2.15
Stoichiometry, anode
1.2
Channel length
200 mmChannel width at anode and cathode
1 mm
Channel height at anode and cathode1 mmMembrane thickness (Nafion 212)
0.05 mmCatalyst layer thickness
0.01 mm
Platinum loading
0.5 mg/cm2
Gas-diffusion layer thickness
0.38 mm
Effective area
2000 mm2
Membrane dry density
2 g/cm3
Membrane molecular weight1100 g/mol

coolant

The governing equations are based on mass, momentum, energy and species conservations
including appropriate sink and source terms. The type of analysis used was steady-state andsingle-phase, including equations for Joule heating, reaction heating, electrochemistry sources,
Butler-Volmer rate and membrane water transport. Water transport equations consist of an
equation for electro-osmotic drag coefficient by Springer et al. [4] and diffusion equations by
Motupally et al. [5] for different membrane water content intervals. The membrane water content
equation used in the software was adopted from Zawodzinski et al. [6].
The governing equations of Fluent PEM fuel cell module are based on energy, mass, momentum
and species conservation including appropriate sink and source terms. For steady-state
simulations, time dependent parameters are omitted from the equations. The resulting equationsare:Energy and the Environment (2016) 147-156

151

3.1. Continuity(1)ሬԦ ൯ = ܵ௠௔௦௦ߘ൫ߩ ܸ
where Smass represents source term for continuity equation. This term is only applicable for the
triple-phase boundary (catalyst) regions. Inside the gas channels, gas-diffusion layers and themembrane, the source term Smass is set to zero.
3.2. Momentum
1
1
(2)
ሬԦ ܸ
ሬԦ ൯ = െߘ‫ ݌‬+ሬԦ ൯ + ߩ݃ + ܵ௠௢௠ߘ൫ߩ ܸߘ൫ߤ ߘܸ
‫(ݏ‬1 െ ‫)ݏ‬‫(ݏ‬1 െ ‫)ݏ‬Where Smom represents the source term for momentum equation and applies only for the porous
medium. For other domains, Smom is set to zero.
3.3. Species(3)ሬԦ ܺ௜ ൯ = െ‫ܦߩ(׏‬௜ ‫ܺ׏‬௜ ) + ܵ௜‫׏‬൫ߩ ܸwhere the index i represents different species – oxygen, hydrogen and water vapor. The term Si
represents the source and sink term for the species inside the catalyst layers and accounts for thereactant consumption in anode and cathode catalyst layers and water generation inside thecathode catalyst layer. In other domains, the term Si value is set to zero.
3.4. Energy(4)ሬԦ ܶ൯ = ‫ ݇(׏‬௘௙௙ ‫ )ܶ׏‬+ ்ܵ‫׏‬൫ߩ ܸwhere ST represents the heat source term for the energy equation. The heat source term ST
applies only for the cathode catalyst layer, for other domains it is set to zero.
3.5. Water transport through the membrane
Electro-osmotic drag represents the water flux from the anode to the cathode side, and is definedby expression
2.5
(5)
݊ௗ =
ߣ
22
where ݊ௗ represents electro-osmotic drag coefficient, and ߣ represents membrane water content,
defined as(6)
ߣ = 0.043 + 17.18ܽ െ 39.85ܽଶ + 36ܽଷ(ܽ < 1)(7)
ߣ = 14 + 1.4(ܽ െ 1)(ܽ ൒ 1)
Where ܽ represents water activity, defined as
‫݌‬௪௩
(8)
ܽ=
+ 2‫ݏ‬‫݌‬௦௔௧
Where ‫݌‬௪௩ represents water vapor pressure, and ‫݌‬௦௔௧ represents water vapor saturation pressure.
Since the model is single phase, the Leverett function term 2‫ ݏ‬value is set to zero.
ௗ௜௙௙Back-diffusion flux ‫ܬ‬௪ is defined as
ߩ௠
ௗ௜௙௙
(9)
‫ܬ‬௪ = െ‫ߣ׏ ܦ ܯ‬‫ܯ‬௠ ுమ ை ௟
where ߩ௠ and ‫ܯ‬௠ represent density and the equivalent weight of the dry membrane,
respectively. The term ‫ܦ‬௟ represents membrane water diffusivity, defined as
ଶଷସ଺
(10)
‫ܦ‬௟ = 3.1 × 10ି଻ ߣ൫݁ ଴.ଶ଼ఒ െ 1൯ ൬݁ ି ் ൰(ߣ < 3)ଶଷସ଺‫ܦ‬௟ = 4.17݁ × 10ି଼ ߣ൫1 + 161݁ ିఒ ൯ ൬݁ ି ் ൰(ߣ ൒ 3)

(11)

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Ž. Penga, F. Barbir: Computational fluid dynamics model…

3.6. Domain boundary conditions
The domain type for all domains is defined as fluid bodies, except for current collectors which
are defined as solid bodies. In work of Tolj et al. [2] the current collector material was stainlesssteel SS316L, therefore this material was selected in this study as well.
3.7. Inlet boundary conditions
The mass flow inlet boundary condition is defined for anode and cathode inlets. The anode inlethydrogen temperature was set to 25°C, with a relative humidity of 0%. Cathode inlet air
temperature was set to 30°C, with a relative humidity of 75%. The anode mixture of gases
consisted of hydrogen and water vapor (while the mass fraction of water vapor was set to zero on
the anode inlet), the cathode mixture of gases consisted of nitrogen, oxygen and water vapor.
The mass flow rate of the coolant is prescribed to result in a temperature profile close to thewater vapor saturation profile.
3.8. Outlet boundary conditions
On the anode and cathode reactant channel outlets, the pressure outlet boundary condition isapplied with a zero gauge pressure and backflow total temperature set according to thetemperature field setup.
3.9. Wall boundary conditions
Non-slip boundary conditions were applied to the walls. The temperature was fixed on terminalsof the anode and cathode current collectors for isothermal temperature field study. For nonuniform temperature field case, the walls are defined as adiabatic surfaces, and the resulting
temperature profile is defined by the coolant mass flow rate. The electric potential on the anodeterminals was set to zero. On the cathode terminals different values of electric potential aredefined in order to extract the polarization curve. The remaining surfaces are defined as walls by
default.
3.10. Prescribing a desired temperature profile
Prescribing a desired temperature profile is done by controlling the mass flow rate of the coolant
liquid flowing in the co-flow direction with the cathode air. The mass flow rate ݉ሶ of the coolant
is determined by expression
(12)
ܳሶ
݉ሶ =
ܿ௣ ȟܶ
where ܳሶ represents generated heat and water phase change enthalpy, ܿ௣ represents specific heat,and ȟܶ represents the desired temperature difference between the outlet and inlet of the coolant
liquid.
The generated heat is defined by a heat source term ܵ௛ inside the software by expression(13)ܵ௛ = ݄௥௘௔௖௧ െ ܴ௔௡,௖௔௧ ߟ௔௡,௖௔௧ + ‫ ܫ‬ଶ ܴ௢௛௠ + ݄௅
where ݄௥௘௔௖௧ is heat released from electrochemical reaction of hydrogen and oxygen on the
triple-phase boundaries inside the cathode catalyst layer, while ܴ௔௡,௖௔௧ represent anode/cathodeover-potential, ߟ௔௡,௖௔௧ transition current, ‫ ܫ‬is the total electrical current, ܴ௢௛௠ are ohmic losses,and ݄௅ is the phase change enthalpy of water evaporation/condensation. The term ݄௅ is neglectedduring the calculations, since the CFD model is single-phase.

Energy and the Environment (2016) 147-156

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4. RESULTS AND DISCUSSION
Since the CFD model has already been validated in a previous study [1] with experimental results from
Tolj et al. [2], the results of the simulations in this work are only shown for the coolant induced
temperature field. The induced temperature field is shown for the cross section planes along the single
cell length in Fig. 3. The resulting temperature profile is quite smooth and more appropriate than step-like
temperature profile induced by Peltier thermo-elements on a segmented cell in the previous study [1].

Figure 3. Temperature contours on the cross-section planes along the single cell length withdenoted flow directions of the reactant gases and the coolant liquid.
In a previous study, the temperature profile was induced by segmenting the cell linearly into fiveequidistant segments. On each of the segments, the temperature was kept at a prescribed value
with Peltier thermo-elements. Such approach resulted in an approximation of the water vapor
saturation profile, but the concept could only be used on a single cell in a laboratory and resulted
in a quite complex experimental setup. The segmented temperature profile on the current
collector terminals is shown in Fig. 4. along with the desired temperature profile, i.e. water vapor
saturation profile, extracted from Mollier h-Z chart. The temperature profile from the CFD
analysis carried out in this work shows very good agreement with the desired temperature profileand shows the potential of application of the concept on a stack level.

Figure 4. Comparisons of temperature profiles
In order to have better insight in the potential for practical application of the concept and to
extract the polarization curve, simulations have been carried out for different operating current
densities. In Fig. 5, a few interesting details can be noticed. At lower current densities, theresulting polarization curve is very close to the polarization curve for isothermal case from workof Tolj et al. [2] at operating temperature of 60°C. This is due to a very low heat generation of
the cell, since the cell has active area of only 20 cm2 and the mass flow rate of the coolant would
have to be extremely low to establish the desired temperature profile. However, in most practical

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Ž. Penga, F. Barbir: Computational fluid dynamics model…

applications, the current densities are higher, and since the membrane degradation is more
prominent at higher operating electric potential, the low current density region is of minor
importance. At the operating current density of 500 mAcm-2, the resulting polarization curve
point is virtually identical to the operating point from segmented non-uniform temperature
profile from Tolj et al. [2], since the simulated temperature profile established with the coolant isvery close to the experimental one. At higher current densities, the mass flow rate of the coolant
was increased to result in a very similar temperature profile to the original one. In the work ofTolj et al. [2], the temperature profile on the current collector terminals was fixed at all times.
This resulted in the occurrence of higher temperature inside the cell, than the temperature on thecurrent collector terminals, which is elaborated in detail in a previous study [1]. By prescribing
the desired temperature field with coolant, this is not the case, since the coolant channels arevery close to the reactant channels. This results in higher performance of the cell on higher
current densities. Since the water generated inside the cell during operation is used for reactant
humidification, the mass transport losses are significantly reduced.

Figure 5. Comparisons of polarization curves
5. CONCLUSIONSThe concept of prescribing a desired temperature profile which will result in high performance of
the PEMFC without external humidification or the requirement for hydrogen recirculation pumphas been proved analytically. The concept is very simple, and the usage of a standardized
PEMFC system component – the coolant loop, as shown earlier in Fig. 1. The desired
temperature profile, i.e. temperature gradient, is prescribed by mass flow rate control of thecoolant fluid, which required one thermocouple to measure the outlet temperature of the coolant
with a feedback for the regulation valve which is used for mass flow rate control. Besides better
performance of the cell, lower initial cost by 30-40%, and simplicity, this concept also results inwider operating range of the fuel cell. Since the generated water inside the cell is used forreactant humidification, there is very little chance that the flooding will occur. The experimental
setup for further investigation of the concept is currently under development.
5. LIST OF SYMBOLS
ܽ – water activity
CFD – Computational fluid dynamics
ܿ௣ – specific heat, Jkg-1K-1‫ܦ‬௜ – gas diffusion coefficient‫ܦ‬௟ – membrane water diffusivity݃ – gravitational acceleration, ms-2

Energy and the Environment (2016) 147-156

155

h – enthalpy, J݄௅ – source term for enthalpy of water phase change, Wm-3
݄௥௘௔௖௧ – electrochemical heat source, Wm-3
‫ – ܫ‬electrical current, Aௗ௜௙௙‫ܬ‬௪ – back diffusion flux, kgm-3s-1
݇ ௘௙௙ – thermal conductivity, Wm-1K-1‫ܯ‬௠ – equivalent weight of the dry membrane, gmol-1‫ܯ‬ுమ ை – molar mass of water, gmol-1
݉ሶ – mass flow rate, kgs-1
݊ௗ – electro-osmotic drag coefficient‫ – ݌‬pressure, Nm-2
PEMFC – proton exchange membrane fuel cell‫݌‬௦௔௧ – water vapor saturation pressure, Nm-2
‫݌‬௪௩ – partial pressure of water vapor, Nm-2
ܳሶ – heat flux, Wܴ௔௡,௖௔௧ – overpotential anode, cathode, Vܴ௢௛௠ – ohmic resistance, :‫ – ݏ‬liquid water saturation
ܵ௛ - source term for heat, Wm-3
ܵ௜ – source term for species, kgm-3s-1ܵ௠௔௦௦ – source term for continuity equation, kgm-3s-1ܵ௠௢௠ – source term for momentum equation, kgm-3s-1
்ܵ – source term for energy equation, Wm-3
SS316L – austenitic chromium- nickel steel containing molybdenum (stainless steel)ܶ – temperature, KሬԦ – velocity vectorܸܺ௜ – species mass fraction
Greek symbols
ȟ – differenceߟ௔௡,௖௔௧ – transition current anode, cathode, Am-3
Ȝ – membrane water content
ߤ – dynamic viscosity, kgm-1s-1
ߩ – density, kg m-3
ߩ௠ – dry membrane density, kgm-3
Ȧ – absolute humidity, kgH O kgିଵair
2

ACKNOWLEDGEMENTS
The research leading to these results has received funding from the Croatian Science Foundation
project IP-11-2013-8700 “Water and Heat Management and Durability of PEM Fuel Cells“. Ž.
Penga also acknowledges support he has received from EU FP7 Programme through Fuel Cells
and Hydrogen Joint Undertaking under grant agreement n° 325275 (Project SAPPHIRE).
REFERENCES[1] Penga, Ž., Tolj, I., Barbir, F.: Computational fluid dynamics study of PEM fuel cell
performance for isothermal and non-uniform temperature boundary conditions, International
Journal of Hydrogen Energy (In-Press)

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Ž. Penga, F. Barbir: Computational fluid dynamics model…

[2] 7ROM,%H]PDOLQRYLü'%DUELU)Maintaining desired level of relative humidity througha fuel cell with spatially variable heat removal, International Journal of Hydrogen Energy,
Volume 36 (2011), Issue 20, 13105-13113[3] Konno N., Mizuno S., Nakaji H., Ishikawa Y. Development of Compact and HighPerformance Fuel Cell Stack. SAE Int. J. Alt. Power 2015;4(1):123-129.
[4] Zawodzinski TA, Springer TE, Davey J, Jestel R, Lopez C, Valerio J, Gottesfeld S. A
comparative-study of water-uptake by and transport through ionomeric fuel-cell membranes. J
Electrochem Soc 1993;140(7):1981-85.
[5] Motupally S, Becker AJ, Weidner JW. Diffusion of water through Nafion 115 membranes. J
Electrochem Soc 2000;147:3171-7.
[6] Zawodzinski TA, Springer TE, Davey J, Jestel R, Lopez C, Valerio J, Gottesfeld S. A
comparative-study of water-uptake by and transport through ionomeric fuel-cell membranes. J
Electrochem Soc 1993;140(7):1981-85.

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Energy and the Environment (2016) 157-168

157

ANALYSIS OF COGENERATION SYSTEM WITH FUEL CELL$PDQGD$OMLQRYLü7DYHOLüHYD3RGVWUDQDamaljino@gmail.com
Gojmir Radica, Faculty of Electrical Engineering, Mechanical Engineering and Naval
Architecture, University of Split, 21000 Split, Croatia, goradica@fesb.hr
Frano Barbir, Faculty of Electrical Engineering, Mechanical Engineering and Naval
Architecture, University of Split, 21000 Split, Croatia, fbarbir@fesb.hr
Abstract: Recently cogeneration systems are getting more and more attention as a solution
for increased energy efficiency and reduction of greenhouse gas emissions. This paper
analyses technical and economical feasibility of a power plant based on fuel cellcogeneration system for a local hospital complex, and compares it to the conventional
technology based on combustion. The selected cogeneration system has to operate on natural
gas and has to satisfy the demand for continuous, uninterrupted production of electricity up to
nominal power of 2800 kW. The system is grid connected so that gains/deficits of generated
power are dealt with its sale/purchase to/from the electrical grid. The by-product heat, frompower generation is supplemented by a conventional natural gas boiler up to nominal 1300
kW thermal energy. Operation of the system is simulated using numerical simulation tools,
which generated interesting results impacting its environmental and economic performance.
While the environmental benefits of the analyzed fuel cell based cogeneration system areundisputable, its current high prices cannot justify the investment without government
subsidies. However, the analysis shows under which scenarios - CO2 credits or penalties,
future technology development and maturing and corresponding price reduction,liberalization of natural gas and electricity markets - such a cogeneration power plant would
become cost competitive.
Key words: cogeneration, fuel cell

1. DFC POWER PLANT
Due to the increasing environmental awareness of the world, climate change, concern for the
future of the planet and the need for rational use of resources, cogeneration systems with fuelcells are considered to be one of the technologies of the future.
DFC power plants are stationary power plants made from Fuel Cell Energy (USA). [1]They contain direct fuel cells (fuel cells with molten carbonate). These systems are
independent power producers and are able to offer high quality base load power with 47%
electrical efficiency, 24 hours a day, 7 days a week. Due to the low environmental impact,
quiet operation and small space that they occupy, they are suitable for locations wheretraditional technologies that generate electricity are not feasible or desirable. [1]2. ANALYSIS OF COGENERATION SYSTEM

158

A. $OMLQRYLü*5DGLFD)%DUELU Analysis of Cogeneration System with Fuel Cell

2.1. User profile
For analysis of cogeneration system is necessary to collect data about annual electricity andheat assumption of hospital. They are obtained from [2] and UNDP. Due to a lack of somenecessary data, some data are estimated, therefore techno-economic analyzes will be made fora fictive year. Observed object is located in Mediterranean area (Split, Croatia) and has
surface of 60 000 m2. Heat energy consumption includes steam production for space heating,for direct consumers and for preparation of domestic hot water. Heat necessary for otheractions such as heating fuel oil tanks, in this paper will be neglected. Electricity consumption
includes electricity consumption for lighting, the launch of instruments and medical
equipment, and for start-up refrigeration equipment and heat pump. By entering data in theselected simulation tool, data of the consumption of electricity and heat during the warmer
and colder months were obtained.
.

Figure 1.Display of annual electricity consumption

Figure2. Display of annual heat consumption

According to the fictive year, the average consumption during the winter months (including
January, February, March, November and December) is 1 MW and 3.2 MW of heat energy.
During the warmer months (include April, May, June, July, August, September, October)average consumption is 1.2 MW electricity, because of partial air conditioning and coolingdemand of rooms that are not covered by the central cooling system, and 1.4 MW of heat
energy because the warmer months don’t have, or have little need for heating. The formerclassic way of getting energy for the building includes two independent sources conventional boiler and electrical grid.
2.1. Selecting the right DFC power plant and its performances
Cogeneration system must satisfy constant electricity and part of the thermal needs of thehospital. The system is grid connected so that gains/deficits of generated power are dealt with

Energy and the Environment (2016) 157-168

159

its sale/purchase to/from the electrical grid because the electricity supply of a hospital, so as
the activity of any electrical device must not be threatened.
Since the average consumption of the hospital, power plant DFC1500 (energent: natural gas)is choosen. By using the simulation tool, work of cogeneration system is optimized. We canconsider 2 cases.
In the first case, only one DFC1500 is used. According to picture 3, one DFC1500 power
plant will work with full load 24h a day (red color) to satisfy the electricity needs of thehospital. That work will increase maintenance costs and possibility of failure, and reduce
lifetime of the power plant.

Figure 3. Annual load of one DFC1500

In second case, two DFC1500 power plants are observed. Their load distribution is much
more favorable than the previous one, Figure 4, so this case will be considered further. Except
the favorable distribution, this system is characterized by greater flexibility and reliability inwork of the power plant.

Fugure 4. Annual load of two DFC1500

Choosen power plant offers high temperature and low temperature work mode. Depending on
the selected mode, thermal energy (heat) that cogeneration system produces is different.
Because of that, total efficency differs. In this paper, high temperature work mode isconsidered because the object (a hospital) has a high requirement for quality and hygeine ofwater.

160

A. $OMLQRYLü*5DGLFD)%DUELU Analysis of Cogeneration System with Fuel Cell

Picture 5. Performances of DFC1500

According to picture 5 and formula (1) [3]:K

OutputInput(1)where : Kefficiency [%]1. Requirement amount of fuelÆPfuel = 2978,7§N:
where:
K = Kel.en.= electrical efficiency [%]Output = Pel.en = produced electricity [kW]Input= Pfuel = requirement amount of fuelneeded for 1400 kW of electricity[kW]2. Total efficiency of power plants in high temperature
work modeÆ Ktotal = 62,9%
where:
K = Ktotal = total efficieny of one power plant [%]Output= Pel.en. + Pheat = total energy produces(electricity and heat) of one plant [kW]Input = Pfuel =. requirement amount of fuel needed for
1400 kW of electricity [kW]2.2. Energy consumption of hospital
Today, all the hospital's electricity needs are met from the electric grid. Annual electricity
conspumtion for fictive year is 9 346 188 kWh. From that consumption about 6 014 920 kW
is high tariff consumption and about 6 6654 270 kWh is low tariff consumption.
From the choosen simulation tool, we can see values of energy coverage during the use of twocogeneration systems (two DFC1500).

Energy and the Environment (2016) 157-168

161

Figure 6. Annual production of eletricicty of two DFC1500 power plants

In Figure 6.,electricity that two DFC1500 produce is marked black , while blue showselectricity that is bought from the grid. Total produced electricity of two DFC1500 is 12 699
082 kWh/year. Since the plant at certain hours during the year does not work, Figure 4 (areas
marked in black) as the simulation tool set that is the optimal operation of the system, theamount of energy the hospital needs to buy from the grid is 2 236 157 kWh/year, and theexcess electricity produced, which is sold to the grid, is 5 589 062 kWh/year
Excluding electricity, the byproduct of cogeneration system is heat. Since the thermalenergy consumption includes production of steam for heating and for direct consumers andfor domestic hot water, savings realized by using this heat is not negligible. Today, thehospitals needs for thermal energy are met with separate productions, i.e. with boiler on fueloil and liquefied petroleum gas, which serves as a safety backup (due to insufficient amount,
his quantity will be ignored in this paper).

Figure 7. Annual production of heat of two DFC1500 power plants

In figure 7., areas marked in black mean thearmal energy that two DFC1500 produced, whileorange marked areas means heat obtained by boiler on natural gas. Thermal excess is small(151 kWh/year) and it is released into the environment. Total thermal energy produced from

162

A. $OMLQRYLü*5DGLFD)%DUELU Analysis of Cogeneration System with Fuel Cellthe cogeneration systems is 7 911 275 kWh/year. Amount of needed thermal energy that is
produced by boiler is 11 434 710 kWh/year.
2.3. 2015. Cost analyses
In order to determine the loss/savings of the hospital, due to the use of cogeneration, it isnecessary to determine the price at which electricity is purchased from the grid, the price atwhich electricity is supplied the grid, and the price at which natural gas as fuel forcogeneration system is bought.
According to the category of consumption of HEP ((Croatian Electricity Company))[4], the observed hospital falls into the category of enterprise customers at low voltage, andthe red tariff model. To simplify the calculation, all months are taken at an equal price, one
for high and one for low tariff. Calculation time of high and low tariffs is calculated according
to data from [4]According to red tariff model of HEP, purchase price of electricity on high tariff is
0,91 kn/kWh, for low tariff is 0,51 kn/kWh, while fixed monthly fee is 41,30 kn. To simplify
the calculation, it will be assumed that the price for selling excess of electricity ofcogeneration system, is the same as the purchase price for missing electricity, which is equal
to the average electricity pricesÆ 0,71 kn/kWh.
By using cogeneration, the amount of natural gas increases. By changing the annual
consumption of natural gas, its price per kWh is changing. Higher consumption of natural gas,means lower price per kWh.[5]Annual consumption of natural gas because of cogeneration is calculated by thefollowing formula (2) and its total is 27 030 895 kWh.

Qtotal _ gas

Where::

Qtotal _ DFC u Qtotal _ fuel(2)

Q2 _ el .en.

Qtotal _ gas - total annual consumption of natural gas of both DFC 1500 [kWh]Qtotal _ DFC - total annual production of electricity of both DFC150 [kWh],
Qtotal _ fuel - total amount of fuel needed for maximum electricity production ofboth DFC1500 in hour [kwh]Q2 _ el .en. - total electricity production of both DFC1500 in hour [kWh]Annual consumption of natural gas because of the boiler (efficiency 90%) calculated
to the formula (1) is 12 705 233 kWh.
Summing these two consumption, total annual consumption of natural gas for thehospital is equal to 39 736 128 kWh. According to total consumption, the hospital falls intariff model TM10 Æ natural gas price: 0,3794 kn/kWh, including tax, with fixed monthly
charge of 412,50 kn. [5]Depending on the already established categories and their associated prices ofelectricity and natural gas, it is necessary to determine the consequences (loss/savings) due tothe use of cogeneration in the hospital. Two cases are considered.
First case is todays situation, i.e. a case where all electricity is purchased from theelectric grid according to already established price, and where all of the heat is obtained byboiler on fuel oil. Second case is cogeneration, i.e. a case where cogeneration manufactures

Energy and the Environment (2016) 157-168

163

the majority of electricity and part of the heat . The rest of the heat is supplied with the boiler
on natural gas.
Costs of electricity that is purchased from electric grid, so as the others costs, are calculating
according to formula 3 [6]:TR

where :¦PuQ

(3)

TR - corresponding cost [kn]P - corresponding price [kn/kWh or kn/months]
Q - corresponding quantity [kWh or moths].

According to formula (3) follows:
Table 1. U Comparison of classical electricity supply and supply with cogeneration
Classic supply of electric energy (electric grid)
Annual consumption of hospital
9 346 188
kWh
Cost of electrical energy
7 172 524.9
kn/year
Charge for electricity supply and metering service
3 964.8
kn/year
The total cost for electricity
7 176 489.7
kn/yearCogeneration
The amount of electricity that needs to be bought
2 236 157
kWh/yearfrom the grid
The cost of electricity that is bought from the grid
1 587 671.47
kn/year
Charges for electricity supply and metering service
3 964.80
kn/yearRequired amount of natural gas
2 703 903
kWh
Costs of natural gas
10 255 524.60
kn/year
Charges for using natural gas
4 950
kn/year
The total cost for electricity
11 852 128.87
kn/year
The amount of sales of excess electricity
3 968 234.02
kn/yearLoss because of cogeneration

707 405.15

kn/year

Table 2. Comparison of classical heat supply and supply with cogeneration
Classic supply of thermal energy (boiler)
Annual consumption of hospital
19 194 984
kWh
Cost of heat (given in available data)
8 548 059.31
kn/year
The use of heat from cogeneration
Lack of heat11 434 710
kWh/year
Required amount of natural gas
12 705 333.33
kn/yearCost of natural gas
4 820 403.50
kn/year
Savings because of cogeneration

3 727 655.81

kn/yearDespite the savings that are achieved because of exploitation of the heat that cogeneration
systems produce, calculation showed that the application of cogeneration system at thehospital is not yet economically viable, since the total annual savings, because of the use ofthermal energy, in the amount of 3 727 655.81 kn, is not sufficient to cover not even theannual maintenance costs. This means that in 25 years what is the projected lifetime of thecogeneration plant, the investment will not be returned.

164

A. $OMLQRYLü*5DGLFD)%DUELU Analysis of Cogeneration System with Fuel Cell

2.4. Possible case in 2020.
With the advance od technology, wider use of cogeneration system with fuel cells,
development of new materials, new designes and new construction methods for electrolytes,
caatalysts, bipolar plates and other improvements that are expected in the field of fuel cells, it
is considered that the prices of cogeneration systems with MCFC fuel cell from 100 kW to 3
MW will fall [13]. According to an internal communication with Fuel Cell Energy related tothe investment costs (equipment) in 2015 [7] follows:
Table 3. Costs of DFC1500 power plants in 2015.and 2020. 1
Investments costs$/kWe
Total [$/year]
Total [kn/year]
2015.
2020.
Maintenance costs
2015.
2020.

Replacement costs
Replacement costs

Total 2 power plants[kn/year]4500
6 300 000
42 840 000
85 680 000
1500
2 100 000
14 280 000
28 560 000$/hTotal [$/year]
Total [kn/year]
Total 2 power plants[kn/year]51
446 760
3 037 968
6 075 93625
219 000
1 489 200
2 978 400
Replacement one stack after 40 000 h of work (5 year) – 2015.
$/kWe
Total [$]
Total [kn]Total 2 power plants [kn]900
1 260 000
8 568 000
17 136 000
Replacement one stack after 80 000 h of work (10 years) – 2020.
$/kWe
Total [$]
Total [kn]Total 2 power plants [kn]360
504 000
3 427 200
6 854 400

According to [8] prices of electricity for industry in Europe in the period from 2008 – 2012
grew approximately 3,5% per year. According to the Commission for climate and energy
policy up to 2030, it is expected that the cost of electricity will increase until 2020, because of
the needed investment in infrastructure and production capacity and the growing costs offossil fuels.
And so it seems that the higher electricity prices in Croatia, but also in Europe, is inevitable.
Therefore, for further analysis it is assumed that the prices of electricity will follow thegrowing European trends, and that it will grow for about 3.7% per year by 2020 [9]Æ price:high tariff 1.11 € / kWh, low tariff 0.62 € / kWh , the charge for supply and metering service
49.53 kn / month.
According to [11], natural gas prices for industry are in decline, due to theliberalization of the domestic gas market. This should result in improved long-termcompetitiveness of the Croatian industry. Despite the expected increase in natural gas prices
in the European Union by 2020, in Croatia it is expected that the prices of natural gas forindustry will fall in order to equalize with European prices. [10] It will be assumed that prices
will fall 1% per year until 2020. (in 2020 prices: 0,3606 € / kWh, a fixed monthly fee for theuse of natural gas 392,00 kn).

1

Course of euros and dollars at the writing time is: 1$ = 0.89 €Course od euros and kune: 1 € = 7.61 kn
ourse of dollar and kune 1 $ = 6.80 kn

Energy and the Environment (2016) 157-168

165

With the same calculation like in 2015., due to formula (3), follows:
Table 4. Comparison of classical electricity supply and supply with cogeneration
Classic supply of electric energy (electric grid)
Annual consumption of hospital
9 346 188
kWh
Cost of electrical energy
8 741 948.60
kn/year
Charges for electricity supply and metering service
4752
kn/year
The total cost of electricity
8 746 700.60
kn/yearCogeneration
The amount of electricity that is needs to be bought
2 236 157
kWh/yearfrom the grid
The cost of electricity bought from the grid
1 934 275.81
kn/year
Charges for electricity supply and metering service
4752
kn/yearRequired amount of natural gas
27 030 903
kWh
Costs of natural gas
9 747 343.62
kn/year
Charges for using natural gas
4 704
kn/year
The total cost for electricity
11 691 075.43
kn/year
The amount of sales of excess electricity
4 834 538.63
kn/year
Savings because of cogeneration

1 890 163.47

Table 5. Comparison of classical heat supply and supply with cogeneration
Classic supply of thermal energy (boiler)
Annual consumption of hospital
19 194 984
Cost of heat
8 548 059.31
The use of heat from cogeneration
Lack of heat11 434 710
Required amount of natural gas
12 705 333.33
Cost of natural gas
4 581 543.20
Savings because of cogeneration

3 966 516.11

kn/yearkWhkn/yearkWh/yearkn/yearkn/yearkn/year

Payback period of investment
Payback period of the investment is the simplest criterion of financial decision makingof real investments. It represents the number of periods (years) for return the invested money
in a particular project [9]:(4)Where : tp – payback period of investment
Io – investment costs
Vt – cash flow
Forecasted lifetime of cogeneration system today is similar to the forecasted lifetime in 2020,
twenty five years. If we assumed that the hospital will have the same consumption in 2020
like it has in 2015. follows:
Table 6. Payback period of investment in 2020.
Years
Investment[kn] Savings (total savings-maintenance costs)

Coverage of166

A. $OMLQRYLü*5DGLFD)%DUELU Analysis of Cogeneration System with Fuel Cellinvestment
0
1
2
3
4

28 560 000-

Annual cost
2 878 279.58
2 878 279.58
2 878 279.58
2 878 279.58

12
13

-

2 878 279.58
2 878 279.58

Cumulative
2 878 279.58
5 756 559.16
8 634 838.74
11 513 118.32-25 681 720.42-22 803 440.84-19 925 161.26-17 046881.68

27 684 954.96
30 563 234.54-875 045.04
2 003 234.53

Investment in cogeneration system in 2020 (two DFC 1500) will be paid during the 13 year of
the exploitation period of the project, because in that year appears positive sign in the column
coverage on investment. After 25 years, what is the life of the plant, it will save 29,688
189.49 kn.
3.

REDUCTION OF CO2

Annual emission od CO2 is calculed using CO2 emission factors due to Pravilniku oenergetskom certificiranju zgrada (NN 36/10). [12]-Cp_natural gas = 0.2 kg/kWh, a Cp_el._en. = 0.53 kg/kWh Cfuel oil = 0.3 kg/kWh [12]:CO2 = Ei * Cp,iwhere:(5)

Ei - annual delivered energy of the i energy source [kWh],Cp,i - CO2 factor of emission for i power source [kg/kWh].

1. CO2 emission for cogeneration system
CO2 (electric grid, boiler, cogeneration system) = 2 236 157 kWh/yearl*0.53 kg/kWh + 11 434 710
kWh/year *0.2 kg/kWh + 12 699 082 kWh/god *0.2 kg/kWh = 6 011 921.61 kg/year

2. CO2 emission with classic way of energy supply
CO2(electric grid, boiler) = 14 935 239 kWh/year *0.53 + 19 194 984 kWh/year*0.3 kg/kWh = 13674 171.87kg/year
Using cogeneration system DFC1500 the local hospital will achieve annual reduction of 7 662
250.26 CO2 in kg.
In one work year of one DFC1500, due to [13], the expected reduction of NOx is more than 25
854 kg, polutant that causes smog, reduction of more than 58 059 kg SOx and more than 1360
kg soot and more than 6700t (which is equivalent to removing more than 1,200 cars off theroad) CO2 when compared to conventional technologies based on combustion.

4. CONCLUSION
The raising environmental awareness on the atmospheric pollution caused by human greed
and negligence, led to the development of cogeneration fuel cell technologies that enable aEnergy and the Environment (2016) 157-168

167

more rational use of energy and reduction in emissions of harmful pollutants. The usage ofhigh power (100kW-3MW) cogeneration systems with fuel cells is not highly represented
globally, due to the economical unprofitability. The fact that analyzed cogeneration system isa relatively new tehnology, leaves a lot of room for research, improvement and further
development. In this paper DFC1500 power plant is observed for application in hospital
facility. Application of power plants today is not economically effective, primarly because of
the high investment, maintenance and replacemet costs. However, with the certain assumption
for 2020. (most significant – lower prices of power plant), they application will become
economical and ecological viable. Even bigger viable can achieved if Croatia bring certain
penalties/credits for those who produce/reduce CO2.
LITERATURE[1] DOSSIER International Status of Molten Carbonate Fuel Cells Technology, 2015.
[2] /XþLQ'9LGRYLü/-DORQVNL=)DEULV2 YRGLWHOMSURMHNWD  6WXGLMDPRJXüQRVWLSRYHüDQMDHQHUJHWVNHHILNDVQRVWLUHYLWDOL]DFLMRPHQHUJHWVNRJSRVWURMHQMD.%6SOLW– lokacije
Firule i Križine'', Split, Županija Splitsko-dalmatinska UO za gospodarstvo, razvitak iobnovu, 2007.
[3] ./HQLü*RGLãQMDHPLVLMD&2X%3DYNRYLü9=DQNLLGUXJL3ULUXþQLN]DHQHUJHWVNR
certificiranje zgrada, Tisak Zelin, Zagreb, 2010., str. 250. - 748.
[4] HEP, http://www.hep.hr/hep/novosti/default.aspx (visited 17.5.2015.)[5] EVN cjenik prirodnog plina, http://www.evn.hr/ (download 17.5.2015.)[6] ZA TROŠAK FORMULA Troškovi,
https://www.google.hr/?gws_rd=ssl#q=tro%C5%A1ak+kostanja, (download 25.5.2015.)[7] DOE Hydrogen and Fuel Cells Program Record,
http://www.usa.gov/directory/federal/department-of-energy.shtml, 2011.
[8] .RPXQLNDFLMDNRPLVLMHHXURSVNRPSDUODPHQWXYLMHüXJRVSRGDUVNRPLVRFLMDOQRP
odboru i odboru regija (Cijene i troškovi energije u Europi), http://eur-lex.europa.eu/legalcontent/HR/TXT/?uri=CELEX:52014DC0021 (visited 26. lipnja 2015.)[9] 7HPHOMQLNULWHULMLILQDQFLMVNRJRGOXþLYDQMDV,QWHUQHWD
http://www.google.hr/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ve
d=0CCIQFjAB&url=http%3A%2F%2Fweb.efzg.hr%2Fdok%2FEPO%2Fldedi%2FP09Kriteriji%2520financijskog%2520odlucivanja-2009web.pdf&ei=PMGSVeeRCeKE7gatxYOgCA&usg=AFQjCNE0_2TDKhq9j0Iowg7kKVowdVnZw (download 30.6. 2015.)[10] „Cijena plina za industriju“, s Interneta, http://www.poslovni.hr/hrvatska/cijena-plina-zaindustriju-u-dvije-godine-pala-20-posto-najvecim-potrosacim-a-hep-u-i-petrokemiji-zatrecinu-280590 , 26. lipnja 2015.
[11] „.2081,.$&,-$.20,6,-((85236.203$5/$0(1789,-(û8EUROPSKOM GOSPODARSKOM I SOCIJALNOM ODBORU I ODBORU REGIJACijene i troškovi energije u Europi“, s Interneta, http://eur-lex.europa.eu/legalcontent/HR/TXT/?uri=CELEX:52014DC0021, 26. lipnja 2015.
[12] Ä3ULUXþQLN]DHQHUJHWVNRFHUWLILFLUDQMH]JUDGD³0LQLVWDUVWYRJRVSRGDUVWYDUDGDLpoduzetništva, listopad 2010.
[13] from web, http://www.fuelcelltoday.com/news-archive/2013/april/fuelcell-energy-toinstall-14-mw-fuel-cell-power-plant-at-a-connecticut-hospital, 30. lipnja 2013

168

A. $OMLQRYLü*5DGLFD)%DUELU Analysis of Cogeneration System with Fuel Cell

ANALIZA KOGENERACIJSKOG
ý/$1&,0$SUSTAVASAGORIVNIM

Sažetak: 8GDQDãQMHYULMHPHNRJHQHUDFLMDVYHYLãHSULYODþLSDåQMXNDRUMHãHQMH]DSRYHüDQMH
HQHUJHWVNH XþLQNRYLWRVWL L VPDQMHQMD ãWHWQLK HPLVLMD 2YDM UDG DQDOL]LUD WHKQR-ekonomsku
isplativost ulagaQMD X SOLQVNR NRJHQHUDFLMVNR SRVWURMHQMH VD JRULYQLP þODQFLPD ]D ORNDOQLEROQLþNL NRPSOHNV L XVSRUHÿXMH VD NRQYHQFLRQDOQLP WHKQRORJLMDPD ED]LUDQH QD L]JDUDQMX
Odabrani kogeneracijski sustav radi na zemni plin i mora opskrbiti kontinuirano, neprekinutu
napDMDQMH HOHNWULþQRP HQHUJLMRP GR PDNVLPDOQH SRWURãQMH RG N: 9LãDNPDQMDNSURL]YHGHQH HOHNWULþQH HQHUJLMH UMHãDYD VH QMHQRP SURGDMRPNXSQMRP L] HOHNWULþQH PUHåH
Toplina dobivena iz kogeneracijskog postrojenja nadopunjuje se sa konvencionalnim kotlom
prRL]YRGHüL  N: WRSOLQH 5DG VXVWDYD MH VLPXOLUDQ SRPRüX VLPXODFLMVNLK DODWD WH VX
UD]PDWUDQH HNRORãNH L HNRQRPVNH ]QDþDMNH 1HRVSRUQH VX HNRORãNH SUHGQRVWL DQDOL]LUDQRJNRJHQHUDFLMVNRJ VXVWDYD VD JRULYQLP þODQNRP DOL VH ]D VDGD VDPR X] VXEYHQFLMX GUåDve
može opravdati visoki trošak investicije. Analiza ujedno pokazuje, kako bi, uz primjenu:
poticaja za smanjenje CO2, pada cijena postrojenja zbog tehnološkog napretka, liberalizacijeWUåLãWDSOLQDLHOHNWULþQHHQHUJLMHXSRWUHEDNRJHQHUDFLMVNRJSRVWURMHQMDVDJRULYQLPþODQFLPD
postala ekonomski isplativa.
.OMXþQHULMHþL NRJHQHUDFLMDJRULYQLþODQDNEnergy and the Environment (2016) 169-176

169

BUILDING ENCLOSURE ELEMENTS AS
INTEGRATED SOLAR COLLECTORS
István Fekete1), István Farkas2)
1)

Department of Technical Engineering, College of Szolnok, Tiszaligeti sétány 14,
Szolnok, H-5000 Hungary, e-mail: feketei@szolf.hu
2)
Department of Physics and Process Control, Szent István University
3iWHU.X*|G|OOĘ+-2100 Hungary, e-mail: Farkas.Istvan@gek.szie.hu

Abstract: The design of the present heat exploitation solar collectors has special structure inmany cases, as it uses special material, therefore the specific expenses of such type of energy
production can be considered high. The literature review confirms that people with solar
collectors appreciated not only by their usefulness, but also according to aesthetic
considerations. In this paper these principles are also included. In addition to traditional
solar collectors is viable to study the solutions how the structural elements of the buildings
can be used to capture solar energy, when the architectural design would not change, but therequired surface operates as solar collector. A recommended use of such protectedarchitectural elements designed the renovation of buildings, increase the active utilization ofsolar energy in order to meet the increasingly stringent building energy standards.
The temperature distributions in the planned shell-structured collector calculated bysimulations were analysed, having a mathematical model and simulation of solar radiationenergy absorption and thermal conductivity processes. The one-dimensional heat and masstransfer differential equations was developed along with the space discretization of thecollector and the energy balance of inputs and outputs depending on the heat transfer liquidmaterial used in the flow circle. Measurements were carried out at different material surfaces
in order to compare the actual capture of solar radiation. Based on the modelling andsimulation results a pilot system was designed and built. The system can serve to perform
comparative measurements as expected in the simulation process.
The outcome of this work was to develop new type of shell-structured solar collectors for theheat exploitation of the solar energy and to determine its thermal efficiency. It is also an
intention to develop shell-structured collector bodies using the proper combination of the
traditional and new materials. The final plan is to contribute in forming new, profitable, small
investment claiming solar-collectors.
Keywords: Irradiation, temperature distribution, thermal efficiency, structure design.

1. INTRODUCTION
It is important to carry out with research and development activities to harness of renewableenergy, which led to the birth and using equipment, systems, the emergence of commercially
viable technologies in the past decades. Surveys, studies show that people with solar
collectors appreciate not only the basis of their usefulness, but also by aesthetic
considerations. This is the basic idea of the present study as well.

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I. Fekete, I. Farkas: Building Enclosure Elements as integrated…

The second issue is that in addition to traditional collectors how is justified a solution when
the building components can also be used to capture solar energy. In terms of energy point ofview, one might draw less efficient, but more surface area available. The proportion of use of
the renewing energy resources in the meeting energy-demands is only a few percent now in
our country. To increase this proportion is of high importance and significance within theentire energy consumption from many points of view. There are significant subsidies tomodernize the energy consumption, primarily for installation of solar collectors, which could
help the structural reform of the energy supply. The design of the present heat exploitation
solar collectors has special structure in many cases, it uses special material, therefore theexpenses of this type of energy production can be considered high (Farkas, 2000).
Flat plate solar collectors (FPSC), a non-concentrating types of units, consist of an absorber(made of copper or aluminium) and a glazing, separated by an air layer. The absorber’s
bottom and sides are insulated. Many studies have been performed to understand the thermal
behaviour of collectors whose efficiency depends on both the value of the incident solar
radiation on the absorber and it is thermal losses (Mekhilef et al., 2011; Vestlund et al., 2012).
According to the studies it has been illustrated that the glazed side of the collector is thesource of the most important thermal losses – between 10% and 35% of them.
Many studies have been performed and techniques have been developed to reduce collector
thermal losses, to modify the properties and form of the glazing, and to focus on themodification of the absorber shape (Slaman and Griessen, 2009). All of these studies gave an
overview of FPSC’s thermal behaviour and have provided many techniques to reduce their
thermal losses but an economic approach has rarely been mentioned. The materials they are
fabricated from make them expensive.
There are also some publications on the thermal behaviour and performance estimations ofpolymer collectors (Mintsa Do Ango et al., 2013). The conclusion of these studies was toreducing the weight by more than half the classic collectors and giving similar performances.
This is a way to an appropriate development, junction of a cheap plastic water chamber, UV
resistant PVC collector bodies to the heating- and water preheating systems.
Many studies have been performed that the temperature difference between urban areas andthe surrounding suburban or rural areas can be as much as 5°C (Kolokotroni and Giridharan,
2008; Bougiatioti et al., 2009; Karlessia et al., 2009; Kolokotsaa et al., 2012). Nearly 40
percent of that increase is due to the prevalence of dark roofs, with the remainder comingfrom dark-coloured pavement. The heat island effect can be counteracted slightly by using
white or reflective materials to build houses, roofs, pavements, and roads, thus increasing theoverall albedo of the city. A cool roof made from a reflective material such as vinyl reflects atleast 75 percent of the sun’s rays, and emit at least 70 percent of the solar radiation absorbedby the building envelope. Several solar collectors could reduce this effect.
The literature review confirms that people with solar collectors appreciated not only by theirusefulness, but also according to aesthetic considerations. In my research this principle, been
built. In addition to traditional solar collectors to examine this area, how is a viable solution
when the building's structural elements can also be used to capture solar energy (Fig. 1).

Energy and the Environment (2016) 169-176

171

Fig. 1. The traditional and advanced structure design of solar collector

2. MODELLING OF BUILDING INTEGRATED SOLAR COLLECTORSThe thermal conductivity of differential equations based, one component of the energy
transfer to the next one, the space part of the energy balance of inputs and outputs dependingon the heat transfer material is formed of flow (Fig. 2).

Fig. 2. Structure and heat balance scheme of tile element
The building integrated solar collector model of the solar thermal technology development,
environmental variables must be entered in addition to the geometry data of the physicalcharacteristics of the materials used. The following mathematical equations necessary for thesimulation:T tT outI A t  k ta A ta (Ta  Tt )  k wt A w (Tt  Tout )ct mt
 w c w (Tout  Tin )k wt A w (Tt  Tout )  m
c w ȡ w Vw

.

,

(1)
(2)

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I. Fekete, I. Farkas: Building Enclosure Elements as integrated…

Establishment of solar collector’s outlet temperature of the working fluid by summarizing
sequential thermal equilibrium state of the elementary particles can be observed. Based on
Eqs (1-2) derived from mathematical simulation process is shown in Fig. 3, including thefollowing notations:U[1]T t ; U[2]T out ; U[3] Tin .

(3)

Fig. 3. Matlab realization of the tile collector model
The temperature distributions in the shell-structured tiles calculated by simulations were first
analysed. Fig. 4 shows the warming process until steady state is reached. Based on the aforementioned parameters, the maximum availabOH WLOH VXUIDFH WHPSHUDWXUH GLIIHUHQFH ǻ7t) is
DERXW&WKHRXWOHWIOXLGGLIIHUHQFHWHPSHUDWXUH ǻ7out) is about 25 °C over, and the inlet
temperature (Tin) is 18 °C.

Fig. 4. Calculated temperature differences of tile and outlet working fluid

Energy and the Environment (2016) 169-176

173

3. THERMAL TEST OF THE SOLAR TILE COLLECTOR
Based on the modelling and simulation results a pilot system was designed and built. The
system can serve to perform comparative measurements as expected in the simulation process.
The collector surface temperature distribution is difficult to measure using conventionaltemperature measuring devices. Therefore, the temperatures detect and verify the modelledvalues calculated infrared camera recordings were used. The thermal infrared image software
accuracy was ± 0.1 °C. A representative image is presented in Fig. 5 showing the recording
features.

Fig. 5. Measured surface temperature distribution of elements and temperature distribution ofa tile element
The fluid enters at point A, and leaves the tile at point B. Point C shows the tile surface
maximum temperature value, which is about 45 °C in the experiment. In this area, there is noheat extraction. The intensity of scale shows the approximate temperature values.
3. CONCLUSIONS AND SUGGESTIONS
In today's high-rising pollution problems associated with sustaining economic growth. The
renewable energy including solar energy available to all, decentralized exploitation could
reduce it significantly. In addition to today's efficiency-driven, but costly development
concepts exploiting the necessary working less efficiently but cheaper options available. The
design is simple and easy to assemble machines that are suitable for a specific period of solar
radiation energy cost of capturing the first conclusions of the results of that structural element
formed by collector items.
The studies and modelling in connection with the question arose of the currently used solar
collector efficiency formula is suitable for the calculations. The medium in the solar collector
when the temperature variable calculations, the change in the intensity of radiation affects thecollector efficiency. The formula for calculating the efficiency of commonly used medium
temperature solar collector does not fully reflect the real efficiency. The internal temperature

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I. Fekete, I. Farkas: Building Enclosure Elements as integrated…

distribution of solar collectors and ascertaining the impact of interconnected solar collectors
on efficiency would be important for more precise control and improved energy-use.
We suggest the building's solar collectors element formed on the basis of results, in cases
when it is incorporated into a conventional solar collectors due reference to aesthetic reasons.
We also recommend these items to reduce the urban heat-island effect, when the heating ofbuildings worsens human comfort.
Finally, Wit is recommend the use of such protected architectural elements designed therenovation of buildings, increase the active utilization of solar energy in order to meet theincreasingly stringent building energy standards.
4. SUMMARY
Important to research and development activities for the capture and utilization of renewableforms of energy that led to the birth of applying them, and equipment, design of systems forthe past two decades, commercially viable technologies.
It has been presented the active solar energy can be a new, non-standard, never used thepossibility. The bodies of many collector thermal stratification developed a mathematicalmodel of optimization and simulation experiments were carried out to establish. The
investigation of the incident solar radiation energy characteristics of measurements were
performed on samples of different surfaces. The equipment is designed based on the ideas,
and we have built to meet expectations in the most options.
We studied the solar system efficiency of the method of calculation. The exact design
measurements, using appropriate mathematical methods can be demonstrated that not only thehigh-precision instruments may be technically correct results are achieved certification. Not
appropriate in some cases, the usual efficiency and accuracy of the formulas. It is definitely
not light up some badly designed components, systems failures.
In summary, noting the collector body shape and design of structural materials by changing, It
can be approached that the maximum thermal efficiency is technically available. The designof the collector bodies of many thermal stratification of their modelling, simulation andmeasurement after the technically high quality manufacture, assemble, inexpensive, highly
efficient collector bodies formed, right-lasting, economical systems can facilitate even greateruse of solar energy.
LIST OF SYMBOLS
At
Ate
Aw
ct
cw
I
kte
kwt

tile surface (m2)surface of the tile element in the direction of environment (m2)surface of the working fluid (m2)specific heat of tile material (J/kg°C)
specific heat of water (J/kg°C)
effective irradiation (W/m2)
heat transfer coefficient between tile and ambient (W/m2°C)
heat transfer coefficient between tile and water (W/m2°C)

Energy and the Environment (2016) 169-176

‫ۦ‬
mt
mw
ȡw
T
܏
Vw
w, h, l175

mass flow rate of the working fluid (kg/s)
mass of tile (kg)mass of the working fluid (kg)density of water (kg/m3)
temperature (°C)
temperature difference (°C)
volume of the working fluid (m3)geometric parameters of tile (width, length, thickness) (m)Subscripts
a
m
in
m
out
t
w

ambient temperature
medium temperature of working fluid
inlet temperature of working fluid to the collector
average temperature of working fluid
outlet temperature of working fluid from the collector
temperature of tile surface
temperature of working fluid (water)

ACKNOWLEDGEMENTS
The research presented in this paper was supported by COST Action of Building Integrationof Solar Thermal Systems (BISTS) TU1205 project.
REFERENCES[1.]Bougiatioti, F., Evangelinos, E., Poulakos, G., Zacharopoulos, E. (2009), The summer
thermal behaviour of “skin” materials for vertical surfaces in Athens, Greece as adecisive parameter for their selection, Solar Energy, Volume 83, Issue 4, April 2009,
pp. 582-598.
[2.]Farkas, I. (2000), A combined solar farm energy/technology system in Hungary,
Hungarian Agricultural Research, Vol. 9, No. 2, June 2000, pp. 18-21.
[3.]Karlessia, T., Santamourisa, M., Apostolakisb, K., Synnefaa, A., Livadaa, I. (2009),
Development and testing of thermochromic coatings for buildings and urban structures,
Solar Energy, Volume 83, Issue 4, April 2009, pp. 538-551.
[4.]Kolokotroni, M., Giridharan, R. (2008), Urban heat island intensity in London: An
investigation of the impact of physical characteristics on changes in outdoor air
temperature during summer, Solar Energy, Volume 82, Issue 11, November 2008, pp.
986-998.
[5.]Kolokotsaa, D., Maravelaki-Kalaitzakib, P., Papantonioua, S., Vangelogloua, E.,
Saliaric, M., Karlessic, T., Santamourisc, M. (2012), Development and analysis of

176

I. Fekete, I. Farkas: Building Enclosure Elements as integrated…

mineral based coatings for buildings and urban structures, Solar Energy, Volume 86,
Issue 5, May 2012, pp. 1648-1659.
[6.]Mekhilef, S., Saidur, R., Safari, A. (2011), A review on solar energy use in industries,
Renewable and Sustainable Energy Reviews, Volume 15, pp. 1777-1790.
[7.]Mintsa Do Ango, A.C., Medale, M., Abid, C. (2013), Optimization of the design of apolymer flat plate solar collector, Solar Energy, Volume 87, January 2013, pp. 64-75.
[8.]Slaman, M., Griessen, R. (2009), Solar collector overheating protection, Solar Energy,
Volume 83, pp. 982–987.
[9.]Vestlund, J., Dalenback, J.-O., Ronnelid, M. (2012), Flow distribution in a solar
collector panel with horizontally inclined absorber strips, Solar Energy, Volume 86, pp.
13-25.

(/(0(17,2027$ý$=*5$'(.$2,17(*5,5$1,681ý(9, KOLEKTORISažetak: VXQþHYL NROHNWRUL ]D XSRUDEX WRSOLQVNH HQHUJLMH sunca imaju posebni dizajn i
VWUXNWXUX X SXQR VOXþDMHYD WH NRULVWH SRVHEQH materijale, tako GD VH VSHFLILþQL WURãNRYL
dobivanja toplinske energije iz ovih izvora mogu smatrati visokima. Iz pregleda literature
SRWYUÿXMHVHGDVXVXQþHYLNROHNWRULFLMHQMHQLQHVDPRSRQMLKRYRMIXQNFLMLYHüLSRHVWHWVNLPkarakteristikama. U ovom radu ti su principi WDNRÿHU X]HWL X RE]LU 2VLP WUDGLFLRQDOQLKVXQþHYLK kolektora, potrebno je SURXþLti kako VHVWUXNWXUQLHOHPHQWLXRPRWDþX]JUDGH mogu
iskoristiti kao površine za uporabu VXQþHYH HQHUJLMH SULWRP QH PLMHQMDMXüL DUKLWHNWRQVNL
izgled zgrade. PreporXþHQD MH Sretvorba arhitektonskih elemenata kod energetske obnove
zgrada, VFLOMHPSRYHüDQMDDNWLYQHXSRUDEHVXQþHYH energije, kako bi se zadovoljili sve stroži
energetski standardi zgrada.
5DVSRGMHOD WHPSHUDWXUD X LQWHJULUDQLP VXQþHYLP NROHNWRULPD analizirana je pRPRüXQXPHULþNLKVLPXODFLMDNRMHVHWHPHOMHQDmatHPDWLþNRP modelXDSVRUSFLMHVXQþHYRJ]UDþHQMD
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prijelaza topline i prijenosa tvari zajedno s prostornom diskretizacijom kolektora i bilancom
topline, ovisno o UDGQRMNDSOMHYLQLXNROHNWRUX5D]OLþLWLPDWHULMDOL površine kolektora ispitani
VXSRPRüXPMHUHQMDNDNRELVHXVSRUHGLODVWYDUQDNROLþLQHDSVRUELUDQRJ VXQþHYRJ]UDþHQMDNa temelju dobivenih rezultata modela i provedenih simulacija, SURMHNWLUDQMHLL]JUDÿHQSLORW
sustav. Ovaj sustav služi za dobivanje podataka mjerenja koji su potrebni u fazi simulacije.
8RYRPUDGXSUHGORåHQDMHQRYDYUVWDLQWHJULUDQRJVXQþHYRJNROHNWRUDXRPRWDþX]JUDGHLRGUHÿHQ MH QMHJRYRJ Woplinskog stupnja djelovanja. Nadalje, namjera je bila razvijanje
integriranog kolektora koji bi se sadržavao i tradicionalne i nove PDWHULMDOH.RQDþQLFLOMMHGRSULQRVSULRVPLãOMDYDQMXQRYRJSURILWDELOQRJLMHIWLQRJVXQþHYRJNROHNWRUD.
.OMXþQHULMHþL VXQþHYR]UDþHQMHUDVSRGMHODWHPSHUDWXUDWRSOLQVNLVWXSDQMGMHORYDQMD
dizajn strukture

Energy and the Environment (2016) 177-186

177

NUMERICAL SIMULATIONS OF THE SOLAR CHIMNEY POWER
PLANT CONCEPT WITH SHORT DIFFUSER
Sandro NižHWLü
Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture,
8QLYHUVLW\RI6SOLW5%RãNRYLüD 32, 21000 Split, Croatia, snizetic@fesb.hrŽeljko Penga
Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture,
8QLYHUVLW\RI6SOLW5%RãNRYLüDSplit, Croatia, zeljko.penga@fesb.hr
Muslum Arici
Kocaeli 8QLYHUVLW\'HSDUWPHQWRI0HFKDQLFDO(QJLQHHULQJ8PXWWHSH<HUOHúNHVL
Kocaeli 41380, Turkey, muslumarici@gmail.com
Abstract: This paper deals with the numerical simulations of the alternative renewable energy
concept. Alternative energy concept is solar power plant with short diffuser which utilizes
convective vortices as heat engine, and were finally it is possible to produce mechanical workfor the electricity production via turbine. The previously mentioned concept is alreadydeveloped from the theoretically point of view but before the potential experimental
investigations it is crucial to perform numerical simulations. Therefore, this paper presents
preliminary results related to the CFD simulations of complex alternative renewable energy
system, where certain issues (influential input parameters, parameters that affect vortex
genesis and stability, surrounding conditions, etc.) have been addressed in order to provide
important base for the experimental approach and to check realistic possibility for realizationof considered alternative energy concept.
Keywords: solar chimney, numerical simulation, renewable energy, energy concept.
1. INTRODUCTION
Development of the alternative renewable energy systems is crucial to reach general goals
related to the restrain of the energy consumption and reduction of carbon dioxide emission in
the whole World. UN climate change conference in the Paris [1] has set goal to limit global
warming effect to less than 2°C compared to the pre-industrial levels. Further, at the moment
by usage of the existing, market available and mostly used renewable energy technologies,
previous goals would be hardly reached. Hence, we seek for new energy solutions, i.e. energy
concepts that will be based on renewables and that will ensure stable energy supply.
Solar energy is nowadays widely used for heat or electricity production where more efficientare solar thermal systems in comparison whit the photovoltaic systems, [2,3]. On a large scale
there is a large potential in the case of the concentrated solar systems (parabolic trough,heliostats, linear Fresnel reflectors, etc.), where we already have a prototype plants that are
successfully running and producing electricity from the Sun. For example, currently in
Morocco construction of the large concentrate solar power plant has started and it is plant of
580 GW in capacity (capable to cover population of around 1.1 million), [4]. Obviously weare entering in the era of large scale solar power plants.

178

61LåHWLüä3HQJD0$ULFL: Numerical simulations of the solar chimney…

This paper deals with the one specific energy concept where convective vortices are assumed
to be used as a sources of the mechanical energy (shaft work) for the turbine drive, i.e.
electricity production. Currently there are two theoretically developed concepts, first AVE(Atmospheric Vortex Engine) by Michaud, [5] and second concept of a Solar power plantwith short diffuser, [6]. I this study we are dealing with the proposed concept, [6].
The objective of this paper is to report preliminary results related to the CFD analysis of thealternative energy concept (the solar power plant with short diffuser) and which is an
important base for the further consideration of the demanding experimental approach.
2. OVERIVEW OF THE ALTERNATIVE RENEWABLE ENERGY CONCEPT
Solar power plant with short diffuser (SPPSD) ZDVSURSRVHGE\1LQLüDQG1LåHWLü>@, basedby their previous theoretical research findings, [7-10]. Simplified schematic overview of the
SPPSD is presented on the Fig. 1 were it is clear that propose alternative energy concept is
consisted from three main parts, i.e. from the solar collector S (collector roof), short diffusor,D, deflector F and specific fluid flow of gravitational vortex column (GVC).

Figure 1 Concept of the SPPSD, [7].
GVC is specific kind of the rotating fluid flow which consists from the updraft of the warm
air UF and of the downdraft of the cooled air, DF, Fig.1. Air downdraft in the central sectionof the GVC is extremely important for vortices genesis and maintenance, [11]. Further,nozzles in the system (N, Fig.1.) are crucial for vortices genesis (as well as also an element ofcontrol) as it ensures the water spray flow in the zone inside the diffuser section (addition of
the water spray has got favorable effect on the enthalpy of the humid air as it increases
working availability of the air). The working principle is simple, surrounding air enters at the
periphery of the solar collector and passing through collector it has been heated. Passing
towards the central section of the SPPSD warm air is forming GVC, which is in essence
rotating fluid flow (rotation is ensured by the helical blades in the central section that are
causing circular movement of the air). As already mentioned water nozzles are providing air
with the water spray and it is assumed to be happening only in the stage of the initial
operation. Finally, by previously explained way, a pressure difference has been produced
between surrounding air and air inside the SPPSD. Produced pressure potential could be thanused for turbine drive, i.e., for the electricity production. An analytical approach forestimation of the produced pressure potential in the case of the convective vortices wasEnergy and the Environment (2016) 177-186

179

elaborated in [12]. Hence, previously elaborated operating principle needs to be proved byexperimental approach, however first step is to provide an CFD analysis to explore all
possible risks and to provide on quality way possible experiment. Elaboration of the specificexperimental small-scale attempts of the similar AVE concept [5] (concept that also deals
with the work production from the convective vortex system) has been provided in the [13],which in essence is a prove that it is possible to create and maintain by artificial way
convective vortex.
3. NUMERICAL MODELLING
Almost every CFD model in the literature [14-16] deals with investigation of laboratory-scalevortex setups. Although small-scale vortex installation can be useful to determine the effect ofdifferent operating parameters on the overall shape and size of the vortex, it does not enable
setup of realistic boundary conditions present during the occurrence of natural gravitationalvortex columns (i.e. waterspouts, hurricanes, tornadoes). The driving force of the atmosphericvortex is the pressure difference between the air at the ground level, and at a certain geodetic
altitude. This pressure difference is a result of a temperature gradient between the warm
ground-level air and cooler air in the lower portions of the stratosphere. The temperature
gradient causes the uplift of ground level air of higher temperature and lower density, driven
by buoyancy, while the cross-winds induce the circumferential velocity of the flow. Air at
higher geodetic altitude has lower temperature, and thereby higher density, and the difference
between the densities of ground level air and air on certain geodetic altitude results in circularmotion of the air, where the warm air is driven upwards, while the cool air is moving towards
the ground. Therefore, in this work, a CFD model was developed to enable the study of thedescribed atmospheric conditions on the global vortex operating parameters – size and shapeof the vortex, and the mass flow rate of the uplifting air driven by the pressure difference. In
order to account the change in temperature and pressure of atmospheric air with geodetic
height, polynomial expressions are introduced in terms of user-defined functions. The
influence of relative humidity of air was not considered in this study due to a highcomputational complexity of multiphase-simulations with heat transfer for domains of thissize and the lack of experimental data to verify the simulation results. The simulations arecarried out in a commercial software ANSYS CFX.
3.1. Geometry
7KHJHRPHWU\ZDVEDVHGRQWKHZRUNVRI1LQLüDQG1LåHWLü>6], with different configurationsof the guide cone and the guide vanes. The maximum diameter of the short diffuser is fixed at
30 m. Figure 1 shows the geometry of the CFD model where the total geodetic height of themodel was chosen 2000 m. The height of the domain enables full development of the vortex
in height and gives insight in vortex height under realistic operating conditions. The shape ofthe guide vanes shown in Figure 2a., and the shape of the guide cone shown in Figure 2b. area result of extensive CFD study of different geometry parameters on the shape of the vortex.
Since the concept is novel, there are no available experimental installations from which thegeometry parameters could be implemented. In order to simplify the guide vane geometry andreduce the number of parameters for the vortex shape study, geometry of the guide vanes is a
two dimensional profile extruded in the vertical direction. Different guide cone geometries
were studied, the first one studied consisted of a cylinder with guide cone on the top, but it
resulted in a very limited range of operating parameters. By omitting the cylinder and leaving

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61LåHWLüä3HQJD0$ULFL: Numerical simulations of the solar chimney…

only the guide cone of a relatively primitive shape, the operating range was significantly
increased.

Figure 2 Numerical domains: a) solar chimney with short diffuser, guide vanes and solar
collector; b) shape of the guide cone; c) domain overview with mesh refinement region
The influence of the solar collector plate size is studied for three different outer diameters.
Furthermore, the solar collector plates have a prescribed temperature field dependent on thecollector radius, and are used to heat up the incoming air for a nominal pressure difference
between the inlet and the outlet of the simulation domain.
3.2. Mesh and boundary conditions
Considering the scale of the model, the mesh used for the simulations was adapted on a global
scale by defining element size of the mesh refinement region shown in Figure 2c. Mesh type
was hybrid, consisting of tetrahedral elements with prism layers on the walls of the solar
collector, guide vanes, guide cone and the chimney walls, while the transition between
tetrahedral and prism elements is achieved by wedge elements. Tetrahedral mesh was used
due to a complex geometry involved. In order to avoid very high computational requirements,
the number of finite volumes was kept in a range of two million cells. Grid dependency study
has shown that global parameters changed very little with higher volume count than 2 million
cells. Since the experimental data is not available for local parameters, which could be used
for calibration of the model, the simulations with relatively coarse mesh are used only to
study the global parameters of the vortex. Dimensionless wall parameter y+ was kept below
the value of 300 in respect to the upper limit value applicable for the RANS k-e turbulencemodel. Figure 3 shows boundary conditions applied for the simulations.

Figure 3 Boundary conditions, model not in scale

Energy and the Environment (2016) 177-186

181

3.3. Inlet
Pressure inlet was defined on the outter surface of the solar collector. Ideal gas was defined asmaterial, where the inlet temperature of the air was defined to be 30°C. Full buoyancy effects
are considered, as well as the change of ideal gas properties with temperature and pressure.
3.4. Opening
Definition of realistic boundary conditions on the opening was achieved by implementing
user-defined functions for gauge pressure pm and temperature T dependency on geodetic
altitude h, in form of polynomial expressions. Gauge pressure was defined aspm (h)=pa ቂቀ1-2.25577×10-5 ቁ h5.25588 -1ቃ

[Pa]

(1)

where pa represents the absolute atmospheric pressure of 101.325 Pa. While the temperaturedependency on geodetic altitude was defined as following,
T(h)=2×10-7 h2 -0.0087h+290.73

[K]

(2)

The polynomial expressions are used to calculate the density of air ideal gas.
3.5. Solar collector surfaces
The solar collector consists of two portions – upper and lower, as shown in Figure 3. In order
to simulate the effect of heating of the incoming air to the chimney, temperature fields aredefined on the collector surfaces. Since the upper portion is considered to be made of amaterial characterized by high solar transmission coefficient, the lower portion of thecollector will have a higher overall temperature profile than the upper portion, due to a greenhouse effect. The data from literature [17] suggests that a reasonable temperature difference
between the collector outer and inner diameter is in order of 25 – 30°C. The lower portion isconsidered to have a similar temperature distribution with slightly a higher overalltemperature profile by 5°C. The ambient air temperature is defined to be 30°C, corresponding
to desert-like climate where the installation would be most applicable. Temperature profile
over the collector surfaces is approximated with linear expressions, for the upper and lower
portion separately by defining the proper user-defined functions inside the software, as shownin Table 1. Parameter R in Table 1 represents diameter of the solar collector.
Table 1 User-defined temperature profile for the solar collector upper and lower portions fordifferent collector diameters
Parameter
Solar collector diameter
Temperature distribution upper collector surface
Temperature distribution lower collector surface
Solar collector diameter
Temperature distribution upper collector surface
Temperature distribution lower collector surface
Solar collector diameter
Temperature distribution upper collector surface

Value
200
T=-0.25R+328
T=-0.3R+333
600
T=-0.083R+328
T=-0.1R+333
1.000
T=-0.05R+328

Unit
m
K
K
m
K
K
m
K

182

61LåHWLüä3HQJD0$ULFL: Numerical simulations of the solar chimney…

Temperature distribution lower collector surface

T=-0.06R+333

K

4. PRELIMINARY RESULTS OF THE CFD ANALYSIS
Results of the CFD analysis, that will be presented in the continuation of the paper are
obtained for diameter of the solar collector of 600 m. Mass flow of the air has ranged fromapproximately 30.700 kg/s up to 46.000 kg/s and maximal achieved height of the vortex was
669 m. Pressure potential, i.e. pressure difference between surrounding air and air in thecentral zone of the convective vortex has ranged from 50 hPa up to 120 hPa. Absolute
velocity profiles with streamlines are presented on the Figure 4 for previously specified
general circumstances.

Figure 4 Absolute velocity profiles with streamlines
From the Figure 4 it is noticeable that vortex is established in the atmosphere for above
specified conditions, however vortex height is significantly lower one than predicted bytheoretical approach. Specific pressure profile is presented on the Fig. 5 where it is clearly
noticeable pressure potential between the surrounding air, and air in the central zone of therotating fluid flow. Circular velocities are being presented on the Fig. 6 and it is also
noticeable that central part of the fluid flow rotates as the solid body, so there is a linear
dependency for the circular velocity with the specific radius of the vortex in consideredregion. Maximal achieved magnitude of the circular velocity was around 70 m/s which is inorder of magnitude that can be found in the case of the natural convective vortices. Figure 7
shows a distribution of the vertical velocities where it is important to detect a one detail.
Namely in the central section of the vortex fluid flow we have negative values of the verticalvelocities, i.e. air downdraft has occurred in that region. Previously CFD gained result werepredicted in theoretical investigations of the proposed concept, [7,8,11]. Hence, it is obviousthat important factor for genesis and maintenance of the specific fluid flow in the surrounding
atmosphere is necessary existence of the air downdraft (in the central section of theconvective vortices system). Regarding general data gained through the CFD analysis it canbe concluded that all numerically gained values for pressure difference and velocities are inagreement with the available field data for the natural convective phenomena’s in the nature,

Energy and the Environment (2016) 177-186

183[18] (although it is not easy to compare them as they are not same vortex structures). Latermeans that on one way preliminary CFD analysis gained reasonable results that hardly can bedirectly validate as in the basis we deal with the artificial fluid structure so we don’t haveavailable experimental results (but we can indirectly validate with the available data from thenatural convective structures).

Figure 5 Pressure contour

Figure 6 Circular velocity distribution for different altitude

184

61LåHWLüä3HQJD0$ULFL: Numerical simulations of the solar chimney…

Figure 7 Vertical velocity distribution at different altitudes
Therefore, in this stage we can provide a wide range of the CFD gained scenarios that needs
to be based on the realistic boundary conditions. Moreover, gained results should be carefully
validated, as previously mentioned, validation with the available data from the meteorologist
scientists that are dealing with the observation of the natural convective phenomena’s.
5. CONCLUSIONSThis paper deals with the numerical modelling, i.e., CFD analysis of the alternative energy
concept. The crucial part of the considered alternative energy concept is specific fluid flow,
i.e. convective vortex. Convective vortex is source of the pressure potential that can be used
for turbine drive, i.e. for the electricity production. Gained preliminary CFD results forpressure difference and velocities showed reasonable results and in general agreement withthe order of magnitude when compared to the natural convective phenomena’s (i.e. inagreement whit the available observation data). However, more intense CFD analysis needs tobe obtained in order to get more precise and more realistic data for all circumstances that canaffect specific convective vortices genesis and maintenance in the surrounding atmosphere.
Finally, previously mentioned circumstances are important to shape future possible
experimental attempt to realize proposed alternative energy concept and that it will be in thefocus of the future research work.
NOMENCLATURE
h – geodetic altitude, mp – pressure, Par – radius, m
T – temperature, K
REFERENCES[1] Web source: http://www.cop21.gouv.fr/en/, Last visited Jun 13, (2016).
[2] Chen, H., Riffat, S.B. Development of photovoltaic thermal technology in recent years: A
review, International Journal of Low-Carbon Technologies 6(1), (2011), 1-13.
[3] Kumar, R., Rosen, M.A. A critical review of photovoltaic-thermal solar collectors for air
heating, Applied Energy, 88(11), (2011), 3603-3614.
[4] Web source: http://edition.cnn.com/2016/02/08/africa/ouarzazate-morocco-solar-plant/,
Last visited Jun 16, (2016).

Energy and the Environment (2016) 177-186

185[5] Michaud, L.M. Proposal for the use of a controlled Tornado-like Vortex to Capture the
Mechanical Energy Produced in the Atmosphere from Solar Energy, Bulletin American
Meteorological Society, 56(5), (1975), 530-534.
[6] NiQLü11LåHWLü S. Solar Power plant with short diffuser, Patented Invention, (2007),
PCT/HR2007/000037-(WO/2009/060245).
[7] 1LQLü11LåHWLü S. Elementary theory of stationary vortex columns for solar chimney
power plants, Solar Energy, 83(4), (2009),462-476.
[8] 1LåHWLü6An atmospheric gravitational vortex as a flow object: improvement of thethree-layer model, Geofizika, 27(1), (2010), 1-20.
>@1LåHWLü6 *UXELãLü-ýDER)%XJDULQ0Experimental setup for the analysis ofvortices, Journal of Applied Fluid Mechanics 8(1), (2015),143-149.
[10] 1LQLü1-XULü=1LåHWLü6Thermodynamical aspect of definitions ‘’CAPE’’ and‘’TCAPE’’, Geofizika, 23 (2),(2006),143-154.
[11] Markowski, P.M., Straka, J.M., Rasmussen E.N. Tornado genesis resulting from thetransport of circulation by a downdraft idealized numerical simulations, American
Meteorological Society, (2003),795-823.
[12] 1LåHWLü6Analytical approach for estimating the pressure drop potential in convective
vortex heat engines, Transactions of the Canadian Society for Mechanical Engineering,38(1),(2014), 81-91.
[13] Web source: http://vortexengine.ca/index.shtml, Last visited, June 21,(2016).
[14] Sharma, G., Ghosh, S., Karmakar, S., Computational Fluid Dynamic Simulation ofSingle and Two-Phase Vortex Flow-A Comparison of Flow Field and Energy Separation,
Journal of Heat Transfer, 138,(2016).
[15] Chinnici, A., Arjomandi, M., Tian, Z.F., Lu, Z., Nathan, G.J. A, Novel Solar ExpandingVortex Particle Reactor: Influence of Vortex Structure on Particle Residence Times andTrajectories, Solar Energy, 122,(2015),58-75.
[16] Gao, X., Kong, B., Vigil, R.D., CFD investigation of bubble effects on Taylor-Couette
flow patterns in the weakly turbulent vortex regime, Chemical Engineering Journal, 270,(2015),508-518.
[17] Haaf, W. Solar chimneys, part II: Preliminary test results from the Manzanares pilot
plant, International Journal of Solar Energy, 2,(1984),141-161.
[18] Renno, N. A thermodynamically general theory for convective vortices, Tellus, 60A,
(2008),688-699.

186

61LåHWLüä3HQJD0$ULFL: Numerical simulations of the solar chimney…

180(5,ý.$6,08/$&,-$ KONCEPTA SOLARNE ELEKTRANE SAKRATKIM DIFUZOROMSažetak: 8RYRPUDGXUD]PDWUDVHQXPHULþNDVLPXODFLMDDOWHUQDWLYQRJHQHUJHWVNRJNRQFHSWD
kao obnovljivog izvora energije. Alternativni energetski koncept se odnosi na solarnu
elektranu sa kratkim difuzorom gdje se konvektivni vrtlog koristi kao toplinski motor, i gdje je
XNRQDþQLFLPRJXüHSURL]YHVWLNRULVWDQPHKDQLþNLUDG]DSRJRQWXUELQHWMJGMHMHPRJXüH
SURL]YHVWL  HOHNWULþQX HQHUJLMX 3UHWKRGQR VSRPHQXWL NRQFHSW MH YHü WHRUHWVNL UD]UDÿHQ DOL
prije razmatranja eksperimentalnog pristupa potrebno je provesti nuPHULþNH VLPXODFLMH
Stoga, u ovom radu predstavljaju se preliminarni rezultati CFD simulacije složenog
HQHUJHWVNRJ NRQFHSWD JGMH VH DQDOL]LUDMX RGUHÿHQL JODYQL XWMHFDMQL SDUDPHWUL NRML XWMHþX QD
nastajanje, održavanje te stabilnost konvektivnog vrtloga u okolnoj atmosferi. Upravo analiza
glavnih utjecajnih parametara je iznimno važna kako bi se mogle definirati realne polazne
RVQRYH]DPRJXüXHNVSHULPHQWDOQXUHDOL]DFLMXDOWHUQDWLYQRJHQHUJHWVNRJNRQFHSWD
.OMXþQHULMHþL VRODUQLGLPQMDNQXPHULþNHVLPXODcije, obnovljivi izvori energije, energetski
koncept.

Energy and the Environment (2016) 187-196

187

ENERGY ANALYSIS OF ACTIVE SOLAR DRYING SYSTEMCONNECTED WITH PHOTOVOLTAIC MODULES
Maytham A. Al-Neama1 and István Farkas2*
1

Mechanical Engineering Doctoral School, Szent István Universty*|G|OOĘ3iWHU.X, H-2103 Hungary, iqmay80@gmail.com

2

Physics and Process Control Department, Szent István Universty,*|G|OOĘ3iWHU.X, H-2103 Hungary, Farkas.Istvan@gek.szie.hu*
Corresponding author
Abstract: Photovoltaic (PV) powered solar dryer offers good solution to the many problems
encountered by farmers in the rural communities of different countries around the world. It is
made the drying systems self-sufficient and independent of any another external source ofenergy. A photovoltaic-thermal solar dryer under active mode has been proposed and different
parameters have been evaluated for climatic condition of Szent István University, *|G|OOĘ,
Hungary (47.5oN, 19.05o E). The dryer was consisted of drying chamber, the solar collector,
chimney, blower and PV module. Airflow velocity control through the dryer is a very important
process because the velocity should be varying according to the product type. The control
process depends on system energy analysis. To achieve this objective, an energy analysis has
been done based on the basic energy balance. The motion of air through the dryer and collector
by a blower. The blower has been connected with photovoltaic module with maximum power of
2×20 Wp. The solar collector was tilted at 45o from the horizontal and facing south according to
the system. The performance parameters of the photovoltaic thermal system were collected interm of the electrical and thermal efficiency.
Key words: Photovoltaic, dryer, solar collector, efficiency
1. INTRODUCTION

Drying of agricultural crops dates back to the beginning of the civilization. along with the rapid
increase in mechanization with high productivity (Hall, 1980). Drying is applied to a wide
variety of food products, from cereals to finished goods, from raw materials to by-products.
Many processes are used, according to the type and quantity of product to dry, the amount ofwater to remove, the final desired quality or functionality of the dried product (Bimbenet et al.,2012).
Drying is a complicated process including transient transfer of mass and heat with several rate
processes, such as physical or chemical transformations, which, in turn, may cause changes in
product quality. The indirect forced convection solar drier (active) integrated with heat storage
material is more suitable for producing high quality copra. (Mohanraj and Chandrasekar, 2009).
Active drying that require the use of the fun or a blower to pump air through the product and alarger mass of materials can be handled with much reduction in drying time. Photovoltaic solar
thermal dryer represents a good solution to the many problems encountered by farmers aroundthe world. PV technology, which utilizes sunlight to generate electricity energy, is an attractive
alternate energy source because it is renewable, harmless, and domestically secure.

188

M. A. Al – Neama, I. Farkas: Energy analysis of active solar drying system…

Adelaja et al. (2009) developed a forced convection solar dryer (active dryer) that powered by asolar PV module. The dryer was consisted of drying chamber, the solar collector, the blower andPV module. The motion of air through the dryer and collector by a blower. The blower has beenconnected with photovoltaic module rated 11 Wp powered DC blower rated 12 V to facilitate air
flow and evacuation of moisturized air within the drying chamber. He concluded that PV
powered solar dryer offers good solution to the many problems encountered by farmers in therural communities of Africa, particularly, the preservation and commercialization of their farm
produce which quality do not meet either or both national and international standards.
Anyanwu et al. (2012) tested and investigated the performance of a PV powered solar dryer.
Solar collector consisted of a black painted absorber plate made of 1.5 mm-thick mild steel,encased in a glazing formed out of 4 mm thick silicon glass panels. The absorber plate wasinsulated with glass wool and sawdust insulators. The blower mounted facing the air channel ofsolar collector with rated power of 90 W AC (positive draft). The supply power to the blower
was provided by 2×80 W photovoltaic panels connected in series. The collector was connectedto the drying chamber with polyethylene pipes of 80 mm internal diameter, which are usually
flexible insulators. The major advantages of the system derive from its independence from gridelectricity also the overall cost could be reduced by using a DC blower.
Many literatures reviewed by Bennamoun (2013) which explained that the PV cell can be used
inside the solar collector in order to increase the total efficiency of the solar drying system.
According the different studies, efficiencies as high as 70% were obtained. On the other hand,PV cells can be used to provide electrical energy that can be consumed by the other componentsof the solar drying system such as the circulation fans. Also electrical energy can be stored byusing batteries to use it during low sun radiation periods. This makes the drying systems selfsufficient and independent of any another external source of energy.
Ahn et al. (2015) studied the performance of photovoltaic/thermal (PV/T) solar air collector
coupled with heat recovery ventilation. From the results, it was obtained that thermal andelectrical efficiencies of PV/T collector were 23% and 15%, respectively. Therefore, the overall
efficiency of the PV/T collector system is the summation of tow efficiencies and equal 38%.
Also, heat transfer efficiency of heat recovery ventilation was improved to about 20%.
The performance of photovoltaic–thermal (PVT) Integrated with a mixed mode solar dryer havebeen analyzed by Tiwari et al. (2016). The device consisted from three PV modules, two DC fan
and a drying chamber. The dimensions of each semi-transparent PV module is 1 m × 0.4 m
which have 36 circular shape cell of 35 Wp power. The rating of DC fan was 12 V and 1 A. The
structure of dryer was made of 3 mm thick glass which fitted in aluminium frame with the helpof rubber gasket. Numerical computations have been done with the using a MATLAB 2013a
software and the results were validated with experimental values. The results showed that thequality of dried product was increased and problem of discoloration has been minimized. Also,
the solar cell efficiency decreases as cell temperature increases. In the same year of this study,
Elbreki et al. (2016) were reviewed many literatures which related to the parameters of climatic,design and operational factors was carried out to evaluate their effect on the thermal, electricaland overall efficiency of photovoltaic thermal (PVT) systems

2. DISCRPTION OF THE DRYER

Energy and the Environment (2016) 187-196

189

The recent study was carried out in connection with a solar dryer installed at the Department of
Physics and Process Control, Szent István University *|G|OOĘ +XQJDU\. The dryer has threemain parts as shown in Fig. 1.

Fig. 1. The schematic scheme of the solar dryer systemxa dryer (drying chamber) with different trays for the different products. A tray holder with 4
trays was developed for the surface drying when the product is too fine to flow the drying air
through it. In this case the trash holder forces the air to flow above the product. Another tray
holder with 7 trays was developed for bulk drying, when to air flows through the productlayers. The drying cabin has a sire of about 0.8 m x 1 m x 0.65 m, and it has four legs withthe height of I m. The tray holders are removable and changeable according to the products
to be dried as shown in Fig. 2.

Fig. 2. Drying chamber traysx

an air solar collector of about 1 m2 attachable to the dryer for preheating the inlet air. The
solar collector has the size of 2 m x 0.5 m x 0.2 m. It has a transparent cover on the top andthermal insulation at the bottom side. For the better energy reception a perforated plastic
absorber plate was installed on the half height of the collector body. The solar collector in190

M. A. Al – Neama, I. Farkas: Energy analysis of active solar drying system…

this work is oriented facing south and tilted at 45o to the horizontal according to the solar
chart for Budapest region (Budapest 47.5oN , 19.05o E).
xthe effects of natural convection will be improved by adding a chimney in which exiting air
is heated even more and enhance the buoyant flow of air. This will have a vital role to theoverall design of solar dryers. Some study showed that the installation of three small fans anda photovoltaic cell is equivalent to the effect of a 12 m chimney.

xa PV module with the maximum power of 2x20 W and an electrical fan for artificial air
circulation connected with the system. The PV panel is installed in the front side of the dryer
with changeable elevation angle which is suitable to the different angle of the sunshine in the
different periods of the year. Two switches make possible that the fan use the half or thewhole power of the PV model.

3. ENERGY ANAYSIS
Solar air collector
Energy balance equation of the air solar collector of is written as:
Useful heat = solar radiation energy + heat losses + inlet air heat content –outlet air heat content.
Mathematically:
M .Cp .

dTout
dt

(1)

Ĳ . I . A  U L . A .(Tc  Ta )  m o . Cp . Tair,in  m o . Cp . Tair,out

then,
dTout
dt

>

1
Ĳ,$  U L .A.(Tc  Ta )  m o .C p .Tair,in  m o .C p .Tair,out
M.C p

@

(2)

The collector overall heat loss coefficient (UL) is the sum of top, bottom and side edges heat loss
coefficients. It means:
UL = UB + US + UT

(3)The bottom and edges heat losses coefficient (UB) and (US):UB = KB / XB

(4)

US = (KS / XS) . [Hc. (L+w) / (L.w)](5)

For most solar collectors the estimation of side edges heat losses is complicated. However, in awell-designed system, the edge loss should be small so that it is not necessary to predict it withgreat accuracy. The top heat loss coefficient (UT) varies with number of glass covers,
temperature of the absorber plate and other parameters. The top heat loss coefficient UT is
calculated empirically, as follow:(6)

Energy and the Environment (2016) 187-196

191

where;&  íȕ2)(7)

f = (1+ 0.089.hw – 0.1166.hw ‫ܭ‬p )(1+0.07866N)(8)

e = 0.43 (1í7C)(9)
hw = 2.8 + 3V
(10)
for the above relations, a MATLAP simulation program has been developed to estimate theperformance of air solar collector.
Dryer
When the dryer is empty, the incoming air from the collector at a temperature ( Td,in ) has relative
humidity ( RHin ) and the outlet air at a temperature ( Td,out ), has a relative humidity ( RHexit ).
Because (Td,out), > (Td,in), and the dryer contains no item, RHin> RHexit . Thus there is tendency
for the exit hot air to pick more moisture within the dryer as a result of the difference between
RHin and RHexit. The total energy required for drying a given quantity of products items can be
estimated using the basic energy balance equation for the evaporation of water. The basic energybalance equation (mass + heat) for the evaporation of water , as written below;
Qair,inlet + Qproduct,inlet = Qair,outlet + Qproduct,outlet + Heat losses.
For well insulated system, the amount of heat losses through the dryer can be neglected. Thenrewriting the mathematically equation;
W. LV = mo . CP . ( Td,in – Td,out).

(11)

The basic theory of drying process was described by Lewis (1921) based on the analogy with
Newton’s law of cooling and is often used to mass transfer in thin-layer drying as follows:dMdt k .(M  Me)(12)

By solving the above Formula for these boundary conditions (at t = 0 , M = Mo DQG DWW 0= Me), get:Mt  MeMo  Mee  KtMR(13)

and the above equation represent to the moisture ratio (MR)(dimensionless).
Chimney
The chimney increases the amount of air flow, through the solar dryer by speeding up the flow ofthe exhaust air. Hence the effects of natural convection will be improved by adding a chimney inwhich exiting air is heated even more and enhance the buoyant flow of air. In the flowing
condition, the mean temperature inside the chimney is relatively higher than the ambient air
temperature. In this case, there exists a pressure head which creates an upward air flow.
Therefore the relation among the buoyancy force that is the pressure drop that creates the air
flow, the height, density difference of the ambient air and chimney is related as follows:

192

M. A. Al – Neama, I. Farkas: Energy analysis of active solar drying system…

¨3b J+ ȡa-ȡch).

(14)

The pressure difference due to the buoyant pressure head in term of temperatures is given by:¨3b J+ȕȡ 7ch -Ta).

(15)

Over the temperature range 25-90°C (within which natural-circulation solar-energy dryers would
operate), the density of dry air is related to the temperature by the following empiricalexpressionȡ – 0.00308 T.

(16)

By substituting equation (16) in (15), get:¨3b = 0.00308 . g . H . (Tch -Ta).

(17)

Within the chimney, pressure drops are due mainly to wall friction. Assuming turbulent flow
(with a friction coefficient of 0.035) , the pressure drop due to friction loss can be given as:¨3b ૦ Y2 .H / 2D),

(18)

where ૦LVWKHDYHUDJHGHQVLW\RIIOXLGWKURXJKWKHF\OLQGULFDOGXFW FRUUHVSRQGLQJWRWKHPHDQ
chimney air density for the case of the solar chimney). Combining equations (17) and (18);૦ Y2 .H / 2D) = 0.00308 . g . H . (Tch -Ta).

(19)

Thus,
v = 0.453 'J¨7ch / ૦ ½(20)

as shown in above relation , the velocity is a function of temperature change across the chimney.
It should be noted that the above expression is derived without taking into account the additional
buoyancy arising from the increased humidity of the air stream. To include this would require
assumptions to be made concerning the amount of moisture added to the air stream.
Photovoltaic module
The energy of a PV system depends on two major components namely electrical energy andthermal energy. While the electricity is generated by photovoltaic effect, the PV cells also getheated due to the thermal energy present in the solar radiation. The electricity generated by aphotovoltaic system is also termed as the electrical exergy, as it is the available energy that cancompletely be utilized in useful purpose (Joshi et al., 2009).
The energy efficiency of a PV system can be defined as the ratio of the output energy of thesystem to the input energy received on the photovoltaic surface, and can be expressed as:(21)
Since the thermal energy available on the photovoltaic surface is not utilized for useful purpose,
furthermore this energy called as heat loss to the ambient, and the input energy represents bysolar radiation, then equation can be rewritten as:(22)

Energy and the Environment (2016) 187-196

193

However, the above definition is restricted to theoretical cases only, and furthermore Eq. (22) iscalled as the maximum (theoretical) electrical efficiency. Other definition related to energy
efficiency is efficiency of power conversion (Șpc) and in practice this efficiency is more
applicable. The power conversion efficiency (Șpc) can be defined as:(23)
where FF is the fill factor. Finally, to estimate the total efficiency for all the system (solar
collector and dryer chamber) in case without using PV module, the following relation represents
the ratio between input energy and output energy to the totally system has been calculated. The
system efficiency indicates the overall thermal performance of a drying system including theefficiency of a solar collector, the drying chamber and any other supplement add to the system.
(24)
Increasing heat transfer by convection, turbulence of air should increase, so, the effects of freeconvection will be enhanced by adding a long chimney in which exiting air is heated even more
by friction and enhance the buoyant flow of air. Some studies showed that the installation of
three small fans and a PV cell is equivalent to the effect of chimney with 12 m length.
The last performance Eq. (24), represents the efficiency of the system with natural convection air
flow (by bouncy forces). But with this test rig, a PV module with the maximum electrical powerof 2x20 W and an electrical fan for good forced air circulation integrated with the system. The
PV panel is installed in the front face (to the south) of the dryer as shown before with changeable
elevation angle. Suitable to the different angles in the different time periods of the year. Thatmeans, an additional input power to the system, the total system efficiency will be:(25)
4. CONCLUSION
Drying process inside solar drying system depend on the temperature and humidity difference
between the product inside the chamber. The difference in latent heat between the product and
air will be the stimulus for drying process. The range of temperature difference depends on
product type. Sometimes, the excessive heating will be harmful for the product (fish, meat ....
etc).
The most important advantages to using flat plate air solar collector to provide the heat fordrying process are low construction costs and minimal effect in pressure drops. However, themain drawback of solar air collectors is the low heat transfer coefficient between the absorberplate and the air stream due to poor thermal conductivity and low heat capacity of air.
Also, the rate of water evaporated from the products inside the drying chamber related with air
stream velocity inside the drying chamber. The chimney is to increase the velocity of air
naturally then will increase the efficiency of drying. From this point, the chimney gets theimportance. So, getting good air speed for which product depends on chimney design (air flow

194

M. A. Al – Neama, I. Farkas: Energy analysis of active solar drying system…

area). But the increasing of air speed more than limits, will give bad side effects for someproducts.
The thermal energy available on the photovoltaic surface is not utilized for useful purpose,
furthermore this energy considered as heat loss to the ambient. So to enhance the performance ofPV module, the thermal losses should be decreased.
This study was as a start point for many future studies about modelling for this types of systems
and developed models by different software for different products.
5. LIST OF SYMBOLS
A
CP
D
FF
g
H
h
I
Imp
K
k
L
Lv
M
MR
mo
N
P
Q
T
t
U
V
Vmp
v
W
w
X

solar collector absorber plate area
air specific heat
Duct diameter
fill factor
Acceleration due to gravity
Height (head)
convection heat coefficientsolar radiationelectrical current
conductivity
drying constantcollector length
latent heat of vaporization of water
air mass inside collector
moisture ratio
air mass flow rate
number of glass covers
pressure
heat rate
temperaturetimeheat transfer loss
wind velocity
voltageair velocity through systemwater mass evaporated from productcollector widthcollector thickness

m2
J/kg.oCm-m/s2m
W/m2.oC
W/m2
A
W/m. oC
-m
J/kg
kg
-kg/s
-Pa
W
o
C
s
W/m2. oC
m/s
V
m/s
kg/s
m
m

Greek letters
ȕ
¨
ȡ
Ĳ
ѓ

bulk coefficient of expansion of airchangedensitytransmitivity
emissivity

K-1-kg/m3---

Energy and the Environment (2016) 187-196

ı195

W/m2 K4

Stefan-Boltzmann constant

Subscripts
a
B
b
c
ch
d
e
en
g

ambient air
bottombuoyancycollector
chimneydryer
equilibrium
energy
glass

in
L
out
p
pc
s
T
w

inlet
lossesoutletplate
power conversion
side
top
wind

ACKNOWLEDGEMENTS
This research presented in this paper was supported by the Stipendium Hungaricum Programmeand Mechanical Engineering Doctoral School at the Szent István University, *|G|OOĘ, Hungary
REFERENCES[1] Hall, C.W.: Drying and storage of agricultural crops, Avi Publishing Co., the University of
Wisconsin, Madison, 1980.
[2] Bimbenet, J. J, Bonazzi, C. and Dumoulin, E.: Drying of foodstuffs, Proceeding of the 13th
International Drying Symposium, 2012, A, pp. 64-80.
[3] Mohanraj, M. and Chandrasekar, P.: Performance of a solar drier with and without heatstorage material for copra drying, International journal global energy issues, 2009, 31(2), pp.
112-121.
[4] Adelaja, A.O., Ogunmola, B.Y. and Akolade P.O.: Development of a photovoltaic powered
forced convection solar dryer, Advanced materials research journal, 2009, 62-64, pp. 543548.
[5] Anyanwu, C.N., Oparaku, O.U., Onyegegbu, S.O., Egwuatu, U., Edem, N.I., Egbuka, K.,
Nwosu, P.N. and Sharma, V. K.: Experimental investigation of a photovoltaic-powered solarcassava dryer, Drying technology journal, 2012, 30, pp. 398-403.
[6] Bennamoun, L.: Integration of photovoltaic cells in solar drying systems, Drying Technology
Journal, 2013, 31, pp. 1284-1296.
[7] Ahn, J.G., Kim, J.H. and Kim, J.T.: A study on experimental performance of air-type PV/T
collector with HRV, Energy procedia journal, 6th International Building Physics Conference,
2015, 78, pp. 3007 – 3012.
[8] Tiwari, S., Tiwari, G.N. and Al-Helal, I.M.: Performance analysis of photovoltaic–thermal(PVT) mixed mode greenhouse solar dryer, Solar energy journal, 2016, 133, pp. 421-428.
[9] Elbreki, A.M., Alghoul, M.A., Al-Shamani, A.N., Ammar, A.A., Yegani, B., Aboghrara A.
M., Rusaln, M.H. and Sopian, K.: The role of climatic-design-operational parameters on
combined PV/T collector performance: A critical review, Renewable and sustainable energy
reviews journal, 2016, 57, pp. 602-647.

196

M. A. Al – Neama, I. Farkas: Energy analysis of active solar drying system…

[10] Joshi, A.S., Dincer, I., Reddy B.V.: Performance analysis of photovoltaic systems: a review,
Renewable and Sustainable Energy Reviews, 13, pp. 1884-1897.

ENERGIJSKA ANALIZA AKTIVNOG SOLARNOG SUŠIONOGSUSTAVA SPOJENOG SA FOTONAPONSKIM MODULIMASažetak: Solarna sušilica pogonjena fotonaponskim (FN) modulima nudi dobro rješenje za
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svijeta. Ovako dizajniran sušioni sustav je samodostatan i neovisan o bilo kojem drugom
vanjskom izvoru energije. Fotonaponska-termalna solarna sušilica u aktivnom režimu rada
SUHGORåHQD MH L UD]OLþLWL UDGQL SDUDPHWUL VX SUHGVWDYOMHQL ]D NOLPDWVNH XYMHWH 6YHXþLOLãWD Szent,VWYiQ*|G|OOĘ0DÿDUVND 47.5o N, 19.05o E). Sušilica se sastoji od sušione komore, solarnog
kolektora, dimnjaka, ventilatora i FN modula. Kontrola brzine strujanja zraka kroz sušilicu jevrlo važan proces jer se brzina varira prema vrsti proizvoda. Kontrolni proces ovisi oenergijskoj analizi sustava. Kako bi se postignuo ovaj cilj, energijska analiza napravljena je na
WHPHOMX ED]LþQH HQHUJLMVNH ELODQFH JLEDQMD ]UDND NUR] VXãLOLFX L NROHNWRU SRPRüX YHQWLODWora.
Ventilator je spojen sa fotonaponskim modulom maksimalne snage 2 x 20 W. Solarni kolektor je
nagnut 45° u odnosu na horizontalu i okrenut je prema jugu. Radni parametri fotonaponskog
WHUPDOQRJVXVWDYDSULNXSOMDQLVXXSRJOHGXHOHNWULþQHLWHUPLþNHXþLnkovitosti.
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Energy and the Environment (2016) 197-208

197

DESIGN OF A 3KW PV POWER SYSTEM FOR A RESIDENTIAL HOME
Marius Viljoen1, Christo Pienaar2
Department: Electronic Engineering/Faculty of Engineering & Technology
Vaal University of Technology/Andries Potgieter blvd/ Vanderbijlpark1
mviljoen@vut.ac.za
2christop@vut.ac.za

Abstract: This paper describes the design considerations of a 3kW PV power system for aresidential house in Vereeniging, Gauteng South Africa. The design starts with a needs analysis
followed by the actual design. After implementation of the design a comparison on power needed
before the PV installation and after the installation is made. The results of the comparison are
discussed and recommendations are made. The purpose of the PV power system design is toimprove energy efficiency and reducing the carbon foot print of a residential home. The firstpriority was to determine the need of the specific residence. The design will specifically consider
string inverter technology.
Keywords: String Inverter, PV Modules, Grid tie, Off-grid, Energy Efficiency, Hybrid PV
Installation, PV panel mounting, Shading analysis

1. INTRODUCTION

Renewable electricity generation equipment such as photovoltaic (PV) modules, small windturbines and micro-hydro turbines has typically been considered as off-grid technology, used inareas where it is considered to be too expensive to bring the grid electricity to a particularcustomer[1]. With the PV current market trends, designers are confronted with two choices of
installation, i.e. off-grid or grid tie, where each approach has its advantages and disadvantages.
“Off-grid” means the residence is on its own: (Like an island away from the main land, also
referred to as an island system) there is no connection to the utility power company. The only
way to accomplish this in a setting where electricity is needed even when the sun is not shining,
is to incorporate batteries into the system. Thus off-grid homes have no grid power, and draw thepower they need from deep cycle battery banks when there is no sunlight.
“Grid-tied,” by contrast, means that the residence is connected to the grid, and power still need
to be purchased from the utility company when needed. But, when the solar array is producing
power, the power can either be sold straight to the utility company via the grid with the goal of
financially reducing the cost of the power purchased, or it can be utilised by the owner of theresidence first, and then sell any extra power via the grid to the utility company.
There are several instances in which it can be desirable to install small-scale renewable energy
generation equipment embedded within the low-voltage distribution network. This may include:a) personal, local, regional or national objectives to increase the renewable energy
component of electricity utilized (again with a whole range of drivers including
sustainability, climate change, future fossil price volatility risk aversion, utility energy
shortages, etc.);[1]198

M. Viljoen, C. Pienaar: Design of a 3 KW PV power system for a residential homeb) changing dynamics of electricity generation costs, with embedded generation close to thesource of consumption becoming economically or financially viable; and c) in particular
contexts where embedded generation may help alleviate localized network capacity
constraints or improve power reliability to key circuits on the customer premises(particularly if it can be dispatched or coupled with energy storage). [1]Internationally, the grid-connected market for renewable electricity generation technologies (andin particular PV) has become far more important than the off-grid market. A key constraint to theimplementation of grid-connected small-scale renewable energy activities in South Africa is thelack of pre-approved, generic standards for utility engineers and system promoters to apply indesigning and approving the utility interface. [1]The advantages of one system over the next come down to cost, comfort and independence. A
grid-tied system will cost less because it does not require batteries, which form a significant
portion of the cost of an off-grid system. A grid-tied system for a net-zero home will also costless because fewer solar panels are needed: When not needed to store energy in batteries for lateruse, it is not needed to produce quite as much energy in order to offset the yearly energy use. [2]A grid-tied system is also more flexible, since power can still be bought from the utility company
managing the grid, a resident won’t suddenly find himself without electricity if accidentally thelights were left on all night—although the resident will have to pay the electric bill for such a
mistake. As the resident isn’t tied in to producing all of his own power, he can use a grid-tiedsystem to install as much solar panels as his budget allows him to install. At present in South
Africa the resident needs permission to supply energy to the grid and there is no remuneration forexcess power supplied.
Although the off-grid array’s capacity can be increased over time, it is better to plan the system
so that there is enough power from the start since panel modules a continuously being improved
and older models might not be available anymore when an increased capacity is needed and it is
not desired to mix different panel types because of different open circuit and Maximum Power
Point (MPP) voltages and currents.
Modern intelligent inverters are an important part of any solar installation; as they are the power“managers” of the system. Although the inverter’s main job is to convert DC power produced by
the solar array into usable AC power, its role in the system is much more. Some inverters enable
online or wifi monitoring of all related parameters of the system so that installers and owners cansee how the system is performing. Inverters can also provide diagnostic information to help
technicians identify and fix system issues. These important components are increasingly taking
on decision-making and controlling functions to help to improve the grid stability and efficiency.
With the growth of solar storage, inverters are also taking on responsibility for battery
management. Next the different types of solar inverters are discussed.

2. INVERTERS
Inverters for PV installations are categorised in three groups. Firstly, string inverters which
utilise a string of PV panels connected to the string inverter, secondly central inverters which
are similar to string inverters but they are much larger and can support more strings of panels andthe third type is micro-inverters as can be seen in Figure 1. They are module-level inverters so
therefore a micro-inverter is installed on each PV panel. Unlike power optimizers which do
optimise output in case of shading but don’t do conversion, micro-inverters convert DC power toEnergy and the Environment (2016) 197-208

199

AC right at the panel and so don’t require a string inverter. Furthermore, a number of them canbe connected in series since they automatically synchronise with each other to produce AC
power.
This design however will only consider the string inverter because it is at present the most cost
restraint effective inverter type available. String Inverters can also be connected in series toincrease the power output and if three are used in series a 3 Phase system can be constructed.

Figure 1 Micro Inverter (Courtesy Renesolar)

Solar panels are usually installed in rows, each on a “string.” For example, if there are 12 panels
there can be 4 rows of 3 panels. Multiple strings are connected to one string inverter. Each string
carries the DC power the solar panels produce to the string inverter where it’s converted into
usable AC power consumed as electricity. Depending on the size of the installation and theinverter, there may be several string inverters each receiving DC power from a few strings.
String inverters are good for installations where there is no shading issues and in which panels
are positioned on a single plane, so do not face different directions. If an installation uses string
inverters and even one panel is shaded for a portion of the day reducing its performance, theoutput of every panel on the string is reduced to the power level of the shaded panel level.
Though string inverters aren’t able to deal with shading issues, the technology is trusted andproven and are less expensive than systems with micro-inverters. String inverters are commonlyused in residential and commercial applications. Also, as technology improves allowing string
inverters to have greater power density in smaller sizes. [3]String inverters can also be paired with power optimizers. Power optimizers are installed on each
PV panel. Some panel manufacturers integrate their products with power optimizers and sellthem as one solution known as a Smart Module. This can make installation easier. Power
optimizers are able to mitigate effects of shading that string inverters alone cannot. They
condition the DC electricity before sending it to the inverter, which results in a higher overall
efficiency than using a string inverter alone. Power optimizers offer similar benefits as microinverters, but tend to be less expensive and so can be a good option using strictly string inverters.
Power optimizers were not used in this installation but will be considered at a future date.

200

M. Viljoen, C. Pienaar: Design of a 3 KW PV power system for a residential home

3. NEEDS ANALYSIS FOR THE PV DESIGNA table of electrical appliances found in the specific residence was listed to determine the needof power consumption at the residence. Table 1. An estimate of the time of use per appliance wasdone to establish the kW hours of each device. The Power needed by each device wasdetermined from the model specification sheets supplied by the manufacturer of each appliance.
Table 1 List of appliances using power

Appliances

Power(Watt)

Geyser – Heat pump
Refrigerator 1 (LG GR-P207BLXV)
Refrigerator 2 (WB5534XP)
Refrigerator 3 (National Luna 65L)
TV (LG 32LK310)
HIFi (Denon AVR1906)
DSTV
Computer
LapTopPhone Charging
KettleOutside Spot Lights
Borehole Pump
Irrigation Pump
Speed Queen washing Machine
Microwave OvenToasterFood Mixer
DVR System (ds-7216hghi-sh)
DVR Camera system
Alarm System
LED Lights
Stove Elba Gas Plates - Electric Oven

1170
40
65
30
120
650
30
180
65
15
2000
10
750
750
1500
1450
1500
250
25
40
4
5
3000

Qty

Hours Used

Daily
Consumption kW
hours

1
1
1
1
1
1
1
1
1
1
1
7
1
1
1
1
1
1
1
10
1
16

3.42
24
24
24
4
12
24
24
4
1
0.2
0.1
1
1
0.25
0.1
0.1
0.1
24
24
24
1

4.0
1.0
1.6
0.7
0.5
7.8
0.7
4.3
0.3
0.0
0.4
0.0
0.8
0.8
0.4
0.1
0.2
0.0
0.6
1.0
0.1
0.0

Total:

25.1

The last column of the table was calculated using the kW hour formula:
E(kW hour) = Power(Watts) x time used(hours) /1000
From the total result of the table above it can be determined that the total monthly consumption
will be (25.1 x 30days) 753 kW hours. This Figure correlates with the monthly average that waspurchased on the smart meter installed at the residence which was 740 kW hours. A Metrel
Power quality logging instrument was connected to the input power lines of the residence and theEnergy and the Environment (2016) 197-208

201

data was logged over a 10-day period of which the most three power consumed days will behighlighted with the following results in Figure 2.
Day 1(Avg) [kVA]
4

kVA

3
2
1
0

Midnight to MidnightDay2 Avg [kVA]

4

kVA

3
2
1
0

Day 3(Avg) [kVA]
6
5

kVA

4
3
2
1
0

Figure 2 – Input load measurement

On the above graphs three busiest days were selected and measurements were done frommidnight to midnight i.e. 24 hour cycles are displayed. Most of the peaks was below 3 kVA
except for the one 5 kVA spike which was when the stove was used and for that reason the stove
was not considered any further in the system design. The stove is used only occasionally andtherefor will only be connected to the utility power in this system. The borehole pump wasstarted every 3 hours until the water supply run dry which took less than 15 minutes to do so.
Another appliance that pushed up the peaks was the 1.1 kW heat Pump used as a geyser and the
kettle was only used in the mornings. The refrigerators, computer and other appliances used
about 500 VA on average. It was found that it is very important to monitor the peaks since theinverters overload protection switches the system of if the load goes above 3 kW.

202

M. Viljoen, C. Pienaar: Design of a 3 KW PV power system for a residential home

With the above information it was decided to install a 5 kVA/4 kW Growatt 5000SL Off Grid
String Inverter. The Growatt 5000SL string inverter has the following important specifications
which were applicable for the system design and needs:
Inverter Mode
Rated Output Power: 5 kVA/4 kW
Output waveform:
Pure Sinewave
Peak Efficiency:
90%
Nominal DC Input Voltage: 48 V
Charging Mode
Rated Power:
3000W (PV Panel Input)
Efficiency:
98% max
Max PV Array Open Circuit Voltage: 145 VDC
PV Array MPPT Voltage Range: 60-115 VDC
Min Battery Voltage: 34 VDC
The PV panels chosen were the WSP-250P6 Winaico 250 W polycrystalline panels because ofpricing and availability with the following specifications:Nominal performance:
Pmax 250 Wp
No-load voltage VOC:
37.52 V
Short circuit current ISC: 8.53 A
Voltage at max. performance VMPP: 30.73 V
Current at max. performance IMPP: 8.15 A
Module efficiency: 15.06%

Figure 3 Derived Output Characteristic Curve of the Winaico WSP-250P6 Solar PanelEnergy and the Environment (2016) 197-208

203

4. DESIGN OF THE 3kW SYSTEM
The important facts which were considered for the design, was firstly the no-load voltage of
37.52 V specified by the manufacturer of the PV Panel multiplied by 3 PV panels in a string
gives a voltage of 112.56 which is below the maximum of 145 V specified by the manufacturerof the inverter and secondly the voltage for maximum performance of 30.73 V specified on the
PV panel multiplied by the three PV panels in a string will give 92.19 V which is well in rangeof the 60-115 VDC maximum array voltage specified by the inverter manufacturer.
It can therefore be concluded that 3 panels in series per string will be used giving 750 W ofpower. Using 4 sets of strings will give 3000 W of power to the inverter which is also the
maximum allowed input power to the inverter as specified by the manufacturer.
The installation was done on a tiled roof which had an incline angle of 23 degrees and facing 4
degrees of north to west (which is the norm for residential houses in the southern hemisphere).
The space available on the roof made it possible to arrange the panels as per the arrangement in
Figure 4

PV Panel

PV Panel

PV Panel

PV Panel

PV Panel

PV Panel

PV Panel

PV Panel

Combiner Box

PV Panel

PV Panel

PV Panel

PV PanelFigure 4 Panel Layout of the PV system

The PV array strings were combined in the combiner box to the positive and negative bus bars
and from where is was also connected to the inverter through a 60 A 150 V DC breaker. It was
decided to not connect the stove trough the PV power but to keep it connected to the utility
power since it is used very occasionally and may cause trips on the inverter.

Figure 5 U-Bracket (Middle Clamp) Z-Bracket (End Clamp)

204

M. Viljoen, C. Pienaar: Design of a 3 KW PV power system for a residential home

Specially manufactured cross rails was used to mount the panels on the tiled roof. The rails madeprovision for easy assembly of the tiled roof brackets to the rails. U-brackets and Z –Brackets
were used as in Figure 5 to mount the PV panels to the cross rails. Cables between PV Panels
were cable tied to the cross rails after connecting the male MC4 connectors to the female counter
parts to ensure a neat installation and to protect the cables from hanging on the roof.
Four AGM 96 Ah batteries were connected to the inverter. Only four batteries connected inseries through 2 x 100 A fuses were used and formed the 48 V supply for the inverter. The
reason why only four batteries were chosen is that at present battery technology is still very
expensive compared to grid power and the idea here was to only use the batteries for load
shedding purposes and current surges on the inverter, the inverter will also not operate if there
are no batteries connected. The batteries will give approximately one hour back up power on the
500 VA average load according to the manufacturer of the inverter.
The string inverter charges the batteries in 3 stages i.e. bulk, absorbsion and floating. The bulk
charging stage was set to charge the batteries up to 56.4 Volts at a maximum of 30 A charging
rate in order to charge the batteries not too fast. When the battery reaches the 56.4 V level theabsorbsion stage is entered were the voltage is kept constant for a fixed time which can varyfrom 10 minutes to 8 hours depending on the setup of the unit. After that the inverter will switch
over to floating voltage which is kept at 54 V until battery starts to discharge again.
The inverter has the following 3 modes of operation for an island installation i.e.:
x Solar first – Solar energy provides power to the loads as first priority and if the solar
energy is not sufficient then battery energy will supply the loads. Utility power will only
supply power to the loads when one of the following conditions happens -: Solar energy
is not available -: or Battery voltage is low or below a specific set point. (In this casepower will be supplied by the batteries if no PV power is available until batteries goes
below the minimum set value, leaving no reserve battery power)x Utility first – Utility provide power to the loads as first priority and solar and batteries
will only supply power when the utility power is not available. (This makes no sense if
power is available from the PV panels)
x Solar-Battery-Utility priority – Solar energy provides power to the loads as first priority
if power is not sufficient the battery energy will supply power to the loads at the sametime. Utility will only supply energy when battery voltage drops to either low-level
waning or to a specific set point. This set point was set to 49 V so that if load shedding
occurs there will be enough battery capacity left in the system to enable the lights in theresidence to stay on.
The third option is the preferred option for this design since solar energy will be the preferredsupply of energy and the batteries will supply up to a set point but if no PV power is available
then the inverter will immediately switch over to grid power. The idea is to reduce the cycle
discharge to a minimum in order to prolong the life of the batteries. It is also preferred to use
utility power rather than battery power since battery power is only used for backup in case of nopower from either PV power or utility power.

Energy and the Environment (2016) 197-208

205

5. CONCLUSION
After commissioning the installation worked fine but it was soon realised that load management
had to be done in order to ensure efficient use of the PV System. Some of the problems that
occurred after the installation were:xxxx

The system switched over to grid power during day time on sudden heavy loads.
The 3-year-old heat pump’s compressor stopped working a week working after the PV
system installation which then forced the resident to use a standard geyser element.
Two palm trees caused the PV panels to be in the shade after only 2 hours of sun shine.
It was also found regular monitoring of the system were needed.

With the switch over to the grid on sudden loads it was found that the minimum setting for SBU
priority programming mode as discussed above in the previous section were set to high on thebatteries. The idea was to cycle the batteries as little as possible and the minimum voltage were
set to 51 V it was later brought down to 49 V which seemed to give the inverter more battery fallback before switching over to the grid. The system was also tested with grid power completely
switched off to test how long the system will stay on with only lights, TV and refrigerator being
used in the evening utilising only battery backup power. The system tested satisfactory with thelights staying on until the resident went to bed at 23h00 and kept on working for about 7 hours’
backup time.
The heat pump for heating up water had to be send in for repairs which took about 8 weeks
before the unit were returned and in this time the electricity bill from the utility supplier wereabout 20% more since the geyser element were a 3 kW element and could not work through the
PV system but had to be bypassed to work straight of the utility power. During this time theutility power usage were monitored with the following results in Figure 6.

Figure 6 Results of power usage using a hot water geyser in a residential home.

From the above graph in Figure 6 It can be seen that the geyser element switched on from time totime to reheat the water and used a considerable amount of power to heat up the water whenwarm water was used. It was then decided to use a geyser timer to ensure less power consumed
and the results can be seen in Figure 7.

206

M. Viljoen, C. Pienaar: Design of a 3 KW PV power system for a residential home

Figure 7 Results of power usage using a hot water geyser in a residential home on a Geyser timer.

From Figure 7 it can be seen that the geyser was switched on only twice a day and ensured quite
a power saving without discomfort to the home resident. It was also found that time management
had to be implemented on the borehole pump as well as the irrigation system and swimming poolpump.
The two palm trees had to be removed and were replanted elsewhere to improve the shading
effect on th e PV Panels as can be seen on Figure 8.

Figure 8 Shading profile done with PV Syst Software with palm trees near dwelling.

From Figure 8 a shadow animation was done with PV Syst software and the results in Figure 9
were obtained. The results from software compared with what was visually observed on thepanels. The graph is drawn for 21 June 2016 which is the shortest day in the southern hemisphere– There were only about 2 hours without shading on the panels.

Figure 9 Shading animation graph done with PV Syst Software with palm trees near dwelling.

Energy and the Environment (2016) 197-208

207

This necessitated the removal of the palm trees in order to reduce the shading effect on thepanels and from our shadow simulation it could be seen in Figure 10 that a great improvement
was possible if the palm trees were removed.

Figure 10 Shading animation graph done with PV Syst Software with palm trees removed near dwelling.

A monitoring hub (Effergy Engage) was installed on the system which enabled remote viewingof the PV system on a smart phone and also enabled logging information of the PV system. This
ensured flawless operation of the PV system and made load management easier to manage forthe resident.
The results of the installation were positive as far as electricity usage is concerned and can beseen in Table 2. July and August is on Winter tariffs and the rest is of the tariffs is on a slide
scale i.e. the more power used the higher the tariff.
Table 2 Electricity Consumption of the residenceMonthApr-16

Meter
ReadingkWh
199,64

Electricity
Usage
kWh
753

Cost in
Rands
R950,00

May-16952,64653

R822,00

Jun-161605,64

511

R590,00

Jul-16

1914,60

309

R491,91

Aug-162196,52279

R443,26

Rate
R/kWh
Activity
R1,26 Before PV Installation
PV Installed
Heat Pump Broken –Use Geyser
R1,26 Element
Heat Pump Broken / Timer on
R1,15 Geyser
Timer on Geyser / Holiday 2
R1,59 weeks
Heat Pump Repaired running on
R1,59 utility power only

Living green is the new way of living and a person becomes much more aware of whichappliances are less energy efficient. The resident continuously finds new ways to improve energy
efficiency because of an increased awareness of energy efficiency.

208

M. Viljoen, C. Pienaar: Design of a 3 KW PV power system for a residential home

REFERENCES
[1]
[2]
[3]

S. S. Division, "GRID INTERCONNECTION OF EMBEDDED GENERATION Part 2 Small-scale embedded generation," Nersa, 2010.
Dickens, L, Green Homes: Building for the future, today – combining the best of historical
wisdom and modern technology.," Mother Earth News, 2013.
Zipp, K, "What are the different types of solar inverters?," Solar Power World, vol. May
2016, 25 May 2016 2016.

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Energy and the Environment (2016) 209-220

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TECHNO-ECONOMIC EVALUATION AND SIZING OPTIMIZATIONOF SOLAR-PV AND WIND ENERGY SOURCES FOR IRRIGATIONWATER PUMPING
1

Mohamed EL-Shimy1%RMDQĈXULQ2
Professor of electrical power systems. Electrical Power and Machines Department, Faculty ofEngineering, Ain Shams University, Cairo, Egypt. Tel: 00201005639589, Email:mohamed_bekhet@eng.asu.edu.eg; shimymb@gmail.com
2
Faculty of Geotechnical Engineering, University of Zagreb, Varaždin, Croatia.
Tel: 0038542408933, Fax: 0038542313587, Email: bojan.djurin@gfv.hr

Abstract: The energy needed for irrigation water pumping systems can be conventionallyobtained from the direct use of fuels (e.g. using diesel engines) or indirectly from theelectrical sources. Despite the adverse environmental impact of the use of fuels, there is alimited availability of conventional energy sources in off-grid and remote locations. The
transfer of fuel or the extension of the grid to these locations is usually uneconomical andfaces some technical challenges. Therefore, the use of the naturally available abundantsources of energy is a possible feasible solution. These energy sources include the solar andwind energy sources. The continual availability of these energy sources is not the only benefit,
but also their highly positive ecological impacts and the associated welfare due to the highdegree of freedom in selecting appropriate locations for various crops. From an operational
point of view, the solar and wind are classified as variable and intermittent energy source.
These adverse characteristics are not of significant importance in supplying deferrable loads
such as the irrigation pumping loads. In comparison with the non-deferrable loads, irrigationloads neither requires instantaneous energy balance nor mandatory energy storage. From thetechno-economic point of view, this paper presents a comparative analysis of various
renewable energy alternatives for irrigation water pumping systems. Three alternativeelectricity supplies are considered; standalone solar-PV, standalone wind, and hybrid solarPV/wind energy sources. The energy producing components of various sources are also
optimized for maximization of the feasibility and effectiveness of the sources. The main
outcome of the paper is the presentation of a framework for optimal sizing and selection of
the renewable energy source(s) for deferrable loads. Although the results are highly
dependent on the considered meteorological conditions, the presented formulation, sizing
algorithm, and analysis approach are general regardless of these conditions.
Keywords: Renewable energy; deferrable loads; irrigation water pumping; sizing
optimization; techno-economic feasibility.

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1. INTRODUCTION
The use of renewable energy sources (RES) for water supply is an already known technology[1]. In [2, 3], the solar photovoltaic (PV) and wind energy are proven to be the most suitable
forms of RES for use in water supply systems of a settlement. Therefore, it is clarified thatthese RES are very suitable for supplying irrigation water pumping systems [4 - 6].
From the operational characteristics point of view, wind and solar energy resources show highvariability, intermittency; however, advances in the meteorological modeling and analysis
makes these resources highly predicable [7 - 10]. Despite the high predictability of these RES,
they cannot be used in off-grid standalone mode to supply regular electrical loads. This isbecause regular loads are non-deferrable. Consequently, a power balance between the energy
source(s) and the load should be provided on instantaneous basis; a situation where
standalone highly variable and intermittent energy sources cannot provide. For the use ofvariable RES to successfully supply non-defferable loads, energy storage and/or conventionalenergy sources can be used in conjunction with variable RES for providing continuous andfully controllable energy to the loads [8].
On the other hand, irrigation water pumping loads are not regular loads from operational
characteritcs point of view. These loads are classified to be deferrable [5]. Therefore, thepower balance constraints is not mandatory for successful operation of these loads. Instead,the energy balance constraint is of the major importance. The energy balance ensures that theenergy source(s) are capable of providing the energy needed by the load over a specific periodof time. Under the energy balance constraint, the energy sources are not required to exactly
match the load active power demand. Therefore, the energy sources can produce surplus ordeficient instantaneous power with respect to the load active power demand. The power
mismatch can be usually compensated by the use, storage tanks; surplus energy is used topump water to the tank while the tank balance the required discharge when there is energy
deficiency.
This paper presents a generic method for sizing minimization of variable sources for
supplying deferrable loads. In case of using a single standalone variable energy source, thesizing optimization is based on the energy balance constraint. On the other hand, the energybalance and cost minimization constraints are used for sizing two (or more) variable
standalone sources. Based on the IEC standard [11, 12], simple and acceptable models for theenergy production of solar-PV and wind energy generators are used. The considered sizing
problems are the determination of the minimum number of solar-PV modules and/or
minimum number of wind turbines. Therefore, the problem falls into a class of traditional
optimization problems called combinatorial optimization. Although such optimization
approach is not feasible for some problems due to its possible exhaustive search, it issuccessfully used in this paper due to the mathematical nature of the considered problems.
Generally, the combinational optimization is possible for a group of problems ' in which theset of feasible solutions is discrete or can be reduced to discrete, and in which the goal is tofind the best solution [13].

Energy and the Environment (2016) 209-220

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2. PROBLEM STATEMENT AND FORMULATION
2.1. Sizing of Variable Sources Supplying Deferrable Loads – Basic Concepts
For a given chronological load curve, generally a well sized standalone variable energy
source(s) cannot provide an active power balance as shown in Figure 1. Sometimes the power
production (PVS(t)) is higher than the load demand power (PD(t)) while the opposite occurs insome other time. For non-deferrable loads, this situation is operationally impossible without
the use of energy storage and/or parallel conventional energy source(s). On the other hand,
deferrable loads (e.g. irrigation water pumping) require an energy balance (rather than active
power balance) over a specified period T (usually a day), Eq. (1) and (2). In Eq. (2),isis the demanded energy
the variable source energy production over the period T while
over the same period. Therefore, the realization of Eq. (1) or (2) ensures the satisfaction ofenergy balance constraints; however, this equation does not suggest an optimal capacity of thevariable energy source(s). Therefore, optimization of the sizing of the standalone variable
sources is essential for the economic feasibility of the use of standalone variable renewablesources.

Figure 1. Basic concepts of sizing variable sources for supplying deferrable loads(1)(2)
Despite the size of the energy source(s), the energy deficiency, surplus energy, and overall
excess energy can be determined using Eq. (2-4) where all the symbols are defined on Figure
1.
(3)
(4)
(5)

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M. EL – 6KLP\%ĈXULn: Techno – economic evaluation and sizing optimization …

The operational philosophy of the energy system is based on the daily energy balance anddeferrable active power balance. Therefore, the surplus energy is available for storage (e.g.
storage tank in irrigation pumping or batteries in electrical loads). This stored energy ispartially used for supplying the energy deficiency while the rest of the surplus energy (i.e. theoverall excess energy) is stored for an emergency situation where the primary energy source
is unavailable in an expected way. For example, the solar energy may be unavailable for asignificant duration due to dense clouds. In these situations, the excess energy present theautonomous energy source and its value define the days or hours of autonomous dependency
on excess storage.
2.2. Sizing Optimization of Solar-PV Arrays
For standalone solar-PV array supplying deferrable loads, the optimization objective is todetermine the minimum number of modules (Nmod) that satisfies Eq. (1). The minimization of
the effective surface area (APV) of the solar-PV can be also used in the optimization. Actually,
the effective surface area can be reduced to a discrete number of modules. Therefore, the area
and the number of modules are dependent variables. The formulation of the problem can bethen represented by Eq. (6) where PPV is the array power production, t is the time, and T is thestudy period. The study period is taken as one day that represents the average daily power
production in the study month. The selection method of the study month will be describedlater.
(6)
Based on the IEC-61724 [11, 12], the energy production of a solar-PV array can be
represented either by
(7)
or
(8)
where
is the rated capacity of the solar-PV array i.e. the output power understandard test conditions (STC). Ymod is the rated capacity of the module. fPV is the PV derating
factor.
is irradiance incident on the solar-PV array while
equals to 1 kW/m2 whichis the STC irradiance.
The standard test conditions are: solar irradiance of 1 kW/m2 at the plane of solar cells, celltemperature of 25oC, and zero wind speed. The PV derating factor is a scaling factor accountfor reduced output in real-world operating conditions compared to the conditions under which
the PV panel was rated. Use the derating factor to account for such factors as soiling of thepanels, wiring losses, shading, snow cover, aging, and so on. For example, if the derating
factor equals to 90%, then the amount of miscellaneous losses of 10 %. Since in theEnergy and the Environment (2016) 209-220

213

considered models (i.e. Eq. (7) and (8)) the effect of the temperature on the power production
is not explicitly modeled, then the temperature related effects should also be included in thevalue of the derating factor.
2.3 Sizing Optimization of Wind Farms
In a similar way, the sizing of a standalone wind farm for supplying deferrable loads can be
represented by Eq. (9). In this case, the objective is to find the minimum number of windturbine generators () that satisfies the inequality constraint of Eq. (9) or (1). Therefore,) produces an overall energy over the period T that is
the wind farm power production (higher than the load energy demand over the same period.
(9)of theThe wind farm power production, Eq. (10), is dependent on the power curve
utilized turbine, which is the relation between the power production and the wind speed. In
Eq. (10), fWF is the wind farm derating factor.
(10)

2.4 Sizing Optimization of Hybrid Wind and Solar-PV
Apart from the economic feasibility and space limits, only standalone solar-PV or wind canbe used for satisfying the energy balance requirements (Eq. (1)). Therefore, formulating the
optimization problem as shown in Eq. (11) will result in many possible alternative solutions
each of which satisfies the energy balance constraint. Therefore, in the hybrid supply system,
the economic indicator should be used for identifying one feasible solution of the
optimization problem as described by Eq. (12). In Eq. (12), Ct is the total cost of the hybrid
source while CPV is the cost of the solar-PV array and CWF is the cost of the wind farm. Eachof these costs have fixed and running cost values [14].
(11)

(12)

2.5 Hydraulic Energy Demand Modeling
The net hydraulic energy demand, the structure of the water source, and the efficiency ofvarious items comprising represent the main data required to be translated into the electrical
power and energy demand.

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Due to the required capacity of pump station QPS and total manometric head HPS, an average
power of a pump station PPS is equal to [4]:(13)
where ȡ is the density of water, g is acceleration of gravity force and ȘPS is the average
efficiency of the pump station.
The required amount of energy E for water pumping during the day period of usable
insolation TS is equal to:(14)
The volume of a water reservoir V is defined by the method of integral curve, i.e. Ripley
method [4]:(15)
where QPS(t) is pumped water and Qhour(t) is the required amount of water in every period
through the day, t = 1, 2..., 24 h.
2.6. Design Month Selection
In this paper, the design month is defined as the month at which the renewable energy
resource is of the minimum value while the hydraulic demand is of its maximum value. Thisis for ensuring that the sizing of the energy source(s) based on that critical monthly averaged
day will be sufficient for all other days in the year.
3. APPLICATION EXAMPLE
In this example, a demonstration of the presented sizing optimization method for various
energy supply types (i.e. solar-PV, wind and hybrid solar-PV/wind) will be considered.
Although the considered hydraulic load is small, the presented methodology can be applied tolarge hydraulic loads.
3.1. Location, Input Data
In this application example, a pitch irrigation for the local football club ‘’Obreš’’ located at
Lat. 46.252o/Long. 16.324o which is near Varaždin, Croatia, on the territory of Sveti Ilija
municipality (Figure 2) is considered. The football pitch covers the area of 105 m x 70 m. The
irrigation will be provided for only the four months; May to August while natural rain isconsidered to be sufficient during the rest of the year. The groundwater, which is situated inshallow layers at a depth of 10 m, is used for irrigation, and the usage of the existing wellshowed that its capacity is sufficient [6]. In the four irrigation months, the daily water
discharge Q requirements are the same as illustrated in Figure 3(a). Based on Eq. (13), thedaily discharge is translated to active power demand PD (Figure 3(b)) considering an overall

Energy and the Environment (2016) 209-220

215

efficiency of the irrigation system of 34.6 % [5] with a total manometric head of 60 m (10 mfor pumping head + 50 m for the irrigation device) [6]. Thus, the required daily water amount,which is also the input capacity of the pump station, QPS is 30 m3/day. The water will be used
for irrigation every day in duration of 10 hours, from 8 AM till 6 PM, with occasional breaks
during busy playground (training, matches, maintaining). For 10 hours of irrigation per day(Figure 3), the required energy is estimated to be 8.5 kWh/day (Figure 3(b)).

Figure 2. Position of the municipality Sveti Ilija, Croatia [6]

(a)

(b)

Figure 3. Load requirements: (a) Discharge; (b) Power and energy
3.2. Design Month for Solar and Wind Energy Sources
The design month is selected based on the criteria stated in section 2.6. The required
meteorological parameters of this study are obtained the NASA meteorological website [15].
Figure 4(a) shows the monthly average solar irradiance on horizontal surface (kWh/m2/day)and Figure 4(b) shows the monthly average wind speeds in m/s at 50 m above the Earth's
surface while Figure 4(c) shows the monthly average daylight hours. As shown in Figure 3,
the load demand is constant during the irrigation months. Therefore, the design monthselection is limited to the resources. Based on Figure 4(a) to 4(c), the minimum solar radiation

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M. EL – 6KLP\%ĈXULn: Techno – economic evaluation and sizing optimization …

and wind speed are both associated to August. Therefore, August is selected as the design
month for both solar, wind, and solar/wind hybrid energy sources. It is clear from Figure 4(a)that the solar resource is excellent while the wind resource is very poor. For the design month,Figure 4(d) shows that the optimal tilt angle of solar-PV modules is 31o. Therefore, the solarPV generator is set at a fixed tilt of that value. The daily average hourly values of the solar
irradiance and wind speeds for August are shown respectively in Figure 4(e) and 4(f).

(a)

(b)

(c)

(d)

(e)

(f)

Figure 4. Meteorological characteristics of the study site
3.3. Technological Selection
The optimal site matching of wind turbine generators [16] as applied to the study site, showsthat the rated wind speed of an optimal turbine is 4.27 m/s. This value is very low and nocommercially available traditional WTG provides this requirement. Therefore, in this study
the WindTronics WTG [17, 18] that is specially designed for low wind speed sites; Fig. 5
shows its power curve. In [14, 19] it is found that the best available solar-PV module is themono-Si Sunpower SPR-320E-WHT-D module which is used in this study.

Energy and the Environment (2016) 209-220

217

Figure 5. Power curve of the Windtronic WTG
3.4. Optimization Results
In this section, the results obtained by solving Eq. (6), (9), (11) and (12) are presented on
Figure 6. The costs are obtained from [14, 17]. The fixed cost of the solar-PV array for DC
standalone, fixed modules are 4030 $/kW, while its running cost is 30 $/kW-year. The costsof the Windtronics are 3181 $/kW fixed and 28.07 $/kW-year running. It is clear that the
fixed costs are very high in comparison with the running costs; a benefit of most renewable
technologies.

Figure 6. Fixed costs of various alternatives of hybrid wind/solar-PV sources

For standalone solar-PV array, the minimum capacity is found to be 1.93 kWp (6 modules).
This array produces 8.917 kWh/day in the design month with an overall excess energy of
0.417 kWh/day. Based on Equation (15), the estimated water reservoir volume is 12 m3.
For standalone wind energy, 6 Windtronics turbines are needed. The maximum capacity ofthese WTGs is 13.2 kW, while their energy production in August is 8.814 kWh/day with an
overall excess energy of 0.314 kWh/day.

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M. EL – 6KLP\%ĈXULn: Techno – economic evaluation and sizing optimization …

For the hybrid solar-PV/wind energy source, seven alternative solutions of Eq. (11) aredetermined. Table 1 shows these alternative solutions. The shaded cells in the table present
the infeasible solutions where the hybrid energy source does not produce the required dailyenergy demand (i.e. 8.5 kWh/day). Based on the cost analysis shown in Figure 6, it is clearthat the 7th alternatives (6 PV modules and zero WTGs) is the most economical one.

Table 1. Alternative solutions of the hybrid wind/solar source

NWTG

0
1
2
Etotal001.486243 2.972485
1
1.468986 2.955229 4.441471
22.937972 4.424215 5.910457
3
4.406958 5.893201 7.379444
45.875945 7.362187
8.848
57.344931
8.831
10.31742
6
8.814
10.30016 11.7864* The optimal alternative solution

Nmod
3
4.458728
5.927714
7.39678.866
10.33467
11.80366
13.27264455.94497 7.431213
7.413956
8.9
8.883
10.36919
10.35193 11.83817
11.82091 13.30716
13.2899 14.77614
14.75889 16.24513
Infeasible solutions

6
8.917*
10.38644
11.85543
13.32441
14.7934
16.26239
17.73137

4. CONCLUSIONS
An efficient approach for sizing optimization of standalone variable energy sources supplying
deferrable loads such as irrigation water pumping loads. Three renewable supply options are
considered for supplying an irrigation pumping load. These options are standalone solar-PV,
standalone wind, and hybrid solar-PV wind. These sources are naturally variable andintermittent. For the operation considered deferrable load, the daily energy balance constraint
is sufficient instead of the momentary power balance constraint that is usually mandatory for
non-deferrable loads. Due to the nature of the load and its deferrable characteristics, thesurplus energy and energy balance is achieved by the use of storage tank rather that batteries
while the total excess energy is used for energy security purposes. For a standalone source,
only an energy-balance based model for the sizing optimization is developed. On the other
hand, the energy balance in conjunction with cost minimization constraints are used in thedevelopment of the sizing optimization formulation of more than one source. The
optimization problems are solved by the combinational optimization approach. Due to thepoor wind resource of the considered site, the traditional site matching optimization of WTG
did not result in a valid commercial design of WTG; however, the Windtronics WTG is used
for its capability of capturing low wind speed energy. The best found recent phtovoltaic
modules are also used for constructing solar-PV arrays. The results show the presented
optimization formulations and the resulting solutions are successful by providing the requiredenergy balance of the load. In addition, the cost analysis successfully reveals the optimalenergy mix in a hybrid fully renewable source.

Energy and the Environment (2016) 209-220

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REFERENCES[1] Gopala, C., Mohanraja, M., Chandramohanb, Chandrasekarb, P.: Renewable energy
source water pumping systems - A literature review. Renewable and Sustainable Energy
Reviews, 25, 2013, 351–370[2] ĈXULQ%Sustainability of the urban water supply system operating, PhD thesis (onCroatian), Faculty of Civil Engineering, Architecture and Geodesy, University of Split, Split,
Croatia, 2014.
[3] Ramos, J.S., Ramos, H.M.: Sustainable application of renewable sources in water
pumping systems: Optimized energy system configuration, Energy Policy, 37(2), 2009, 633643.
[4] ĈXULQ%Some Aspects of the Operation Work of Pump Station and Water Reservoir.
Periodica Polytechnica Civil Engineering, 60 (3), 2016, 345-353.
[5] EL-Shimy, M.: Sizing optimization of stand-alone photovoltaic generators for irrigationwater pumping systems, International Journal of Sustainable Energy, 32(5), 2013, 333-350.
[6] %RULVRY%ĈXULQ%0DWLQ-The concept of sustainable irrigation on the example offootball field of F.C. ''Obreš'', Sveti Ilija, Croatia, Inženjerstvo okoliša, 3(1), 2016, 71-81.
[7] EL-Shimy, M.: Dynamic Security of Interconnected Power Systems - Volume 1, Lap
Lambert Academic Publishing, Omniscriptum Gmbh & Company Kg, Germany, 2015.
[8] EL-Shimy, M.: Dynamic Security of Interconnected Power Systems - Volume 2:
Dynamics and stability of conventional and renewable energy systems, Lap LambertAcademic Publishing, Omniscriptum Gmbh & Company Kg; Germany, 2015.
[9] EL-Shimy, M.: Probable power production in optimally matched wind turbine
generators, Sustainable Energy Technologies And Assessments, 2, 2013, 55-66.
[10]
EL-Shimy, M.: Stability-based minimization of load shedding in weaklyinterconnected systems for real-time applications, International Journal of Electrical Power &Energy Systems, 70, 2015, 99-107.
[11]
IEC 61724:1998 - Photovoltaic system performance monitoring - Guidelines formeasurement, data exchange and analysis, Available at:https://webstore.iec.ch/publication/5733, access date 18.7.2016.
[12]
EPM623 lecture notes, Available at: http://shimymb.tripod.com/id12.html, accessdate 18.7.2016.
[13]
Combinatorial optimization. Available at:https://en.wikipedia.org/wiki/Combinatorial_optimization, access date 18.7.2016.
[14]
Said, M., EL-Shimy, M., Abdelraheem, M. A.: Photovoltaics energy: Improved
modeling and analysis of the levelized cost of energy (LCOE) and grid parity–Egypt casestudy, Sustainable Energy Technologies and Assessments, 9, 37-48, 2015.
[15]
NASA: Surface meteorology and Solar Energy-A renewable energy resource website, (release 6.0), https://eosweb.larc.nasa.gov/sse/, access date 10.5.2016.
[16]
EL-Shimy, M.: Optimal site matching of wind turbine generator: Case study of the
Gulf of Suez region in Egypt, Renewable Energy, 35(8), 2010, 1870-1878.
[17]
WindTronics Availability, Pricing and Retailers. Available at: http://goo.gl/Sml6d5,
access date 18.7.2016.
[18]
Honeywell Windtronics Wind Turbine. Available at:https://www.youtube.com/watch?v=fIBWUK7OZsI, access date 18.7.2016.
[19]
EL-Shimy, M., Abdo, T.: PV Technologies: History, Technological Advances, andCharacterization, In Sohail Anwar (ed.) Encyclopedia of Energy Engineering andTechnology – Volume III, Taylor & Francis - CRC Press, Abingdon, United Kingdom, 2014.

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M. EL – 6KLP\%ĈXULn: Techno – economic evaluation and sizing optimization …

TEHNOLOŠKI-EKONOMSKO VREDNOVANJE I OPTIMIZACIJADIMENZIONIRANJA SOLARNIH FOTONAPONSKIH-FN IZVORAENERGIJE I IZVORA ENERGIJE VJETRA ZA CRPLJENJE VODE ZA
NAVODNJAVANJESažetak: Potrebna energija za sustave za crpljenje vode za potrebe navodnjavanja može se
GRELWLXRELþDMHQLPSXWHPGLUHNWQLPNRULãWHQMHPJRULYD QSUGL]HO-agregati) ili indirektno iz
L]YRUD HOHNWULþQH HQHUJLMH 2VLP QHJDWLYQLK XWMHFDMD QD RNROLã NRULãWHQMH NODVLþQLK L]YRUDHQHUJLMHMHRJUDQLþHQRQDXGDOMHQLPORNDFLMDPDNDRLQDORNDFLMDPDEH]HQHUJHWVNHPUHåH
7UDQVSRUW JRULYD LOL SURãLUHQMH PUHåH QD WDNYLP ORNDFLMDPD MH QHHNRQRPLþQR D XMHGQR
postoje i tehnološki problemi vezani uz to. Samim time, korištenje obilnih, prirodno
raspoloživih izvora energije je ostvarivo rješenje. Pri tome se prvenstveno misli na solarne
izvore energije i energiju vjetra. Trajna raspoloživost tih izvora energije nije njihova jedina
prednost. Tu su još visoki ekološki utjecaj NDR L GUXãWYHQD NRULVW V RE]LURP QD PRJXüQRVWL]ERUD SULNODGQH ORNDFLMH ]D UD]OLþLWH XVMHYH 6 RE]LURP QD NRULãWHQMH VRODUQD HQHUJLMD L
energija vjetra su promjenjivi i povremeni izvori energije. Ovakve negativne karakteristike
QLVXRG]QDþDMQHYDåQRVWLX povremenim (odgodivim) potrebama za vodom, kao što je potreba
kod crpljenja za navodnjavanje. U usporedbi sa ostalim konstantnim (trajnim) potrebama za
vodom, navodnjavanje ne zahtijeva niti trenutno uravnoteženje ulaza i izlaza energije, niti
potrebe za spremanjem energije. S tehnološko-ekonomskog pogleda, ovaj rad prikazuje
XVSRUHGQX DQDOL]X UD]OLþLWLK YDULMDQWL REQRYOMLYLK L]YRUD HQHUJLMH ]D FUSQH VXVWDYH NRG
navodnjavanja. Razmatraju se tri varijante; samostalni solarni (FN) sustav, samostalni sustav
sa energijom vjetra i hibridni solarni (FN)/vjetar sustav. Dijelovi spomenutih sustava koji
SURL]YRGH HQHUJLMX RSWLPL]LUDWL üH VH ]D QDMYHüH PRJXüH SRYHüDQMH L]YRGOMLYRVWL LXþLQNRYLWRVWL1DMYDåQLMLUH]XOWDWRYRJUDGDMHSULND]VPMHUQLFD]DRSWLPDOQRGLPHQzioniranjeodabir obnovljivih/obnovljivog izvora energije kod povremenih potrošnji. Usprkos tome što
dobiveni rezultati uveliko ovise o razmatranim meteorološkim uvjetima, oni u pravilu neXWMHþXQDIRUPXODFLMXSUREOHPDSRVWXSNHGLPHQ]LRQLUDQMDLSULVWXSanalizi.
.OMXþQH ULMHþL obnovljiva energija; povremena potrošnja; crpljenje vode za navodnjavanje,
optimizacija dimenzioniranja; tehnološko-ekonomska izvodljivost.

Energy and the Environment (2016) 221-228

221

SMART PV SYSTEM USING BUILDING'S HEAT STORAGE
Istvan Ervin Haber, Istvan Farkas
Department of Technical Informatics, University of Pecs, Boszorkany Str. 2., Pecs, H-7624
Hungary, ihaber@mik.pte.hu
Abstract: Widely known problem is, that at peak production of renewable energy systems, thegrid becomes overloaded, while the electricity is hard to store. Developments relating to thedevelopment and control of the smart buildings, solar systems could be realized with central
processing for building management. At buildings with high heat capacitance (governmental,
community, sport facilities), the part over the required amount can be stored as heat, e.g. as
building cooling if the usage habits are well known.
In case of proper heat isolation of the building, the provided energy can be stored as heat if thebuilding management system is prepared for this case. This work investigates the possibilities ofstorage and analyses a way of a cheap solution.
Key words: photovoltaic, energy storage, smart system, building management, smart grid, smart
city, cfd
1. INTRODUCTION

Renewable energy production goes in an uncertain way, which is shown on the German
example. In 11th May of 2016 the renewable energy production reached the level, when electricenergy market could not take the excess energy and the market prices went to negative level.
This will happen even more time if the production goes on higher level, so time has come to go
smarter. The commercial and residential producers should provide storage capacity or atechnology which can transfer the energy in storable form and providers to distribute it smarter.
These systems are called smart grid, which is an electrical grid, includes a variety of operationaland energy measures including smart meters, smart appliances, renewable energy resources,
energy efficiency resources and storage system. Electronic power conditioning and control of the
production, distribution and storage of electricity are important aspects of the smart grid. The US
Energy Independence and Security Act of 2007 (EISA-2007) [1] also describes, that
"Deployment and integration of advanced electricity storage and peak-shaving technologies,
including plug-in electric and hybrid electric vehicles, and thermal storage air conditioning" ismandatory field of the smart grid topic.
An energy storage system (ESS) regarding to the base technology can be a battery system(electro-chemical storage) - also in form of an electric vehicle, compressed or liquid air storage,hydro pump systems, hydrogen storage, electro mechanical (flywheel) and thermal storage.
According to 2016 state, in rated power 183 GW hydro pumped systems were installedworldwide, 3.6 GW of thermal storage, 3 GW batteries, 2.6 GW electro mechanical and theothers are altogether less than 1 MW. [2] The cost start from 350 $/kWh for sodium/sulfur
batteries and goes until 1200 $/kWh at pumped hydro systems as an average. [3]New technologies as part of the smart grid helps to distribute and save energy, as demand side
management, and net metering and these work as IoT (Internet of Things) entities. The smart net
metering has an effect for the consumption if renewable energy credits (REC) are used. [4]222

I. Ervin Haber, I. Farkas: Smart PV system using buildings heat storage

1.1 Smart micro-grids with energy storage systems
Smart micro-grids have been identified as essential components of future power systems with thepotential to assist with energy security, environmental sustainability and energy equity
challenges faced globally [5]Under smart grid (Fig. 1.) is basically meant the grids connected to provider network, butpartially, or even full autonomous can be. From this sight we can name the following systems:[6]xAutonomous: Full energy need is provided from inside the grid.

xPartially autonomous: Taken into consideration the economical prospects thepredictable demands will be covered; Adapting to renewable energy production;
Does not produce high amount excess energy; Discovers the future load and stores
according to the needs.

x

Grid connected, designed for large scale consumption need. (This type meets the
Smart Grid principle not.)Energy storage is the meaning of smart settlement's autonomy. The key property of a smart city
is, that the produced goods (also the energy) has to be used up locally, and this is how thesmallest ecological footprint will secured.
Several control methods for energy management systems have been developed for smart grids todistribute energy between ESS sites and production. Newton-Raphson technique based method
exist [7], recursive least square methods [5], space vector pulse-width modulation [8] and also
genetic algorithm based control systems [9], but agree in the same, that weather forecast needed
to lower uncertainty in the system.

Fig. 1. An example smart grid with distributed generation and distributed control [6]The micro-grid can be AC or DC but it becomes even more acceptable, that the small size DC
grid has lower losses, as the demonstration experiment at Okinawa Campus project verified theeffectiveness of DCOES [10].
In an ideal model for distributed energy storage system in micro-grid, when electrical storage isfull, then the peak generation is fed as heat into buildings. This can't be regenerated to electricity

Energy and the Environment (2016) 221-228

223

but if the capacity and the heat resistance of the building envelope is big enough, the stored
energy can be used for long time, making it effective in the personal comfort level.
The building mass can be used for demand side management (DSM) by its coupling with air
conditioning in buildings, where it can provide a spinning reserve on the demand side withminimal changes to conventional operation and without disturbing thermal comfort in asacrificing level [11].
It is also accepted, that a DSM is the most important issue for the smart grids, e.g. to utilize theenergy produced at the same site, to lower the dependence from the distribution grid control.
Office and education buildings are said to be ideal for DSM purposes, because of shorter
occupancy period. Interesting conclusion that thermal energy storage can higher energy demand,
but lower costs by shifting away demand from peak hours, when the prices are high [12].
DSM can be also practically combined with passive building ventilation for cooling purposes as
it was investigated by the authors [13].
Some researchers have compared the dynamic behavior of different heat emission systems andhighlighted their large influence on thermal comfort: "not only the availability of the thermalmass, but also the interaction between the heating system and the thermal mass is of significant
importance [14]. This statement is considerable in cooling interaction too, obviously the direct
cooling of the building structure is more acceptable from this sight, but that needs special
planning and financial investments.
The level of insulation has an important influence on the heat reservation, at good level ofinsulation the time constant is high, and the stored energy can last for more than eight hours in a
residential building [15] and possibly even more in a building with higher capacitance.
In this paper an existing high-educational building is investigated from DSM purposes. The
building itself has been renovated in 2002, heat isolation applied, windows changed, etc. On thebuilding, since 2015, a 22kWp PV system is producing electricity, feeding it into the gridthrough an inverter.
2. DYNAMIC CONTROL SOLUTION FOR BUILDING MANAGEMENT SYSTEM

2.1. Heat capacity and heat resistance.
A building, if it has been built by traditional technologies from concrete, should have a big heat
capacitance. To utilize this well, the structure has to be heat-isolated as much as possible andother energy saving technologies has to be used (at least triple layer glazing, high air tightness,heat recovery ventilating system, etc). This heat capacitance can be used for store energy inside
the structure of the building, with keeping the user habits and comfort in sight. Therefore it
needs a smart or well programmed building management system (BMS), which takes thebuilding's heat capacity and the heat losses into consideration for the control of the temperature.
There are several techniques to determine the total resistance (RT) and capacitance (C) of abuilding. At new houses it is mandatory in Hungary to let an Energy Certification made,according to law 7/2006 TNM which is based on MSZ EN ISO 6946 and other related standards.
This certificate contains the heat conductance value in W/K for the building, as in line 6$86O<
is described. The heat capacity for the structure is not calculated in the simplified method, but
the specific heat and density values for all materials are given, just the solid volume has to be
calculated. The air volume is also given in the certificate.
Other way to calculate the total resistance, is to build up a thermal resistance model (Fig. 2), andsummarize it.

224

I. Ervin Haber, I. Farkas: Smart PV system using buildings heat storage

Fig. 2. An example for thermal model of a house
The main building of the Faculty of Engineering and IT, University of Pecs (Fig. 3.) were chosen
to calculate what amount of energy can be stored in a building with a good predictable usage ofenergy. A simplified thermal resistance model after Fig. 2 was written up and calculated thestorage capacity of the building. The thermal resistance of the building is RT = 0,039 K/W andthe capacitance is around C = 1140 kWh/K according to Table 1.
Table 1. The related material properties
Density (kgm-3) Specific heat(Jkg-1K-1)
Concrete
2200
880
Heat isolation
100
1300
Air
1,12
1020

Heat conduction(Wm-1K-1)
1,2
0,04
0,02

Volume at thebuilding (m-3)
2121
540
27092

The calculated capacity is the same amount to 1000 m3 water tank, which could be considered as
investment instead of the using the building envelope, which is there.

Fig. 3. The simplified model and a photo of the building
Using the building as cooling storage, at 2 K of change in the structure is doubling the capacity
which has low influence on the thermal comfort. To better understand the behavior, a LabView
simulation has made. It shows that the time constant of the building is high, can be even 2 days.

Energy and the Environment (2016) 221-228

225

Fig. 4. The temperature change diagram in LabView
For describing the heat properties of a building, better models are existing than this simple RC
circle, but this can be simply implemented in control systems. In our case a legal regulation has
driven us to start investigating the surplus energy production of the installed PV system.
The Hungarian Law about the electric energy (VET 2007. years LXXXVI. law), states that thefacilities having an own electric transformer system (from middle frequency to low), have to
make the authorization of the planned PV system as it were a MW size power plant, which
would mean incredible plus load for the budget and paperwork.
The solution was to make an isolated system, which still feeds onto the grid, but a technicalsolution cuts the PV system off the grid in case of positive balance (at peak production). Thatwould be wasting of energy, so the HVAC system connection had to be made.
2.2. Building management system
At this rate of sizing, the positive balance in production and demand can only occur on weekends
and in summer when the building is not occupied (Fig. 5).
A photovoltaic systems data acquisition technology connected to the grid-feeding inverters weremade for typical inverter types. With the existing LabView-based environmental monitoring
system accessed through RS485 channel USS protocol. The importance of the measurements is,
to investigate the possibility of turning the grid connected system into an isolated system if thegrid load is high.
At this special case, in the basement of the dormitory building takes place the 0,4 kV transformer
facility, where 3 pieces of current switches were planted. In connection with these, one current
direction sensor were placed (PQRM 5100 31 type, manufactured by DATCON).

226

I. Ervin Haber, I. Farkas: Smart PV system using buildings heat storage

Fig. 5. Production and consumption of the building on a weekend day, middle of June
If the energy direction turns into export, the transmitter sends a protection sign through its
potential-less contact. This is acknowledged by an IP relay, and sends the sign into the structured
IP network with high reliability. On the other side, the same hardware in receiving statusconverts it back to a discrete sign and splits the AC side of the inverter, so the PV production
stops immediately. If the protection sign is cancelled, the inverter follows the normal protocol toturn back the system into production mode.
It is cleared that a scheme of energy consumption would be necessary, which provides the PV
system won’t be isolated, or if it still happens, the BMS involves consumers into the system,
whose are easily controllable (HVAC, heating, domestic hot water production, etc.)
Based on these, the aim was to develop a scheme for consumption and a module which converts
the industrial channels of the inverters into widely usable signs, to possibly connect to BMS andother monitoring systems. With the help of this hardware, investigating the consumption habits,
the whole system can be optimized.
The solution is using the inverters open channel for USS protocol, where the date structure wasprovided through Siemens, against a non-disclosure agreement and use it to monitor the
production values. If the energy usage and production closing to each other, the controller can
decide whether to let the system cut off, or to use the energy for cooling.
3. CONCLUSIONSAs success of integrating the PV system in the BMS the surplus energy will not wasted (cut off),
if the building needs the cooling power or it is derived, that the amount of cooling will last until
it is needed (next weekday, or an event in the summer). It is also clear, that this control increases
the consumption, but the whole system reaches higher efficiency. Due to the relatively small
sized PV system, the positive balance only occurs on few days a year and gives only 5 - 15 % in
the heat capacity in ratio.
Increasing the peak power of the PV grid would be necessary to reach 1-2 C in ratio and in the
progress, the comfort values could be analyzed, next to other important processes.

Energy and the Environment (2016) 221-228

227

ACKNOWLEDGEMENT
Supported through the New National Excellence Program of the Ministry of Human Capacities.
(ÚNKP-16-3)
REFERENCES[1] 110th US Congress 2007: Energy Independence and Security Act of 2007, US Government
Printing Office[2] Sandia National Renewable Laboratories: DOE Global Energy Storage Database,www.energystorageexchange.org, 09.10.2016.
[3] Schoenung, S.: Energy Storage System Costs Update, Sandia National Energy Laboratories
Report, Vol. 2730, 2011, pp. 1-30.
[4] Thakur, J., Chakraborty, B.: Smart net metering models for smart grids in India, 2015
International Conference on Renewable Energy Research and Applications (ICRERA), IEEE
Xplore, Proceedings of ICRERA 2015, 22-25 Nov. 2015, Palermo, Italy, pp 173-177.
[5] Doorsamy, W., Cronje W.A.: State estimation on stand-alone DC microgrids throughdistributed intelligence, 2015 International Conference on Renewable Energy Research andApplications (ICRERA), IEEE Xplore, Proceedings of ICRERA 2015, 22-25 Nov. 2015,
Palermo, Italy, pp. 227-231.
[6] Ekanayake et al.:Smart Grid technology and applications, Wiley, 2012
[7] Atia, R., Yamada, M.: Distributed Renewable Generation and Storage Systems Sizing in
Deregulated Energy Markets, 2015 International Conference on Renewable Energy Researchand Applications (ICRERA), IEEE Xplore, Proceedings of ICRERA 2015, 22-25 Nov. 2015,
Palermo, Italy, pp 258-262.
[8] Alfaitori, K.A., Khalil, A., Asheibi, A.: Distributed Control of Photovoltaic-Based
Microgrid, 2015 International Conference on Renewable Energy Research and Applications(ICRERA), IEEE Xplore, Proceedings of ICRERA 2015, 22-25 Nov. 2015, Palermo, Italy,
pp 203-208.
[9] Utsugi, Y., Obara, S., Ito, Y., Okada, M.: Planning of the Optimal Distribution of Renewable
Energy in Hokkaido, 2015 International Conference on Renewable Energy Research andApplications (ICRERA), IEEE Xplore, Proceedings of ICRERA 2015, 22-25 Nov. 2015,
Palermo, Italy, pp 254-257.
[10] Sakagami, T., Asai, Y., Werth, A., Kawamoto, D. Tokoro, M., Kitano, H.: Performanceof a DC-Based Microgrid System in Okinawa, 2015 International Conference on Renewable
Energy Research and Applications (ICRERA), IEEE Xplore, Proceedings of ICRERA 2015,22-25 Nov. 2015, Palermo, Italy, pp. 311-316.
[11] Palacio, S.N., Kircher, K.J., Zhang K.M.: On the feasibility of providing power sistem
spinning reserves from thermal storage, Energy Build, 2014, Vol. 104, pp. 131-138.
[12] Arteconi, A., Ciarrocchi, E., Pan, Q., Carducci, F., Comodi, G., Polonara, F., Wang R.:
Thermal energy storage coupled with PV panels for demand side management of industrial
building loads, Applied Energy, 2016, Vol. 2016, pp. 1-10.
[13] Haber, I., Kistelegdi, I., Farkas, I.: Investigation of the solar- and wind energy usage of apositive energy factory building, Technical Gazette, 2014, Vol.21, pp. 1243-1248.
[14] Reynders, G., Nuytten, T., Saelens D.: Potential of structural thermal mass for demandside management in dwellings, Build Environment, 2013, Vol 64., pp. 187-189.
[15] Wolisz, H., Harb, H., Matthes, P., Streblow, R., Müller, D.: Performance assesment forheat distribution systems for sensible heat storage in building thermal mass, CIS-BAT 2013,
Vol. 2., Lausanne, Switzerland, 2013, pp. 945-950.

228

I. Ervin Haber, I. Farkas: Smart PV system using buildings heat storage

SUSTAV NADZORA FOTONAPONSKOG SUSTAVA VISOKE SNAGESPOJEN NA SUSTAV UPRAVLJANJA ZGRADOMSažetak: Nadaleko poznati problem je da na vrhuncu proizvodnje obnovljivih izvora energije,
SULMHQRVQDPUHåDSRVWDMHSUHRSWHUHüHQDVWRJDãWRMHHOHNWULþQXHQHUJLMXYUORWHãNRXVNODGLãWLWL
Razvoji koji se odnose na razvoj i kontrolu solarnih VXVWDYDSDPHWQHNXüHPRJXVHRVWYDULWLV
centralnom obradom za upravljanje zgradama. Na zgradama (državnih, društvenih, sportskihVDGUåDMD VYLVRNLPWRSOLQVNLPNDSDFLWHWLPDGLRL]QDGSRWUHEQHNROLþLQHPRåHELWLSRKUDQMHQNDRWRSOLQDQSUKODÿHQMHP]JUade ako su navike korisnika dobro poznate.
U tom kontekstu, tehnologija prikupljanja podataka fotonaponskih sustava spojenih na mrežne
SUHWYDUDþHL]UDÿHQDMH]DWLSLþQHYUVWHSUHWYDUDþD8]SRVWRMHüLVXVWDYSUDüHQMDVWDQMDRNROLãDbaziran na LabView-u kojePVHSULVWXSDSXWHP56NDQDOD866SURWRNROD=QDþDMPMHUHQMDMHLVWUDåLWL PRJXüQRVW SUHWYRUEH PUHåQR SRYH]DQRJ VXVWDYD X L]ROLUDQL VXVWDY XNROLNR MH PUHåDYLVRNRRSWHUHüHQD8 RYRP SRVHEQRP VOXþDMX X SRGUXPX ]JUDGH VSDYDRQLFD SRVWDYOMHQD MH WUDQVIRUPDtorska
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i jedan senzor smjera struje.
$NR MH VPMHU HQHUJLMH L]OD]QL RGDãLOMDþ ãDOMH VLJnal zaštite kroz svoj bezpotencijalni kontakt.
6LJQDO MH SULKYDüHQ RG VWUDQH ,3 UHOHMD L SRVODQ GDOMH VWUXNWXULUDQRM ,3 PUHåL V YLVRNRPSRX]GDQRãüX6GUXJHVWUDQHLVWLKDUGZDUHXVWDWXVXSULPDWHOMDSUHWYDUDJDQDWUDJXGLVNUHWDQsignal i odvaja AC stranu SUHWYDUDþDWDNRGDSURL]YRGQMDIRWRQDSRQVNRJVXVWDYDRGPDKVWDMH
$NR MH VLJQDO ]DãWLWHRWND]DQSUHWYDUDþVOLMHGLQRUPDODQSURWRNROGDYUDWLVXVWDYXSURL]YRGQLrežim rada.
-DVQRMHGDMHSRWUHEQDVKHPDSRWURãQMHHQHUJLMHNRMDRPRJXüXMHGDIRWRQDSRQVNLVXVWDYQHüH
ELWLL]ROLUDQDDNRVHWRLSDNGRJRGLVXVWDYXSUDYOMDQMD]JUDGRP %06 XNOMXþXMHSRWURãDþHX
sustav koji je lako kontrolirati (HVAC, grijanje, proizvodnja potrošne tople vode, itd.)
Na temelju toga, cilj je bio razviti plan za potrošnju i modul koji pretvara industrijske kanale
SUHWYDUDþD X ãLURNR XSRWUHEOMLYH VLJQDOH ]D HYHQWXDOQR VSDMDQMH QD %06 L GUXJH VXVWDYHQDG]RUD 8] SRPRü RYRJ KDUGYHUD LVWUDåXMH QDYLNH SRWURãQMH FLMHOL VXVWDY PRåH ELWL
optimiziran.
.OMXþQHULMHþLfotonaponski, skladištenje energije, pametni sustav, upravljanje zgradama, Smart
Grid, pametni grad, CFD

Energy and the Environment (2016) 229-238

229

PHOTOVOLTAIC POWER PLANT RITEH-1 – LESSONS LEARNED'XEUDYNR)UDQNRYLü9HGUDQ.LULQþLü'DPMDQ.D]DODF-Miljan
Faculty of Engineering, University of Rijeka,
Vukovarska 58, Rijeka, Croatia, +385 51/651-439, dfranko@riteh.hr

Abstract: The project “Photovoltaic power plant RITEH-1” was initially launched in April
2012. The goal was to realize a photovoltaic (PV) plant in the premises of the Faculty ofEngineering – University of Rijeka with the guiding principle to build a "real" PV plant that,on one hand possesses all the features and components as any other commercial PV plant ofsimilar type and size, and on the other hand, which would be a testing facility for performing
laboratory exercises and scientific experiments. The project has passed all necessary steps
and was finally completed in 2014 ending with the grand opening of the PV plant. The PV
plant RITEH-1 is designed as a moving, non-integrated PV plant, with dual-axis Sun tracking.
The PV plant consists of 15 serially connected PV panels rated at 235W each, giving the totalof 3.5 kW. The plant is operating in parallel with the low voltage (LV) distribution grid, thus
feeding all produced energy to the grid. The connection to the LV grid is done via a singlephase inverter placed on the tracker itself. Upon the opening ceremony of the plant, the PV
plant has served as a testing facility for performing laboratory exercises within university
graduate courses “Electrical installations design” and “Power plants”. The paper discusses
basic operating indicators of plant’s past work, lessons learned, as well as all the benefits ofincluding power plant RITEH-1 in the teaching process.
Keywords: Photovoltaic plant, Project, Operational experience, Teaching process, Laboratory
exercises
1. INTRODUCTION
Renewable energy sources (RES) have become a considerable part of electric transmission
networks as well as of medium and low voltage (LV) distribution networks. Understanding
the overall process from the design stage up to the installation stage, followed by thecommissioning and startup of RES plants is essential knowledge that electric engineers
nowadays should possess. Therefore, at the Faculty of Engineering, University of Rijeka,
Croatia, a fully operational, grid connected photovoltaic (PV) power plant with dual-axis
tracking system has been installed. Consequently, upon PV plant’s installation andcommissioning, our students are able to have “hands-on” on a fully functional PV power plantand perform supervised, “live” measurements and compare it with previously calculated
values. Therefore, new - dedicated laboratory sessions have been introduced in an existing
subject to make the most of the PV installation in the teaching process. Some of theexperiments that our students are able to perform include AC and DC operating values
measurements (PV string and inverter voltages, currents, power, efficiency, etc.),
environmental parameters measurements (irradiance, air temperature, wind direction andvelocity, etc.) and grounding parameters measurements (soil resistivity, PV plant’s grounding
resistance).
The project “Photovoltaic power plant RITEH-1” was initially launched in April 2012. The
goal was to realize a photovoltaic (PV) plant in the premises of the Faculty of Engineering –230')UDQNRYLü9.LULQþLü'.D]DODF-Miljan: Photovoltaic Power Plant…

University of Rijeka with the guiding principle to build a “real” PV plant that, on one handpossesses all the features and components as any other commercial PV plant of similar typeand size, and on the other hand, which would be a testing facility for performing laboratory
exercises and scientific experiments. The project has passed all necessary steps and was
finally completed in 2014 ending with the grand opening of the PV plant. The PV plant
RITEH-1 is designed as a moving, non-integrated PV plant, with dual-axis Sun tracking. The
PV plant consists of 15 serially connected PV panels rated at 235W each, giving the total of
3.5 kW. The plant is operating in parallel with the low voltage (LV) distribution grid, thus
feeding all produced energy to the grid. The connection to the LV grid is done via a singlephase inverter placed on the tracker itself. The paper discusses basic operating indicators ofplant’s past work, lessons learned, as well as all the benefits of including power plant RITEH1 in the teaching process.
2. PROJECT OF THE PHOTOVOLTAIC POWER PLANT RITEH-1
Even though the overall project „from idea to realization” of the PV power plant RITEH-1
lasted for almost two years, the design process was completed within 7 months. During thistime preliminary, main and as-built designs for civil works and electrical works were made.
The construction of the power plant from excavation works, foundation works and finally toelectrical installation works followed by commissioning and testing of the PV plants’s
regulation and protection functions effectively lasted a month. In the remaining time allnecessary permits, approvals, decisions were waited, all of which points to the problems
encountered by the investors in RES projects. The following table provides an overview of
key activities and their duration during the development of the project PV power plant
RITEH-1.
TABLE 1
PV power plant RITEH-1 key project phases
Project stage
Activity
Start date Duration
Preliminary
Permit request for
12/04/2012 2 months
phase
land use
Conceptual electricand0construction
01/07/2012 6 months
designs
Location0permit
28/12/2012 5 months
requestMain electric andPre-construction construction
01/06/2013 1 monthphase
designs
Construction
01/07/2013 3 months
permit request
Construction0site
electric0and
01/10/2013 15 days
construction
designs
Construction0site
PV0plant
enclosing0and
20/10/2013 1 day
construction
preparingphase

RemarkPublic0bodies
approvals collecting
Administrative
procedure
Designing
Administrative
procedure
Designing

Preliminary works

Energy and the Environment (2016) 229-238

Postconstruction
phase

Mast0foundationbuilding
Mounting0of
equipment, cabling
Parameterization,
protection testing
Technical
inspection0of
construction0andelectrical works
Use permit request

231

21/10/2013

7 daysConstruction works

07/11/2013

1 dayElectrical works

28/12/2013

1 day

Testing0andcommissioning

02/04/2014

1 day

Administrative
procedure

02/04/2014

2 months

Administrative
procedure

Although the PV plant RITEH-1 was not intended to be a commercial project, in order to get
all necessary permits, a feasibility study had to be carried out.1 Daily, monthly and yearly,
electric energy production estimates had been calculated using PV-Sol software tool.2
Hereafter some of the results are reported in Table 2 and later, in section 3, a comparison of
the estimated data with recorded data will be presented.
TABLE 2PV power plant RITEH-1 feasibility study results
Number and size of PV panels

15x235 Wp

Peak power

3.525 kW

Inverter size and number of phases

5.0 kW; 1-phase

PV plant’s capacity factor

1,361 kWh/kWp

Yearly energy production

4,704.1kWhYearly income

1,300 EUR

Investment

11,500 EUR

ROI (Return Of Investment)

9.7 years

3. RESULTS OF PREVIOUS WORK OF THE PV POWER PLANT RITEH-1
Photovoltaic power plant RITEH-1, Fig. 1, is in operation for more than two years, andvaluable operational experience has been gained. During these two years 9.971,00 kWh ofelectrical energy has been produced. Hereby, not only the Faculty of Engineering,
University of Rijeka contributed to the production of electrical power from RES, but has
also influenced the reduction of CO2 emissions for 5.284 tons.
Fig. 2 shows the monthly electrical energy production for the period from August 2014 to
July 2016.

232')UDQNRYLü9.LULQþLü'.D]DODF-Miljan: Photovoltaic Power Plant…

Fig. 1 PV plant RITEH-1

The maximum recorded instantaneous power of the PV plant RITEH-1 was 4.5 kW andrealized in January 2014, resulting from the negative power-temperature coefficient of theinstalled PV panels, since at lower temperatures and with nominal irradiance, the voltage
is increased at the ends of PV cells, while the current is slightly reduced compared to thevalue at standard test conditions (Standard Test Conditions - STC).3
kWh

800
700
600
500
400
300
200
100
0

2014

2015

2016

Plan

Fig. 2 PV plant RITEH-1 monthly production (08/2014-07/2016)

It is interesting to note in Fig. 2 the deviation of actual production and the production
plan, made in the PV-Sol software tool. Total deviation for 2014 was -191 kWh, for 2015
+478 kWh, and for 2016 -66 kWh. A positive sign means that the actual production was
better than planned, while a negative sign means the opposite. Expressed as percentage,
the deviation was -10.73% in 2014, +9.81% in 2015, and -2.13% in 2016. The reason forlower production than planned could be found in higher monthly cloudiness in relation toEnergy and the Environment (2016) 229-238

233

the perennial average, dirty PV panels, strong winds that triggers the power plant
protection and moves the panels in a horizontal position. This can be perceived on thefollowing figures that show the daily production of the PV power plant RITEH-1 during asunny day, cloudy day and during the two days when the strong wind bora blew in the cityof Rijeka and its surroundings.

Fig. 3 PV plant RITEH-1 production during a sunny day (30/07/2016)

Fig. 4 PV plant RITEH-1 production during a sunny day with periodic clouds (02/08/2016)

234')UDQNRYLü9.LULQþLü'.D]DODF-Miljan: Photovoltaic Power Plant…

Fig. 5 PV plant RITEH-1 production during a day with heavy clouds (01/08/2016)

Fig. 6 The impact of strong wind (bora) to PV plant RITEH-1 production(05/08/2016 - 06/08/2016)

From the given figures it can be observed a very irregular profile of the daily production for
the PV plant RITEH-1, which certainly confirms the reputation of RES as unpredictable anduncontrollable, unless they are coupled with systems for energy storage. It should also be
noted that the power produced can quickly and rapidly fluctuate up and down, with a slightdifference when ramping-up, due to speed limitation of the ramp-up process limited byinverter setting, in accordance with the distribution network grid-code.

4. INCLUDING THE PV PLANT RITEH-1 IN THE TEACHING PROCESS
Apart from acquiring fundamental knowledge on PV systems and components, thestudents enrolled in master courses “Power substation design” and “Power plants” havethe opportunity to gain an insight into the overall administrative procedures and key

Energy and the Environment (2016) 229-238

235

project phases, shown in Table 1, necessary to realize a real-world PV installation alongwith all the above mentioned design considerations, calculations and measurements.
By simple inspection of Table 1, it is clear that administrative procedures and slowness of
public bodies constitute an enormous weight in the overall process of RES development
and implementation. Therefore, the students become familiar with the exceptionally
important time-component of RES projects and observe that, besides technical problems
that must and can be over passed, other potential threats to the project exist.
On the other hand, the technical side of PV projects is much more certain. In fact, toachieve project success, thorough understanding of physical principles in the backgroundof system components and system operation as a whole, is of paramount importance.
Thus, it is important to familiarize the students with physical principles as well as basic
RES components and dedicated measuring instruments as well as principles intended formeasurement of relevant physical quantities (irradiance, temperature, voltage, current,
power, etc.).
Hereafter a brief description of some of the student experiments conducted using a“Metrel EurotestPV MI 3108” measuring instrument is presented, Fig. 7-10.4
Insulation resistance measurement – applying a DC voltage of 50, 100, 250, 500 or 1000
V to positive and negative conductors, a small leakage current flows. By dividing applied
voltage with the leakage current, insulation resistance is obtained. Hence students become
familiar with test voltage ranges and the typical values of low voltage cables insulation
resistance, Fig. 7.

Fig. 7 DC cabling insulation resistance measurement

AC and DC voltage-current measurements – appropriately connecting lead wires andcurrent clamps, DC voltage and current of the PV string are measured, Fig. 8. Afterwards,
removing and reconnecting test leads and current clamp on inverter’s AC side, AC voltage
and current are measured. Obviously, DC and AC power of the PV plant can be readily
obtained, and students can easily calculate the actual efficiency of DC/AC conversion,
insofar as environmental parameters are constant (irradiance, outside temperature, windspeed and direction, etc.).

236')UDQNRYLü9.LULQþLü'.D]DODF-Miljan: Photovoltaic Power Plant…

Fig. 8 AC voltage and current measurement

PV panel U-I characteristic measurement – the standard test that demonstrates PV panel’scharacteristics and indicates weather a panel or a string of panels operates satisfactory. Bymeasuring panel’s U-I characteristic, the students become familiar with the concepts of
STC, nominal operating cell temperature (NOCT), short-circuit current (Isc), open circuit
voltage (Voc), maximum power point current (Impp), maximum power point voltage (Vmpp),
maximum power point (Pmax) and fill factor (FF), Fig. 9.
STANDARD CONDITIONS

5000W
Power [W]

Current [A]

10A

500V

500V
MEASURED
5000W

10A

Voltage [V]600V

Voltage [V]600V

Fig. 9 I-U and P-U characteristic recording

Environmental parameters measurement – irradiance and cell temperature are the mostprominent parameters that determine actual PV cell operating point, Fig. 10. Knowing
cell’s/panel’s voltage-power characteristic temperature and irradiance dependency,

Energy and the Environment (2016) 229-238

237

students are able to predict PV plant’s actual power and compare it with acquired powerrecordings (e.g. Fig. 3-6) or dedicated software.5

Icell

Tcell

Fig. 10 Measurement of cell’s actual temperature and irradiance

The above described experiments are perhaps the most characteristic for PV installations
but by no means represent the whole range of experiments that our students perform.
Other experiments, not described previously, include: residual current device test, faultloop impedance measurement, grounding resistance measurement, specific groundresistance measurement (Fig. 11), protective conductor continuity check, etc. Fig. 11
presents the students during the laboratory session.

Fig. 11 Specific ground resistance measurement

5. CONCLUSION
This paper presented an educational PV power plant with dual-axis tracking systemconstructed at the Faculty of Engineering, University of Rijeka. The project named “PV238')UDQNRYLü9.LULQþLü'.D]DODF-Miljan: Photovoltaic Power Plant…

power plant RITEH-1”, except for the educational component, realized through improvementof laboratory exercises on existing courses, has a commercial side since the power producedin the power plant is fed into the local low voltage distribution network. The PV power plant
RITEH-1 in the period from 08/2014 to 07/2016 produced almost 10 MWh of electricity andthus reduced the emissions of 5.3 tons CO2 into the atmosphere. The paper presented the basic
indicators of power plant’s previous operating experience, and emphasized the intermittent
character of power production influenced by many factors such as outside temperature, wind,dirt and others. The paper also addresses renewable energy projects development problems
arising from the slowness of the state administration and the complexity of the process ofobtaining all the necessary permits, approvals, opinions and decisions. Future work includes
upgrade of the existing power plant with a small vertical-axis turbine, an energy storage
system and an appropriate ICT system, altogether forming a small, advanced microgrid.
REFERENCES[1] Frankovic, D.: Photovoltaic power plant with dual-axis tracking system at the location ofFaculty of Engineering - University of Rijeka feasibility study, 2013[2] Dr. Valentin EnergieSoftware: PV*SOL Design and Simulation of Photovoltaic Systems,
User Manual[3] Skoplaki, E., Palyvos, J. A.: On the temperature dependence of photovoltaic module
electrical performance - A review of efficiency/power correlations, Solar Energy, Volume
83 (2009), pages 614–624[4] Dobric, G., Durisic, Z., Stojkovic, Z.: Software tool for evaluation of electrical energy
produced by photovoltaic systems, International Journal of Electrical Engineering
Education, Volume 49 (2012) Issue (4), pages 383-401.
[5] EurotestPV, MI 3108 Instruction manual, Metrel, 2012.

FOTONAPONSKA ELEKTRANA RITEH-1 – 67(ý(1$,6.8679$
Sažetak: Projekt fotonaponske elektrane (FNE) Riteh-]DSRþHWMHMRãXWUDYQMXJRGLQH
s ciljem realizacije FNE XVNORSX7HKQLþNRJIDNXOWHWD0LVDRYRGLOMDELOa je izgraditi „pravu”
FNE koja bi s jedne strane bila elektrana sa svim obilježjima i komponentama kao i bilo koja
GUXJDNRPHUFLMDOQDHOHNWUDQDVOLþQRJWLSDLYHOLþLQHDVGUXJHVWUDQHNRMDELELODSROLJRQ]D
L]YRÿHQMH ODERUDWRULMVNLK YMHåEL L ]QDQVWYHQLK LVWraživanja. Projekt je prošao sve potrebne
NRUDNHWHMHNRQDþQRGRYUãHQJRGLQHVYHþDQLPRWYDUDQMHPLSXãWDQMHPXUDG elektrane.
FNE Riteh-L]YHGHQDMHNDRSRPLþQDQHLQWHJULUDQDHOHNWUDQDVGYRRVQLPSUDüHQMHP)1(sastoji se od 15 serijski vezanih fRWRQDSRQVNLK )1  SDQHOD SRMHGLQDþQH VQDJH :
odnosno 3,5 kWp ukupno. Elektrana je u paralelnom radu s niskonaponskom (NN)GLVWULEXFLMVNRPPUHåRPQDNRMXMHSULNOMXþHQDSUHNRMHGQRID]QRJSUHWYDUDþDVPMHãWHQRJQD
SRPLþQRMQRVLYRMNRQVWUXNFLML)1SDQHOD2GVYHþDQRJRWYDUDQMDHOHNWUDQH, FNE je poslužila
NDR SROLJRQ ]D L]YRÿHQMH ODERUDWRULMVNLK YMHåEL L] NROHJLMD «3URMHNWLUDQMH HOHNWULþQLK
postrojenja» i kolegija «Elektrane» SULVYHXþLOLãQRPGLSORPVNRPVWXGLMXHOHNWURWHKQLNHVPMHU
Elektroenergetika. U radu su dalje prikazani osnovni pokazatelji dosadašnjeg rada elektrane,VWHþHQD LVNXVWYD NDR L VYH NRULVWL RG XNOMXþHQMD IRWRQDSRQVNH HOHNWUDQH 5LWHK-1 u nastavni
proces.
.OMXþQHULMHþL Fotonaponska elektrana, Projekt, Operativno iskustvo, Nastavni proces,
Laboratorijske vježbe

Energy and the Environment (2016) 239-246

239

BIDIRECTIONAL POWER CONVERTER FOR PHOTOVOLTAICAPPLICATIONS: DESIGN CONSIDERATIONS
6DãD6ODGLü7RPLVODY'RãHQ/XND'DQþXORYLü
Faculty of Engineering, Vukovarska 58, 51000 Rijeka, +385 51 651-582,
sladics@riteh.hr, tdosen92@gmail.com, ldanculovic@riteh.hr

Abstract: In this paper a classic bidirectional buck-boost power converter has been analyzed
in order to accomplish cost effective solution for low power photovoltaic applications.
However, same topology could be realized with different transistor switch positioning which
implies different transistor driver circuits and different transistor gating conditions. Bothsimulation results and practical results with ARM cortex-M processors and TI UC3854
industrial solution have been obtained in order to support analysis.
Keywords: Bidirectional power converter, buck-boost topology, transistor driver circuits,
semiconductor switch, thermal stress
1. INTRODUCTION
Bidirectional power converters have been used in photovoltaic (PV) applications in order tocontrol the PV system battery voltage. During the day time PV source is supplying the loadby produced energy. In the same time the energy surplus could be stored in PV systembatteries. In order to prevent overcharging of batteries, charging should be stopped at thecertain voltage (depends on battery type). In case there is not enough PV energy, bidirectional
converter should supply additional energy from battery. Different converters could be used[1], however combination of buck and boost converters has been mostly used in photovoltaic
systems [2-4], for locomotives [5] or as battery-supercapacitors interface [6] or in otherapplications [6-10] even for aerospace applications [9]. In this article a two approaches has
been compared in order to explore design, functionality and financial considerations oftransistor positioning in frame of same topology.
2. BIDIRECTIONAL POWER CONVERTER IN PV SYSTEM
2.1. Photovoltaic Power System
Photovoltaic (PV) systems are using as house supply or in hybrid and electric vehicles, or for
yachts and in other applications. Bidirectional power converter with batteries or other powersource is using for balancing of current production and consumption of electric energy. For
example it ensures power supply in stand-alone PV system during the night (Fig.1.).

240

66ODGLü7'RãHQ/'DQþXORYLü: Bidirectional power converter for photovoltaic …

energy flow direction

PV module

energy flow direction

DC link

batteries

bidirectional
power
converter

MPPT power
converter

DC load or AC grid interface

Figure 1. Stand-alone photovoltaic (PV) system schematic with bidirectional power converter position andmaximum power point tracker (MPPT)

Power production and consumption are not equal and constant, so the energy storage isneeded. In spite of large weight lead-acid batteries are used in PV systems because of its
mature technology. Furthermore, PV systems in houses are not mobile so their weight is notof consider. Since, energy surplus has to be stored in batteries and used during the absence ofsunlight bidirectional power converter has to be used. It consists of Buck and Boost power
converters which control energy flow in both directions. Buck converter from higher to lower
voltage and Boost converter from lower to higher voltage.
2.2. Variants of Bidirectional Buck-Boost Power Converter
Classic topology of bidirectional buck-boost power converter has been shown in figure 2.aand proposed topology with same function has been shown in figure 2.b.
T1

iL

D1

L1

L1

vL

D2

T2

vH

D2

T2

vL

vH

D1
T1

a)
b)
Figure 2. Variants of bidirectional converter; a) classic bidirectional buck-boost power converter and b)
modified (proposed) bidirectional buck-boost power converter with repositioned switch of buck converter (T1)

Both circuits consist of single buck and single boost converter (Fig. 3). In first case (Fig. 3.a)DC side of higher voltage VH (e.g. PV source as shown in Fig. 1) transfers its energy to lower
voltage side (VL) usually to lead acids batteries during the operation of buck converter. Other
battery types could be used also, however because of their maturity lead acid batteries are still
first choice for PV systems. In second case, energy from DC source of lower voltage VL has
been transferred to DC source of higher voltage VH during the operation of boost converter(Fig. 3.b).
T1

D1
L1

L1
vH
vL

D2

a)

vL

vH

T2

b)

Energy and the Environment (2016) 239-246

241

Figure 3. a) Buck converter schematic with buck (T1) transistor and buck (D2) diode; and b) boost converter
schematic with boost converter (T2) transistor and boost converter diode (D1)

Switching conditions of power semiconductor switch (power transistor) has been defined byits switching voltage and current. However, its gating signals generation could be different inspite the fact that the same currents and voltages have been switched. Generally, the buckpower converter (Fig. 3.a) gating conditions are more demanding to accomplish than in boost
converter (Fig. 3.b). That is consequence of different potentials referred to neutral circuit
point (battery minus pole). That means driver circuit which can obtain 15V square wave
control signal for boost converter (Fig. 3.b), generally is not sufficient for switching thetransistor switch in buck converter (Fig. 3.a), in spite the fact that booth transistors arecontrolled with the same waveform. In this article a variant where both power transistors
appears on ground potential or even closer to ground potential (Fig. 2.b) is analyzed andcompared with is classic variant (Fig. 2.a).
2.3. Simulation Results
According to simulation results transistor waveforms are not dependent to switch position inframe of same topology. It could be stated that buck converter act as a buck converter
whatever the power transistor position is (Fig. 4.a).

iL

-i L

vg2

vg2

vg1

vg1

t

t

a)

b)

Figure 4. Simulated waveforms of transistors control signals, and inductance current for a) buck converter and b)
boost converter (10A/div., 10V/div., fs=30 kHz)

iL

vg2

vg2

vg1

vg1
t

t

a)
b)
Figure 5. Waveforms of gating signals for buck boost converter a) simulated results, b) measured results(10V/div., 10A/div., fs=30 kHz)It can be noted that simulation and measured results coincide (Figs. 5.a and 5.b). However,measured signals are not perfect filtered so the few percentage AC component could bemeasured in both signals (Fig. 5.b). Similar is also with other measured signals which also
have ringing which has been neglected.

242

66ODGLü7'RãHQ/'DQþXORYLü: Bidirectional power converter for photovoltaic …

2.4. Practical Results and Measurements
Considering the practical realization of bidirectional converter with boost driver circuits itshould be stated that buck converter, according to schematic 2.a cannot be switched on at all.
For its realization, professional drivers as SKHI23 [11] are needed, making the second variantof buck-boost converter the only one in consideration for a cost effective drivers approach.

-i L

iL
vg2

vg2
vg1

vg1

t
t

a)

b)

Figure 6. Measured waveforms of inductance current iL and gating signals for booth transistors a) buck converter
operation with its gating signal or charging a lead-acid battery according to Fig. 1, b) boost converter operation,discharging of lead-acid battery according to Fig. 1 (10V/div., 10A/div, ȝVGLY

Practical circuit realization discovers that buck and boost converters has influence on eachother. For the start, they could not operate in the same time. Furthermore, emiter potential ofboost (T2) converter depends on fact is it buck transistor in on or in off state. During the onstate boost converter emiter is very close to ground potential, because conducting transistor
prodeces voltage drop beetwen 1 V and 2 V. In other case its emiter potential rises todiference beetven DC levels of input and output.

iL

vg2

vg1
t

Figure 7. Measured potential swing which appears as disturbance to gating signals could be succesifully
overcamed by cost effective power transistor drivers (10 V/div., 10 A/div., 18ȝVGLY

Waveforms from Figure 6.a was taken again (Fig. 7) with other potential reference in order toshow that potential swing could be neglected with different selection of referent point,
however in that case each converter operation mode (buck or boost) has its owen referent
point.

Energy and the Environment (2016) 239-246

243

iL

vg2
vg1
t

Figure 8. Measured potential swing of emiter of buck (T1) converter transistor as a consequence of boost
converter operation with reversed inductance current iL flow (10 V/div., 10 $GLYȝVGLY
iL

vg2

vg1
t

Figure 9. Measured switching from boost to buck power converter operation involves change of potentials inframe of bidirectional power converter (10 V/div., 10 A/div., 1s/div.)

In spite the fact that booth converters has simple drivers, and optical coupling of two signals
could be avoided in suggested circuit (Fig 2.a) an influence of buck converter to boost
converter could be recorded (Fig. 9). Waveforms has been recorded with referent point at theemiter of buck (T1) transistor and it can be shown that boost transistor (T2) gating signal
potential is cloaser to referent point when the buck converter transistor (T1) is conducting(Fig. 9).

low voltage DC
sidehigh voltage DC
side with PV
source 25W(and battery)bidirectional
power converter

Figure 10. Modified bidirectional power converter

Bidirectional buck-boost power converte (Fig.10) could be used for different applications
including PV supply for houses and applications in electric (or hybrid electric) cars [10] andyachts. PV appliance could be difficult to simulate in laboratory, however experiments werealso conducted in open field (in front of the buiding) obtaining the PV power from 1 W(cloudy day) to 25 W (sunny day) enabling the charging of cost effective lead acid batteries atdifferent intensityes.

244

66ODGLü7'RãHQ/'DQþXORYLü: Bidirectional power converter for photovoltaic …

Laboratory prototype enables recording a different waveforms, however its thermal image
discovers that it has been operated close to its thermal border (Fig. 11), resulting even in few
transistors malfunction during testing. For the practical implemeentation and long-term usagea coolers or even a cooling system should be added to prototype. It could be noted that during
the boost converter operation, boost transistor (T2) and diode D1 has been hardly termaly
loaded and during the buck converter operation buck transistor (T1) with its accompagning
diode (D2) has been heavly termaly loaded (Fig. 11).

measurement
probe

inductanceconnection
cables

D2
T2

T1
D1

transformer

conditioning ofcontrol circuit

control circuitwith transistors
driverFigure 11. Thermal image of modified bidirectional power converter with its power and control circuits during
charging a battery according to Fig. 1 (transistor T1 reaches temperature of 60 ࡈC)

Thermal image of modified power converter discovers high thermal stress in power circuit
especially on inductance L and on both transistors, especially on buck transistor. Thiscondition could be expected since thermal image was taken for charging a battery fromexternal (PV) source. However, control circuits involving PWM generator (UC3854) andlevel shifter (CD40109BE – level shifter / amplifier) is also thermally loaded. In case of
appliance of cortex-M4 microprocessor in frame of STM32F4 microprocessor systemdevelopment board, more compact microcontroller achieving higher temperature than larger
integrated circuits.
3. CONCLUSION
In this paper a difference between two bidirectional buck-boost converters with different
switch positioning was analyzed in order to estimate cost effectiveness of both solutions.
Classic solution enables application of integrated power devices which are more cost effective
than discrete transistors and diodes which could be used in low gating signal potential variantof bidirectional power converter. However, second option has more simple driver circuits(without optical or magnetic connections for gating signals) which means this option could
avoid application of sophisticated driver circuits and achieve cost effectiveness at low(few kHz) and especially higher (>100kHz) frequencies. In the sense of dynamics and power
circuit design there are no differences between considered variants of bidirectional converters
and they could be equally applied in PV systems, hybrid cars, yachts and for otherEnergy and the Environment (2016) 239-246

245

applications. Furthermore, thermal image offers additional and precise information for
optimization of particular components, especially transistors.
4. LIST OF SYMBOLS
VH – DC source of higher voltage
VL – DC source of lower voltage
T1 – buck converter transistor
T2 – boost converter transistor
D1 – boost converter transistor
D2 – buck converter transistor
IL – inductance current
vG1 – gating signal of buck converter transistor (T1)vG2 – gating signal of boost converter transistor (T2)
ACKNOWLEDGE
In this way authors would like to thank to colleagues from Laboratory of Thermodynamics,
Faculty of Engineering Rijeka SURI %HUQDUG )UDQNRYLü 3K' KHDG RI WKH /DERUDWRU\ for
Thermodynamics and to his colleague Paolo Blecich, Ph.D. who help us by additional
equipment to improve our research.
REFERENCES[1] Abu-Rub, H., Malinowski, M., Al-Haddad, K.: Power Electronics for Renewable Energy
Systems, Transportation and Industrial Applications, IEEE Press and Wiley, 2014.
[2] Cpham, C., Kerekes, T., Teodorescu, R.: High Efficient Bidirectional Battery Converter
for Residental PV Systems, in Proceeding of the 3rd IEEE International Symposium on
Power Electronics for Distributed Generation Systems, PEDG 2012. IEEE Press, pp. 890894.
[3] Chao K. H., Tseng, M. C., Huang C. H., Liu, Y. G., Huang, L. C.: Design and
Implementation of Bidirectional DC-DC Converter for Stand-Alone Photovoltaic
Systems, International Journal of Computer, Consumer and Control (IJ3C), Vol. 2, No. 3,
2013.
[4] Karthikeyan, P., Chidambaranathan V. S.: Bidirectional Buck-Boost Converter-Fed Drive,
Dash, S. S. (eds.), Artificial Intelligence and Evolutionary Computations in Engineering
Systems, Advances in Intelligent Systems and Computing, Springer India 2016.
[5] Zinov’ev, G. S., Lopatkin, N. N., Vais, H.: High-Voltage DC-DC Converter for NewGeneration Electric Locomotives, Russian Electrical Engineering, Vol. 80, No. 12., 2009.
[6] Wu, Z. W., Zhang, Z. L., Yin, C. L., Zhao, Z.: Design of a Soft Switching Bidirectional
DC-DC Power Converter for Ultracapacitor-Battery Interfaces, International Journal ofAutomotive Technology, Vol 13. No.2, pp.325-336, 2012.
[7] Wu, Z., Zhang, J., Zhang, X., Yin, C.: Peak Current Control Strategy with Extended-State
Tracking Compensator for DC-DC in Hybrid Energy Storage System, Shangai Jiaotong
University and Springer-Verlag Berlin Heidelberg 2013.
[8] Sagert, C., Sawodny, O.: Modeling of the electrical DC-link in fuel cell vehicles for DCDC converter control design, 15. Internationales Stuttgarter Symposium, Proceedings,
Springer Fachmedien Wiesbaden, 2015.
[9] Themozhi, G., Reddy, S. R.: On Chip Pulse Width Modulator and Dead Time Controller
in Bidirectional DC to DC Converter for Aero Space Applications, Arab J. Sci. Eng. 2014.

246

66ODGLü7'RãHQ/'DQþXORYLü: Bidirectional power converter for photovoltaic …

[10] Bhajana, V. V. S. K., Drabek, P.: A New Non-isolated ZCS Bidirectional Buck-Boost
DC-DC Converter for Energy Storage Applications in Electric Vehicles, Arab J. Sci. Eng.
2015.
[11] ___: Semikron datasheet SKHI23/12 https://www.semikron.com/dl/servicesupport/downloads/download/semikron-datasheet-skhi-23-12-r-l5002371 (02.08.2016)%,',5(.&,-6.,8ý,16.,35(79$5$ý=$35,0-(188
FOTONAPONSKIM SUSTAVIMA
Sažetak: 8RYRPUDGXMHDQDOL]LUDQLVWRVPMHUQLELGLUHNFLMVNLSUHWYDUDþVDþLQMHQRGVLOD]QRJHQJEXFN LX]OD]QRJ HQJERRVW SUHWYDUDþaWYRUHüLQDWDMQDþLQVLOD]QR-uzlazni istosmjerni
ELGLUHNFLMVNL SUHWYDUDþ 3URPRWUHQL SUHWYDUDþ MH VNORSRYVNL L]PLMHQMHQ DOL je funkcionalno
RVWDR QHSURPLMHQMHQ 2EMH VX LQDþLFH XVSRUHÿHQH VD VWDMDOLãWD FMHQRYQH SULVWXSDþQRVWL NDRSRVOMHGLFD UD]OLþLWLK XYMHWD ]D XSUDYOMDQMH SRMHGLQLP WUDQ]LVWRULPa. U radu su predstavljeni
simulacijski i SUDNWLþQL UH]XOWDWL GRELYHQL XSRWUHERP 3:M generatora (UC3854) i
mikroprocesorskog sustava s ARM cortex M4 procesorom.
.OMXþQH ULMHþL: 'YRVPMHUQL SUHWYDUDþ VQDJH silazno-uzlazna topologija, tranzistorno
XSUDYOMDþNLNUXJ SROXYRGLþNDVNORSNDWHUPLþNRRSWHUHüHQMH

Energy and the Environment (2016) 247-256

247

180(5,ý.$6,08/$&,-$ +,'5$8/,ý.2*6867$9$=$
POZICIONIRANJE 3$5$%2/,ý1OG SOLARNOG
KOLEKTORA
Z. Bilandžija, G. Gregov
6YHXþLOLãWHX5LMHFL7HKQLþNLIDNXOWHW, Vukovarska 58, 51000 Rijeka, Hrvatska
Phone: +385-(0)51-651528, fax: +385-(0)51-651416, e-mail: gregovg@riteh.hrSažetak: 8 RYRP UDGX DQDOL]LUDQL VX VRODUQL NROHNWRUL V QDJODVNRP QD SR]LFLRQLUDMXüH
SDUDEROLþQHVRODUQHNROHNWRUH6RODUQLNROHNWRULVXSRVHEQDYUVWDL]PMHQMLYDþDWRSOLQHþLMDMH
RVQRYQD QDPMHQD SULMHQRV HQHUJLMH 6XQþHYH UDGLMDFLMH UDGQRP PHGLMX 3R]LFLRQLUDMXüLpDUDEROLþQL VRODUQL NROHNWRUL VX XQDSULMHÿHQL NROHNWRUL þLMD NRQVWUXNFLMD RPRJXüDYD]JXãQMDYDQMH 6XQþHYLK ]UDND RGQRVQR QMLKRYR IRNXVLUDQMH QD površini kolektora V þLPH VH
SRYHüDYDQMLKRYDLVNRULVWLYRVW$QDOL]LUDQLVXSR]LFLRQLUDMXüLVXVWDYL solarnih kolektora te jeodabran KLGUDXOLþNLVXVWDYVGYRUDGQLPKLGUDXOLþNLPFLOLQGURP. Proveden MHQMHJRYSURUDþXQte su na temelju dobivenih rezultata odabrane VWDQGDUGQH KLGUDXOLþNH NRPSRQHQWH NRMHSUHGVWDYOMDMX XOD]QH YULMHGQRVWL VLPXODFLMVNRJ PRGHOD .RULVWHüL SUogramski pakte ITI-Sim
L]UDÿHQMHVLPXODFLMVNLPRGHO]DSR]LFLRQLUDQMHSDUDEROLþQRJVRODUQRJNROHNWRUD5HJXODFLMVNLVXVWDY]DSR]LFLRQLUDQMHMHL]UDÿHQQDSULQFLSX]DWYRUHQHSHWOMDV3UHJXODWRURP.OMXþQHULMHþL: SDUDEROLþQLVRODUQLNROHNWRUKLGUDXOLþNo upravljanje, pozicioniranje
1. UVOD
Solarna HQHUJLMD REXKYDüD VYX HQHUJLMX proizvedenu od strane Sunca koja se u oblikuVXQþHYRJ ]UDþHQMD UDVSURVWLUH VYHPLURP 6XQFH HPLWLUD [20 MW energije radijalno usvim smjerovima SULþHPXQD=HPOMXGRVWLåH 175x109 MW. Iako energija na površini Zemlje
SUHGVWDYOMD VDPR SRORYLQX PLOLMDUGLWRJ GLMHOD 6XQþHYH HQHUJLMH X OMXGVNRP VPLVOX RQDpredstavlja 100 000 puta YHüXYULMHGQRVWRGHQHUJLMHSURL]YHGHQe u svim elektranama [1].
Tijekom 19. VWROMHüD SRþLQMX SUYL SRNušaji korištenja solarne energija za proizvodnju
QLVNRWODþQH SDUH $XJXVW 0RXFKRW MH SUYL NRQVWUXLUDR VRODUQR SRJRQMHQH SDUQH VWURMHYH.
*RGLQH  0RXFKRW MH RVWYDULR ]QDþDMDQ QDSUHGDN X VDPRP GL]DMQX VRODUQRJ NROHNWRUDREOLNRYDQRJ X REOLNX þXQMD .ROHNWRU VH VDVWRMDR RG PHWDOQLK SORþD SUHVYXþHQLK VUHEURP
promjera 5,4 m te je imao kolektorsku površinu od 8,6 m2. Godine 1912. Shuman je pokrenuo
L]JUDGQMXQDMYHüHVYMHWVNHSXPSQHVWDQLFHX0HDGLX(JLSWX3URMHNWMH]DåLYLRJRGLQH
a temeljio se na tako]YDQLPSDUDEROLþQLPNRULWLPD NRMLVXIRNXVLUDOL6XQþHYH]UDNHQDGXJXDSVRUEHUVNX FLMHY 6YDNL RG IRNXVLUDMXüLK korita je bio dug 62 m a ukupna kolektorska
površina 1200 m2. Postrojenje je razvijalo do tada impresivnih 45 kW energije, kontinuirano
SHWVDWL8QDWRþYHOLNRPXVSMHKXSURMHNWDVXVWDYMHXJDãHQJRGLQHXVOLMHGWXUEXOHQWQLKGRJDÿDMDNRMLVXSUHWKRGLOLSUYRPVYMHWVNRPUDWXLQLVNLPFLMHQDPDIRVLOQLKJRULYD [2].
2. 32=,&,21,5$-8û,3$5$%2/,ý1,62/$51,.2/(.725,
6RODUQL NROHNWRUL VX SRVHEQD YUVWD L]PMHQMLYDþD WRSOLQH þLMD MH RVQRYQD QDPMHQD SULMHQRVHQHUJLMH 6XQþHYH UDGLMDFLMH UDGQRP PHGLMX =ERJ VYRMH IXQNFLMH SUHGVWDYOMDMX RVQRYQX

248

Z. Bilandžija, G. Gregov: 1XPHULþNDVLPXODFLMDKLGUDXOLþNRJVXVWDYD«

komponentu bilo kojeg solarno NROHNWRUVNRJVXVWDYD2YLPVHXUHÿDMLPDDSVRUELUD6XQþHYD
UDGLMDFLMDNRMDVHSRWRPSUHWYDUDXWRSOLQXWHVHSUHGDMHUDGQRPPHGLMXRELþQR]UDNYRGDLOL
ulje. Energija prikupljena ovim principom dalje se odvodi cirkulacijom radnog medija te se
GLUHNWQR SUHGDMH SRWURãDþX LOL SDN RGYRGL X VSUHPQLNH WRSOLQVNH energije kako bi se
RPRJXüLORNRULãWHQMHXSHULRGXNDGD6XQþHYDHQHUJLMDQLMHGRYROMQRJLQWHQ]LWHWD
Prva i najosnovnija vrsta solarnih NROHNWRUDVXWDNR]YDQLQHIRNXVLUDMXüLVWDFLRQDUQLVRODUQL
kolektori. Kao što im i naziv govori spadaju u kategoriju fiksnog položaja i nemaju
PRJXüQRVWSUDüHQMDSRORåDMD6XQFDWHimaju istu površinu prikupljanja odnosno apsorbiranja
6XQþHYHUDGLMDFLMH. U navedenu skupinu spadaju: pORþDVWLVRODUQLvakumski te NRQFHQWULUDMXüL
kolektori
Druga vrsta kolektora su takozvani IRNXVLUDMXüL SR]LFLRQLUDMXüL VRODUQL NROHNWRUL)RNXVLUDMXüL VRODUQL NROHNWRUL VX XQDSULMHÿHQL NROHNWRUL þLMD NRQVWUXNFLMD RPRJXüDYD]JXãQMDYDQMH 6XQþHYLK ]UDND RGQRVQR QMLKRYR IRNXVLUDQMH QD SRYUãLQX DSVRUSFLMH ,DNR VH
IRNXVLUDMXüL NROHNWRUL RELþQR NRULVWH NDR SR]LFLRQLUDMXüL SRVWRMH L]YHGEH VWDFLRQDUQLKIRNXVLUDMXüLK NROHNWRUD RG NRMLK VX QDMSR]QDWLML WDNR]YDQL &3& HQJ Compound Parabolic
Collectors) kolektori.
Solarni kolektori se još razlikuju u ovisnosti o principu pozicioniranje pa tako postoje
SR]LFLRQLUDMXüL MHGQR-osni te dvo-osni solarni kolektori [3]. Jedno-osni sustavi za
SR]LFLRQLUDQMH VH NRULVWH NRG OLQLMVNL IRNXVLUDMXüLK NROHNWRUD 7R VX kolektori koji koriste
reflektore u obliku polu cilindra kako bi fokusirali 6XQþHYR]UDþHQMHQDSRYUãLQXDSsorbera u
REOLNXFLMHYL 6OLNDD 8RYRMVNXSLQLQDMYDåQLMHMHLVWDNQXWLGYDWLSDOLQLMVNRIRNXVLUDMXüLKkolHNWRUD SDUDEROLþQD NRULWD i Fresnelov kolektor. Dvo-osni sustavi za pozicioniranje sekoriste kod kolektora s IRNXVLUDQMHPXMHGQRMWRþFL1DM]QDþDMQLMLNROHNWRULWHPHOMHQLQDRYRP
principu su takozvani tanjurasti i centralno apsorpcijski sustavi.
6PMHUSUDüHQMD
Sunca
Apsorber

Jedno-osno
pozicioniranje

Reflektor

Dvo-osno
pozicioniranje

Radni medij(a)(b)
Slika 1. a) Jedno-RVQRSR]LFLRQLUDMXüL SDUDEROLþQLVRODUQL kolektor [3] , b) Dvo-osno
SR]LFLRQLUDMXüLtanjurasti solarni kolektor
3DUDEROLþQL VRODUQL NROHNWRUL L]UDÿXMX VH QD QDþLQ GD VH WDQND UHIOHNWLUDMXüD SORþD VDYLMH X
REOLN SDUDEROH þLPH VH GRELYD UHIOHNWRU ]D SULNXSOMDQMH 6XQþHYRJ ]UDþHQMD 8 QMHJRYRM
fokusnoj ravnini postavlja se metalna cijev crne presvlake koja se naziva apsorber (Slika 1a).
.DGDMHSDUDEROLþQLUHIOHNWRUXVPMHUHQSUHPD6XQFX6XQþHYH]UDNHNRMHXOD]HXUHIOHNWRUVH
preusmjeravaju na površinu apsorbera te zagrijavaju radni medij koji prolazi kroz njega.
=DJULMDYDQMHPUDGQRJPHGLMDRVWYDUXMHVHSUHWYRUEDVXQþHYe energiju u toplinsku energiju.
Jedno-RVQRSUDüHQMHVXQFDVHPRåHRVWYDULWLQD GYD QDþLQD WDNR GD je uzdužna os kolektora
paralelna smjeru sjever-MXJSULþHPXSUDWLNUHWDQMH6XQFDVLVWRNDSUHPD]DSDGXLOLX]GXåQDX
smjeru istok-]DSDGSULþHPXSUDWL6Xnce u smjeru sjever-MXJ3UHGQRVWLSUDüHQMDLVWRN-zapad
VX PLQLPDOQH SRWUHEH ]D NRUHNFLMRP SRORåDMD WRNRP GDQD WH MH PDNVLPDOQD RVXQþDQRVWkolektora u podne iako konfiguracije sjever-MXJRVWYDUXMX YHüH NROLþLQH SULNXSOMHQH HQHUJLMH
tokom godine. Ali konfiguracije istok-zapad prikupljaju više energije u zimskim periodima sEnergy and the Environment (2016) 247-256249þLPH RVLJXUDYD SRYROMQLMX JRGLãQMX ELODQFX =ERJ QDYHGHQLK þLQMHQLFD L]ERU QDMSRYROMQLMHNRQILJXUDFLMHXYHOLNHRYLVLRQDPMHQLLSURVMHþQim vremenskim uvjetima lokacije.
Glavna komponenta VXVWDYD]DSUDüHQMHSXWDQMH6XQFDMHSR]LFLRQLUDMXüLVXVWDY koji se sastoji
od aktuatora za pokretanje solarnog kolektora te raznih senzora. Regulacija SR]LFLRQLUDMXüHJVXVWDYDVHRVWYDUXMHSRPRüXXSUDYOMDþNHMHGLQLFHWHDOJRULWPD]DSUDüHQMH6XQFD$OJRUitamUDþXQD D]LPXW L ]HQLW 6XQFD þLMH VH YULMHGQRVWL NRULVWH ]D SR]LFLRQLUDQMH VRODUQRJ NROHNWRUD
SUHPD6XQFX3RVWRMHþLVWRPDWHPDWLþNLDOJRULWPLWHPHOMHQLQDDVWURQRPVNLPSUHGYLÿDQMLPDL
algoritmi koji koriste podatke dobivene u realnom vremenu.
2.1 Aktuatorski sustavi za pozicioniranje SDUDEROLþQRJVRODUQRJNROHNWRUD,VNRULVWLYRVW VXVWDYD RGQRVQR NROLþLQD SUHWYRUHQH HQHUJLMH XYHOLNH RYLVL R PRJXüQRVWLPD
NROHNWRUD GD ]DX]PH ãWR RSWLPDOQLML SRORåDM X RGQRVX QD SRORåDM 6XQFD 2VLP WRþQRVWL
pozicionirDQMD L EU]LQH JLEDQMD ELWDQ þLPEHQLN SUHGVWDYOMD L SRWURãQMD HQHUJLMH VWRJD RGDELU
YUVWH DNWXDWRUD PRUD ELWL GREUR SURPLãOMHQD RGOXND SUL SURMHNWLUDQMX 1DMþHãüH VH NRULVWH
elektrLþQL hLGUDXOLþNL WH PHKDQLþNL DNWXDWRUL Noji mogu funkcionirati kao linearni ili
rotacijski aktuatori.
(OHNWULþQL OLQHDUQL DNWXDWRUL VX RELþQR HOHNWUR-PHKDQLþNRJ SULQFLSD RGQRVQR WHPHOMH VH QD
SULPMHQL HOHNWURPRWRUD L OLQHDUQRJ PHKDQLþNRJ SULMHQRVQLND .DR OLQHDUQL PHKDQLþNL
SULMHQRVQLFLNRULVWHVHR]XEOMHQHOHWYHL]XSþDQici, navojna vretena i matice. Ovakvi sustavi se
ponajprije koriste zbog svoje jednostavnosti i robusnosti te kompaktne konstrukcije.
.RGKLGUDXOLþNLOLQHDUQLDNWXDWRUDXRELþDMHQR se koriste dvoradni hidrauOLþNLFLOLQGUL koji su
pogonjeni od strane hidraulLþNRJDJUHJDWD+LGUDXOLþNLDJUHJDWLPRJXELWL]DVHEne kompaktne
izvedbe ãWRQXGLSULPMHQXMHGQRJ]DMHGQLþNRJDJUHJDWDNRMLQDSDMDFLMHOLQL]FLOLQGDUDãWRMHþHVWLVOXþDMNRGYHOLNLKVRODUQLKSROMDLOLNRPSDNWQH]DVHEQHKLGUDXOLþNHSRNUHWDþNHMHGLQLFH
RoWDFLMVNL SRNUHWDþL NDR L OLQHDUQL QDMþHãüH VX HOHNWULþQL L KLGUDXOLþNL D WR VX RELþQR
elektromotori ili hidromotori. Elektromotori se koriste kod foto-naponskih sustava ili kod
SRNUHWDQMD PDQMLK NROHNWRUVNLK VXVWDYD GRN VH ]D SDUDEROLþQH VRODUQe kolektore koriste
hidromotori. %XGXüL GD VX ]DKWMHYL SUL VRODUQRP SUDüHQMX YUOR PDOH EU]LQH L ãWR YHüH
UD]OXþLYRVWLSRPDND X] GRYROMDQ PRPHQWskoro uvijek se NRULVWH X NRPELQDFLML V UD]OLþLWLPPHKDQLþNLP SULMHQRVQLFLPD (pužni reduktor, planetarni reduktor ili ciklo-reduktor). Druga
YUVWDURWDFLMVNLKSRNUHWDþDNRMLVHþHVWRNRULVWH]DSRNUHWDQMHVRODUQLKNROHNWRUDVX KLGUDXOLþNL
moment cilindri 3UHGQRVW RYLK SRNUHWDþD MH PRJXüQRVW RVWYDULYDQMD PDOLK SRPDND L PDOLKbrzina EH]PHKDQLþNLKSULMHQRVQLND. Postavljaju se dLUHNWQRQDURWLUDMXüHYUDWLORUHIOHNWRUDWH
mogu pogoniti dva solarna kolektora istodobno (Slika 2b).

(a)(b)
Slika 2. Princip ugradnje: a) KLGUDXOLþNRJFLOLQGUD, b) moment cilindra

250

Z. Bilandžija, G. Gregov: 1XPHULþNDVLPXODFLMDKLGUDXOLþNRJVXVWDYD«

3. REGULACI-6., 6867$9
SOLARNOG KOLEKTORA=$

32=,&,21,5$1-(

3$5$%2/,ý12*

PrinFLS SR]LFLRQLUDQMD SDUDEROLþQRJ VRODUQRJ NROHNWRUD QDMþHãüH VH WHPHOML QD WDNR]YDQom
servo-pozicioniranju (Slika 3). Ulazna varijable predstavlja željeni položaj koji kolektor morazauzeti prema položaju Sunca. U kontrolnoj jedinici se definira signal položaja ili vektorpoložaja sunca koji upravlja aktuatorom. Aktuator pozicionira kolektor te šalje povratnu
informaciju novog položaja kolektora što VHRþLWDYDVHQ]RURPSRORåDMD$QDOL]LUDVHUD]OLND
L]PHÿX åHOMHQRJ L L]PMHUHQRJ SRORåDMD WH X VOXþDMX postojanja greške aktuator nastavlja s
pozicioniranjem sve dok UD]OLND L]PHÿX YULMHGQRVW QH EXGH jednaka nuli. Navedeni servo
VXVWDYL XSUDYOMDQMD WDNRÿHU HOLPLQLUDMX RGVWXSDQMD pozicioniranja sustava koja mogu biti
rezultat naleta vjetra ili odstupanja pri instalaciji.

Ulaz:Željeni položaj

8SUDYOMDþNDjedinica

Povratna veza: Stvarni položaj

Aktuator

Senzorpoložaja

Slika 3. Blok dijagram sustava servo pozicioniranja solarnog kolektora
Algoritmi NRMLVHNRULVWHNRGSR]LFLRQLUDMXüHJVXVWDYDUDGHQDSULQFLSX otvorene petlje (eng.
Open-loop) ili zatvorene petlje (eng. Closed-loop). Sustavi s otvorenom petljom ostvaruju
SUDüHQMHVXQFDEH]SULPMHQHVHQ]RUDWHVHNRUiste XVOXþDMHYLPDREODþQRJYUHPHQDSULþHPXdolazi do izostanka povratnog signala. Sustav s otvorenom petljom se temelje na
PDWHPDWLþNLPIRUPXODPDNRMHGHILQLUDMXDOJRULWDPD]DSUDüHQMHVXQFD
Zatvorena petlja se koristi u svrhu eliminacije greški u sustavu koje mogu biti rezultat grešaka
instalacije, montaže ili pojedinih komponenti unutar sustava. Sustavi s zatvorenim petljama
RVWYDUXMX SUDüHQMH Sunca SRPRüX VHQ]RUD NRML RGUHÿXMX VWYDUQL SRORåaj Sunca u realnomvremenu. Navedeni senzori mogu biti razne foto-diode, foto-otpornici ili foto-QDSRQVNHüelije.
3.1 Regulacija sustava na principu otvorene petlje
5HJXODFLMD RWYRUHQRP SHWOMRP VH WHPHOML QD DOJRULWPLPD VXQþHYRJ NUHWDQMD GRELYHQLK
astronomskim mjerenjima. U ovim sustavima XSUDYOMDþND jedinica prati položaj kolektora
kako bi se utvrdio njegov trenutni položDM WH JD XVSRUHÿXMH V SRORåDMHP NRML MH GHILQLranDOJRULWPRPVXQþHYRJNUHWDQMD. UVSRUHÿXMXüLGRELYHQHSRGDWNHVåHOMHQLPSRGDFLPD XWYUÿXMH
se dali postoji razlika te dali je potrebno generirati XSUDYOMDþki signala. 3R]QDMXüL koordinate]HPOMRSLVQHãLULQHLGXåLQHELORNRMHJSRORåDMDQD=HPOMLPRJXüHMHL]UDþXQDWLSRORåDMD6XQFDSRPRüXDVWURQRPVNLKDOJRULWDPDXYLGXVXQþHYRJYHNWRUD=DLPSOHPHQWDFLMXRYRJSULQFLSD
L]UDþXQDYDQMD SRORåDMD VXQFD GRVWXSQH VX UD]QH SURJUDPVNH SRGUãNH QD WUåLãWX NDR ãWR MH
programski paket Siemens S7-1200 CalcSolarVector [4].

Energy and the Environment (2016) 247-256

251

Glavni nedostatak korištenje RWYRUHQHSHWOMHMHRJUDQLþHQRVWSULPMHQHVRODUQLKDOJRULWDPVNLKSDUDPHWDUD EXGXüL GD sustav nema PRJXüQRVW RWNULYDQMD L NRPSHQ]LUDQMD JUHãDND QDVWDOLK
instalacijskim odstupanjima ili vremenskim uvjetima. U navedenom sustavu nema
NRPSRQHQWL ]D RSWLþNR XWYUÿLYDQMH SRORåaja Sunca, stoga XSUDYOMDþNL VXVWDY MHGQRVWDYQR
pretpostavlja da su svi ulazni SDUDPHWUL WRþQL WH VOLMHSR L]YUãDYD QDUHGEH GRELYHQH
PDWHPDWLþNLPDOJRULWPLPD
3.2 Regulacija sustava na principu zatvorene petlje
Kod regulacijskih sustava s ]DWYRUHQRP SHWOMRP WRþQRVW SUDüHQMD 6XQFD VH SRVWLåH
HOHPHQWLPDSRYUDWQHYH]HNRMLPDVHSUDWLLDQDOL]LUDNUHWDQMH6XQFD2YLHOHPHQWLVXRELþQRtemeljeni na foto-VHQ]LWLYQLPHOHNWURQLþNLPNRPSRQHQWDPD tj. senzorima. Senzori zDSUDüHQMH
6XQFDSRVWDYOMHQLVXQDNRQVWUXNFLMXUHIOHNWRUDWHVHRELþQRQDOD]HX]DãWLWQRPNXüLãWX
Princip rada RYDNYRJ QDþLQD upravljanja temelji se na slanju povratne signala od senzora
prema XSUDYOMDþNRM jedinici V þLPH VH GLUHNWQR pratit trenutni položaj kolektora te ga se
XVSRUHÿXMHsa stvarnim položajem Sunca. Glavni nedostatak sustava s zatvorenom petljom je
RJUDQLþHQR GMHORYDQMH X REODþQLP XYMHWLPD VWRJD VH ULMHWNR NRULVWL NDR VDPRVWDOQL REOLNXSUDYOMDþNRJVXVWDYD8VOXþDMHYLPDGXåHJREODþQRJYremena sustav se ne može re-kalibrirati
što dovodi do neupotrebljivosti sustava. Ukoliko ne postoji integracija s otvorenom petljom,
VXVWDY LPD SRWHãNRüH XWYUGLWL VWYDUQL SRORåDM 6XQFD X QDYHGHQLP XYMHWLPD .ako bi se
eliminirao ovaj problem, povratna veza se integrira s otvorenom petljom u takozvanu hibridnu
petlju.
3.2 Regulacija sustava na principu hibridne petlje
Hibridna petlja je rezultat integracije otvorene i zatvorene petlje s ciljem objedinjavanja
njihovih prednosti i kompenziranja njihovih nedostataka. Ovakvi hibridni sustavi ostvaruju
SUDüHQMH 6XQFD SRPRüX DVWURQRPVNLK DOJRULWDPD SULWRP NRULVWHüL VHQ]RUH ]D SUDüHQMH L
NRUHNFLMX6XQþHYRJYHNWRUDDWLPHLSRYHüDYDMXWRþQRVWSR]LFLRQLUDMXüHJVXVWDYD
Kod hibridne petlje kao i kod otvorene petlje, prvo se XWYUÿXMHrežim u kojem se nalazi (danili QRü 8NROLNRVXVWDYXWYUGLGDMHGDQNUHüHVDRGUHÿLYDQMHPSRORåDMDNROHNWRUDXNRMHPVHQDOD]L WH JD XVSRUHÿXMH VD SDUDPHWULPD VRODUQRJ YHNWRUD GRELYHQRJ DOJRULWPRP L RSWLþNLPXUHÿDMHP 8NROLNR VXVWDY utvrdi da postoji potreba za korekcijom položDMD XSUDYOMDþNDjedinica JHQHULUD XSUDYOMDþNL VLJQDO dok se ne ostvari optimalan položaj kolektora. Nakon
SR]LFLRQLUDQMDVHQ]RURPVHPMHULWRþDQSRORåDM6XQFDWH povratnom vezom LVSUDYOMDSRVWRMHüD
greška. Logika navedenog sustava prikazana je u dijagramu toka signala na slici 5.
1Rü
Dan
U
pripravnosti

6XQþHYL
algoritam'DQQRü

UsporedbaPoložaj2SWLþNL
element

Slika 5. Dijagram toka signala regulacijskog sustava s hibridnom petljom

Aktuator

252

Z. Bilandžija, G. Gregov: 1XPHULþNDVLPXODFLMDKLGUDXOLþNRJVXVWDYD«

4. 3525$ý81 +,'5$8/,ý.2* 6867$9$ 3$5$%2/,ý12* 62/$512*
KOLEKTORA$QDOL]RP DNWXDWRUVNLK VXVWDYD NRML VH NRULVWH ]D SR]LFLRQLUDQMH SDUDEROLþQLK VRODUQLKkolektora odabran je sustav s GYRUDGQLP KLGUDXOLþNLP FLOLQGURP 'YRUDGQL KLGUDXOLþNL
cilindar kao aktuator je odabran zbog svoje jednostavnosti i nižih investicijskih troškova.
%XGXüL GD FLOLQGDU RVWYDUXMH WUDQVODFLMVNR JLEDQMH SRWUHEQR MH RVWYDULWL SUHWYRUEX
translacijskog gibanja klLSQMDþH X URWDFLMVNR JLEDQMH YUDWLOD NROHNWRUD 2YX IXQNFLMX üH VH
RVWYDULWLSRPRüXURWDFLMVNRJGLVNDSRVWDYOMHQRJQDVUHGLQL vratila kolektora. %XGXüLGDVLODQD
NOLSQMDþLFLOLQGUDsvladava samo dio momenta koji je potrebno ostvariti na vratilu kolektora,nužno je izraditi model kolektora NRMLPüHVHXWYUGLWLraspodjela sila (Slika 6).

rd
Ȗ

ȟ

Fy
Fx

ș

Į0
Į

V0

lk
Ȝ

Xd

ȟ

rx

Slika 63DUDPHWULJHRPHWULMVNRJPRGHODSDUDEROLþQRJVRODUQRJNROHNWRUD.RULVWHüL VRIWYHU ]D ' PRGHOLUDQMH L]UDÿHQ MH PRGHO SDUDEROLþQRJ VRODUQRJ NROHNWRUD SULþHPX VX GLPHQ]LMH RGDEUDQH QD WHPHOMX NRPHUFLMDOQLK VRODUQLK NROHNWRUD [5]. S model suRþLWDQH JHRPHWULMVNHYULMHGQRVWLSRWUHEQH]DSURUDþXQV0=786 mm, rd=150 mm, Xd=202 mm,
Į0=16,25°, Ȝ=70°. Rotacijom reflektora kolektora oko svoje osi, kut zakretanja ș se mijenja od
 GR  SUL þHPX GROD]L L GR SURPMHQH YULMHGQRVWL PRPHQWD QD YUDWLOX 0RPHQW NRML VH
može ostvariti QD YUDWLOX NROHNWRUD GMHORYDQMHP KLGUDXOLþNRJ FLOLQGUD L]UDþXQDYD VH SRPRüX
izraza:T

Fx cos M rd  Fy rx(1)

Vrijednost momenta na vratilu kolektora mora biti dostatna za pokretanje kolektora uovisnosti o promjenjivom kutu zakretanja ș3RWUHEQRMH SURYHVWL SURUDþun momenta koji semora ostvariti na vratilu kolektora a koji ovisi o vjetru koji djeluje na kolektor te samoj težini
kolektora. 3UL SURUDþXQX PRPHQWD YMHWUD NRULãWHQD MH YULMHGQRVW PDNVLPDOQH EU]LQH YMHWUD
dobivene iz karte vjetrova Hrvatske za odabranu lokaciju (44° ƍ Ǝ N, 13° ƍ Ǝ E) u
kojoj se navodi maksimalna vrijednost vjetra od 100 km/h, pULþHPXMHPMHUHQMHizvršeno na
visini od 10 m. 3URUDþXQ PRPHQWD YMHWUD proveden je na temelju OLWHUDWXUH >@ 3URUDþXQEnergy and the Environment (2016) 247-256

253

PRPHQWD NRML X]URNXMH YODVWLWD WHåLQD NROHNWRUD WHPHOML VH QD L]UDþXQX XNXSQH WHåLQH
pokretnog dijela kolektora NRMDGMHOXMHX]DMHGQLþNRPWHåLãWX1DWHPHOMXL]UDÿHQRJ'PRGHOVRODUQRJNROHNWRUDRþLWDQHVXNRRUGLQDWHWHåLãWDXRGQRVXQDFHQWDUURWDFLMH te masa pokretnog
dijela kolektora od 435 kg. Zbrojem dobivenih vrijednosti momenta proizlazi vrijednost
ukupnog momenta koji se mora svladati na vratilu kolektora (Slika 7). NDMYHüL XNXSQL
moment pojavljuje pri nagibu reflektora od 70° u odnosu na vertikalu te iznosi T=851 Nm.
900
800

Tuk / Nm

700
600
500
400
300
200
100
0
0

10

20

30

40

50

60

70

Slika 7. Ukupni moment na vratilu kolektora

80

ĭ°

90

=QDMXüL QDMYHüX vrijednost moment na vratilu kolektora te geometriju samog kolektora iz
L]UD]D   L]UDþXQDYDMX VH VLOH NRMH KLGUDXOLþNL FLOLQGDU PRUD RVWYDULWL L] þHJD SURL]OD]L VLOD
L]YODþHQMD FLOLQGUD RG 11,6 kN. Maksimalni WODN KLGUDXOLþNRJ VXVWDYD je odabran na temeljuVOLþQLK KLGUDXOLþNLK VXVWDYD WH L]QRVL 150 bar =QDMXüL YULMHGQRVW VLOH L WODND Sroveden je
SURUDþXQGYRUDGQRJKLGUDXOLþNRJFLOLQGUD, te je na temelju dobivenih vrijednosti iz kataloga
SURL]YRÿDþD odabran cilindar Bosch Rexroth CDT3 MP5 [7].
Brzina izYODþHQMD FLOLQGUDPRUDELWLXVNODÿHQDVSULYLGQLPJLEDQMHP6XQFDQDQHEX3URVMHþQD
promjena položaja sunca iznosi 0,25°/min odnosno 15°/h. .DNR MH XWYUÿHQR JHRPHWULMVNLP
modelom, za svaki 1° okretaja kolektora, cilindar VHPRUDL]YXüL približno 1 mm. Sukladno
QDYHGHQRPHXSUDYOMDþNLVXVWDYüHJHQHULUDWLVLJQDO]DNRUHNFLMXSRORåDMDVYDNLKKWHüHVH
klipQMDþD FLOLQGUD L]YXüL 15 mm brzinom od 0,015 m/s. Na tePHOMX SURUDþXQDWH EU]LQH
L]YODþHQMD cilindara proizlazi vrijednost protoka na ulazu u cilindar tj. stvarnog protoka pumpe
QP=1,85 l/min. Vrijednost protoka osnova je za SURUDþXQKLGUDXOLþNHSXPSHQDWHPHOMXþHJDje odabrana pumpa Bosch Rexroth AZPBB11 4.0 ORH >@7DNRÿHUMHRGDEUDQL elektromotor]DSRJRQSXPSH.RQþDU$=%-6 [8].
5. SIMULACIJA HID5$8/,ý.2* SUSTAVA ZA POZICIONIRANJE
3$5$%2/,ý12*62/$512*.2/(.725$
Simulacija model KLGUDXOLþNRJ VXVWDYD ]D SR]LFLRQLUDQMH SDUDEROLþQRJ VRODUQRJ NROHNWRUD
L]UDÿHQMHXSURJUDPVNRPSDNHWX ITI-Sim (Slika 8). Primarna svrha izrade ovakvog modela je
potvrda LVSUDYQRVWLPDWHPDWLþNRJSURUDþXQDWHXYLGXSRQDãDQMHVXVWDYDLSRMHGLQLKQMHJRYLKNRPSRQHQWL 6LPXODFLMVNL PRGHO RVLP RGDEUDQLK NRPSRQHQWL WHPHOMQLP QD PDWHPDWLþNRP
SURUDþXQXVDGUåLLNRPSRQHQWH]DJHQHULUDQMHXSUDYOMDþNLKVLJQDODVHQ]RUSRYUDWQHYH]e kao
i dodatne elemente za adekvatnu reprezentaciju sile i mase.

254

Z. Bilandžija, G. Gregov: 1XPHULþNDVLPXODFLMDKLGUDXOLþNRJVXVWDYD«

6LPXODFLMD ]DSRþLQMH JHQHULUDQMHP XSUDYOMDþNRJ VLJQDOD HOHNWURPRWRUD GHILQLUDMXüL QMHJRYRYULMHPHXNOMXþivanja i trajanja(OHNWURPRWRUSRJRQLSXPSXVþLPHVHRVWYDUXMHåHOMHQLSURWRN
radne WHNXüLQH u definiranom vremenu. 5DGQDWHNXüLQDSUROD]LNUR]SURSRUFLRQDOQLUD]YRGQLYHQWLOSRPRüXNRMHJVHRVWYDUXMHSURPMHQDVPMHUDVWUXMDQMDLSURPMHQDNROLþLQHSURWRNDUDGQHWHNXüLQH. 3URPMHQRP VPMHUD VWUXMDQMD RVWYDUXMH VH XYODþHQMH LOL L]YODþHQMH GYRradnog
KLGUDXOLþNRJ FLOLQGUD D SURPMHQRP NROLþLQH SURWRND XWMHþH VH QD EU]LQX L]YODþHQMD LOLXYODþHQMD NOLSQMDþH FLOLQGUD 5HJXODFLMD SRORåDMD NOLSQMDþH FLOLQGUD RVWYDUXMH VH SRPRüXzatvorene regulacijske petlje i P regulatora. Usporedbom željenog položajD NOLSQMDþH L
stvarnog položaja, izmjerenog senzorom, u regulacijskom krugu se javlja vrijednost koja seSRMDþDYD X 3 UHJXODWRUX GD EL QD L]OD]X GRELOL XSUDYOMDþNL VLJQDO za razvodni ventil u
granicama od -1 do 1. .DGD UD]OLND L]PHÿX åHOMHQRJ L VWYDUQRJ SRORåDMD NOLSQMDþH SRVWDQH
QXOD UD]YRGQL YHQWLO VH YUDüD X QHXWUDOQL SRORåDM WH QHPD SURWND UDGQH WHNXüLQH SUHPD
cilindru.
SENZOR

SIGNALŽELJENOG
POLOŽAJAP REGULATOR

MASA./,31-$ý(

DVORADNI+,'5$8/,ý.,CILINDAR

SILA
237(5ý(1-$./,31-$ý(

PROPORCIONALNIRAZVODNIVENTILVENTIL ZA
2*5$1,ý(1-(
TLAKA
PUMPA

835$9/-$ý.,
SIGNALELEKTROMOTORAELEKTROMOTOR

6OLND6LPXODFLMVNLPRGHOKLGUDXOLþNRJVXVWDYD]DSR]LFLRQLUDQMHSDUDEROLþQRJVRODUQRJ
kolektora(OHNWURPRWRU NDNR MH YHü QDYHGHQR GRELYD SREXGX XSUDYOMDþNLP VLJQDORP SUL þHPXostvaruje brzinu vrtnje od 930 min-1 sukladno matematiþkom proraþunu. 8SUDYOMDþNL VLJQDOSRNUHüHelektromotor svakih sat vremena u periodu od 12 sati. Svrha ovakve konfiguracije ještedljiv rad sustava, elektromotor se pokreüe i radi samo u periodu kada je potrebna promjenapoložaja dok je u ostalim periodima u stanju mirovanja. Pošto je stvarni protok kroz pumpu
funkcija brzine vrtnje elektromotora, pumpa ostvaruje kratkotrajni protok svakih sat vremena.
3URUDþXQDWD vrijednost stvarnog protoka pumpe iznosi 1,85 l/min što u potpunosti odgovara
YULMHGQRVWLGRELYHQRMVLPXODFLMVNLPPRGHORP 6OLND 6XNODGQRQDYHGHQRPGDVH]DNOMXþLWLda je simulaFLMVNLPRGHOKLGUDXOLþNHSXPSHUHDOQDSUH]HQWDFLMDVWYDUQRJKLGUDXOLþNRJVXVWDYD.

255

2

2

1,8

1,8

1,6

1,6

1,4

1,4

QHP / l/min

QHP / l/min

Energy and the Environment (2016) 247-256

1,2
1
0,8
0,6

1,2
1
0,8
0,6

0,4

0,4

0,2

0,2

0
0

1

2

3

4

5

6

7

8

9

10 11 1203565 3595 3625 3655 3685 3715 3745

t/h
t/s
(a)
(b)
Slika 9. Stvarni protok pumpe: a) unutar 12 sati, b) pri jednom pokretanju
Rezultati simulacije gibanja klipQMDþHFLOLQGUDSULND]DQLVXQDVlici 10a. ,]YODþHQMH cilindra je
WDNRGDVHRVWYDUXMHNRUHNFLMDSRORåDMDVYDNLKVDWVXQþHYRJVYMHWOD,]YODþHQMHNOLSQMDþDMHWRþQR GHILQLUDQo geometrijskim modelom s þLPH VH RVWYDUXMH NRUHNFLMD SRORåDMD RG 
stupnjeva WM NOLSQMDþD VH L]YODþL  PP. Na kraju dana kada je sunce zašlo sustav ostaje u
danRPSRORåDMXMRãKQDNRQþHJDVHXYODþHQMHPFLOLQGUDYUDüDXSUYRELWQLSRORåDMWHþHNHponovni izlazak Sunca. Na slici 10b XYHüDQR MH SULND]DQD usporedba željenog položajaNOLSQMDþH FLOLQGUD L VWYDUQRJ SRORåDMD L] þHJD VH PRåH ]DNOMXþLWL GD MH UHJXODFLMVNL VXVWDY
ispravno definiran tj. parametri P regulatora su optimalno definirani.

lHC / mmlHC / mm

165
150
135
120
105
90
75
60
45
30
15
0
0

1

2

3

4

5

6

7

8

9 10 11 12

t/h

31
30
29
curve3.y[mm]Željenipoložaj
28
27
mass1.x[mm]Stvarnipoložaj
26
25
24
23
22
21
20
19
18
17
16
15
14
3596
3598
3600

3602

3604

t/s

(a)
(b)
Slika 10. 3R]LFLRQLUDQMHNOLSQMDþHFLOLQGUD: a) unutar 12 sati, b) SULL]YODþHQMXRGPP
6. =$./-8ý$.
Kako bi se RVLJXUDR RGDELU RSWLPDOQRJ UMHãHQMD ]D SR]LFLRQLUDQMH SDUDEROLþQRJ VRODUQRJ
kolektora nužno je DQDOL]LUDWL VYH SRVWRMHüH sustave, prije svega s aspekta investicijskogWURãND 'HWDOMQLP SUHJOHGRP SRVWRMHüLK VXVWDYD XWYUÿHQR MH GD VH SULPMHQRP MHGQRVWDYQRJVXVWDYD NDRãWR MH VXVWDY V GYRUDGQLP KLGUDXOLþNLP FLOLQGURP XYHOLNH PLQLPL]LUDMX WURãNRYLXJUDGQMH VXVWDYD X] SULKYDWOMLYR SREROMãDQMH LVNRULVWLYRVWL 8 UDGX MH SURYHGHQ SURUDþXQKLGUDXOLþNRJ VXVWDYD V GYRUDGQLP KLGUDXOLþNLP FLOLQGURP NDR DNWXDWRURP &LOLndar je
SURUDþXQDt QDWHPHOMXGLPHQ]LMDSDUDEROLþQRJVRODUQRJNROHktora koje su dobiven na temelju

256

Z. Bilandžija, G. Gregov: 1XPHULþNDVLPXODFLMDKLGUDXOLþNRJVXVWDYD«

L]UDÿHQRJ'PRGHODNROHNWRUD7DNRÿHUMHSURYHGHQSURUDþXQPRPHQDWDNRMLVHMDYOMDMXQD
vratilu kolektora a to su moment vjetra i moment od vlastite težine kolektora. Na temelju
SURUDþXQDWRJ PDNVLPDOQRJ PRPHQWD QD YUDWLOX NROHNWRUD SURUDþXQDW MH FLMHOL KLGUDXOLþNLsustav te su odabrane standardne KLGUDXOLþNH NRPSRQHQWH 7DNRÿHU MH L]UDÿHQ VLPXODFLMVNLPRGHO KLGUDXOLþNRJ VXVWDYD ]D SR]LFLRQLUDQMH SDUDEROLþQRJ VRODUQRJ NROHNWRUD NRULVWHüL
programski paket ITI-Sim. Rezultati simulacije su dokazali da je odabrani princip upravljanja
VXVWDYRP WH UHJXODFLMD SRPRüX ]DWYRUHQH SHWOMD V 3 UHJXODWRURP RVWYDULOD UHDOQR SRQDãDQMH
sustava.
LITERATURA
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]

Anderson, B.: Solar energy: fundamentals in building design, McGraw-Hill, New York,1977
Meinel, A.B., Meinel M.P.: Applied solar energy: an introduction, Reading, MA:
Addison-Wesley, 1976.
'RYLü ' 6XQþHYL NROHNWRUL-VXQþHYL VXVWDYL, Fakultet strojarstva i brodogradnje,
6YHXþLOLãWHX=DJUHEX
http://www.siemens.com/en/xc/19.07.2016.
Bilandžija. Z.: 3URMHNW KLGUDXOLþNRJ VXVWDYD ]D SRGHãDYDQMH SRORåDMD SDUDEROLþQRJ
solarnog kolektora'LSORPVNLUDG6YHXþLOLãWHX5LMHFL
Popovic, K.: Design and Analysis of Hydraulically Driven Actuation System For a
Parabolic Solar Trough, doktorska disertacija, Massachusetts Institute of Technology,
Department of Mechanical Engineering, 2013.
http://www.boschrexroth.com/en/xc/11.07.2016.
http://www.koncar-mes.hr/proizvodi/elektromotori/19.07.2016.
Gregov, G.: Contribution to Research Modelling of the Hydrostatic Transmission
Applied to the Forest Vehicle. Doctoral thesis, University of Rijeka, Faculty ofEngineering, Croatia (in Croatian), 2012.
NUMRERICAL SIMULATION OF A HYDRAULIC SYSTEM FOR A

PARABOLIC SOLAR COLLECTORS POSITTIONING
Abstract: In this paper an analysis of solar collectors is carried out with emphasis on a
positioning parabolic solar collectors. Solar collectors are type of a heat exchanger which
they are enabled transition of the solar radiation to a working fluid. Positioning solar
collectors are advanced collectors which design enables adsorption of the solar ray i.e.
adsorption of the solar ray on the collector surface, thus increasing the overall efficiency ofthe solar collector. Analysis of solar collector actuator systems have been carried out and it
has been chosen the hydraulic system with hydraulic differential cylinder. Calculation of thehydraulic system is conducted and standard hydraulic components are chosen which they are
represent input values into the simulation model. Using a software ITI-Sim, simulation model
for parabolic solar collector positioning are performed. Regulation of developed simulation
model is based on the closed-loop regulation with the P regulator.
Key words: parabolic solar collector, hydraulic actuator system, positioningEnergy and the Environment (2016) 257-266

257

A DYNAMIC DATA-DRIVEN FORECASTING METHODOLOGY FOR
SMALL-SCALE PHOTOVOLTAIC POWER SYSTEMS
Zoltán Kapros
Szent István University, Faculty of Mechanical Engineering, Institute of Environmental
Systems, Department of Physics and Process Control,
Páter KároO\X*|G|OOĘ+-2103, Hungary,Tel.: +36 28 522055, Fax: +36 28 410804, E-mail: zkapros@t-online.hu
Abstract: At present in Hungary, the weather-dependent variable renewable power plants(wind and solar power) share of gross electricity consumption is only around 1.8%, although
this is increasing value. But a realistic goal for the next 20-30 years can be to reach the 2025% VRE ratio in the electricity consumption. However, barriers also in Hungary, that there
is a lack of models and methods, which can be provided by the grid integration of a large
number of photovoltaic systems.A dynamic data-driven forecasting methodology is worked
out and tested by examining the Budapest District Heating Co. Ltd. top installed solar
systems. Firstly the forecasts were tested only for a reference PV system; secondly it wasmade for a group of PV systems with establishing the monitoring data only from the reference
system. The tested forecast method was only for 5 minutes ahead, but not only for the
expected performance was evaluated, but also for the expected average performance in a 15minute period. By the reliability of the methodology the accuracy dependence on weather
conditions also were evaluated. The main elements of the tested methodology and soma main
result will be presented on the conference and the paper.
Key words: small scale photovoltaic systems, dynamic data driven forecast, equivalent peakload hour, short time prediction for 15 minutes period
1. INTRODUCTION
The integration ability one key component by the small scale photovoltaic systems is the
reduction the variability and uncertainty with more accurate forecast. By the optimal grid
control and balancing activities the short-term forecasting relative error of energy production
should be below 10% (Wu and Xia, 2015). The forecast accuracy and develop the conditions
for determining the accurate prediction of solar power systems considered to be a key factor
aspect of integration to the electricity network (Lorenz és Heinemann, 2012). A reliablenetwork operation requires a different horizon forecasts (Kostylev and Pavloski, 2011).
Therefore the forecasting tasks are complex challenges which are significantly differentiatedby the photovoltaic system integration:- Planning, optimization, network assessment, cost-benefit analysis, evaluation ofalternatives, verification by supports;- 15 minutes schedule giving an electricity trader;- Clarification of the planned schedule before the beginning of the relevant period;- Clarification of the planned schedule within the relevant 15 minutes long period;

258

Z. Kapros: A Dynamic Data-Driven Forecasting Methodology for…

-

Forecast for a very short periods (balancing) forecast, for example only 1 minuteahead.

My PhD research in progress examines the possibilities by the last two points. This paper
illustrates some of the results of the research.

2. ASSESEMENT
The popular forecast is an intuitive method which is based on the experienced data and local
knowledge. So the Typical Meteorological Year built many time series parameters. The
resulting values in terms of long-term durability overall give a good approach, but in terms ofa given year, there may be significant inaccuracy. A further disadvantage is the global andlocal environmental changes are not built into the calculations. Thus, analysis of trends andoutline additional parameters are required. These tests, however, is practically not feasible
and the data of the parameters are expensive.
The latest generation for prediction methods works with numerical methods and simulation
techniques (as adaptive artificial neural networks) with the most commonly used software(PSpice, Mathlab Simulink and Labview). So there are a number of meteorological, temporaland geographic parameters exist, such as temperature, relative humidity, wind speed, sunshine
duration (SSD), a specific day of the year, the latitude and longitude or altitude that affect the
global radiation modeling values. A recent forecast is based on artificial neural net global
radiation predict the values of these parameters is known and expected (Hussain and Al-Alili,2015).
By the new direction the typical meteorological year is only determined with easily andcheaply available data, but this simplified data set can only be treated as a first approximationand the forecast could be based on variation of this data set and some dynamically measured
parameters (actual whether parameters). In the University of Leeds the global radiation
quantity with one minute dividing was forecasted in this way (Bright, 2015).
The demand for forecasts for the shorter period first appeared by the larger photovoltaic
power generation systems. For larger PV plants the cloud migration and its impact on theintensity changes can follow. The average intensity in an area can be estimated with moving
average of the radiation profiles (spatial smoothing effect) (Longhetto, 1989). The solar
energy forecast by the high PV power plants can be managed by the Wavelet Variability
Model which use 25 radiometer sensors the plant around (Dyreson, 2014). Those types ofsolutions as the „Wavelet Variability Model”, which for multi-megawatt power plants are
acceptable (Lave, 2013) even for small scale sizes often not cost effective solution.
3. DATA AND METHODES
The amount of electricity generated by a photovoltaic system is expressed by the following
equation based on the effective global radiation (Earthscan, 2008):(eq. 1)
qel H D ,E uK M u APV .

Energy and the Environment (2016) 257-266

259

The equivalent peak load hours are characterized by the energy-generating capacity in a given
moment. It means if same amount of power will produced in one year, the equivalent peakload hours is equal the traditional peak load hours (Sharma and Tiwari, 2012):] real(eq. 2)hekv.
PP

If the performance is expressed as an equivalent peak load hour, the expected value can be
written as follows:
hekv,t (t )(GPV (t ) u K (t ) u APV ).
PP(eq. 3)The equivalent peak load hours shows a reachable capacity at a given moment withdimension of the hour or kWh/kW. If the system is functioning at a given time at a specificequivalent peak load hours, then in an imagined year with equal continuous output power,same value would result for the peak load hours for that year. This value represents an actual
capacity of the PV power plant, which is clear, meaningful and comparable. Therefore in
every minute it may be obtained to get the expected equivalent peak load hour:
PAC (t )(eq. 4)
hekv , AC (t )u 8760.
( Pp u1000)

From the differences between the observed (measured) and the expected equivalent peak load
hours the error factors could be calculated according to the next equation:(hi* (t )  hi (t ))(eq. 5).
H i (t )hi* (t )It can be defined a specific series of error factors between t-n and t-m. From this the current
characteristics of their changes (dH/dt) can be deduced:( H  H i 1 )  ( H i 1  H i 2 )  ...  ( H m1  H m )dH i 'H i(eq. 6)
60 i
.
|
't
dt
't nmWhere are true, thatti  ti 1

ti 1  ti 2... t m1  t m .

Thus, the error factor prediction is described here:'t't
dH i 60t n'H i 0, 4 60t ndH
H t H t 1  (1 
) | H i  (1 )).
| H i  (1 
dt
dt
't

(eq. 7)(eq. 8)Under the average conditions the 0.4n exponent has formed to be approximately an optimalvalue during by measurements. View of the above the revised forecast comes according tonext equation:(eq. 9)N t ht*  H t u ht* ht* u (1  H t ) .
The parameters, which were used during the analysis, are shown in Table 1.
Table 1: The main parameters of the tests

260

Z. Kapros: A Dynamic Data-Driven Forecasting Methodology for…

The duration of thepredicted period
1 minutes

tt-n-tt-n-1nm

1 minutes

5 minutes

15 minutes

Therefore during the measurement and analysis the series of țt was available in 5 minutes
before time t. This gave the opportunity to give other forecast for the average performance inevery full quarter-hour with 5 minutes before the end of the period. During the test theprediction for average performance (equivalent peak load hours) in 15 minutes periods basedon 5 minutes measured data and 10 minutes predicted data with get from the presented
method.. The method of determining is illustrated with next equations.
(eq. 10)hq1 h(t 14 )  h(t 13)  h(t 12 )  h(t 11)  h(t 10 ) .

hq 2

N (t 9)  N (t 8)  N (t 7 )  N (t 6)  N (t 5)  N (t 4)  N (t 3)  N (t 2)  N (t 1)  N t .
hq1 (t )  hq 2 (t )N q (t )15(eq. 11)(eq. 12).

The significance of the error factor is stronger in these times when the radiation is more
intensive, so the period between 10:00 – 16:00 were also separately analyzed.
The research examined reference power plant owned by the Budapest District Heating Co.
Ltd. The PV plant is located in the company’ headquarter in Budapest in the top of the ‘D’building. The research analyzes data from seven different days which was randomly selected(Table 2). The reference power plant was considered only one part of the whole (the one
inverter part form the 8). With the same orientation and the same angle 19 panel units has asingle inverter. The main data of the plant:
Location: Latitude: 47.4584o, Longitude: 19.045o;
PV module type: AS-60P 250 W ECO;
Rated power of a panel: 250 Wp;
The number of solar panels installed: 150;
Position: +10.7 degrees (SSW) (as determined by measuring from map),
Angle of inclination: 20 degrees
The PV Power Plant nominal connection capacity: 40 kW.

-

Table 2: The test days and characteristics
Nb.

Dates

The serial
number ofthe day

SunriseSunsetAzimuth atsunriseAzimuth atsunsetPotential
sunshineduration [h]1.

1 April 2014.

91

6:23:09

19:13:13-97.58o97.89 o12.84

19:39:56-108.07o

108.37 o

13.89

o

113.89

o

14.16

2.

20 April 2014.

110

5:46:32

3.

1 May 2014.

121

5:27:32

19:55:15-113.55

4.

20 May 2014.

140

5:01:25

20:20:01-121.36 o

121.58o

15.31

5.

1 June 2014.

152

4:50:58

20:32:51-124.80o

124.96o15.69

o126.91o

15.93

122.38o

15.42

6.

14 June 2014.

165

4:46:12

20:42:09-126.867.

20. July 2014.

201

5:07:10

20:32:34-122.58o

4. RESULTS
The results of the forecast by a clear sky are demonstrated in Figure 1. It shows the relative

Energy and the Environment (2016) 257-266

261

error according to prediction with the equation 9, where the forecast is for a one minuteequivalent peak load hour and it was made 5 minute earlier. This figure shows that therelative error of the forecast is often more than 10% and sometimes more than the 20%.
However, it also shows that the relative error is below 5% in the intense sunshine period
between 9 and 15 hours. However interesting to note that an error, which a short-acting
dynamic effect caused, incorporates into the next dynamic forecasts and it causes opposite
errors. It is an observed oscillation which could depend on the length of the interior effect(which causes the basic error and starts the oscillation) and the length of the past period whichis considered in the dynamic forecast method.

The average relative error between
10:00 – 16:00 was 4.34%.

Fig. 1: Prediction with the equation 9 (AC relative error of the forecast, 01. April 2014)
By the forecasting the numeric value error is also important. It characterized the uncertainty
effects which are caused by the PV system in the network's stability (Figure 2.). The dynamic
forecast error in most cases below 500 hour, and only one case was more than 2000 hour witha short oscillation. It seems that if that the effect which caused the error, and its length would
be known, the forecast could be more accurate by error the oscillations’ attenuating.

262

Z. Kapros: A Dynamic Data-Driven Forecasting Methodology for…

7000
6500
6000
5500
5000

equivalent peak load hours [h]

4500

error

4000

measured data

3500
3000
2500
2000
1500
1000
500
18:23:00

17:58:00

17:33:00

17:08:00

16:43:00

16:18:00

15:53:00

15:28:00

15:03:00

14:38:00

14:13:00

13:48:00

13:23:00

12:58:00

12:33:00

12:08:00

11:43:00

11:18:00

10:53:00

10:28:00

9:38:00

10:03:00

9:13:00

8:48:00

8:23:00

7:58:00

7:33:00-1000

7:08:00

0
-500

-1500
-2000
-2500

Fig. 2: Prediction with the equation 9 (AC error of the forecast, 01. April 2014)
Figure 3 and 4 show the relative error according to prediction with the equation 12, where theforecast is for a 15 minutes average equivalent peak load hour and it was made also 5 minutes
earlier, than the end of the period.

The average relative error between
10:00 – 16:00 was 1.55%.

Fig. 3: Prediction with the equation 12 (AC relative error of the forecast, 01. April
2014)

5000

4500

-500

-1000

7:30:00
7:45:00
8:00:00
8:15:00
8:30:00
8:45:00
9:00:00
9:15:00
9:30:00
9:45:00
10:00:00
10:15:00
10:30:00
10:45:00
11:00:00
11:15:00
11:30:00
11:45:00
12:00:00
12:15:00
12:30:00
12:45:00
13:00:00
13:15:00
13:30:00
13:45:00
14:00:00
14:15:00
14:30:00
14:45:00
15:00:00
15:15:00
15:30:00
15:45:00
16:00:00
16:15:00
16:30:00
16:45:00
17:00:00
17:15:00
17:30:00
17:45:00
18:00:00
18:15:00
18:30:00
18:45:00
19:00:00
19:15:00

equivalent peak load hours [h]
5000

4500

-500

-1000
7:15:00
7:30:00
7:45:00
8:00:00
8:15:00
8:30:00
8:45:00
9:00:00
9:15:00
9:30:00
9:45:00
10:00:00
10:15:00
10:30:00
10:45:00
11:00:00
11:15:00
11:30:00
11:45:00
12:00:00
12:15:00
12:30:00
12:45:00
13:00:00
13:15:00
13:30:00
13:45:00
14:00:00
14:15:00
14:30:00
14:45:00
15:00:00
15:15:00
15:30:00
15:45:00
16:00:00
16:15:00
16:30:00
16:45:00
17:00:00
17:15:00
17:30:00
17:45:00
18:00:00
18:15:00

equivalent peak load hours [h]Energy and the Environment (2016) 257-266
263

7000

6500

6000

5500

error

measured data

4000

3500

3000

2500

2000

1500

1000

500

0

-1500

-2000

-2500

Fig. 4: Prediction with the equation 12 (AC error of the forecast, 01. April 2014)

In a highly volatile day the method also was tested. Even in this case the forecast accuracy
was an average of around 9% (Figure 5.)
8000

7500

7000

6500

6000

5500

error

measured data

4000

3500

3000

2500

2000

1500

1000

500

0

-1500

-2000

-2500

Fig. 5: Prediction with the equation 12 (AC error of the forecast, 01. June 2014)

Based on the differences between the monitoring forecasted values and the measurement data
it was determined in both the absolute and relative errors for each minutes with the next

264

Z. Kapros: A Dynamic Data-Driven Forecasting Methodology for…

equations. The results of the prediction are shown in the table 3 and table 4.
'ht hekv,t  ht** .
hh

100 u

(eq. 13)'ht.
hekv ,t(eq. 14)

Tab. 3: One-minute’ forecast performance data between 10:00 and 16:00
Errors (equivalent peak load hour)Date
01. 04.
20. 04.
01. 05.
20. 05.
01. 06.
14. 06.
20. 07.

Averag Abovee error 200 hour
37,95%
235
55,68%
885
55,40%
693
29,64%
798
80,33%
1 203
72,58%
1 880
12,19%
175

Between
100 and200 hour
20,22%
13,85%
24,38%
17,73%
9,97%
13,02%
16,90%

Under
Average
100 hourerror
41,83%
4,34%
30,47% 20,68%
20,22% 17,18%
52,63% 34,56%
9,70%
28,74%
14,40% 55,75%
70,91%
3,87%

Relative errors
Above
15%
4,43%
30,47%
26,59%
15,51%
54,85%
47,92%
3,60%

Between
10% and
15%
5,26%
13,02%
12,47%
0,55%
12,19%
5,54%
1,39%

Between 5%
and10%
19,11%
16,07%
22,71%
4,16%
13,57%
12,47%
4,99%

Under
5%
71,19%
40,44%
38,23%
79,78%
19,39%
34,07%
90,03%

Table 4: Fifteen-minute’ forecast performance data between 10:00 and 16:00 (5 minutes
before the end of the period)
Absolute errors (equivalent peak load hour)Date
01. 04.
20. 04.
01. 05.
20. 05.
01. 06.
14. 06.
20. 07.

Averag Abovee error 200 hour
12,50%
87
37,50%
302
37,50%
256
29,17%
260
58,33%
397
75,00%
694
8,33%
56

Between
100 and200 hour
25,00%
16,67%
29,17%
8,33%
20,83%
8,33%
4,17%

Under
Average
100 hourerror
62,50%
1,55%
45,83%
6,63%
33,33%
5,92%
62,50%
4,36%
20,83%
9,29%
16,67% 13,09%
87,50%
0,93%

Relative errors
Above
15%
0,00%
12,50%
12,50%
8,33%
20,83%
37,50%
0,00%

Between
10% and
15%
0,00%
0,00%
8,33%
8,33%
12,50%
12,50%
0,00%

Betwee
n 5%
and
10%
4,17%
29,17%
25,00%
4,17%
20,83%
16,67%
8,33%

Under
5%
95,83%
58,33%
54,17%
79,17%
45,83%
33,33%
91,67%

5. CONCLUSIONSThe overall conclusion is that the developed dynamic forecast method appears to be an
applicable method in the case of the mall scale solar systems. It is verified that the forecast foreach 15-minute period within five minutes before the end has a good accuracy even understrongly variable weather.
6. LIST OF SYMBOLS
Apv

the useful photovoltaic solar surface, m2

Energy and the Environment (2016) 257-266

265

Gpv

The effective global radiation (effective direct (normal to the plain) and diffuse
solar radiation, with south orientation, W/m2

HD,E

The total effective radiation to the PV plain with D tilt angle and E orientation,
W/m2

hekv
Hi
ht
ht*
PAC
Pp
qel
KM
Nt
Nq
[real

The equivalent peak load hour kWh/kW or hError factor, %Measured real value of the equivalent peak load hour kWh/kW or h
Typical Meteorological Year’ analytically expected equivalent peak load hour
kWh/kW or h
Te PV generator’ expected alternating current performance at a given time, W
the nominal capacity of the PV system kWp
The photovoltaic power generation capacity, W
Module efficiency,%
The predicted dynamic data-driven value of the equivalent peak load hour at ttime kWh/kW or h.
The predicted 15 minute average data of the average equivalent peak load hours in
the given 't period, kWh/kW or h.
A typical solar electricity generating capacity of a given t period, kWh

REFERENCES[1] Bright, J. (2015): Methodology to stochastically generate synthetic 1-minute irradianceprofiles derived from mean hourly weather observational data, Solar World Congress, 812. November 2015, Daegu, Korea, 2 p.
http://swc2015.org/index.php?g_page=program&m_page=program11
Downloading is on 10. December 2015.
[2] Dyreson, A. R., Morgan, E. R., Monger, S. H., Acker T. L. (2014) Modeling solar
irradiance smoothing for large PV power plants using a 45-sensor network and Wavelet
Variability Model, Solar Energy 110, pp. 482-495.
[3] Earthscan (2008): Planning and installing photovoltaic systems. A guide for installers,architects and engineers, Earthscan Publications Ltd, ISBN-10: 1844074420, 396 p.
[4] Hussain, S., Al-Alili, A. (2015): Selection of relevant input parameters for solar radiation,
ISES Solar World Congress, 8-12. November 2015, Daegu, Korea, 2 p.
http://swc2015.org/index.php?g_page=program&m_page=program11
Downloading is on 10. December 2015.
[5] Kostylev, V., Pavlovski, A., (2011): Solar power forecasting performance towards
industry standards. Proceedings of the 1st International Workshop on the Integration ofSolar Power into Power Systems, 24. October 2011, Aarhus, Denmark, 8 p.
https://ams.confex.com/ams/92Annual/webprogram/Manuscript/Paper203131/AMS_VK_%20AP_Paper%202011%20submitted.pdf
Downloading is on 28. December 2015.

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Z. Kapros: A Dynamic Data-Driven Forecasting Methodology for…

[6] Lave, M., Kleissl, J. and Stein, J.S. (2013): A wavelet-based variability model (WVM) for
solar PV power Plants, IEEE Trans. Sustain Energy 4, pp. 501-509.
[7] Longhetto, A., Elisei, G. and Giraud, C. (1989): Effect of correlations in time and spatial
extent on performance of very large solar conversion systems, Solar Energy 43, pp. 77-84.
[8] Lorenz, E., Heinemann, D. (2012): Prediction of solar irradiance and photovoltaic power,
Comprehensive Renewable Energy, pp. 239-292.
[9] Sharma, R., Tiwari, G.N. (2012): Technical performance evaluation of stand-alone
photovoltaic array for outdoor field conditions of New Delhi, Applied Energy, 92. pp.
644-652.
[10] Wu, Z., Xia, X. (2015): Optimal switching renewable energy system for demand side
management, Solar Energy 114. pp. 278-288.

0(72'2/2*,-$352*12=(3202û8',1$0,ý.,+32'$7$.$
ZA MALE FOTONAPONSKE SUSTAVE NAPAJANJASažetak: Trenutno u Maÿarskoj, vremenski-zavisne varijabilne obnovljive elektrane (energija
YMHWUDLVXQFD þLQHXGLRXXNXSQRMSRWURãQMLHOHNWULþne energije od samo oko 1.8%, iako je to
YULMHGQRVW NRMD VH SRYHüDYD 5HDODQ FLOM ]D QDUHGQLK -30 godina može biti dostizanje
omjera 20-25% u potrošnji elektriþne energije. Ipak, u Maÿarskoj takoÿer postoje barijere,
postoji nedostatak modela i metoda, što se moåH QHXWUDOL]LUDWL SRPRüX PUHåQH LQWHJUDFLMHYHOLNRJEURMDIRWRQDSRQVNLKVXVWDYD0HWRGRORJLMDSURJQR]HSRPRüXGLQDPLþNLKSRGDWDNDMH
razraÿena i testirana ispitivanjem instaliranih solarnih sustava tvrtke Budapest District
Heating Co. Ltd. Primarno prognoze su testirane samo za referentni fotonaponski sustav;
VHNXQGDUQRVXQDSUDYOMHQH]DJUXSXIRWRQDSRQVNLKVXVWDYDX]XVSRVWDYXSUDüHQLKSRGDWDNDVDPR L] UHIHUHQWQRJ VXVWDYD 7HVWLUDQD PHWRGD SURJQR]H SUHGYLÿD SRGDWNH VDPR  PLQXWD
unaprijed, ali ne samo za oþHNLYDQH SHUIRUPDQVH YHü WDNRÿHU L ]D Rþekivane prosjeþne
performanse u periodu od 15 minuta. Zbog pouzdanosti metodologije, ovisnost toþnosti ovremenskim uvjetima je takoÿer vrednovana. Glavni elementi testirane metodologije i nekiglavni rezultati biti üe predstavljeni na konferenciji i u samom radu.
.OMXþQH ULMHþL 0DOL IRWRQDSRQVNL VXVWDYL 3URJQR]D SRPRüX GLQDPLþNLK SRGDWDND
Ekvivalentni sat najveüeg optereüenja, Kratko vrijeme predviÿanja za razdoblje od 15 minuta

Energy and the Environment (2016) 267-276

267

MOBILE SOLAR-POWERED BUSINESS UNIT FOR OFF-GRID AREAS
IN SOUTH AFRICA
Johan Bekker1, Marius Viljoen2#

Telkom Centre for Alternative Energy, Vaal University of Technology, Andries
Potgieter Boulevard, Vanderbijlpark, South Africa
1bekkerj@vut.ac.za, +27 16-9509952 (tel), +27 16-9509999 (fax)2marius@vut.ac.za, +27 16-9509428 (tel), +27 16-9509999 (fax)

Abstract: This paper presents the planning, design and implementation of a mobile solarpowered unit that can be used to execute the running of any small business within a region
where there is no electricity available. It also enables the entrepreneur to move the mobile
unit without the challenge of being dependent on an electrical grid connection. The unit
presented in this paper is solar-powered sufficiently in order to provide enough electricity forvarious applications in retail as well as entertainment business. It is equipped with satelliteinternet and Wi-Fi, as well as the option to have a DStv connection. Furthermore, designs canbe altered for different business units with unique solar systems, depending on business needs
and loads within the business. The results presented are in the form of load readings takenover an extended period of time, as well as graphical representation of power usage as loads
within the unit varies. Usage of battery power during night time was also monitored andoptimized.
Keywords: Solar-Powered, mobile, business unit, loads
1. INTRODUCTION
Unemployment and poverty in rural areas in South Africa is a major socio-economic
problem. One reason for this is the lack of infrastructure, among which electricity is a big
part. Furthermore, load shedding as well as the need to move a business unit to locations inurban areas where an electrical connection is not available, were further considerations. With
this in mind, the idea originated to design and build a completely self-electrified unit that canbe utilized to provide any service at any location.
This paper present the challenges of the structural design and building process, as well as
the important electrical design and considerations needed to make the unit practical andeconomically viable. The experimental procedures and setups involved in the design process
are discussed and illustrated, highlighting and concentrating on the electrical installation. The
results and discussions as well as conclusions complete the paper, where suggestions are also
made for possible improvements and/or additions/omissions to the unit.
2. DESIGN AND CONSTRUCTION
2.1 Structural
The size of the unit is directly linked to the electricity need, in that the number of solar
panels needed to deliver a certain amount of electric power, determines the size of the roof,

268

J. Bekker, M. Viljoen: Mobile solar – powered business unit….

hence the dimensions of the unit. The unit that is discussed in this paper, was constructed byTwin Boats and trailers on the R59 highway, Meyerton, South Africa. Twin Boats also
specializes in the construction of mobile homes, hence their involvement. The materials used
are lightweight, and the structural composition is available on request. This unit will fromnow on be referred to as a “Spaza shop”, as various client needs can be met within. This
includes retailing of various items, hence the need of cooling/freezing facilities. Satelliteinternet with Wi-Fi is available; therefore clients will have access to general internet on one
laptop, as well as another exclusively for internet banking. Cell phone airtime/data can besold, as well as numerous cell phone charging facilities made available. These charging
facilities will be in the form of 12-V sockets, where car chargers are used. Entertainment will
be provided to clients in the form of a television with digital satellite dish and decoder, on
which sporting events of the day will be screened. Battery charging facilities (12 V carbatteries) are also available. All these services/products are made available through a solar
system providing the electricity needed. The spaza shop is powered by 9 solar panels with a 5
kW inverter, providing the AC power. A 10th solar panel is used to provide DC power for
lighting, cell phone and battery charging, which will be discussed in the next section. The
dimensions of the solar panels are 1650 x 992 mm, and with small spacing between after
mounting, determines the size of the shop. The arrangement of the panels when mounting on
the roof will also be discussed and illustrated in the next section under electrical systemdesign. Fig. 1 shows the design of the spaza shop in the form of a floor plan as well as
graphical representation from different angles, while Fig. 2 depicts the actual unit from theoutside. The design features, including the satellite internet as well as Dstv dishes, are clearlyvisible.

(a)

(c)

(b)

(d)

Figure 1: Design of the “Spaza” shop. Dimensions are given in (a), whereas (b) shows an
outside view of the shop. Interior views are shown in (c) and (d).

Energy and the Environment (2016) 267-276

269

(b)

(a)

(c)

Figure 2: Outside back-and-side (a), front-and-side ((b) and (c)) view of the spaza shop. The
satellite internet dish (b); and dstv dish (c) can clearly be seen, with solar panels on the roof.
2.2 Electrical System
The unit in the current spaza shop is equipped with ten 285 W Trina Honey Plus [1] solar
panels on the roof. These panels deliver a peak voltage and current of 31.8 V and 8.97 A,
respectively, while the open-circuit voltage and short-circuit current are 39.3 V and 9.45 A,
respectively. In order to have a sufficiently powered unit, it was decided that a 5 kW Growatt
maximum output string inverter [2] will be used, as the only smaller inverter commerciallyavailable, is a 2 kW device, which can only accommodate limited solar panels [2]. The 5 kW
inverter can accommodate a maximum of 12 solar panels (4 strings of 3), but with the newtechnology high-wattage modules currently available, it was decided that 9 panels (3 stringsof 3) would be sufficient to provide DC input energy for the inverter in order to be converted
to 220 V AC. The tenth panel is utilized, through a charge controller, to charge 12 V batteries
and cell phones, as well as power LED light sources.
The panels were mounted on the roof using state of the art prescribed railings, brackets andclamps, taking into account all necessary installation and safety regulations. The arrangementof mounted panels on the roof of the unit is shown in Fig. 3.
String 1 to inverter

+
-

+
-

+
-

+
-

+ -

String 3 to inverter

-

+ -

+

-

+ -

+

To DC charge controller+ -String 2 to inverter

270

J. Bekker, M. Viljoen: Mobile solar – powered business unit….

Figure 3: Solar panel arrangement as mounted on the roof of the spaza shop. Panels are drawn
to scale, therefore in this diagram can also be seen how panel 10 hangs over slightly, as is also
depicted in Fig. 2 (c).
The panels were connected to the inverter through 63-A DC breakers contained in a suitable
distribution board (DB), and from the inverter connected to the load plugs through AC
breakers, again in a suitable DB. For night-time electricity, a battery pack of 48 V (4 x 12 V
batteries) is connected to the inverter. The battery pack will be charged by unutilized solar
power during daytime, and then supply electricity for cooling devices during the night.
As mentioned earlier, the minimum size of the unit is determined by the electricity needs, i.e.
the number of solar panels. Therefore, for applications where less electrical power is needed,a 2 kW inverter can be used, where only a minimum of two solar panels will supply sufficientelectricity. Examples of such units include a small bar, barber shop and general office, as canbe seen in Fig. 4.

(a)

(b)

(c)

Figure 4: Examples of other applications for the solar powered business unit. In (a) a small
bar is illustrated, while (b) and (c) shows a barbershop and small office, respectively.
3. SETUP AND EXPERIMENTAL PROCEDURE
In order to determine and establish the electricity needs for the current application,
electricity-usage monitoring needed to be done on the solar system described in the previous
paragraph. The monitoring was done through and by the inverter, over an extended period.
Fixed loads within the unit connected to the system include 2 laptop computers, a kettle,
microwave oven, as well as an AA energy saving fridge/freezer. From time to time, anelectric heater was switched on to test the power capacity, in order to establish whether it canbe used for periods in wintertime.
During night-time, all loads except the fridge/freezer were switched of, in order to limit theelectricity usage when all power is supplied by the battery bank only. It must be kept in mind
that ideally, batteries should not be discharged below around 70% of their capacity [3]. For

Energy and the Environment (2016) 267-276

271

the purpose of this paper, no monitoring results are presented for the stand-alone solar modulesupplying DC voltage for battery charging and LED lighting.
4. RESULTS AND DISCUSSION
Results are presented in the form of load wattage as well as battery pack voltage
measurements for a period of seven hours. Readings were taken for extended periods, and thegraphs presented are representative. In order to monitor all possible scenarios, measurements
are presented for a fully sunny and fully cloudy day, as well as night-time usage from thebattery pack. These measurements were done during late May and early June, which is near
the middle of the South African winter, hence close to the least amount of sunshine-hours perday.
4.2 Day-time monitoring
4.2.1

Full sunny day

The measurements presented for day-time monitoring in this section, were taken between
9h00 and 16h00. Fig. 5 represents a graph of Output-apparent-power versus time for a sevenhour period, representative of a busy working day.
Output-apparent-power vs time
2500

HeaterKettle2000
1500

Microwave

1000
500
0

Figure 5: Output-apparent-power versus time for a seven hour period. This graph isrepresentative of readings taken on a full sunny day, when maximum solar power is available
from the solar system.
It is clear from the graph in Fig. 5 that enough power is always available to operate all devices
sufficiently. However, the sudden spike that is created by the high-power devices (kettle,
heater and microwave), causes the inverter to resort to battery power, as can be seen on thecorresponding graph of battery-voltage vs time in Fig. 6.

272

J. Bekker, M. Viljoen: Mobile solar – powered business unit….

Battery-voltage vs time

Batteries draining

60
58
56
54
52
50
48
46
44

Figure 6: Battery-voltage versus time for a clear, sunny winter’s day.
Because of sufficient power supplied by the solar panels, the battery-bank voltage is restored
instantly, also clearly visible in the graph. At around 15h00, the solar panels are not charging
the battery bank any longer (lack of sunlight), and the batteries are gradually drained, as
indicated by the arrow in Fig. 6. Batteries that are fully charged under no load, has a bankvoltage of around 57.6 V (14.4 V per battery), and are then allowed to discharge to around 41
V (70%), as can be set on the inverter [2].
4.2.2

Cloudy day

In order to test and verify for all conditions and scenarios, measurements were also done on a
cloudy winter’s day, with very limited sunlight. The graphs in Fig. 7 and Fig. 8 arerepresentative of these measurements.
Output-apparent-power vs time
2500

Kettle
2000

1500

1000

500

0

Figure 7: Graph of Output-apparent power versus time measured on a cloudy winter’s day,Fig. 7 shows a single spike, caused by the electric kettle for boiling water. This spike inpower usage caused an immediate drop in battery-pack voltage, as is visible on the graph inFig 8. Unlike the situation for a bright sunny day, the battery voltage did not recover
immediately, because of the lack in electrical power supplied by the solar panels. This createsa problem on cloudy days, hence the limited use of high-power devices on this particular day.

Energy and the Environment (2016) 267-276

273

Battery-voltage vs time
70
60
50
40
30
20
10
0

Figure 8: Battery-voltage versus time for a cloudy day.
The problematic issue is that, on a cloudy day, the use of high-power devices such as kettles
and heaters, causes the system to switch to battery power to often, and recharging of thebattery pack is not possible due to the lack of power supplied by the solar array.
4.3

Night-time monitoring

When considering the results in graphical form for the night-time monitoring, it has to be
kept in mind that the settings on the inverter was of such a nature so as to not allow thebattery-pack voltage to drop too low in order not to damage the batteries. It was decided that,for night-time measurements, the system will be set to shut down when the death-of-dischargeof the batteries reaches 20%, i.e. a bank voltage of around 47 V.
Output-apparent-power vs time
800
700

Electronic devices
switched off.

600
500
400
300
200
100
0

Figure 9: Graph of Output-apparent power versus time, representing night-timemeasurements. No high-power devices were used.
Fig. 9 shows the graph of Output-apparent power vs time for a period between 16h00 and
23h00. The unit operated purely on battery power, with no high-power devices utilized. Up
to around 21h00, the laptop computers and television set was switched on, with the
fridge/freezer operating at all times. The drop in power used after 21h00 (only fridge/freezer
operational) is clear, and therefore minimal drainage from the battery pack. The limited

274

J. Bekker, M. Viljoen: Mobile solar – powered business unit….

spikes after 21h00, represent the starting of the fridge/freezer motor. As can be seen from Fig
10, the battery-pack voltage has an initial decrease from 57 v to around 50 V, from where it
gradually has a limited decrease to around 48 V. As mentioned earlier, the limit on the
inverter was set at 47 V, and that may cause the system to shut off in the early hours of themorning. However, the shut-off will have no noticeable effect, in that the fridge/freezer will
only be off for a few hours until sunshine, and will remain cold.
Battery-voltage vs time
70
60
50
40
30
20
10
0

Figure 10: Graph of Battery-voltage versus time for a seven hour period at nigh-time. The
limited low-power devices that is utilized, operate purely from the battery pack.
When required, the settings on the inverter can be changed in order to allow the battery-packto discharge to a lower capacity. This should be limited, and never below 40 V, as it will
influence battery-life to a large extend [3]. The most problematic and maintenance-requiring
part of our system is the battery pack, and should be looked after extremely carefully.
5.

Conclusions and Future Work

The operation of the business unit in this paper depended largely on the needs and demandsof customers. In order to supply warm beverages, like coffee and heated up food,consideration should be given to revert to gas-driven devices. This is also applicable toheating of the unit in winter time, it is recommended that a gas heater and two-burner stove be
added. However, as can be seen from the graphs in the paper, sufficient electrical power wascontinuously supplied for the basic needs of customers, as well as the general operation of theunit. It should be noted that continuous alterations must be made as the business grow, andalso for special occasions, like the screening of a late night sports event on television.

Energy and the Environment (2016) 267-276

6.

275

References[1] (2016). The Trina website. [Online]. Available:
http://www.trinasolar.com/us/product/ALLMAX-M-PLUS.html J[2] (2016). The Growatt website. [Online]. Available:
http://www.growatt.com/html/2014/01/09/2014010903050937575617.html[3] (2016).
6). The battery university website.
webs [Online]. Available:
http:////www.batteryuniversity.com

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276

J. Bekker, M. Viljoen: Mobile solar – powered business unit….

Energy and the Environment (2016) 277-286

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DQG%6FURVDWL (GV (QF\FORSHGLDRI(OHFWURFKHPLFDO3RZHU6RXUFHV9RO(OVHYLHU
$PVWHUGDP  SS>@)%DUELU3(0)XHO&HOOV7KHRU\DQG3UDFWLFHQGHG(OVHYLHU$FDGHPLF3UHVV
>@.=KRX-$)HUUHLUD6:+GH+DDQ2SWLPDOHQHUJ\PDQDJHPHQWVWUDWHJ\DQGV\VWHPVL]LQJPHWKRGIRUVWDQGDORQHSKRWRYROWDLFK\GURJHQV\VWHPV,QW-+\GURJHQ(QHUJ\  SS
>@ 8OOHEHUJ7KHLPSRUWDQFHRIFRQWUROVWUDWHJLHVLQ39±K\GURJHQV\VWHPV6RODU(QHUJ\,QVWLWXWHIRU(QHUJ\7HFKQRORJ\.MHOOHU1RUZD\
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286

J. Šimunoviü, F. Barbir: Simulation and Analysis of an Electrolyzer…



6,08/$&,-$,$1$/,=$5$'12*352&(6$(/(.752/,=$725$
81(29,61206867$982%129/-,9,+,=925$(1(5*,-(Sažetak: Neovisni energijski sustav koji se sastoji od fotonaponskog sklopa, vjetroturbine,elektrolizatora, spremnika vodika, gorivih üelija i baterijskog sklopa je analiziran. Strategija
upravljanja energijom korištena za ovaj sustav temelji se na kontrolnim petljama dvostruke
histereze gdje se stanje napunjenosti baterije koristi za pokretanje elektrolizatora i gorivihüelija te njihovo ukljuþivanje/iskljuþivanje. Razvijen je simulacijski program korištenjem
Matlab-a. Optereüenje krajnjeg korisnika definirano je kao konstantno, dok su ulazni
vremenski podaci dobiveni od Hrvatskog hidrometeorološkog zavoda. Simulacije su
provedene korištenjem dvije razliþite radne toþke elektrolizatora: (i) toþka maksimalne snage
i (ii) toþka maksimalne uþinkovitosti. Vrijednosti za snagu elektrolizatora, veliþinu
baterijskog sklopa i stanje napunjenosti baterija za kontrolu elektrolizatora variraju za svaku
simulaciju. Rezultati simulacije pokazuju kako promjena bilo kojeg parametra utjeþe nauþinkovitost sustava i na prosjeþno vrijeme rada elektrolizatora.
Kljuþne rijeþi: Elektrolizator, Baterijski sklop, Strategija upravljanja energijom, Radna toþka
elektrolizatoraEnergy and the Environment (2016) 287-294

287,675$ä,9$ý.20(',&,16.,&(17$51$*(27(50$/120
IZVORIŠTU
5REHUW*UDGHþNL, mentor: SURI/MXERPLU0LãþHYLü
Arhitektonski fakultet, KaþLüHYD=DJUHE-420
robert.gradecki6@gmail.com miscevic@arhitekt.hrSažetak: 3URVWRUNRQWLQHQWDOQH+UYDWVNHSUHSXQMHL]YRULãWDJHRWHUPDOQLKYRGDNRMHVXþHVWRL
mineralne. 1D JRWRYR VYLP NDSDFLWHWRP MDþLP L]YRULãWLPD L]JUDÿHQD VX NXSDOLãWD Mnoge
vode su same pronašle svoj put do površine, a velik dio njih pURQDÿHQ MH VOXþDMQR X
potragama za naftnim i plinskim poljima. Upravo takvo je izvorište „Jokobanja” na bušotini=H X VHOX .UHþDYHV SRUHG 6Y ,YDQD =HOLQH Na pokusnoj bušotini iz 1978. godine nije
SURQDÿHQDQDIWDDOLMHVDGXELQHRGPSRWHNODYRGDVoda iznimnih karakteristika, stalne
temperature od 49 ºC i bez mineralizacije je trenutno potpuno neiskorišten potencijal.
6ORERGQRWHþHXSUHOMHYXDNRULVWLVHVDPR]DLQGLYLGXDOQRWXãLUDQMH]DNRMHPQRJLVPDWUDMX
da je ljekovito. Bušotina Ze1 nije jedino izvorište geotermalne vode u gradu Sv. Ivanu Zelini.
1D SULURGQRP L]YRULãWX 7RSOLþLFD VD VWDOQRP WHPSHUDWXURP RG  & MH  JRGLQH
L]JUDÿHQ  SUYL YDQMVNL RWYRUHQL ROLPSLMVNL ED]HQ X -XJRVODYLML ,]QLPDQ WXULVWLþNL SRWHQFLMDO
jednog i zdravstveno-OMHþilišni drugog izvorišta unutar istog grada je potpuno neiskorišten.
Iako su ova dva izvorišta udaljena samo 8 kilometara, dijeli ih rasjed doline rijeke Lonje, te
QLMH GRND]DQD KLGUDXOLþka veza. 2YLP UDGRP LVWUDåHQL VX ]GUDYVWYHQL OMHþLOLãQL L HQHUJHWVNL
potencijali ovog jedinstvenog geotermalnog izvorišta.
.OMXþQHULMHþL*HRWHUPDOQLL]YRU6ORERGQLSUHOMHY,VWUDåLYDþNR-medicinski centar

1. UVOD*HRWHUPDOQDHQHUJLMDVHXEUDMDXQDMþLãüHL]YRUHHQHUJLMH,]YRULãWDNRMDVXVDPDQDãODSXWGR
površine zemljine kore prepoznata su od davnina. Prostor kontinentalne Hrvatske izuzetno je
bogat geotermalnim izvorištima, a od rimskih doba poznate su Aque Iasse (Varaždinske
toplice), Aquae Balissae (Lipik) i Aqua Vive (Tuhovec kod Cestice). Na takvim prirodnimi]YRULãWLPDJUDÿHQDVXRWYRUHQDNXSDOLãWDX]SULURGDQSURWRN6LWXDFLMDMHVWDJQLUDODGR-ih
JRGLQD GYDGHVHWRJ VWROMHüD NDGD MH WYUWND ,1$-1DIWDSOLQ ]DSRþHOD VD LQWHQ]LYQLP
istraživanjem rezervi nafte i plina u kontinentalnoj Hrvatskoj. Postignuti su iznimni
LVWUDåLYDþNL UH]XOWDWL WH RYDM SURVWRU WUHQXWQR EURML  QDOD]LãWD RG NRMLK MH  X XSRWUHEL,]YRULãWD VH YHüLP GLMHORP NRULVWH ]D SRJRQ WRSOLFD L MDYQLK ED]HQD 'LR EXãRWLQD ELR MH
SODQLUDQ]DWHKQLþNLSRJRQL]DJULMDYDQMHQLNDG]DYUãHQH6YHXþLOLãQHbolnice u Zagrebu, dok
QHNROLNR EXãRWLQD XVSMHãQR NRULVWL ]D SRJRQ VSRUWVNLK FHQWDUD âDODWD L 0ODGRVW 3RGUXþMH
središnje Hrvatske bogato je izvorištima razOLþLWRJNDUDNWHUDVDYRGRPRGºC do 80ºC štoVSDGD X SRGUXþMD VD VUHGQMRWHPSHUDWXUQLP PHGLMLPD 6Meverni i sjevero-LVWRþQL GLMHORYLXEUDMDMX VH X SDQRQVND SRGUXþMD WH MH YULMHGQRVW JHRWHUPDOQRJ JUDGLMHQWD QD QMLPD ]QDWQRYLãDVDSURVMHþQRPWHPSHUDWXURPRG&288

5*UDGHþNL/M0LãþHYLü,VWUDåLYDþNRPHGLFLQVNLFHQWDUQDJHRWHUPDOQRPL]YRULãWX

=D YULMHPH LVWUDåLYDQMD QDIWQLK SROMD XSUDYR MH WDM UDVMHG L]PHÿX VUHGLãQMH L SDQRQVNH
HrYDWVNH GDYDR QDMLQWHUHVDQWQLMH UH]XOWDWH 'Xå WH OLQLMH SURQDÿHQD VX QDIWQD SROMD X
3RGUDYLQL NRG ,YDQLü *UDGD QD 0DUWLQEUHJX NRG 'XJRJ 6HOD WH SOLQVND SROMD X 0ROYDPD
1D WRP SRGUXþMX QDOD]H VH L GYD QDMYUHOLMD L]YRULãWD – Ferdinandovac u Podravini satemperaturom od 125ºC WH9HOLND&LJOHQDNRG %MHORYDUD VD þDN ºC. Ravnica Lonjskog
SROMDSRVWDODMHQDMMDþDLQWHUHVQD]RQDSDMHWDNRJRGLQH]DSRþHOREXãHQMHGYLMHSUREQH
bušotine na prostoru Svetog Ivana Zeline. Nakon bušenja do dubine od 1500 metara, bušotina
Ze-2 pokazala se lošom, dok je kod bušenja Ze-NRGGXELQHRGPSURQDÿHQYRGRQRVQL
sloj geotermalne vode.
2. 32672-(û($1$/,=(%8â27,1(=(-1Grad Sv. Ivan Zelina se nalazi 20 km sjevero-LVWRþQRRG=DJUHEDQDGUåDYQRMFHVWL'SUHPD
9DUDåGLQX *HRJUDIVNL VH QDOD]L X 3ULJRUMX QD SRGUXþMX L]PHÿX MXJRLVWRþQLK SDGLQD
Medvednice i rubova Lonjskog polja. Predmetna lokacija izvorišta se nalazi na 45º56'22''
VMHYHUQH ãLULQH L    LVWRþQH GXåLQH RG *UHHQZLFKD QD FFD  m nadmorske visine u
VHOX.UHþDYHV Selo se nalazi na županijskoj cesti ŽC3288 Sv. I. Zelina-Vrbovec, 1.5 km od
rijeke Lonje u smjeru Vrbovca. Autocesta A3 Zagreb - *RULþDQSUROD]LX]VHORDQDMEOLåLþYRUje Sv. Helena i nalazi se 3 kilometra južno od lokacije. Na parceODPDNþ
415/3 i 415/4 k.o. Novo Mjesto 300m od sela je GDQDVþLVWRSRGUXþMHNRMHVWDQRYQLFLQD]LYDMX“Jokobanja”. Lokalni toponim za lokaciju upotrebljava se više od trideset godina. Kupalište iWXãLUDOLãWHQDL]YRULãWXMH]DJUDÿDQH prvi uredio stanovnik sela Drago Posavec - -RNLüSDMH
lokacija dobila ime upravo po njemu.

Slika 1. i 2. 6YDNRGQHYQLNXSDüLQDVORERGQRm preljevu geotermalnog izvorišta
JOKOBANJA
joko-banja, (toponim, ž, im.)MRNRVNUDüHQLFDLPHQLFH-RNLü nadimak)banja: 1. mineralno kupalište; toplice
2. banj - SURVWRULMD]DNXSDQMHXNXüL
PMHVWRXNRMHPVHQLãWDLOLYUORPDORUDGLDQDODNQDþLQGROD]LGRQRYFDLOLNDNYD
druga probitka - banjaža
LRNDFLMD MH VWDOQR SRVMHüHQD L UHGRYQR MX NRULVWL YHOLN EURM OMXGL VD ãLUHJ SRGUXþMD Mnogi
SRWYUÿXMXSREROMãDQMH]GUDYVWYHQRJVWDQMDNRGUD]QLKSRWHãNRüDQDNRQUHGRYLWRJWXãLUDQMDQD
tušu kod slobodnog ispusta geotermalne bušotine. Izvorište i okoliš nisu dovoljno iskorišteni i

Energy and the Environment (2016) 287-294

289

eksploatacija se vrši u neprihvatljivom obliku za zaštitu okoliša, zdravlja i zaštite ljudi, biljakai životinja. 9RGDYLVRNHWHPSHUDWXUHVORERGQRRWMHþHXWHUHQDSRVMHWLRFLXSRWUHEOMDYDMXUD]QH
agresivne šampone i sl.
3RGX]HüH ,1$-Naftaplin, služba razvoja TIM6 zatražilo je 1980. godine izradu
balneokemijske analize vode iz bušotine Ze- NDNR EL VH GRELOD VWUXþQD PLãOMHQMD R
PRJXüQRVWLPDNRMHYRGDSUXåD]DXSRWUHEX7HPHOMHPWRJWUDåHQMDLQJUXG6WMHSDQ*DORYLüXVYRMVWYX SUHGVWDYQLND QDUXþLRFD LQJJHRO 5DGRYDQ ýHSHODN NDR VOXåEHQLN L SURI 1LNROD
7LSLü X]LPDQMHP X]RUDND ]DSRþHOL VX DQDOL]X 8WYUÿHQD VX RSüD VYRMVWYD EXãRWLQH
7HPSHUDWXUD YRGH QD L]OD]X MH VWDOQLK & QHRYLVQR R SURWRNX ,]GDãQRVW MH XWYUÿHQDmjerenjem slobodnog preljeva i iznosila je 300 l/min, dok je pumpanjem porasla do 500
l/min. Glavni vodonosni sloj nalazi se na dubini od 840m, dok je ukupan vodonosni pojas na
SRGUXþMXL]PHÿX P L P GXELQH 2UJDQROHSWLþND VYRMVWYD YRGH VX GD MH RQD Nristalno
bistra, bezbojna, bez mirisa i okusa. pH vode iznosi 7,4. Utrošak permanganata u vodi je
unutar granica za pitke vode. Voda se pri stajanju ne mijenja.
BALNEOLOŠKA ANALIZA
Voda je karakterizirana kao natrijeva - hidrokarbonatna hiperterma (t 47,3-49 ºC min
830mg/l, mval ukup. 19.1. Na 94,0%, HCO3 91,5%). Voda je jaka hiperterma, a pomineralizaciji se ne može ubrojiti u mineralne vode, jer joj je mineralizacija ispod 1000mg/l.
1DNRQ DQDOL]H VDVWDYD VWUXþQL WLP X þLWDYRM GRVWXSQRM OLWHUDWXUL QLMH SURQDãDR QLMHGQXKLSHUWHUPX LVWRJ VDVWDYD 6OLþQD YRGD SRVWRML X -RãDQLþNRM %DQML X 5HSXEOLFL 6UELML DOL Va
VXPSRURPXVYRMHPVDVWDYX.DRWDNYHRYHWHUPHVXRSLVDQHNDRþLVWHKLSHUWHUPHJGMHSRVDVWDYXYRGHQHPRåHPRXVSRUHGLWLVYRMVWYDVDYHüGRND]DQLPVYRMVWYLPDVOLþQLKL]YRULãWD
HIDROGEOLOŠKI IZVJEŠTAJ
Sama lokalitet je sondiran 1966. godine, a do kraja LVSLWLYDQMDLEXãHQMDSRVWLJQXWDMHNRQDþQD
dubina od 1.318,39 metara. 3RVWRMHüH WOR VDVWDYOMHQR MH RG VORMHYD ODSRUD L SMHãüHQMDND GR
dubine od 600 m granulacije 0,316-0,100 mm. Akvifer bušotine ima prirodno hranilište i nije
potrebno upumpavanje iskorištene vode. Iskorištena voda mora imati temeperaturu u skladu s
uvjetima okoliša. Voda se zbog svog sastava može bez opasnosti upuštati u otvorene
vodotokove. Bušotina Ze1 nije jedino izvorište geotermalne vode u gradu Sv. Ivanu Zelini.
Na prirodnom izvorišWX 7RSOLþLFa sa stalnom temperaturom od 26 & L]JUDÿHQ MH VSRUWVNR
rekreacioni centar. 9RGRQRVQLN QHPD KLGUDXOLþNH YH]H V L]YRURP 7RSOLþLFD Mješanim
ispitivanjem mjerenja slobodnog preljeva, te preljeva ispumpavanjem vode dosegnut je
maksimalni protok od 32 m3/h, a nakon ispitivanja preljev se ponovno stabilizirao na
15,48m3/h. Bušotina je zatvorena na 24 sata nakon što se stabilizirao protok. Grafovi porasta
WODND QLVX XND]LYDOL QD QLNDNYD RãWHüHQMD QDVWDOD NRG LVSLWLYDQMD D NRG SRQRYQRJ RWYDUDQMD
tlak jH RVWDR QHSURPLMHQMHQ +LGUDXOLþNLP PMHUHQMLPD 5/7 PMHUHQMLPD  XWYUÿHQD MH
KLGUDXOLþND EDULMHUD QD  m od bušotine što se poklapa sa položajem rasjeda uz rijeku
Lonju u smjeru sjever-jug7DNRÿHUSURQDÿHQLVXVODWNRYRGQLYRGRQRVQLVORMHYLQDGXELQDPD
do 80 m koji se mogu koristiti za potrošnu pitku vodu.
3. POTENCIJAL KORIŠTENJA LOKALITETA
7UDGLFLMDNXSDOLãQRJWXUL]PDX6Y,YDQX=HOLQLVHåHXGYDGHVHWHJRGLQHVWROMHüDNDGDVX
nakon I. svj. rata organizirana prva kupališta i tada suvremeni tereni za tenis na malom
ULEQMDNX X JUDGX =HOLQVNL NUDM MH RGXYLMHN ELR SR]QDW SR RþXYDQRM SULURGL XNXVQRM KUDQL L290

5*UDGHþNL/M0LãþHYLü,VWUDåLYDþNRPHGLFLQVNLFHQWDUQDJHRWHUPDOQRPL]YRULãWXYLQX WH MH NDR WDNDY SULYODþLR EURMQH L]OHWQLNH 1DNRQ ,, VYM UDWD SRMDYLOD VH LQLFLMDWLYD ]D
izgradnju javnog betonskog bazena. Ispitivanjima SURWRþQRVWL L NDNYRüH YRGH RGDEUDQD MH
lokacija neposrednRX]L]YRULãWH7RSOLþLFD8VYLEQMX*RGLQHRWYRUHQMHSUYLROLPSLMVNL
bazen na prostoru Jugoslavije, upravo u Zelini. Grad koji se naglo industrijski razvijao tada je
dobio prvi kompleks vanjskih bazena. Olimpijski bazen dimenzija 25x50m i dubine 1,75 do
3,30 PELRMHSUYLED]HQWLKGLPHQ]LMDQDSURVWRUXELYãHGUåDYH,]JUDÿHQMHUXþQLPNRSDQMHPi betoniranjem, a radove su izvodili dobrovoljci i stanovnici grada. Zelinski bazeni uskoro su
postaOL PHÿXQDURGQR SR]QDWL L X] NRPSOHNV MH XEU]R L]JUDÿHQ L DXWRNDPS Kompleks je
poslovao do novog milenija, a od tada je zatvoren i propada. Grad Sv. Ivan Zelina je 2014.
godine donio strategiju razvoja od 2014. do 2020. godine. Kao glavna osnova za pokretanje
UD]YRMD JUDGD SUHSR]QDW MH WXULVWLþNL SRWHQFLMDO GYD L]YRULãWD QD SRGUXþMX JUDGD Strategija
postavOMD VOLNX JUDGD NDR LGHDOQRJ PMHVWD ]D NUDWNL RGPRU X RþXYDQRM SULURGL X] WUDGLFLMX L
ORNDOQHRELþDMHLOLGXOMXUHODNVDFLMXLVSRUWVNHSULSUHPH

Slika 3. Panoramski pogled na predmetnu lokaciju
Zdravstveni turizam je jedan od najstarijih specijaliziranih oblika turizma. KontroliranimNRULãWHQMHP SULURGQLK OMHNRYLWRVWL WXULVWL þXYDMX L XQDSUHÿXMX VYRMH ]GUDYOMH =GUDYVWYHQLWXUL]DP ]D VRERP SRYODþL LQWHQL]LYDQ UD]YRM L SODVPDQ SUDWHüLK GMHODWQRVWL NDR ãWR MH
proizvodnja i plasman eko-hrane, razvoj obiteljskih poljoprivrednih gospodarstava, sportskih iVOLþQLK VDGUåDMD 3UHPD QDYRGLPD +*. QDMYHüL UD]YRM ELOMHåH JUDQH SRSXW RUWRSHGLMH
kirurgije, fizioterapije i talasoterapije, te produženi boravak starijih gostiju. Ulaskom u EU
VWUDQL SDFMHQWL PRJX RVWYDULWL SRYUDW GLMHOD WURãNRYD OLMHþHQMD 8SUDYR OMHþLOLãQL SRWHQFLMDO
geotermalne vode koja u sastavu ima 94% otopine NaHCO3 – tj. sode bikarbone – je glavna
pretpostavka iskorištavanja izvorišta. Toplice u Hrvatskom Zagorju rijetko prelaze
WHPSHUDWXUX RG & ,]X]HWDN VX9DUDåGLQVNH WRSOLFH VD WHPSHUDWXURP RG & 9HüLQD LK
LPDYRGXSXQXPLQHUDODL]SOLüLKVORMHYDYRGRQRVQLNDERJDWXRWRSLQDPDPDJQH]LMDNDOija i
NDOFLMD 3UHPD WDNYRM XVSRUHGEL WHãNR MH RFLMHQLWL L]YRULãWH .UHþDYHV MHU QLMHGQR SR]QDWRL]YRULãWH QHPD WDNYD VYRMVWYD 2VLP EDOQHRORãNH DQDOL]H OLMHþQLþND SURXþDYDQMD MRã QLVX
potvrdila ili odbila ljekovitost sode bikarbone iako je lokacija JokobaQMH VWDOQR SRVMHüHQDLQGLYLGXDOFLPDNRMLGRNXPHQWLUDMXVYRMHL]OMHþHQMH
4. 352-(.7,675$ä,9$ý.20(',&,16.2*&(175$
Projekt centra na geotermalnom izvorištu izradio sam pod mentorstvom profesora Ljubomira0LãþHYLüD GLD 9DåQR MH QDJODVLWL LVWUDåLYDþki aspekt rada ovog centra. Kako ne postojiVOXåEHQDSRWYUGDOMHNRYLWRVWLYRGHDLQLMHMXPRJXüHRVWYDULWLSR]QDWLPDQDOL]DPDSRWUHEQREnergy and the Environment (2016) 287-294

291

MH ]DSRþHWL VD NRQWUROLUDQLP HNVSORDWLUDQMHP 1D ELUDQRP X]RUNX UHGRYQLK SRVMHWLWHOMDPRJXüH MH SUDWLWL PHGLFLQVNR VWDQje te bilježenjem ustvrditi utjecaj ove vode na
dijagnosticirana oboljenja. Sadržaji medicinskog centra služe za stalnu medicinsku skrb
stacioniranih pacijenata, kao i vanjskih korisnika kojima bi se u kompletnom sustavu
RPRJXüLORXSR]QDYDQMH]GUDYLMHJRGUåLYLMHJLHNRORãNRJQDþLQDåLYRWD

Slika 4. i 5. Prostorni prikazi projektirane zgrade=JUDGD MH VPMHãWHQD L]YDQ JUDÿHYLQVNRJ SRGUXþMD QDVHOMD  PHWDUD ]UDþQH XGDOMHQRVWL RG
SUYLK NXüD 3DUFHOD MH UDYQD L RWYRUHQD EH] RNROQLK ]DVMHQMHQMD X NUXJX od 500 metara.
Dominantni su sjeverni vjetrovi duž doline rijeke Lonje, dok povišena kota terena osigurava
mali broj maglovitih dana u odnosu na okolicu. Uvjeti na parceli su ovime gotovo idealni za
iskorištavanje obnovljivih izvora energije. Sama zgrada je konceptirana kao spoj dva
YROXPHQD ELWQR UD]OLþLWRJ NDUDNWHUD 1LåL L]GXåHQL YROXPHQ VDþLQMDYDMX SURVWRUL ]Dsvakodnevno korištenje stacionarnih, ali i vanjskih korisnika. U njemu su smješteni kongresni
centar, medicinski centar, restoran i bazenska dvorDQD.DNRELVHSRVWLJODþLPEROMDWRSOLQVND
izolacija podovi su izolirani sa 35cm XPS-D VD SREROMãDQMHP VWDWLþNH RWSRUQRVWL ]JUDGH
VHL]PLþNL RWSRUQLML  .URYRYL VX L]YHGHQL NDR UDYQL VD FP NDPHQH YXQH L ]DYUãQLP
slojevima PVC membrana WH ]DVDÿHQLP SOLtkim zelenim krovom sa raslinjem kratkog
korijenja. 7DNDYVXVWDYVHQD]LYD%LR7UD\LRPRJXüDYDGRMDP]HOHQRJNURYDVDYUORQLVNLPRSWHUHüHQMHP SR MHGLQLFL SRYUãLQH L JRWRYR QLNDNYLP SRWUHEDPD ]D RGUåDYDQMHP %LOMH MH
niskog rasta i potrebe za vodom potpuno zadovoljava kišnicom. Staklena dvostruka fasadaL]YHGHQD MH RG YDQMVNLK URPERLGQLK MHGQRVORMQLK VWDNDOD PHÿXSURVWRUD RG FP VD
UHJXODFLMRP SURWRND ]UDND WH XQXWDUQMHJ WURVWUXNRJ RVWDNOMHQMD 2YDNDY VXVWDY RPRJXüDYD]DWYDUDQMH PHÿXSURVWRUD L ]DJULMDYDQje zraka kod hladnijih vanjskih utjecaja, te otvaranje i
SULURGQR SURYMHWUDYDQMH NDGD MH PHÿXSURVWRU SUHYLãH ]DJULMDQ &HQWUDOQLP XSUDYOMDQMHP]JUDGRP PRJXüH MH UHJXOLUDWL WRþQH XYMHWH X VYDNRM SURVWRULML SUHPD SRWUHEL ,VNRULãWDYDQMH
SRWHQFLMDOD6XQþHYHHQHUJLMHQLMHVDPRX]DJULMDYDQMXGYRVWUXNRJSURþHOMDZaštita staklenih
VWLMHQDRGSUHYHOLNRJVXQþHYRJ]UDþHQMDMHL]YHGHQDEULVROHMLPDVDIRWRQDSRQVNLPSDQHOLPD-XåQR SURþHOMH L NURYQD WHUDVD KRWHOVNRJ QDMYLãHJ YROXPHQD VX SUHNULYHQL IRWRQDSRQVNLP
paneliPD3RWUHEHHOHQHUJLMH]DQRüQDUD]GREOMD]DGRYROMDYDMXVHL]EDWHULMVNRJVSUHPLãWDX
podrumu zgrade. Ukupna instalirana snaga integrirane fotonaponske elektrane iznosi 110kw
sa ukupno 834m2 fotonaponskih panela. Autonomnost zgrade je ostvarena i korištenjem
potencijala geotermalne energije samog izvorišta. Geotermalna voda se crpi iz zacijevljenog
SUHOMHYD þLML VH JODYQL YHQWLO QDOD]L X SRGUXPX ]JUDGH 1DNRQ ILOWULUDQMD YRGD VH UD]GYDMD X
sustav za pripremu potrošne tople vode i grijanje zgrade, te u sustav za pripremu bazenske
vode. Osim kupanja i tuširanja u glavnoj bazenskoj dvorani, svaka soba je opremljena
hidromasažnom kadom na terasi sa geotermalnom vodom. Potrošena voda se prikuplja i
LVNRULãWDYD X GL]DOLFDPD WRSOLQH VD L]PMHQMLYDþHP YRGD-zrak za grijanje unutarnjih prostora.
6YLXQXWDUQMLSURVWRULVXPHKDQLþNLYHQWLOLUDQLVDSRYUDWRPWRSOLQH292

5*UDGHþNL/M0LãþHYLü,VWUDåLYDþNRPHGLFLQVNLFHQWDUQDJHRWHUPDOQRPL]YRULãWX

Slika 6. Tlocrt podruma zgrade s WHKQLþNLPSRJRQRP

Slika 7. Presjek s prikazom instalacijskih vodova i pozicije preljevnog odvoda geotermalnebušotineEnergy and the Environment (2016) 287-294

293*ULMDQMH L KODÿHQMH VYLK SURVWRUD VH RVLJXUDYD SUHNR YHQWLODFLMVNRJ VXVWDYD VD GRYROMQLPEURMHP L]PMHQD ]UDND GRN VH NODVLþQLP SRGQLP JULMDQMHP GRJULMDYDMX VDPR VDQLWDUQH
SURVWRULMH 9LãDN YRGH X VORERGQRP SUHOMHYX PRJXüH MH NRULVWLWL ]D RWDSDQMH SDUkirnih
površina zimi. Nakon upotrebe, voda se sa otpadnim fekalnim vodama sakuplja u vanjskom
bio-rotoru te nakon procesuiranja i propuštanja kroz aerator upušta u vanjsko betonsko korito]DKODÿHQMHGRWHPSHUDWXUHSULKYDWOMLYH]DRNROLãU tehnološkom parku i perivoju oKODÿHQDvoda se dodatno biološki tretira u zelenoj laguni te upušta u teren kroz retencijski kanal i
XSRMQH EXQDUH 2KODÿHQD YRGD VH SRQRYQR FUSL L] NRULWD L QDNRQ ILOWULUDQMD NRULVWL ]Dzalijevanje travnatih površina, pranje prometnica i vaQMVNLK RSORþHQLK SRYUãLQD L RVWDOH
tehnološke potrebe. Na ukupnoj bruto površini zgrade od 4.996,12 m² sadržani su svi potrebnisadržaji za rad autonomnog medicinskog centra sa kupalištem i hotelom za 50 osoba
klasifikacije 4 zvijezdice. 3URUDþXQRPMHGRNDzano kako ukupne potrebe kupališta ne prelaze
L]GDãQRVWRGOPLQãWRRPRJXüDYDNRULãWHQMHLEH]GRGDWQRJLVSXPSDYDQMD

Slika 8. i 9. Prostorni prikaz zgrade i okolnih prostora sa tehnološkim parkom za obradu
geotermalne vode
5. =$./-8ý$.
Gotovo nije shvatljivo da u današnje doba kada je energija jedna od najvažnijih, ali i
QDMVNXSOMLK þRYMHNRYLK VYDNRGQHYQLK SRWUHED SRVWRML JHRWHUPDODQ L]YRU NRML YHü YLãH RG 
JRGLQDVORERGQRL]OLMHYDYRGXRG&XSULURGX'YDGHVHWLþHWLULVDWDGQHYQRVHGDm dana u
WMHGQXWRNRPFLMHOHJRGLQHXVORERGQRPL]OMHYXSULJRWRYROPLQXWHUHQXSXãWDPRþLVWX
prirodnu energiju. Ukupno je do sada izgubljeno gotovo 6 milijuna metara kubnih
geotermalne vode. Geotermalna voda promijenila je okoliš. Biljne vrste prilagodile su se
GRWRNX YUXüH YRGH D GLYOMH åLYRWLQMH QDSXVWLOH VX REOLåQMH ãXPDUNH 3URVWRU RYDNYRJSRWHQFLMDOD VWRML QHLVNRULãWHQ 3URMHNWRP LVWUDåLYDþNR PHGLFLQVNRJ FHQWUD GRND]DQD MH
PRJXüQRVW ]D L]JUDGQMRP DSVROXtno samodostatne zgrade. Kontrolirana eksploatacija
RPRJXüLOD EL SURYMHUX OMHþLOLãQRJ SRWHQFLMDOD D RSüHQLWR NXSDOLãQL FHQWDU EL SRQRYQR
revitalizirao zelinski turizam.

294

5*UDGHþNL/M0LãþHYLü,VWUDåLYDþNRPHGLFLQVNLFHQWDUQDJHRWHUPDOQRPL]YRULãWX

6. LITERATURA
1. 'LNOLü 6 Mineralna i termalna vrela u kotaru zelinskom, Knjižnica Zelina, Sv. Ivan
Zelina, 1950.g.
2. 3URIGU 0DQGLü 9 Ispitivanje termalne vode bušotine Ze- X .UHþD 9HVL NRG =HOLQH,
Medicinski fakultet, Zagreb, 1980.g.
3. 'LSOLQJ *DORYLü 6  Hidrogeološki izvještaj o bušotini Ze-1, INA-naftaplin služba
razvoja, Zagreb, 1980.g.
4. Skupina autora, Sveti Ivan Zelina – 6MHüDQMHXUD]JOHGQLFDPD, Matica hrvatska Sveti Ivan
Zelina, Tiskara Zelina, 2000.g.
5. Killory C. i Davids R., Details, Technology and Form, AsBuilt, 2012.g.
6. Verderber S. i Fine D.J., Healthcare Architecture in an Era of Radical Transformation,
Yale University press, 2000.g.
7. Mostaedi A., New Health Facilities, Architectural design, 2001.g.

MEDICAL RESEARCH CENTRE ON A WELLHEAD
Summary: The continental part of Croatia is teeming with natural geothermal wellheads,
often containing mineral properties. Spas are built on almost every geothermal wellhead witha higher level of capacity. Many underground mineral waters have found their way to thesurface on their own and the rest were discovered by accident in search of oil and gas fields,much like tKH -RNREDQMD ZHOOKHDGRQD=HOGULOOKROHLQDYLOODJHRI.UHþDYHVQHDU6YHWL,YDQZelina. There wasn't any oil discovered during a test drill in 1978 but water started to flux all
the way from 750 metres below. Such kind of water, with extraordinary attributes, consistanttemperature of 49 ºC and with no need for mineralization, at this moment, is nothing morethan an unused potential. Perpetually brimming, it is currently used only as an individual
shower, and regarded by many as therapeutic. Zel oil drillhole is not the only geothermal
ZHOOKHDGLQ6YHWL,YDQ=HOLQD7RSOLþLFDQDWXUDOVSULQJZLWKLWVFRQVLVWHQWWHPSHUDWXUHRI
ºC was used in 1955 as the source for the first outdoor Olympic swimming pool in Yugoslavia.
The remarkable tourist potential from one wellhead and the large healing and therapeuticpotential from the other remain unutilized. Although these two wellheads are spaced out by amere 8 kilometres, they are divided by a river Lonja fault and no hydraulic connection
between the two was established. This paper contains the research for healing, medicinal andenergetic potentials of this unique geothermal wellhead.
Keywords: Geothermal source, Openly overflow, Research-Medical Centre

Energy and the Environment (2016) 295-304

295

BOREHOLE TEMPERATURE DISTRIBUTION DURING THERMALRESPONSE TEST/XND%REDQ9ODGLPLU6ROGR0DUNR0DQGLüUniversity of Zagreb, Faculty of Mechanical Engineering and Naval Architecture,YDQD/XþLüD+5-10000 Zagreb, Croatia;
e-mail: luka.boban@fsb.hr
Abstract: Study on shallow geothermal energy in Republic of Croatia as part of EU funded
project “Research and promotion of shallow geothermal potential in Croatia” included drillingof exploratory borehole on location of Faculty of Mechanical Engineering and Naval
Architecture, University of Zagreb.
Grouted 130 m deep borehole incorporates double U pipe heat exchanger equipped with fiber
optic cables for distributed temperature sensing. Separate optic cables are placed inside one U
pipe of heat exchanger and in borehole grouting. Such configuration of measuring equipment
enables monitoring of vertical temperature distribution along the borehole heat exchanger andhorizontal temperature distribution inside the borehole cross section.
Borehole heat exchanger was subjected to the distributed thermal response test consisting of
three stages to determine thermal parameters relevant for the design of ground coupled heatpump system. First measurements are carried out without water circulation to determine
undisturbed ground temperature profile, second stage involved 120 hour long heating of theunderground with constant heat flux and in the last phase of the test, thermal recovery of theborehole was observed for two weeks.
Analytical interpretation of thermal response test results yielded effective thermal conductivity of
1.66 W/(m K) and effective borehole thermal resistance of 0.072 (m K)/W.
Vertical temperature profiles of undisturbed and disturbed ground are presented and influenceof fluid temperature distribution on a results of thermal response test discussed.
Key words: Distributed thermal response test, shallow geothermal energy, ground thermal
parameters
1. INTRODUCTION
Prospect of ground coupled heat pump systems has been recognized in recent decades and theirapplication in commercial and residential buildings accumulated to the approximately 50 GW ofheating capacity installed worldwide [1,2]. The use of renewable shallow geothermal energy bymeans of heat pumps results in thermally efficient and environmentally friendly systems. Most
commonly, borehole heat exchangers (BHE) are used to exchange heat with the underground andtheir design can vary in depth, diameter and pipe geometry [3–5].
Designing efficient and reliable system requires knowledge of thermophysical properties of theground surrounding the heat exchanger as they play vital role in heat transfer of BHE [6]. Most
relevant design parameters include thermal conductivity, undisturbed ground temperature of theunderground and borehole thermal resistance affected by the BHE design and installation.
Mentioned effective parameters are often determined by Thermal Response Test (TRT) [7].
During TRT borehole heat exchanger is subjected to the constant heat flux while temperaturechanges of circulating fluid are recorded. Recorded temperatures are used to obtain relevant
thermal parameters, commonly by application of analytical infinite line source model. The line

296

/%REDQ96ROGR00DQGLü: Borehole temperature distribution during…

source model, based on Kelvin line source equation, assumes several simplifications such as
ground to be homogenous medium, only radial conductive heat transfer and constant heat flux
per unit length of BHE. More details about standard TRT procedure and its development can befound in [8,9].
Heat transfer process in the underground can differ from homogenous medium assumption due
to subsurface heterogeneity or groundwater flow. Therefore, different methods of distributed
temperature measurements along the BHE were introduced as an improvement of conventional
TRT [10–12], one of them being fiber optic cables [5].
Fiber optic technology for distributed temperature sensing was utilized in scope of study on
shallow geothermal energy in Republic of Croatia. As part of EU funded project “Research andpromotion of shallow geothermal potential in Croatia” team of researchers at the University ofZagreb, Faculty of Mechanical Engineering, in collaboration with the Croatian Geological
Survey, drilled and installed 8 exploratory borehole heat exchangers equipped with fiber optic
cables for application of Distribute Thermal Response Test (DTRT).
One of the boreholes is located on premises of Faculty of Mechanical Engineering and Naval
Architecture, University of Zagreb, and in this paper results obtained on the location arepresented and discussed.
2. METHODOLOGY
2.1. Borehole heat exchanger
Zagreb is located in Pannonian part of Croatia where material with intergranular porosity
dominate and location represents sedimentary cover with coarser-grained sediments
Double polyethylene U-pipe (32x2.9 mm) borehole heat exchangers is installed into 130 m deep
exploratory borehole. The outer diameter of the borehole is 152 mm and the borehole was
grouted by a grout manufactured by Fischer, type GeoSolid 235. The declared thermal
conductivity of grouting material is 2.35 W/(m K) for the mixture density of 1800 kg/m3.
2.3. Distributed Thermal Response Test
Fiber optic DTS technology is based on Raman optical domain reflectometry where introduced
light causes re-emitted Raman scattered light with parts of wavelengths that depend on
temperature. Time delay of arrived backscattered light provides location of temperature reading.
Therefore, ground temperature profile along the borehole heat exchanger can be obtained.
Distributed thermal response test was carried out in three stages. Undisturbed groundtemperature was measured for 120 hours without water circulation. Thus, no heat gains due topump work are present. The second phase of measurement consisted of 120 hour long constantheat flux injection by circulation of heated water. Finally in third stage thermal recovery wasobserved for more than 300 hours.
Multimode 50/125 fiber optic cable was coupled to the AP Sensing Linear Pro Series DTS
instrument. All temperature measurements were carried out with spatial resolution of 2 m and an
integration time of 300 s. Thermal response test was performed with GEOgert 2.0 unit, a two
module system for testing of geothermal probes. As specified by the manufacturer, TRT unit iscapable of measuring supplied heat flux with 1-3% precision. More details of the TRT
configuration and design parameters were reported in a previous paper [13].
2.2. Infinite line source theory
Conductive heat transfer in medium is governed by heat equation:

Energy and the Environment (2016) 295-304

Uc p

wwt

297

(O- )  Qgen

(1)Line-source theory simplifies conduction as one-dimensional process and ground is considered
to be isotropic medium of uniform temperature. Temperature field development around an
instantaneous line-source in an infinite solid was found by Carslaw and Jaeger, where
exponential integral E1 is approximated by the first two expressions of the Taylor series [14].

q f e udur2
4OS ³4Dt u'- (r , t )

r2
q
E1 (
)
4OS
4Dt

º
q ª r2) J »
ln(
4OS «¬ 4Dt
¼

Dt
r2

!5

(2)

Approximation with Taylor series is valid after certain amount of time of the heating phase has
elapsed. For typical boreholes and geological settings condition is met after 5-15 hours.
Effect of borehole heat exchanger thermal resistance, e.g. resistance between fluid in pipes andborehole wall, is taken into consideration by Equation 3.
- f (t ) -b (t )  q  Rb

(3)

Equation 2 applied for borehole wall and combined with Equation 3 can be written in linear
form (Equation 5). When recording circulating fluid temperature and applied heat flux, former
equation can be used to determine thermal conductivity (Ȝ) and borehole thermal resistance (Rb).
q
4Dt(ln( 2 )  J )  qRb
4OSr- f  -0-fk ln(t )  cOq /(4Sk )(4)(5)

Where:- f  -0

Rb

q



1
4SO

(ln(t )  ln(

4D) J )
r2(6)

In conventional TRT fluid temperature is approximated as an average between borehole inlet andoutlet temperatures (Equation 7) or using p-linear method [15,16] that approximates real
borehole temperature profile (Equation 8). Distribute temperature sensing enables use of fluid
temperature that is averaged between all measured points (in this case, every 2 m) (Equation 9).
-f1(-in  -out ) / 2

-f 2

-0 

p ( '-in(7)
p 1

 '-out(1  p )( '-in

p

p 1

)
p

 '-out )

(8)

n

-f 3

¦-

fi

i

n

(9)

Variable heat flux rates can be taken into account with superposition technique [17]. Total heatrate is divided into several pulses and each following pulse is superposed to former ones:q (t )­ q1 , 0  t  t1
°® q 2 , t1  t  t 2
°q , t  t  t
n 1
n
¯ n

(10)

298

/%REDQ96ROGR00DQGLü: Borehole temperature distribution during…

- (r , t )n¦ q q
i

i

i 1

E1 (

r2
)
4D (t  ti1 ) qRb  -0
4OS

(11)

Thermal recovery of the ground can be treated as variable heat pulse and Equation 11 is used toreproduce recovery temperatures.
Final expression of ILS model has three unknown parameters: ground thermal conductivity (Ȝ)
and diffusivity of (Į) and borehole thermal resistance (Rb). If one parameter is estimated, othertwo parameters can be obtained directly by Equation 4. Alternatively, parameter estimation or
curve fitting can be used to simultaneously obtain unknown parameters by minimizing objectivefunction (commonly root mean squared error) [18]:
RMSE

1 n
¦ (-measure,i  -simulated ,i ) 2
n i

(12)

Ground thermal diffusivity is usually estimated based on geological configuration of theunderground and expected borehole thermal resistance can be constrained by calculating theresistance based on BHE geometry [19]. Accuracy of parameters determination can be increased
when recovery temperatures are recorded as monitoring of recovery period provides additional
data to estimate ground thermal conductivity (Ȝ) independently from borehole thermal resistance(Rb) [20].
3. RESULTS AND DISCUSSION
Undisturbed ground temperature profile obtained in first phase of DTRT is presented on Figure
1. Temperatures were recorded every 20 minutes between April 3rd and April 8th. Temperature ofupper sections of underground are result of grounds damping of conditions on surface, e.g.
rainfall, solar radiation, air temperature. The amplitude of seasonal effect decreases with depth
and the effect becomes negligible for Zagreb location between 10 and 12 m [21]. Temperature at
the mentioned depth is 14.70 ϶C. Due to existing heat sources on ground surface characteristic
for urban areas temperature profile deviates from linear trend and has local minimum of 13.52
϶C at the depth of 40 m [22]. Below that depth influence of geothermal gradient has dominant
effect and temperature linearly increases by 0.037 ϶C/m.
On the right side disturbed temperature profiles are presented with two temperature profile
approximations (Equations 7 and 8).

Figure 1 Undisturbed and disturbed ground temperature profile (5th and 10th hour)Energy and the Environment (2016) 295-304

299

Heating and recovery phase are presented on the Figure 2. Average heat flux of 56.32 W/m was
supplied to the ground. Black line is real average fluid temperature while green line istemperature recorded by optic cable installed on the borehole wall, although exact position
cannot be determined after the heat exchanger installation. Figure 2 clearly shows thattemperature evolution in recovery phase is affected only by ground thermal parameters as there
is no temperature difference between fluid and borehole wall, while in heating phase borehole
thermal resistance is additional influential parameter. Use of recorded temperature difference forcalculation of borehole thermal resistance with Equation 3 is limited by uncertainty in exact
location of cable outside the U pipe and fact that temperature distribution on the borehole wall is
not uniform [4].

Figure 2 Supplied heat flux and average temperatures during heating and recovery phase of DTRT

Due to the transient nature of heat transfer in beginning of the DTRT, first 12 hours are
discarded according to limitations of equation 2. Additionally, due to noticeable heat flux
fluctuations data in heating phase after 85th hour was omitted from data for linear regression.
a)b)

Figure 3 (a) Comparison of real average temperature and approximation with p linear and inlet/outlet
average, (b) Temperature vs. ln(t) used for determination of ground thermal properties by equation 6

300/%REDQ96ROGR00DQGLü: Borehole temperature distribution during…

On Figure 3 different average temperatures are presented and error introduced in contrast to thereal average temperature of fluid in BHE. P linear average was used with pї1 based on analysis
made in [15]. In early stage of heating phase, p-linear approximates the real temperature well but
temperature difference increases with test duration. It is important to note that value of pї1 wasrecommended by authors based on the results of numerical simulation and the volumetric flowrate during this DTRT of 0.34 l/s is close to threshold limit for the validity of approximation[23]. Average of inlet and outlet returns higher fluid temperature than real average but withconstant temperature difference.
Plot of fluid temperatures were used for determination of thermal properties for different phasesof DTRT, results are presented in Table 1. Recovery period is observed separately as earlyrecovery period from 165th to 235th hour and late period from 285th to 500th hour.
Thermal conductivity obtained in recovery periods was used to recalculate borehole thermal
resistance using temperature curve for real average temperature. Inlet/outlet average and real
average temperature profile exhibit close results in contrast to p linear average. Borehole thermal
resistance obtained by latter is smaller than one obtained with inlet/outlet average, similar
conclusions are reported elsewhere in literature [15,23], as is the thermal conductivity. Results
obtained in recovery period overestimate parameters obtained in heating phase [18]. Early andlate recovery periods results indicate that overestimation increases with time. All borehole
resistances are larger than one calculated with equation 4 from measured data presented on
Figure 2. Mean value of 0.061 (m K)/W can be only used as constrain value as the real thermal
resistance can only be equal or larger due to uncertainty in precise location of cable.
Table 1 Obtained properties for different DTRT phases by direct method

RecoveryHeatingHeatingHeating
periodphase (‫ׇ‬f1) phase (‫ׇ‬f2) phase (‫ׇ‬f3)(1st)
Thermal conductivity
1.6545W/(m K)
Borehole
thermalresistance
0.0713(m K)/W

Recovery
period(2nd)

1.62251.6611

1.72761.75120.06780.07200.07900.0815Governing equation of ILS model was used with sets of data presented in Table 1 to model thetemperature response and compare to measured data. RMSE was calculated separately forheating phase, both recovery periods and cumulative for all data except first 12 hours. Figure 4a) represents percentage difference of RMSE for each set of properties versus minimum RSME
achieved for the evaluation period. Value zero represent set of parameters with best match forobserved period. As expected, in heating phase RMSE is zero for real average temperature and isclosely matched by the p linear average although parameters obtained by that approximation aresmaller than for real average. This supports the fact that ILS model has multiple set ofparameters that can be obtained as solution [20]. When recovery period is considered, lower
RMSE values are calculated when late period values are used due to influence of transient heattransfer on data of early recovery period. For cumulative data, with first 12 hours omitted, lowest
RMSE value is calculated for real average temperature profile.
All set of parameters presented in Table 1 fall into the low RMSE area presented on Figure 4 b)
where strong positive correlation of thermal conductivity and thermal resistance can be seen andis evident that multiple solutions can satisfy measured data.

Energy and the Environment (2016) 295-304

a)

301

b)

Figure 4 a) RMSE percentage difference for different set of thermal parameters and b) RMSE surface
obtained with various values of thermal conductivity and thermal resistance

4. CONCLUSION
Undisturbed ground temperature, thermal conductivity and borehole thermal resistance are
crucial parameters when shallow geothermal systems are analyzed or designed. For large BHE
fields, application of thermal response test on location is mandatory. Most commonly used ILS
model is simple and robust but it is used to obtain multiple parameters from one governing
equation. Additionally, direct method provides only one set of thermal parameters when it isobvious that multiple set of solutions exist. Additional constraints can be introduced by means ofrecovery period observation, more sophisticated fluid average temperature determination,
geological data form the site, use of analytical expressions to calculate certain parameters, likeborehole thermal resistance, etc.
Improvement of the data obtained can be achieved by means of advanced thermal response test
procedures, including application of fiber optic cables, but the implementation of such methods
must be justified as they are more time and resource demanding. Additional data enables
calculation of geothermal gradient and vertical temperature profiles.
When RSME is observed, most reliable results are acquired by the use of real fluid averagetemperature that is measured by fiber optic cable. P linear average follows closely, but values ofboth ground conductivity and thermal resistance are underestimated in comparison to trueaverage.
Alternative approach would be use of numerical model and parameter estimation procedure that
require sensitivity analysis of estimated parameters and more detail input data, especiallyregarding grouting properties. Such approach is planned in future as continuation of research in
the field of shallow geothermal utilization.
ACKNOWLEDGEMENTS
This research was conducted in the scope of the EU funded IPA project titled "Research and thePromotion of the Use of Shallow Geothermal Potential in Croatia" (Grant no.
IPA2007/HR/16IPO/001-040506).

302/%REDQ96ROGR00DQGLü: Borehole temperature distribution during…

5. LIST OF SYMBOLSc- line intercept
cp- specific heat capacity (J/(kg K))k- line slopeq- heat injection rate per length of the borehole (W/m)
r- radial distance (m)Rb- borehole thermal resistance ((m K)/W)t- time (s)u- exponential function argument in exponential integral- volumetric flow rate (m3/s)v
Greek symbols
ɲ- ground thermal diffusivity (m2/s)

-b
-f
-o
O
U
J

- temperature at the borehole wall (°C)
- fluid temperature (°C)
- undisturbed ground temperature (°C)- ground thermal conductivity (W/(m K))- fluid density (kg/m3)- Eulers consWDQW §

Abbreviations
BHE- borehole heat exchanger

DTRT - distributed thermal response test
DTS

- distributed temperature sensing

ILS- infinite line source

RMSE – root mean square error
REFERENCES[1] Yang H, Cui P, Fang Z: Vertical-borehole ground-coupled heat pumps: A review of models
and systems, Appl. Energy, 87 (2010), 16–27.
[2] Lund JW, Boyd TL: Direct utilization of geothermal energy 2015 worldwide review,
Geothermics, 60 (2016), 66–93.
[3] Luo J, Rohn J, Bayer M, Priess A: Thermal efficiency comparison of borehole heatexchangers with different drillhole diameters, Energies, 6 (2013), 4187–206.
[4] Esen H, Inalli M, Esen Y: Temperature distributions in boreholes of a vertical groundcoupled heat pump system, Renew. Energy., 34 (2009), 2672–9.
[5] Acuña J, Mogensen P, Palm B: Distributed thermal response tests on a multi-pipe coaxial
borehole heat exchanger, HVAC&R Res, 17 (2011), 1012–29.
[6] Luo J, Rohn J, Xiang W, Bertermann D, Blum P: A review of ground investigations forground source heat pump (GSHP) systems, Energy Build., 117 (2016), 160–75.

Energy and the Environment (2016) 295-304

303[7] Sanner B, Hellström G, Spitler JD, Gehlin S: More than 15 years of mobile Thermal
Response Test – a summary of experiences and prospects, European Geothermal Congress 2013,
Pisa, Italy, 2013[8] Zhang C, Guo Z, Liu Y, Cong X, Peng D: A review on thermal response test of groundcoupled heat pump systems, Renew. Sustain. Energy Rev., 40 (2014), 851–67.
[9] Spitler JD, Gehlin SE: Thermal response testing for ground source heat pump systems—An
historical review, Renew. Sustain. Energy Rev., 50 (2015), 1125–37.
[10] Fujii H, Okubo H, Nishi K, Itoi R, Ohyama K, Shibata K: An improved thermal response
test for U-tube ground heat exchanger based on optical fiber thermometers, Geothermics. 38(2009), 399–406.
[11] Raymond J, Lamarche L, Malo M: Field demonstration of a first thermal response test witha low power source, Appl. Energy., 147 (2015), 30–9.
[12] Martos J, Montero Á, Torres J, Soret J, Martínez G, García-Olcina R: Novel wireless sensor
system for dynamic characterization of borehole heat exchangers, Sensors, 11 (2011), 7082–94.
[13] Soldo V, Borovic S, Leposa L, Boban L: Comparison of different methods for groundthermal properties determination in a clastic sedimentary environment, Geothermics, 61 (2016),
1–11.
[14] Carslaw HS, Jaeger JC: Conduction of Heat in Solids, Second edition, Clarendon Press,
Oxford; 1959.
[15] Marcotte D, Pasquier P: On the estimation of thermal resistance in borehole thermal
conductivity test, Renew. Energy., 33 (2008), 2407–15.
[16] Du C, Chen Y: An average fluid temperature to estimate borehole thermal resistance ofground heat exchanger, Renew. Energy., 36 (2011), 1880–5.
[17] Monzó P, Acuña J, Palm B: Analysis of the influence of the heat power rate variations indifferent phases of a Distributed Thermal Response Test, 12th Interantional Conference on
Energy Storage. Lleida, Spain, 2012.
[18] Christodoulides P, Florides G, Pouloupatis P: A practical method for computing the thermal
properties of a Ground Heat Exchanger, Renew. Energy., 94 (2016), 81–9.
[19] Lamarche L, Kajl S, Beauchamp B: A review of methods to evaluate borehole thermal
resistances in geothermal heat-pump systems, Geothermics, 39 (2010), 187–200.
[20] Raymond J, Therrien R, Gosselin L, Lefebvre R: A Review of Thermal Response Test
Analysis Using Pumping Test Concepts, Ground Water, 49 (2011), 932–45.
[21] Tomislav K, Domagoj V: Determining Undisturbed Ground Temperature As Part of
Shallow Geothermal Resources Assessment, Rudarski Zbornik, 2 (2010), 2-27.
[22] Rybach L, Bayer P, Rivera JA, Blum P: Influence factors in the depth domain of boreholeheat exchangers – global warming and urban heating, European Geothermal Congress 2016,
Strasbourg, France

304/%REDQ96ROGR00DQGLü: Borehole temperature distribution during…

[23] Beier R a. Vertical temperature profile in ground heat exchanger during in-situ test, Renew.
Energy, 36 (2011), 1578–87.

RAZDIOBA TEMPERATURA U BUŠOTINI TIJEKOM ISPITIVANJATOPLINSKOG ODZIVA TLASažetak: Tijekom istraživanja plitke geotermalne energije u sklopu europskog projekta„Istraživanje i promocija plitkih geotermalnih potencijala u Hrvatskoj” izvedena je istražna
EXãRWLQDQDORNDFLML)DNXOWHWDVWURMDUVWYDLEURGRJUDGQMH6YHXþLOLãWDX=DJUHEXU EXãRWLQLGXELQHPXJUDÿHQMHL]PMHQMLYDþWRSOLQHXREOLNXGYRVWUXNH8FLMHYLWHRSUHPOMHQNDEHOLPDVRSWLþNLPYODNQLPD]DGLVWULEXLUDQRPMHUHQMHWHPSHUDWXUH1HRYLVQLRSWLþNLNDEHOLSRVWDYOMHQLVXXMHGQRMRG8FLMHYLL]PMHQMLYDþDWHXLVSXQLEXãRWLQH. Takav postav mjerne
RSUHPHRPRJXüXMHPMHUHQMHYHUWLNDOQHUD]GLREHWHPSHUDWXUDGXåEXãRWLQVNRJL]PMHQMLYDþD
topline te horizontalne razdiobe temperatura po presjeku bušotine.
%XãRWLQVNLL]PMHQMLYDþWRSOLQHSRGYUJQXWMHLVSLWLYDQMXGLVWULEXLUDQRJWRSOLQVNog odziva tla u tri
ID]HVFLOMHPRGUHÿLYDQMDWRSOLQVNLKVYRMVWDYDWODELWQLK]DL]YHGEXVXVWDYDGL]DOLFHWRSOLQH
povezane s tlom. U prvoj fazi provedena su mjerenja bez cirkulacije vode kako bi se odredio
SURILOWHPSHUDWXUHWRSOLQVNLQHSRUHPHüHQRJWODGUXJDID]DXNOMXþXMHVDWLGXJSHULRG
zagrijavanja tla konstantnim toplinskim tokom, dok je u posljednjoj fazi toplinski oporavak
bušotine promatran tijekom dva tjedna.
$QDOLWLþNRPLQWHUSUHWDFLMRPUH]XOWDWDLVSLWLYDQMDWRSOLQVNRJRG]LYDWODGRELYHQDje efektivna
toplinska vodljivost od 1,74 W/(m K) te efektivni toplinski otpor bušotine od 0,075 (m K)/W.
8UDGXMHSULND]DQDYHUWLNDOQDUD]GLREDWRSOLQVNLKVYRMVWDYDRGUHÿHQDL]WHPSHUDWXUQHSRUHPHüHQRJWODXID]LJULMDQMDLID]LRSRUDYNDEXãRWLQHWHDQDliziran utjecaj razdiobe
temperature u bušotini na rezultate ispitivanja toplinskog odziva tla.
.OMXþQHULMHþLdistribuirano ispitivanje toplinskog odziva, plitka geotermalna energija, toplinska
svojstva tla

Energy and the Environment (2016) 305-314

305

TRANSIENT THERMAL RESPONSE ANALYSIS OF OPAQUEBUILDING ENVELOPES FOR ENERGY EFFICIENT CONSTRUCTION
0LWMD.RãLU 5RPDQ.XQLþ%ODå+XGRELYQLN/XND3DMHN
University of Ljubljana, Faculty of Civil and Geodetic Engineering, Chair for Buildings
and Constructional Complexes, Jamova cesta 2, 1000 Ljubljana, Slovenia*tel: +386 1 4768 609 fax: +386 1 4250 688 e-mail: mitja.kosir@kske.fgg.uni-lj.si
Abstract: In recent decades the construction industry in the EU has been focused on the
improvement of energy performance of buildings. The principal focus is on the reduction oftransmission and ventilation losses of a building, where transmission losses are predominantly
reduced by thermally insulating the building envelope. Therefore, the U value of a building
envelope component is the basic parameter describing its thermal response. Nonetheless, the Uvalue does not represent an accurate thermal response of a building’s envelope due to stationary
boundary conditions used in the calculation. In order to realistically represent the thermal
response of building envelopes a transient thermal response should be calculated using real
weather data for a selected location.
In the presented paper a finite element model (FEM) approach to the study of building
envelopes’ thermal response is presented. The model is composed of a 2D building envelope
section (e.g. external wall) to external and internal dynamic boundary conditions. The transient
behaviour of five typical external walls was studied during summer time conditions for thelocation of Ljubljana. The observed parameters were the 2D thermal field as well as indoor
temperature fluctuations. The results of the executed analysis represent a new approach to thestudy of envelope thermal performance, as walls with equivalent U values but different
composition (e.g. thermal inertia) are characterized by different thermal behaviour,
consequentially influencing indoor user comfort and energy performance of buildings.
Key words: building envelope, transient thermal analysis, summer time thermal response,
thermal inertia
1. INTRODUCTION
Indoor environmental quality in respect of energy consumption of buildings has become a hugeconcern when speaking of summer time overheating of buildings. It is caused by high external
air temperatures, influence of solar radiation on transparent and opaque elements of the building
envelope and internal heat sources. The climate in most parts of continental Europe is favourable
to make overheating of buildings completely manageable by the proper design and application ofpassive solar architecture features (e.g. shading, night-time ventilation, high thermal mass, etc.).
Therefore, it is not very common in this region to use mechanical cooling devices in residentialbuildings, which means that the majority of residential buildings in temperate climate zone are in
free-run mode during summer. In view of that and with consideration of ensuring comfortableindoor environment it is essential to understand and predict the thermal response of buildings
and their envelopes. Nevertheless, the statistical data of the European Union [1] show that in2012 approximately 19% of the total population lived in dwellings not comfortably cool during
summer time. The number is a bit lower for Slovenia (17%), though overheating is much more
apparent in the cities than in the rural regions [1]. The relatively large share of dwellings being

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too hot during summer is probably the result of interconnectedness of multiple factors, one ofthem being unquestionably inappropriate building design, not suited for the environmental
conditions of a specific location. Although the improvement of indoor environmental conditions
in residential and more commonly in commercial buildings can be resolved by using mechanicalcooling devices, a bioclimatic approach, focusing on proper design, is much more energy
efficient [2]. The best passive strategies for free-run buildings during cooling season are shadingof transparent elements and night-time ventilation in conjunction with high thermal mass of thebuilding, which is especially effective in climates characterized by high diurnal temperaturefluctuations (i.e. temperate climate and hot dry climate) [2, 3]. However, it has to be emphasizedthat the overall performance of buildings is closely related to the thermal mass of the opaqueenvelope. In general it has been shown that in the field of energy consumption as well as indoor
occupant comfort buildings with lightweight construction (LWC) and the related small thermal
mass underperform compared to those with heavyweight construction (HWC) [4–7].
Nevertheless, a study conducted by Kitek Kuzman et al. [8] showed that a trend in EU's
construction industry is moving towards the application of LWCs, especially in the residential
sector.
In this respect the presented study focuses on the non-stationary thermal performance of opaquebuilding envelopes under realistic climatic conditions in order to study the differences in theperformance among the building envelopes with different thermal masses. This cannot be
achieved by conventional steady state approach [9], where thermal performance of building
envelopes is reduced to only one parameter, the U value. A more complete picture of nonstationary performance of building envelopes can be attained by using the calculation inaccordance to the method specified in the EN ISO 13786 standard [10].This approach describes
the thermal response of building envelope more realistically and is frequently used byresearchers as well as professionals in order to describe the thermal response of envelope
elements by calculating the decrement factor and time lag of the studied elements [10, 11]. In
general, the conclusion of all such studies is that the inclusion of thermal mass as well as the
position of thermal insulation have a profound influence on the thermal response of the envelope
and therefore buildings [4–6]. As a result, it can be concluded that in order to evaluate theinfluence and thermal behaviour of LWC and HWC building envelopes, a non-stationary
analysis has to be executed. However, the majority of recent studies dealing with the nonstationary thermal response of building envelope have been conducted using rather high U values[4, 11, 12]. Therefore, they might not be directly applicable to a typical European situation,
where due to severe EU policy [13] regarding energy performance of buildings the prescribed U
values of building envelope elements are low [14].
The presented issues address the topics with a need of further investigation, as the importanceand influence of opaque building envelope is generally overlooked in present-day building
design. Nonetheless, this issue is essential in regard to the design and performance of energy
efficient and comfortable buildings, in particular if the buildings are in a free-run mode during
summer conditions. Therefore, the main goal of the paper is to evaluate the overall thermal
response of various building envelope construction systems, under realistic Central European(i.e. Ljubljana, Slovenia) climatic conditions. A non-stationary finite element analysis was usedin order to simulate thermal performance during summer conditions for selected external wallsegments. The results of the conducted research should further clarify the importance ofunderstanding the transient thermal behaviour of opaque envelope elements in energy efficientbuildings.

Energy and the Environment (2016) 305-314

307

2. METHODOLOGYThe non-stationary thermal performance of different multi-layer external wall envelope types
was investigated during summer conditions (i.e. cooling season) from June till August. For the
executed analysis the location and climate of Ljubljana, Slovenia (N 46.05°, E 14.51°) wereselected, considering daily fluctuation of dry bulb air temperatures and global solar irradiation.
2.1. Climate
Climate data for the city of Ljubljana were obtained from weather file available on EnergyPlus
web site [15]. Ljubljana as a Central European city has a typical continental climate with slightinfluence of northern Mediterranean climate due to the relative proximity of the Adriatic Sea.
The climatological averages of Ljubljana are comparable to other Central European cities, like
Vienna, Prague and Munich. Therefore, the acquired results can be considered as representative
for the locations with similar climatic characteristics. The meteorological data used in the
numerical simulations are presented in Figure 1.

Figure 1: Climate data for Ljubljana from 1st of July to 10th of August.

2.2. Model
The governing equations, required for the calculation of non-stationary heat flow inside multilayered wall, are derived from the local energy conservation equation [16, 17]. A weak form ofgoverning differential equation, required for the finite element method, can be written for
arbitrary body B and its boundary %, as presented in Hudobivnik et al. [18] and shown inEquation 1.
,(1)

where Ȝ is thermal conductivity (W/mK), ȡ density (kg/m3) and c specific heat capacity (J/kgK)of chosen material. Q is internal heat source (W/m3). Surface heat flow q (W/m2) and convective
heat flow h (T–T) can be prescribed on boundary % of body B. h is convective heat-transfer
coefficient (W/m2K) and T ambient temperature (°C). Finite element code was derived using
automatic code generation system AceGen [19] and computer algebra system Mathematica [20].

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The numerical model was solved using AceFEM [19] software tool. The simulations were
performed with constant time step of ǻt = 1 h.

Figure 2: Model description.

The base for designing a 2D numerical model [18] was a model of 1 m2 segment of exterior wall,with a corresponding adjacent interior volume, considering its properties to be proportional to a
generic residential building. The 2D numerical model of the described representative 1 m2 wall
section is presented in Figure 2. The wall model consists of different layers of construction
materials which form a building envelope. The material properties were obtained in Slovenian
Technical guidelines [21]. On the external side of the building envelope section, ambient
temperature is defined as a convective boundary condition. External surface of the wall is
additionally exposed to the radiative heat gains (i.e. solar radiation in the plane of the envelope
element) and radiative heat losses to the environment. On the interior side, an internal heatsource (i.e. occupants and appliances) is prescribed, in accordance with standard EN ISO 13790[22] for residential buildings. Air exchange of internal air with external is considered as 0.7 ACH
and is constant throughout the simulation period.
The wall in Figure 2 is modelled either as a filigree construction or as a solid construction.
Various LWC and HWC wall types were selected for further analyses; these are presented inTable 1. As a representative of typical lightweight envelope systems, a wall used in timber
framed buildings (i.e. filigree construction) was selected (labelled as LWC). Typically such wallconstruction consists of an external thermal insulation and additional thermal insulation between
elements of the load bearing construction. The interior and exterior surfaces are finished withappropriate materials, while a construction board (e.g. OSB board) is placed between the twolayers of thermal insulation. For thermally insulated HWC envelope systems a typical structure
is composed of load bearing layer with thermal insulation placed on the exterior (HBE) or interior(HBI) surface. As in the case with LWC, the wall assembly is finished with appropriatematerials. Additional example of thermally insulated solid construction wall assembly utilizing
massive cross-laminated timber wall (X-LAM) was included in the study. During the last
decades such envelope elements are becoming more common in construction of prefabricatedbuildings in Central Europe. Since historical buildings in the Central European as well as in the
Mediterranean areas used to be usually executed with very thick massive walls, made of brick,stone or mix of both, we included two such examples (STONE and HB) in the study. We wereparticularly interested whether the lack of thermal insulation is compensated by larger total
thermal capacity of walls when they are used in buildings that are not actively cooled. Eachbuilding envelope was, unless otherwise specified, insulated with thermal insulation to have a U

Energy and the Environment (2016) 305-314

309

value of 0.28 W/m2K, as prescribed by Slovenian legislation [21]. The latter does not apply to
STONE and HB constructions, which are not thermally insulated; their corresponding U values
are presented in Table 1.
Table 1: Chosen wall construction systems.
Construction

Label

Thickness[mm]

U value[W/m2K]

Thermalcapacity[kJ/m2K]

Very thick massive stone wall w/o thermal insulation

STONE

530

2.17

980

Hollow brick wall w/o thermal insulation

HB

340

1.88

466

Hollow brick wall w/ external thermal insulation

HBE

443

0.28

468

HBI

443

0.28

468

Cross-laminated timber wall w/ external thermal insulation

X-LAM

225

0.28

117

Lightweight timber framed wall w/ external thermal insulation

LWC

219

0.28

102

Hollow brick wall w/ internal thermal insulation

3. RESULTS
The results of the analysis of the described light and heavy construction envelope systems arepresented in the following section.

Figure 3: Comparison of external temperature Text and indoor air temperature T of selected wall systems (Table 1)
from 1st of July to 10th of August. The indicated period (gray area) from 5th to 10th of August is presented in greater
detail on Figure 4.

The maximum external environmental temperature of 33.4 °C was reached on 31st of July, while
the lowest temperature during the selected time period was 10.0 °C, identified on 14th of July.
The difference in performance between the analysed construction systems can be noted in Figure
3, where indoor air temperatures of all analysed construction systems seem to slightly follow theexternal temperatures, though they never drop below 20 °C.

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The highest average daily indoor temperature TLWC = 29.7 °C is reached with LWC system,
while the maximum temperatures in general occur around 22:33 in the evening. Similar
behaviour can be identified in the case of X-LAM and HBI constructions, where the maximal
reached average daily temperatures are TX-LAM = 29.5 °C (22:31) and THBI = 29.6 °C (23:04),
respectively. Although the HBI construction has the same thermal capacity as HBE (Table 1), therecorded average indoor temperatures (THBE = 28.2 °C, 22:31) of the latter are much lower as aresult of internally positioned thermal mass.
Surprisingly, the lowest identified average daily indoor temperatures are for the thermallyuninsulated constructions HB and STONE, where in the case with HB construction averageindoor temperatures reached only THB = 27.5 °C (22:52), while in the STONE case with a
traditional massive stone construction the average indoor air temperatures are the lowest (TSTONE= 27.2 °C) with an occurrence at around 23:02. Thus, in the conducted simulations STONE wall
exhibits overall the best performance during the studied period. Its average daily indoor air
temperature is the lowest and the average diurnal fluctuations are also low (ǻ7STONE = 0.73 K).
The STONE construction is followed by the HB wall, where average indoor temperatures are
low although the average diurnal temperature fluctuations are relatively high ǻ7HB = 1.73 K.
Similar, in the cases of LWC, X-LAM and HBI constructions, the indoor air temperaturefluctuations are about 2- to 3-times (i.e. ǻ7LWC = 1.98 K, ǻ7X-LAM = 1.71 K, ǻ7HBI = 1.25 K)
higher than in the case of STONE. If the thermally insulated constructions are compared, the by
far best performance is identified in the case of HBE, where the thermal mass on the internal side
can be activated while the external thermal insulation attenuates the temperature fluctuations
resulting in average diurnal fluctuations of ǻ7HBE = 0.90 K. (Figure 4).

Figure 4: Comparison of indoor air temperature T of selected wall systems (Table 1) from 5th to 10th of August.

According to the results of the executed study, the envelope systems can be divided into
distinctive groups. The first group is comprised of uninsulated thick massive walls such as
STONE and HB wall. The thermal stability of these wall types is the highest, due to their highthermal capacity, since the excess heat is accumulated inside the massive envelope. This resultsin the lowest average daily indoor air temperatures in comparison to the other analysedEnergy and the Environment (2016) 305-314

311

constructions (Figures 3 and 4). Similar can be observed from surface heat flow, since suchenvelope systems exhibit the largest heat flow into the wall during daytime and the lowest during
night time, when the role is reversed and the stored heat is released into the interior and exterior(Figure 5). The influence of exterior heat gains and losses which are not reduced due to the lackof thermal insulation is also apparent. Consequently, the heat is accumulating in the massive
envelope as a result of heat gains from both sides. Therefore, the mean indoor air temperatureslowly increases towards the average wall surface temperature. In addition, it can be seen in
Figure 4 that STONE and HB constructions also have the fastest reaction to the change ofexternal environmental conditions after 7th of August.

Figure 5: Comparison of thermal flux qT,X of selected envelope systems (Table 1) with constant ventilation from 5th
to 10th of August. Negative values on the diagram represent the time when the heat flows into the wall.

The second group of envelope systems are thermally insulated constructions HBE, HBI, X-LAM
and LWC, which in general take longer period to cool down and the heat flow through the wall is
lower, when external temperatures fall (Figures 4 and 5). Unlike externally insulated HBE
construction, HBI, X-LAM and LWC have similar thermal response. HBI envelope is incapableof storing excess internally generated thermal energy since the internally applied thermal
insulation reduces the interior heat flow into the wall, resulting in higher interior temperatures(Figures 4 and 5).
A construction with thermal insulation on the interior side, such as HBI, behaves much likelightweight envelopes, such as LWC or X-LAM, which lack thermal mass. All of the threeenvelopes have similar thermal responses, although the total thermal capacity of HBI is 4 times
larger in comparison to LWC or X-LAM (Table 1). Therefore, the choice of material, even for
example the thick massive one, on the external side of thermal insulation has almost no effect on
the interior temperatures. Nevertheless, such envelope systems can be quickly actively or
passively cooled when required and if the outside temperature conditions are favourable [18]. As
evident in Figure 4, such envelopes respond faster to the environmental changes than HBE.
However, the response to change of external temperatures in the cases of HBI, LWC and X-LAM
is still slower than in the case of STONE or uninsulated HB, which can be in some cases
positive, while in others negative. In general it can be concluded that due to high average daily

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indoor temperatures, high diurnal fluctuations and quick thermal response, the lightweight timber
construction (LWC) has the overall worst performance, which is mainly caused by the total lackof thermal inertia.
4. CONCLUSION
The understanding of summer time thermal response of buildings is very important, since themajority of legislation and design strategies are particularly focused on the interaction ofbuilding and environment in heating season (i.e. winter time). In addition, the overall thermal
response of opaque building envelope is mostly determined only by the thermal analysis in thestationary state and the corresponding U value of constructions. However, thermal transmittanceis not the only characteristic that should be taken into consideration, especially in summer time,
when thermal response of buildings in free-run mode is crucially influenced by the transient
thermal response. Thus, the presented approach to building envelope analysis demonstrates theimportance of understanding the non-stationary thermal response of different construction types,
specifically by means of thermal mass. To summarise, the use of high thermal mass with apossibility of its activation is highly appreciated in summer time, when high external
temperatures are reached, while the U value of construction is mostly irrelevant. This wasshowed on an example of a very thick thermally uninsulated massive stone wall construction(STONE), traditionally used in historical buildings of the Central European and Mediterranean
areas. The STONE wall outperformed all the others when comparing the thermal response(Figures 3 and 4). Since thermal mass can play a significant role in summer time thermal
response, a thoughtful approach to building applications is necessary to ensure thermally
comfortable living conditions in buildings, especially in non-mechanically cooled ones. This isof particular interest due to a growing trend in construction industry where lightweight envelopes(LWC and X-LAM) are preferred, especially in the construction of residential buildings. Even
though the overall thermal response of a building is a combination of multiple influences (e.g.
orientation, building shape, window to wall ratio and the envelope composition) [23], the resultsof the executed analysis can serve as initial information for designers when preliminary decisions
regarding envelope composition are conducted.
REFERENCES
[1]
[2]
[3]
[4]
[5]

Eurostat: Share of population living in a dwelling not comfortably cool during summer
time by income quintile and degree of urbanization, accessed: 2016-02-29 (2012). URL:
http://ec.europa.eu/eurostat/data/database?node_code=ilc_hcmp03.
Ramponi R, Angelotti A, Blocken B: Energy saving potential of night ventilation:
Sensitivity to pressure coefficients for different European climates, Applied Energy, 123(2014), 185–195.
Santamouris M, Sfakianaki A, Pavlou K: On the efficiency of night ventilation techniquesapplied to residential buildings, Energy and Buildings, 42 (2010) 8, 1309–1313.
Al-Sanea SA, Zedan M, Al-Hussain S: Effect of thermal mass on performance of insulatedbuilding walls and the concept of energy savings potential, Applied Energy 89 (2012) 1,
430–442, special issue on Thermal Energy Management in the Process Industries.
Zhu L, Hurt R, Correia D, Boehm R: Detailed energy saving performance analyses onthermal mass walls demonstrated in a zero energy house, Energy and Buildings 41 (2009)
3, 303–310.

Energy and the Environment (2016) 305-314

[6]

313

AndjeONRYLü%96WRMDQRYLü%9, Stojiljkoviü00, Janevski JM, Stojanoviü0% Thermal
mass impact on energy performance of a low, medium and heavy mass building in
Belgrade, Thermal Science, 16 (2012) 735, 447–459.
[7] Buonomano A, Montanaro U, Palombo P, Santini S: Dynamic building energy
performance analysis: A new adaptive control strategy for stringent thermohygrometricindoor air requirements, Applied Energy, 163 (2016) 361–386.
[8] Kitek Kuzman M, Grošelj P, Ayrilmis N, Zbašnik-6HQHJDþQLN0Comparison of passive
house construction types using analytic hierarchy process, Energy and Buildings, 64(2013), 258–263.
[9] EN ISO 6946:2008, Building components and building elements – Thermal resistance andthermal transmittance – Calculation method, ISO, Geneva, Switzerland.
[10] EN ISO 13786:2007, Thermal performance of building components – Dynamic thermal
characteristics – Calculation methods, ISO, Geneva, Switzerland.
[11] Al-Sanea SA, Zedan M: Improving thermal performance of building walls by optimizing
insulation layer distribution and thickness for same thermal mass, Applied Energy, 88(2011) 9, 3113–3124.
[12] Gregory K, Moghtaderi B, Sugo H, Page A: Effect of thermal mass on the thermal
performance of various Australian residential constructions systems, Energy and Buildings
40 (2008) 4, 459–465.
[13] EPBD, Directive 2010/31/EU of the European Parliament and of the Council on theenergy performance of buildings (recast), Official Journal of the European Union L153
(2010) 1335.
[14] Kunkel S, Kontonasiou E, Arcipowska A, Mariottini F, Atanasiu B: Indoor Air Quality,
Thermal Comfort and Daylight An analysis of residential building regulations in eight
Member States, Buildings Performance Institute Europe (BPIE), 2015, accessed: 2016-0309. URL http://bpie:eu/publication/indoor-air-quality-thermal-comfort-and-daylight-ananalysis-of-residential-building-regulations-in-8-member-states-2015/.
[15] Energyplus
weather
data,
accessed:
2016-02-15(2016).
URL:
https://energyplus:net/weather-location/europe_wmo_region_6/SVN.
[16] Simo J, Miehe C: Associative coupled thermoplasticity at finite strains: Formulation,
numerical analysis and implementation, Computer Methods in Applied Mechanics andEngineering, 98 (1992) 1, 41–104.
[17] Lewis RW, Nithiarasu P, Seetharamu KN: Fundamentals of the Finite Element Method for
Heat and Fluid Flow, John Wiley & Sons, Ltd, 2004.
[18] +XGRELYQLN%3DMHN/.XQLþ5.RãLU0FEM thermal performance analysis of multilayer external walls during typical summer conditions considering high intensity passive
cooling, Applied Energy, 178 (2016), 363–375.
[19] Korelc J: AceGen and AceFEM user manual, University of Ljubljana, 2011. URL:
http://symech:fgg:uni-lj:si/.
[20] Mathematica version 9, Wolfram Research, Inc., Champaign, Illinois, 2013. URL:
http://www:wolfram:com/mathematica/.
[21] TSG-1-004: 2010, Technical guidelines for efficient energy use in buildings, 1st edition,
Ljubljana, Ministry of the Environment and Spatial Planning, 2010: 106.
[22] EN ISO 13790:2008, Energy performance of buildings Calculation of energy use for spaceheating and cooling, ISO, Geneva, Switzerland.
[23] Košir M, Gostiša T, Kristl Ž: Search for an Optimised Building Envelope Configuration
During Early Design Phase with Regard to the Heating and Cooling Energy Consumption,
CESB 16 – Central Europe Towards Sustainable Buildings: Innovations for Sustainable
Future, Prague, 2016, 805-812.

314

0.RãLU5.XQLþ%+XGRELYQLN/3DMHN: Transient thermal response…

ANALIZA NESTACIONARNOG TOPLINSKOG ODZIVA NEPROZIRNIH
2027$ý$=*5$'(=$(1(5*(76.,8ý,1.29,78*5$'1-8

Sažetak: 8 QHNROLNR SRVOMHGQMLK GHVHWOMHüD JUDÿHYLQD u EU usmjerena je prema poboljšanju
HQHUJHWVNHXþLQNRYLWRVWLX]JUDGDma. Osnovni ciljevi su smanjenje transmisijskih i ventilacijskih
toplinskih gubitaka zgrade, gdje se gubici topline uglavnom smanjuju postavljanjem toplinske
L]RODFLMH QD YDQMVNRP RPRWDþX ]JUDGH 6WRJD VX NRHILFLMHQWL SUROD]D WRSOLQH 8-vrijednosti)
pojediQLK GLMHORYD X RPRWDþX ]JUDGH RVQRYQL SDUDPHWUL NRML RSLVXMX WRSOLQVNL RG]LY ]JUDGH
0HÿXWLP8-YULMHGQRVWLQHPRJXWRþQRRSLVDWLWRSOLQVNLRG]LYRPRWDþD]JUDGH]ERJVWDFLRQDUQLKUXEQLKXYMHWDNRMLVHXVYDMDMXXSURUDþXQLPD6FLOMHPUHDOLVWLþQRJRSLVLYDQMa toplinskog odziva
RPRWDþD SRWUHEQR MH NRULVWLWLVWYDUQH PHWHRURORãNH SRGDWNHQD SURPDWUDQRM ORNDFLML ]JUDGH 8
RYRPUDGXDQDOL]LWRSOLQVNRJRG]LYDRPRWDþD]JUDGHSULVWXSDVHPRGHORPNRQDþQLKHOHPenata0.(  0RGHO VH VDVWRML RG GYRGLPHQ]LMVNLK GLMHORYD X RPRWDþX ]JUDGH QSU YDQMVNL ]LG  VYDQMVNLP L XQXWDUQMLP QHVWDFLRQDUQLP UXEQLP XYMHWLPD 'LQDPLþNR SRQDãDQMH SHW WLSLþQLKvanjskih zidova analizirano je u ljetnim vremenskim uvjetima za lokaciju u Ljubljani. Promatrani
parametri bili su dvodimenzijske raspodjele temperatura i toplinskih tokova, kao i promjene
WHPSHUDWXUD X SURVWRULML 5H]XOWDWL SURYHGHQH DQDOL]H SUHGVWDYOMDMX QRYL SULVWXS SURXþDYDQMXWRSOLQVNLK VYRMVWDYD RPRWDþD ]JUDGH MHU ]LGRYL s ekvivalentnim U-YULMHGQRVWLPD DOL UD]OLþLWLPVDVWDYLPD QSU WRSOLQVND LQHUFLMD  SRND]XMX UD]OLþLWH WRSOLQVNH RG]LYH L NDR WDNYL XWMHþX QD
XQXWDUQMLWRSOLQVNLNRPIRUNRULVQLNDLHQHUJHWVNXXþLQNRYLWRVW]JUDGH.OMXþQHULMHþL RPRWDþ]JUDGHQHVWDFLRQDUQDWHUPRGLQDPLþNDDQDOL]DWRSOLQVNLRG]LYXOMHWQRP
razdoblju, toplinska tromost

Energy and the Environment (2016) 315-326

315

329(û$1-(8ý,1.29,7267,6867$9$-$91(5$69-(7(Leila Luttenberger
Energetski institut Hrvoje Požar, Savska cesta 163, 10000 Zagreb,
lluttenberger@eihp.hr
Lidija Runko Luttenberger
0LQLVWDUVWYR]DãWLWHRNROLãDLSULURGH5DGQLþNDFHVWD=DJUHE
lidija.runkoluttenberger@mzoip.hr
Sažetak: Jedinice lokalne samouprave dužne su pružiti uslugu javne rasvjete na svom
SRGUXþMX D SRX]GDQRVW VXVWDYD MDYQH UDVYMHWH VH RVLJXUDYD RGJRYDUDMXüLP VWDQGDUGomNDNYRüH GRVWXSQRVWL L XþLQNRYLWRVW XVOXJH WH RGJRYDUDMXüLP XSUDYOMDQMHP 8 UDGX VH
DQDOL]LUD ]QDþDM MDYQH UDVYMHWH VD VWDQRYišta SURVWRUQRJ XUHÿHQMD IXQNFLRQDOQRVWL
pouzdanosti i sigurnosti. 7DNRÿHU DQDOL]LUDMX VH RGUHGQLFH SUL SURMHNWLUDQMX XþLQNRYitog
VXVWDYDMDYQHUDVYMHWHNRMDMHYHOLNLSRWURãDþHQHUJLMHREYH]HHQHUJHWVNLXþLQNRYLWRJJUDGDX
primjeni djelotvornih mjera i smanjivanju emisija CO2 uz poseban osvrt na pouzdanost
SRVWRMHüLK VXVWDYD MDYQH UDVYMHWH 'DMH VH SULND] VWDQMD X *UDGX 5LMHFL, uz pregled]DVWXSOMHQRVWL SRMHGLQLK L]YRUD VYMHWORVWL WH QDþLQH XSUDYOMDQMD L UHJXODFLMH 2EUDÿXMX VH
NULWLþQH WRþNH NRMH XWMHþX QD SRX]GDQRVW L VLJXUQRVW VXVWDYD MDYQH UDVYMHWH 5D]PDWUDMX VH
WURãNRYL SRWURãQMH HOHNWULþQH HQHUJLMH L RGUåDYDQMD MDYQH UDVvjete kao i problemi uUD]JUDQLþHQMX YODVQLãWYX MDYQH UDVYMHWH $XWRULFH SUHGODåX SULPMHQX GDQDV SRVWRMHüLKWHKQRORJLMD NDR ãWR MH /(' HOHNWURQLþNH SUHGVSRMQH QDSUDYH L XJUDGQMX IRWRQDSRQVNLKPRGXOD QD UDVYMHWQH VWXSRYH WH SRVHEQR LVWLþH ]QDþDM GREURJ XSravljanja sustava u svrhu
VPDQMHQMD SRWURãQMH HOHNWULþQH HQHUJLMH þLPH VH SRVWLåX HNRORãNL ]DKWMHYL VPDQMHQMD HPLVLMD
CO2 na globalnoj razini. Mišljenje je autorica da je prije svake obnove energetski efikasnim
svjetiljkama potrebno izvršiti mjerenja koja üHELWLXVSRUHGLYDVDPMHUHQMLPDQDNRQXJUDGQMH
i pružati pouzdane podatke o ostvarenoj uštedi. Nadalje, neophodno je iz mješovitih sustava
LQIRUPDFLMVNL L SURJUDPVNL L]GYRMLWL SD REMHGLQLWL VXVWDY MDYQH UDVYMHWH NDNR EL VH RPRJXüLR
nadzor, analiza ulaznih parametara, upravljanje i regulacija vlasniku javne rasvjete odnosno
jedinici lokalne samouprave.
.OMXþQH ULMHþL MDYQD UDVYMHWD HQHUJHWVND XþLQNRYLWRVW SRX]GDQRVW VXVWDYD HQHUJHWVNL
efikasni grad, smanjenje emisija
UVOD
Javna rasvjeta je veliki SRWURãDþ HOHNWULþQH HQHUJLMH WH MH WHPHOMHP VYH YHüLK potreba zaštednjom neophodno SULODJRGLWLLREQRYLWLSRVWRMHüDUDVYMHWQDUMHãHQMDQRYRP tehnologijom
X VYUKX SRYHüDQMD HQHUJHWVNH HILNDVQRVWL WRJ YHOLNRJ SRWURãDþD HOHNWULþQH HQHUJLMH [1].
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aQDOL]LUDMX VH SRGDWFL R SRWURãQML HOHNWULþQH HQHUJLMH L WURãNRYL RGUåDYDQMD VXVWDYD WH
razmatraju mjere s ciljem postizanja cjelovitog energetski efikasnog sustava javne rasvjete.

316

L. Luttenberger, L. Runko Luttenberger: 3RYHüDQMHXþLQNRYLWRVWLVXVWDYDMDYQHUDVYMHWH

1. =1$ý$--$91(5$69-(7(Prvi zapis o javnoj rasvjeti seže daOHNR X  VWROMHüH X âSDQMROVNRP JUDGX &RUGREL WDGD
glavnom gradu Maurskog carstva gdje je navedeno da su lampioni punjeni kerozinomXJUDÿHQL GXå JODYQLK XOLFD JUDGD 3RþHWNRP  VWROMHüD JODYQD VYUKD MDYQH UDVYMHWH ELOD MH
VPDQMHQMH XþHVWDORVWL QHVUHüa na javnim prometnicama, poboljšanje uvjeta prometovanja teSUXåDQMH SRWUHEQH YLGOMLYRVWL YR]DþLPD U Republici Hrvatskoj pod pojmom javne rasvjeteUD]XPLMHYD VH XSUDYOMDQMH L RGUåDYDQMH REMHNDWD L XUHÿDMD VDPH UDVYMHWH ãWR XNOMXþXMH
podmirivanje troškova HOHNWULþQH HQHUJLMH D RGQRVL VH QD UDVYMHWOMDYDQMH MDYQLK SRYUãLQD
javnih cesta koje prolaze kroz naselja te nerazvrstanih cesta. Javna rasvjeta je pod nadzorom
jedinica lokalne samouprave od 1998. godine, dok su Hrvatske autoceste i Hrvatske ceste
nadležni za javnu rasvjetu koja osvjetljavanja autoceste, državne ceste, tunele i mostove kojeRGUåDYDMXLSRGPLUXMXWURãNRYHHOHNWULþQHHQHUJLMH. [2]Kao šta sam naziv kaže „javna rasvjeta“ se tako naziva jer su elementi rasvjete u vlasništvu
RSüLQD LOL JUDdova, pa su JUDGRYL L RSüLQH QDGOHåQL ]D održavanje, izgradnju nove ili
proširenje javne rasvjete,]JUDGQMDMDYQHUDVYMHWHQDSRGUXþMXJUDGRYDLOLRSüLQDILQDQFLUDVH
L] QDPMHQVNLK VUHGVWDYD SURUDþXQD JUDGD RGQRVQR L] NRPXQDOQRJ GRSULQRVD GRN VH
održavanje javne rasvjete financira iz namjenskih sredstava komunalne naknade. Gradovi i
RSüLQHPRUDMXMDPþLWLXVOXJXMDYQHUDVYMHWHQDFLMHORPVYRPWHULWRULMX6XVWDYLMDYQHUDVYMHWH
PRUDMX RVLJXUDWL RGJRYDUDMXüX SRX]GDQRVW VWDQGDUG NDNYRüH GRVWXSQRVW L XþLQNRvitostpružene usluge kako bi se zadovoljile potrebe zajednice u pogledu sigurnosti i kvalitete života
na javnim površinama.
Javna rasvjeta je integralni dio našeg društva koje rasvjetljava okoliš da bi se zadovoljila
potreba ]DSRYHüDQMHVLJXUQRVWLNUHWDQMDSMHãDNDLYR]LODVWYDUDQMHDPELMHQWDOQRJXJRÿDMDQD
javnim prostorima trgova i ulica te akcentiranje arheoloških zdanja i povijesnih znamenitosti.
1HåHOMHQDSRVOMHGLFDMDYQHUDVYMHWHMHSUHNRPMHUQDSRWURãQMDHOHNWULþQHHQHUJLMHLVYMHWORVQRRQHþLãüHQMHRNROLãDXYLGXQHåHOMHQRJUDVYMHWOMDYDQMDQHEDLRPHWDMXüHJVYMHWODLOLEOMHãWHQMD3ULOLNRP SURMHNWLUDQMD L]JUDGQMH L RGUåDYDQMD MDYQH UDVYMHWH PRJXüH MH NRQWUROLUDWL L VX]ELWLQMHQ QHJDWLYDQ XþLQDN SD MH SRWUHEQR MDVQR GHILQLUDWL ãWR MH SRWUHEQR RVYLjetliti, u koje
YULMHPHVNRMRPMDNRãüXLNRMHWHKQRORJLMHWUHEDSULPLMHQLWL [2]7UHQXWQRUDVYMHWDþLQLXNXSQHSRWURãQMHHOHNWULþQHHQHUJLMHSURVMHþQRJHXURSVNRJJUDGD(XURSVNLJUDGRYLLRSüLQHWHåHSRYHüDQMXHQHUJHWVNHHILNDVQRVWLLVPDQMHQMXWURãkova usluga]D VWDQRYQLNH SRVHEQRXGDQDãQMHGREDSURYRÿHQMDVWURJLKPMHUD ãWHGQMH *UDGRYL L RSüLQH
PRJXLPDWLYDåQXXORJXXVPDQMHQMXXJOMLþQRJRWLVND]DKYDOMXüLUD]YRMXYLVRNRLQRYDFLMVNHLHNRORãNH /(' UDVYMHWH (NRORãND UDVYMHWD MH VXVWDY XUHÿDMD SURMHNWLUDQLK QD SURSLVDQL QDþLQ
WDNRGDRPRJXüDYDMXQDMYLãHVWDQGDUGH]DãWLWHRNROLãDLQDMYLãHVLJXUQRVQHVWDQGDUGH
2. 2'5('1,&( 35, 352-(.7,5$1-8 8ý,1.29,72* 6867$9$ -$91(RASVJETE
6YDNL VXVWDY UDVYMHWH SURMHNWLUDQ MH NDNR EL RGJRYDUDR VLJXUQRVQR XWYUÿHQLm standardima
NRMLPD MH FLOM DGHNYDWQRVWXPMHWQHUDVYMHWH6YMHWORWHKQLþNDQRUPD +51 (1  GHILQLUD
sve aspekte projektiranja i ispitivanja javne rasvjete, dok standard EN 13201 sadrži zahtjeve]D L]YHGEX SR WRþQR GHILQLUDQLP NODVDPD .ODVD UDVYMHWH MH karakterizirana skupinom
fotometrijskih zahtjeva koji se odnose QDYL]XDOQHSRWUHEHVXGLRQLNDXSURPHWXQDUD]OLþLWLP
vrstama prometnica. Klase u standardu su relativno opširno definirane pa se mogu
pojednostavljeno definirati tri kategorije vezane uz vrstu prometnica s obzirom na potrebnu

Energy and the Environment (2016) 315-326

317

rasvijetljenost. Prva kategorija odnosi se na prometnice motornih vozila s velikim brzinama
kretanja, gdje su zahtjevi vezani uz svjetlinu rasvijetljene površine (luminacija), koja se
GHILQLUDNDRRGQRVL]PHÿXVYMHWORVQHjakosti rasvijetljene površine i projekcije te površine na
VPMHU ]UDþHQMD D L]UDåDYD VH X FGP2. Druga kategorija odnosi se na mješovite prometnicenamijenjene motornim vozilima s malom brzinom kretanja, prometovanje biciklista i pješakaWH WDNRÿHU LPD ]DKWMHYH YH]DQH X] VYMHWOLQX UDVYLMHWOMHQH SRYUãLQH 7UHüD NDWHJRULMD
REMHGLQMXMH W]Y VSRUH SURPHWQLFH RGQRVQR XUEDQH L SMHãDþNH ]RQH. Zahtjevi se odnose na
UDVYLMHWOMHQRVWRGQRVQRPMHUX]DNROLþLQXVYMHWORVQRJWRNDNRMDSDGDQDMHGLQLþQXSRYUãLQXLizražava se u luksima [lx]. Tri pojednostavljene norme prikazane su u tablici 1. [3]Tablica 1. Zahtjevi za rasvjetu po definiranim klasama iz standarda EN 13201 [3]Vrsta prometnice
6SHFLILþDQVOXþDM
EN 13201 klasa cd/m2 lx
Brze prometnice
ME12/gusti promet i velika brzina
1,5/
gusti promet i normalna brzine ME2ME3a1/
slab promet i kiša
ME4a
0,75
/
rijedak promet
Miješane prometnice
ME2
1,5
/
gusti promet
ME3a1/
normalni promet
ME4a
0,75
/
rijedak promet
Spore prometnice
CE2/20
gusti promet
CE3/
15
normalni promet
CE4/
10
rijedak promet
S2/
10
gusti promet
S4/
5
normalni promet
S6/
2
rijedak promet
Usporedno sa definiranim ]DKWMHYLPDXPMHWQRJVYMHWODVYMHWORWHKQLþNLKVWDQGDUGDL]WDEOLFH
za javne površine, u tablici 2 prikazana je rasvijetljenost izražena u luksima i u tablici 3
prikazana je luminacija za prirodne svjetlosti.
Tablica 2. Rasvijetljenost na primjerima prirodnog izvora svjetlosti [2]Izvor svjetla
Rasvijetljenost
6XQþDQOMHWQLGDQ
60 000 – 100 000 lx
2EODþDQOMHWQLGDQ
20 000 lx
2EODþDQ]LPVNLGDQ
3 000 lx
1DMPUDþQLMLROXMQLREODFLXSRGQH<200 lx
Zora ili zalazak sunca u vedrom danu
400 lxZora ili ]DOD]DNVXQFDXREODþQRPGDQX
40 lx=RUDLOL]DOD]DNVXQFDSRQDMPUDþQLMLPROXMQLPREODFLPDPMHVHþLQD <1 lx
Tablica 3. Luminacija na primjerima prirodnog izvora svjetlosti [2]Izvor svjetla
Luminacija
6XQþDQGDQXSRGQH
1,4*109 cd/m2
Vedro nebo
3000 – 5000 cd/m2
Mjesec2500 cd/m2
1RüQRQHER
10 – 3 cd/m2
6YMHWOR MH PHGLM NRML RPRJXüDYD YL]XDOQX SHUFHSFLMX SD QHGRVWDWDN VYMHWOD VWYDUD RVMHüDMQHVLJXUQRVWL UDGL QHGRVWDWND LQIRUPDFLMD R RNROLQL 6YMHWOR MH HOHNWURPDJQHWVNR ]UDþHQMH X
þRYMHNX  YLGOMLYRP GLMHOX VSHNWUD WH X XOWUDOMXELþDVWRP L LQIUDFUYHQRP SRGUXþMX 2SWLþNR

318

L. Luttenberger, L. Runko Luttenberger: 3RYHüDQMHXþLQNRYLWRVWLVXVWDYDMDYQHUDVYMHWH]UDþHQMHNUHüHVHL]PHÿXYDOQLKGXOMLQDRGQPGRQP6YMHWORVWMHMHGLQLL]YRUERMH
na svijetu, a ne može proizvesti nikakvu boju koje nema u spektru te svjetlosti. Zastupljenost
pojedinih boja može se odrediti analizom pojedinih valnih duljina. [4]7UDGLFLRQDOQR VX VH X MDYQRM UDVYMHWL ]D UDVYMHWOMDYDQMH UD]OLþLWLK JUDÿHYina, kulturnih
spomenika i sl. NRULVWLOHYLVRNRWODþQHQDWULMHYHåDUXOMHNRMHLPDMXORãIDNWRUX]YUDWa boje, kao
što je vidljivo iz slike 1. Takve žarulje isijavaju žutu boju svjetlosti koja umrtvljuje ambijent i
uspavljuje ljude. Ukoliko neki prostor želimo oživjeti, suvremeno rješenje predstavljaju
NYDOLWHWQL ELMHOL L]YRUL VYMHWORVWL HIHNWD VOLþQRJ SULURGQRM VXQþHYRM VYMHWORVWL NDR ãWR VX
PHWDOKDORJHQHLOLIOXRNRPSDNWQHåDUXOMHWH/('VYMHWORVQHGLRGH6SHNWDU]UDþHQMD/('-a je
VSHFLILþDQSUHPDWRPHãWRMHXJODYQRPNRQWLQXLUDQte SRVWRMLRþLWDNRQFHQWUDFLMDSODYHERMH
te svih ostalih boja spektra u relDWLYQR XMHGQDþHQLP NROLþLQDPD 7LMHNRP HYROXFLMH OMXGVNRRNR VH SRVHEQR SULODJRGLOR VSHNWUX ]UDþHQMD VXQFD NRMH SUROD]L NUR] DWPRVIHUX X GRYROMQRM
NROLþLQLLMHGQROLþQRVWLSlika 1. Primjer uzvrata boje LED-DLYLVRNRWODþQLKQDWULMHYLKåDUXOMD [5]3UHPD=DNRQXR]DãWLWLWLRGVYMHWORVQRJRQHþLãüHQMD11L]JRGLQH]DEUDQMHQDMHXSRUDED VYMHWORVQLK VQRSRYD ELOR NDNYH YUVWH LOL REOLND PLUXMXüLK LOL SRNUHWQLK DNR VX
usmjereni prema nebu ili prema površinama koje reflektiraju više od 25% intenziteta premanebu [6]/('LPDNDUDNWHULVWLþDQNXW]UDþHQMDRGVWXSQMHYDLVYLR]UDþHQLOXPHQLLGXX
korisnom smjeru, za razliku od izotropnih izvora svjetlosti gdje samo dio svjetla ide u
NRULVQRPVPMHUXDYHüLGLRL]OD]LRGELMHQRGUHIOHNWRUDQDNojem se dobar dio svjetlosti gubi.
6YHQDYHGHQHNDUDNWHULVWLNHGRYRGHGR]DNOMXþNDGD /('WHKQRORJLMHSUXåD]QDþDMQXXãWHGX
po pitanju energetske efikasnosti u javnoj rasvjeti uz kvalitetno rasvjetljavanje površine.
3. OB9(=( (1(5*(76., 8ý,1.29,72* *5$'$
DJELOTVORNIH MJERA I SMANJIVANJU EMISIJA CO28

PRIMJENI(XURSVND NRPLVLMD MH  VLMHþQMD  SRNUHQXOD LQLFLMDWLYX SRYH]LYDQMD JUDGRQDþHOQLND
energetski osviještenih europskih gradova u trajnu mrežu s ciljem razmjene iskustava u
primjeni djelotvornih mjeUD ]D SREROMãDQMH HQHUJHWVNH XþLQNRYLWRVWL XUEDQLK VUHGLQD L
smanjenju emisija CO2 *UDG 5LMHND MH X] =DJUHE L ,YDQLü *UDG SUYL SULVWXSLR 6SRUD]XPXJUDGRQDþHOQLNDLREYH]DRVHL]PHÿXRVWDORJQDVPDQMHQMHHPLVLMD]DGRJRGLQHX
odnosu na 2008. godinu. [7]Temeljem preuzetih obveza Grad Rijeka je u svibnju 2010. godine usvojio Akcijski plan
HQHUJHWVNRJRGUåLYRJUD]YLWNDXNRMHPXVHDQDOL]LUDSRVWRMHüHVWDQMHHQHUJHWLNHXVHNWRULPDL
podsektorima zgradarstva, prometa i javne rasvjete. Sektor zgradarstva se dijeli na stambene i
MDYQH ]JUDGH X YODVQLãWYX *UDGD 5LMHNH QD VWDPEHQL VHNWRU RGQRVQR NXüDQVWYD L QD ]JUDGH

Energy and the Environment (2016) 315-326

319uslužnih i komercijalnih djelatnosti dok sektor prometa sadrži tri podsektora tj. vozni park u
YODVQLãWYX*UDGDMDYQLSULMHYR]QDSRGUXþMu Grada i osobna i komercijalna vozila. Za izradu
referentnog inventara uzeta je 2008. godina kada je provedena energetska analiza sektora koja
MHSRND]DODGDXMHXVHNWRUX]JUDGDUVWYDPRJXüHSRVWLüLQDMYHüHXãWHGHHOHNWULþQHLWRSOLQVNH
energije. Slijedi sektor prometa i u manjem udjelu sektor javne rasvjete koji predstavlja veliki
SRWHQFLMDO]DHQHUJHWVNHXãWHGHLVPDQMHQMHVYMHWORVQRJRQHþLãüHQMDNRULãWHQMHPVXYUHPHQLKekoloških rješenja.
Prema tadašnjoj referentnoj analizi potrošnja energije u javnoj rasvjeti je 2008. iznosila 8.322
MWh što je odgovaralo emisiji od 2.688 tCO2. Na osnovu provedenih energetskih analiza
sektora u ukupnoj emisiji CO2 za sektor zgradarstva su zabilježene emisije od 200.358 tCO2
ili 53% i u sektoru prometa 175.224 tCO2 ili  ãWD EL ]QDþLOR GD MH XGLR HPLVLMD &22 uukupnoj emisiji od samo 1%.
3UHPDSRGDFLPDSRWURãQMDHOHNWULþQHHQHUJLMHVHSRYHüDODQD0:KãWRMHviše u odnosu na referentnu potrošnju iz 2008. godine. To svakako nije zanemariv podatak ali
VH PRUD LPDWL XYLGXGDMHMDYQDUDVYMHWDVSHFLILþDQVXVWDYNRMLMHSRGORåDQVWDOQRPãLUHQMXUDGL]DGRYROMDYDQMDVWDQGDUGDMDYQLKSRYUãLQDLSURPHWQLFDþLPHVHSURSRUFLRQDOQRSRYHüDYDXNXSQD VQDJD VXVWDYD 9DåQR MH QDSRPHQXWL GD MH X] RGJRYDUDMXüH UHJXOatorne mjere radi
SRYHüDQMD HQHUJHWVNH XþLQNRYLWRVWL X VHNWRUX ]JUDGDUVWYD MHGQRVWDYQLMH SURMHFLUDWL XãWHGHVOLþQR NDR L X VHNWRUX JUDGVNRJ SURPHWD JGMH VH X EXGXüQRVWL LGH SUHPD LVNOMXþLYRP
korištenju ekološki prihvatljivog javnog prijevoza. Procjena ukupnih troškova za provedbu
SUHX]HWLK REYH]D L]QRVL  PLOLMXQ HXUD GR  JRGLQH .DNR VH UDGL R YUOR ]QDþDMQRPL]QRVXRþHNLYDORVHRELOQRNRULãWHQMHEHVSRYUDWQLKVUHGVWDYDL]SURJUDPD(XURSVN e unije ali
se do sada to nije pokazalo kao praksa.
Energetskim pregledom javne rasvjete iz 2013. je ustanovljeno da se od ukupno 14.629
VYMHWLOMNL UD]OLþLWLK WLSRYD L JRGLãWD SULEOLåQR  PRåH VYUVWDWL X QHXþLQNRYLWH 7DNRÿHUsamo 29% svjetiljki je potpuno zasjenjeno prema kriterijima Zakona o svjetlosnomRQHþLãüHQMX 9ODVQLN MDYQH UDVYMHWH RGQRVQR *UDG 5LMHND WUHEDR EL þLP SULMH QDSUDYLWL SODQnjihove izmjene želi li udovoljiti postavljenim kriterijima Europske Unije koje je preuzeo
SRWSLVRP'RVDGDMH]DMDYQXUDVYMHWXLVNRULãWHQRLVNOMXþLYRVXILQDQFLUDQMHRd 40% Fonda za]DãWLWXRNROLãDLHQHUJHWVNXXþLQNRYLWRVW]D]DPMHQXVDPRVYMHWLOMNHRGQRVQRXNXSQLK
svjetiljki javne rasvjete. Za navedeno financiranje trebalo je prethodno obaviti Energetski
SUHJOHGNRMLGDQDVSUHGVWDYOMDRGOLþDQWHPHOM]DGDOMQMHstrukturno planiranje ulaganja u sustav
javne rasvjete. [8]4. TEMELJNI PODACI O SUSTAVU JAVNE RASVJETE U GRADU RIJECIJavna rasvjeta Grada Rijeke sastoji se od 14.629 rasvjetnih tijela, 325,8 km napojnih vodova iQDSRMQLKWRþDND PMHUQLK PMHVWD  WUHQutno instalirana snaga javne rasvjete iznosi 2,299
MW [9]. Javna rasvjeta je u funkciji 4.100 radnih sati, dok SURVMHþQD PMHVHþQD SRWURãQMD
Grada Rijeke iznosi 696.000 kWh.
Iz prikaza na slici 2 razvidna je zastupljenost pojedinih izvora svjetlosti u sustavu javne
UDVYMHWH9LGOMLYRMHGD]QDþDMQRSUHYODGDYDMXYLVRNRWODþQHQDWULMHYHåDUXOMHLGDVXMRãXYLMHN
prisutne živine žarulje koje se godišnje otklanjaju i zamjenjuju drugim izvorima svjetlosti
sredstvima redovnog održavanja.

320

L. Luttenberger, L. Runko Luttenberger: 3RYHüDQMHXþLQNRYLWRVWLVXVWDYDMDYQHUDVYMHWH

Zastupljenost pojedinih izvora svjetlosti (kom)LEDsŝƐŽŬŽƚůĂēŶĂǎŝǀŝŶĂǎĂƌƵůũĂ
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&ůƵŽŬŽŵƉĂŬƚŶĂǎĂƌƵůũĂ
DĞƚĂůŚĂůŽŐĞŶĂǎĂƌƵēũĂƐŬĞƌĂŵŝēŬŝŵŐƌůŽŵ
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Slika 2. Zastupljenost pojedinih izvora svjetlosti u sustavu javne rasvjete Grada Rijeke [8]%URMLOD SRWURãQMH HOHNWULþQH HQHUJLMH SRQHJGMH VX VPMHãWHQD X WUDIRVWDQLFDPD NRMH QLVX X
YODVQLãWYX ORNDOQH VDPRXSUDYH  WH X VDPRVWRMHüH UD]YRGQH RUPDUH NRji su dostupni službi
RGUåDYDQMD8QRYLMLPGLMHORYLPDJUDGDLVNOMXþLYRVXVUHüHPRSRG]HPQXNDEHOVNXPUHåXDX
UXUDOQLPLVWDULMLPGLMHORYLPDQDVHOMDQDOD]LPRYHüXNROLþLQX]UDþQHNDEHOVNHPUHåHXVXVWDYX
javne rasvjete, od kojih dio stupova nije u vlasništvu Grada Rijeke, ali postoji pravo služnosti[9]. 3RVWRML SHW UD]OLþLWLK WLSRYD UD]JUDQLþHQMD YODVQLãWYD *UDGD 5LMHNH L +(3 GLVWULEXFLMH X
sustavu javne rasvjete iako je ponekad vrlo teško odrediti granice nadležnosti što uvelike
RJUDQLþDYDHILNDVQRXSUDYljanje i održavanje.
Upravljanje i regulacija važni su za kvalitetan rad sustava javne rasvjete, a upravljanje jevezano uz logiku rada i signalizaciju odnosno davanje komandi prema regulaciji. Opreme
XSUDYOMDQMDVXPUHåQRWRQIUHNYHQFLMVNLXSUDYOMDþNLXUHÿDML 078 OXNVRPDWLDVWURQRPVNLVDW[9] &LOMHYL XSUDYOMDQMD YDQMVNRP UDVYMHWRP VX SRYHüDQMH VLJXUQRVWL QD XOLFDPD UHGXFLUDQMH
troškova energije, smanjenje emisije CO2, kontrola nad izvršenim održavanjem, preciznijeREUDþXQVNR PMHUHQMH SRYUDWQD LQIRUPacija o stanju rasvjete, fleksibilnost na podešavanju
VYMHWORVQLKUD]LQDWHEROMDXVOXJDJUDÿDQLPDNRULVQLFLPD
5HJXODFLMDVHRGQRVLQDSURPMHQXIL]LNDOQLKYHOLþLQDNDRãWRVXQDSRQVWUXMDLIUHNYHQFLMDWH
UD]OLþLWD XNOMXþLYDQMD L LVNOMXþLYDQMD 7LSLþDn primjer opreme regulacije su sklopnik,
prigušnica s dva izlaza i autotransformator. 5HJXOLUDQL UHåLP UDGD NRULVWL VH LVNOMXþLYR NRGYLVRNRWODþQLKQDWULMHYLKL]YRUDVvjetlosti, a u reduciranom režimu radi 8,5% svjetiljki iz
VXVWDYDMDYQHUDVYMHWH9HüLQDSUHGVSRMQLKQDSUDYDMHNRQYHQFLRQDOQHL]YHGEHWHMHVXVWDY]DUHJXODFLMX SULVXWDQ QD PDQMHP GMHOX ORNDFLMD 9LVRNRWODþQH QDWULMHYH åDUXOMH PRJX UDGLWL V
50% smanjenim nazivnim svjetlosnim tokom, a potrošnja energije se uz to smanji za 35% [8].
Uvjet je za to da se start uvijek izvede s punom nazivnom snagom izvora svjetlosti. Ako izvor
VYMHWORVWLSRþQHRGPDKQDNRQVWDUWDUDGLWLSUHEDþHQQDSRORYLþQLVYMHWORVQLPRGXVXpravilu
QH GROD]L GR VWDELOQRJD UDGQRJ VWDQMD SUHPDOR VYMHWORVWL VNUDüHQL UDGQL YLMHN L]YRUD
svjetlosti). Za rješavanje takvih negativnih primjera postoji redukcijski relej s preklopnim
VDWRP WLPHURP  NRML RVLJXUDYD GD üH L]YRU VYMHWORVWL VWDUWDWL SXQRP snagom u svakomVOXþDMX
7HKQLþND GRNXPHQWDFLMD YRGL VH GLJLWDOQR SUHNR JHRJUDIVNRJ LQIRUPDFLMVNRJ VXVWDYD X
GDOMQMHPWHNVWX*,6 ]DMDYQXUDVYMHWX*,6MDYQHUDVYMHWHVDVWRMLVHRG*,6SRGORJDNRMHþLQHEnergy and the Environment (2016) 315-326

321

GLJLWDOQL NDWDVWDU MDYQH UDVYMHWH L þLMD MH QDGRgradnja specijalizirana GISLight aplikacija
L]UDÿHQD SUHPD SRWUHEDPD *UDGD 5LMHNH 'LJLWDOQL NDWDVWDU MDYQH UDVYMHWH *,6/LJKW  SUXåDSUHJOHG SRGDWDNDRLQVWDODFLMDPDMDYQHUDVYMHWHX SURVWRUXSULND]XMH WRþQH WUDVH SRG]HPQLK
vodova, parametre instalirane RSUHPH RPRJXüDYD ODNãX UD]PMHQX SRGDWDND V RVWDOLPNRPXQDOQLP VXEMHNWLPD L XþLQNRYLWLMX DQDOL]X WUHQXWQRJ VWDQMD L SRWUHED $SOLNDFLMD MH X
praksi namijenjena prvenstveno za ažuriranje i obradu podataka za radne naloge i sve
aktivnosti na toj instalaciji SUXåDMXüL SRGDWNH R VWDQMX LQVWDODFLMH RGQRVQR LQVWDOLUDQLK
rasvjetnih tijela (broj, tip i snage) i o materijalu elemenata javne rasvjete (rasvjetna tijela,
izvori svjetlosti, prigušnice i sl.) [9].
Treba naglasiti da lokalna samouprava iako je nadležna za javnu rasvjetu nema poseban
REMHGLQMHQVXVWDYGDOMLQVNRJSUDüHQMDVWDQMDMDYQHUDVYMHWH2EMHGLQMHQLVXVWDYSUDüHQMDMDYQH
UDVYMHWH QDOD]L VH X GLVSHþHUVNLP FHQWULPD GLVWULEXFLMVNRJ VXVWDYD +(3 2'6-a. Takvo
upravljanje ne sagledava sustav javne rasvjete kao jednu cjelinu. Pouzdanost sustava javne
UDVYMHWH NDR VDVWDYQLFH VXVWDYD GLVWULEXFLMH VH X RYRP VOXþDMX GLUHNWQR QDUXãDYD -DYQD
rasvjeta se stoga razmatra tek kao sastavni dio cjelokupnog sustava distribucije koji je ranije
bio u nadležnosti istog suEMHNWD +(3  D QH NDR ]DVHEDQ SRWURãDþ L]UD]LWR VSHFLILþQLK
RELOMHåMD ãWR VXVWDY MDYQH UDVYMHWH þLQL QHGRYROMQR RSWLPL]LUDQLP L SRX]GDQLP 3RYHüDQDSRX]GDQRVWVXVWDYDVHPRåHSRVWLüLMHGLQR]DVHEQLPVXVWDYRPXSUDYOMDQMDMDYQHUDVYMHWH
.ULWLþQHWRþke sustava javne rasvjete,DNRVXNULWLþQHWRþNHVXVWDYDMDYQHUDVYMHWHSR]QDWHMHGLQLFLORNDOQHVDPRXSUDYHUMHãDYDQMH
MH QHGRVWDWQR .ULWLþQH WRþNH VX GMHORPLþQR REXKYDüHQH X HQHUJHWVNRP SUHJOHGX L] 
godine. U sustavu javne rasvjete se ne nalaze isNOMXþLYR UDVYMHWQD WLMHOD QDPLMHQMHQD ]DUDVYMHWOMDYDQMH SURPHWQLFD L SMHãDþNLK ]RQD QHJR L HOHPHQWL NRML ]D IXQNFLRQLUDQMH WUHEDMXHOHNWULþQXHQHUJLMXDVWUXMQLNUXJMDYQHUDVYMHWHMHELRQDMEOLåL]DSULNOMXþHQMH5DGLVHQSUR
reklamnim panoima postavljenima na stupovima javne rasvjete i predstavljaju tzv. parazitne
SRWURãDþH 3RVWRML WDNRÿHU YHOLNL EURM NRURGLUDQLK VWXSRYD MDYQH UDVYMHWH þLPH MH XJURåHQDsigurnost ljudi i vozila te je narušen vizualni dojam grada [8].
-HGDQ RG QDMYHüLK SUREOHPD X *UDGX Rijeci koji uvelike smanjuje sigurnost prometovanja i
SRYHüDYD UL]LN QD FHVWDPD MH ]HOHQLOR RGQRVQR UDVOLQMH NRMH ]DNODQMD UDVYMHWQD WLMHOD L WLPHGMHORPLþQR LOL X SRWSXQRVWL VPDQMXMH IXQNFLRQDOQRVW LVWLK. Zelenilo duž ulica u gradu Rijeci
predstavlja speFLILþQRRELOMHåMH]DSULPRUVNLNUDMLSRWUHEQRMHULMHãLWLUDVYMHWXEH]XNODQMDQMD
VWROMHWQRJ]HOHQLOD7RVHPRåHSRVWLüLSRVWDYOMDQMHPDGHNYDWQLKYLVHüLKYDQMVNLKVYMHWLOMNLXVYUKX]DGRYROMDYDQMDVYMHWORWHKQLþNLKXYMHWDQDSURPHWQLFDPDSlužbe održavaQMD VH VYDNRGQHYQLP GMHORYDQMHP VXVUHüX se ne samo s problemom
upravljanja kao što je prethodno spomenuto, YHü L V SUREOHPRP UD]JUDQLþHQMD YODVQLãWYD QD
WHUHQX5DGLVHSUHWHåLWRRQRVDþLPDUDVYMHWQLKWLMHODNRMLVXXYODVQLãWYX+(3(OHNWURSULPRUMD
Rijeka i nerijetko se nalaze na privatnim parcelama, što uvelike otežava službama pristup
svjetiljkama u vlasništvu Grada Rijeke.
5. $1$/,=$ 32752â1-( (/(.75,ý1(ODRŽAVANJE JAVNE RASVJETE(1(5*,-(,752â.29$

$QDOL]RP UDþXQD HOHNWULþQH HQHUJLMH ]D MDYQX UDVYMHWX ]a prethodnih pet godina dobiven je
XVSRUHGQLJUDILþNLSULND]SRWURãQje u kWh po mjesecima na slici 3. Vidljivo je da je potrošnja

322

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u 2015. porasla na iznose iz 2011., dok je u 2012., 2013. i 2014. potrošnja bila niža i relativno
XMHGQDþHQD

Slika 3. PregOHGSRWURãQMHHOHNWULþQHHQHUJLMHSRPMHVHFLPDXN:K [8]3URMHNWUHDOL]LUDQJRGLQHREXKYDüDRMH]DPMHQXVYMHWLOMNHQDGLMHOXJUDGVNHMDYQH
rasvjete. Svjetiljke snage 47,43 kW zamijenjene su LED svjetiljkama snage 28,22 kW.
Projekt modernizacije javne rasvjete Grada Rijeke iznosio je nešto više od milijun kuna, a
Fond ]DHQHUJHWVNXXþLQNRYLWRVWL]DãWLWXRNROLãDje za njegovu provedbu odobrio poticaje odNXQD6RE]LURPQD]DELOMHåHQXSRYHüDQXXNXSQXSRWURãQMXHQHUJLMHQDNRQXJUDGQMH
LED svjetiljaka postavlja se pitanje jesu li ulazni podaci za prethodne godine usporedljvi i da
OLVXNULWHULMLPMHUHQMDSRWURãQMHHOHNWULþQHHQHUJLMHELOLMHGQDNL6HJPHQWDOQRP DQDOL]RP SRWURãQMH X  XRþHQR MH VPDQMHQMH SRWURãQMH QD PMHUQLP
mjestima gdjHMHXJUDÿHQ/('RGRWSULOLNHDOLVHEURMPMHUQLKPMHVWDFMHORYLWRJVXVWDYDMDYQH UDVYMHWH SRYHüDR þLPH VH SRYHüDOD XNXSQD SRWURãQMD 1D WDM QDþLQ MH WHãNR RGUHGLWL
energetsku efikasnost i uštede dobivene iz energetski efikasnijih izvora. Postavlja se i pitanje]D GRGDWQH DQDOL]H NDR QSU GD OL VX JUDQLFH UD]JUDQLþHQMD VXVWDYD MDYQH UDVYMHWH VYXJGMHSRVWDYOMHQH GD OL MH VXVWDY MDYQH UDVYMHWH X SRWSXQRVWL SRNULYHQ PMHUQLP XUHÿDMLPD ]DHYLGHQWLUDQMHSRWURãQMHLNRMDMHHQHUJHWVNDXþLQNRYLWRVWSRYHüDQRJ EURMDSDUD]LWQLKSRWURãDþD
spojenih na sustav javne rasvjete.
Iz priloženih podataka vidljivo je da je sustav javne rasvjete vrlo kompleksan sustav i da bi ga
WUHEDOR UD]PDWUDWL NDR VSHFLILþQX FMHOLQX DåXUQLP SRGDFLPD MHU MH X SURWLYQRP QHPRJXüH
pratiti XãWHGHL]LQYHVWLFLMDNRMLPDMHVYUKDHQHUJHWVNDXþLQNRYLWRVW
7URãNRYLRGUåDYDQMDVXWDNRÿHUUDGQLWURãNRYLVXVWDYDMDYQHUDVYMHWH6RE]LURPQD]DVWDUMHOXRSUHPX RVLP YLVRNH SRWURãQMH HOHNWULþQH HQHUJLMH YLVRNL VX L WURãNRYL RGUåDYDQMD 3RVORYLodržavDQMDMDYQH UDVYMHWH REXKYDüDMX ERMDQMH VWXSRYD ]DPMHQX HOHPHQDWD þLãüHQMH L SUDQMH
stakla, podešavanje i zamjenjivanje brtvi, zamjenu dotrajalih stupova i svjetiljki, popravak
NDEHODSRSUDYDNXUHÿDMD]DXSUDYOMDQMHMDYQRPUDVYMHWRPLVO,]DQDOL]HWURãkova prethodne

Energy and the Environment (2016) 315-326

323þHWLUL JRGLQH JRGLãQMH VH ]D RGUåDYDQMH VXVWDYD MDYQH UDVYMHWH RGYDMD L] SURUDþXQD FFD
2.900.000,00 kn, odnosno 26% od ukupnih troškova rada javne rasvjete [8].
6. 35,-('/2*0-(5$81$35(ĈENJA SUSTAVA JAVNE RASVJETE U GRADURIJECI
Kao što je iz prethodnih podataka vidljivo troškovi rada i održavanja sustava javne rasvjete su
YHOLNL D ãLUHP XUEDQLK SRGUXþMD üH VH SRYHüDYDWL 2E]LURP QD QLzak SRVWRWDN YLVRNRWODþQLKnatrijevih svjetiljki koje rade u reduciranom režimu treba ozbiljno razmotriti isplativost
RSOHPHQMLYDQMH SUHGVSRMQLP QDSUDYDPD SRVWRMHüH UDVYMHWH WRJ WLSD X RGQRVX QD  ]DPMHQX
cjelokupne svjetiljke LED-RP3RQHNLPSURFMHQDPD/('UDVYMHWDSUXåDXãWHGXRGþDNXRGQRVXQDåLYLQHåDUXOMHLXRGQRVXQDYLVRNRWODþQHQDWULMHYHåDUXOje [10]3RYHüDQMHPživotnog vijeka svjetiljke istovremeno se smanjuju i njezini troškovi održavanja.
Nadomještavanje zastarjelih instalacija LED-RP L REQRYD XSUDYOMDþNRJ VXVWDYD QDþLQ MH ]DSRVWL]DQMHYHüHHQHUJHWVNHXþLQNRYLWRVWLLXãWHGHHOHNWULþQHHQHUgije u gradovima. Temelj za
razvoj održive javne rasvjete jest /(' UDVYMHWD 7DNYD UDVYMHWD MH LGHDODQ QDþLQ ]D SUXåDQMH
RSWLPL]LUDQH GLQDPLþNL SULODJRGOMLYH XVOXJH NRULVQLFLPD X] SRWHQFLMDOQR SRYHüDQMH
SRX]GDQRVWL FMHORYLWRJ VXVWDYD MDYQH UDVYMHWH SRPRüX daljinskog sustava upravljanja inadzora.
'DOMLQVNL QDG]RU MH XQDSUMHÿHQMH VXVWDYD UDGL GRKYDüDQMD WUHQXWQRJ VWDQMD L GHWHNFLMH NYDUD
svake pojedine jedinice u rasvjetnoj mreži, dok daljinsko upravljanje doprinosi upravljivosti
skupinom rasvjetnih tijela ili pojedinom svjetiljkom regulacijom intenziteta i podešavanjem
vremenskih intervala rada. Korištenjem HQHUJHWVNLK HILNDVQLMLK VYMHWLOMNL X] RGJRYDUDMXüH
upravljanje i regulaciju smanjuje se potrošnja energije, uz istovremeno smanjenje emisije CO2
pri SURL]YRGQML HOHNWULþQH HQHUJLMH 8 GDOMQMHP UD]YRMX VXVWDY MDYQH UDVYMHWH üHpodrazumijevati povezanost inovativne rasvjete sa komunikacijskim sustavima, obnovljivim
L]YRULPDHQHUJLMHLXSUDYOMDþNLPVXVWDYLPDQDPLMHQMHQLK]DSURPHWãWRSRGUD]XPLMHYDYHOLNa
investicijska ulaganja.
Pozorno gospodarenje energijom neophodno je za smanjenje potrošnje energije u sustavu
MDYQH UDVYMHWH .DGD MH ULMHþ R MDYQRM UDVYMHWL QMHQD HQHUJHWVND XþLQNRYLWRVW SRGUD]XPLMHYDHQHUJHWVNLXþLQNRYLWHVYMHWLOMNHLUDVYMHWXWHVXstav za gospodarenje energijom. Grad Rijeka
ima zaduženu osobu za gospodarenje energijom, ali dodatno angažira vanjske suradnike za
VSHFLILþQH SUREOHPH X VXVWDYX MDYQH UDVYMHWH ãWR L]LVNXMH GRGDWQH WURãNRYH L] SURUDþXQD
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SUDüHQMDLPMHUHQMDXVYUKXXþLQNRYLWRJJRVSRGDUHQMDHQHUJLMRP7DNDYVXVWDYNRQWLQXLUDQR
SULEDYOMD  XOD]QH SRGDWNH L GLQDPLþNL SUDWLWL SRWURãQMX HQHUJLMH RþLWDYDQMHP VYLK PMHUQLKXUHÿDMD 1DLPH VDPR  LVSUDYQD DQDOL]D SRGDWDND RPRJXüXMH RVWYDUHQMH RGUHÿHQLK FLOMHYDSRWURãQMHX]URNHSRYHüDQHSRWURãQMH
7. =$./-8ý$.
-DYQDUDVYMHWDSUHGVWDYOMD]QDþDMDQUHVXUV]DUD]YRMPUHåHQDSUHGQRJJUDGD8WRMGMHODWQRVWLPRJXüH MH SRVWLüL ]QDWQH HQHUJHWVNH XãWHGH SUDYilnim gospodarenje energijom i odabirom
HQHUJHWVNL XþLQNRYLWH RSUHPH ,]D]RYL UD]YRMD HQHUJHWVNL XþLQNRYLWH MDYQH UDVYMHWH VX
PQRJREURMQL WH VH SRVWRMHüD UDVYMHWD PRUD SULODJRGLWL UDFLRQDOQLMRM L XþLQNRYLWLMRM SRWURãQML
HOHNWULþQHHQHUJLMH

324

L. Luttenberger, L. Runko Luttenberger: 3RYHüDQMHXþLQNRYLWRVWLVXVWDYDMDYQHUDVYMHWH

Iz podataka izQLMHWLK X UDGX UD]YLGQR MH GD VH QDNRQ ]DPMHQH HQHUJHWVNL QHXþLQNRYLWLKsvjetiljki LED-RP SRYHüDR VYHXNXSQL UDþXQ HOHNWULþQH HQHUJLMH ]D MHGLQLFX ORNDOQH
samouprave. Iako izmijenjena rasvjetna tijela u naravi troše manje od prijašnjih istovremeno
VH SRYHüDo broj dodatnih trošila, koji se mogu nazvati parazitnim trošilima, pa je zbog
PDQMNDYRJQDG]RUDVXVWDYDLQHSULPMHUHQRJXSUDYOMDQMDGRãORGRNDRWLþQRJSRYHüDQMDEURMDWURãLOD R NRMLPD ]DGXåHQL ]D MDYQX UDVYMHWX QHPDMX SULPMHUHQR VD]QDQMH QLWL RGJRYDUDMXüH
XSUDYOMDþNHLQVWUXPHQWH
Autorice smatraju da je prije svake obnove energetski efikasnim svjetiljkama potrebno izvršiti
PMHUHQMD NRMD üHELWLXVSRUHGLYDVPMHUHQMLPDQDNRQXJUDGQMHLSUXåDWLSRX]GDQHSRGDWNHR
RVWYDUHQRM XãWHGL .DGD MH ULMHþ R *UDGX 5LMHFL QXåQR MH SRYHüDWL NRPSHWHQFLMH RVREDQDGOHåQLK]DL]UDGXUHNRQVWUXNFLMVNRJSODQDVXVWDYDMDYQHUDVYMHWH7DNRÿHUQHRSKRGQRMHL]
mješovitih sustava informacijski i programski izdvojiti pa objediniti sustav javne rasvjete
NDNR EL VH RPRJXüLR QDG]RU Dnaliza ulaznih parametara, upravljanje i regulacija vlasniku
MDYQHUDVYMHWHRGQRVQRMHGLQLFLORNDOQHVDPRXSUDYH3RYHüDQMHPXSUDYOMLYRVWLVXVWDYDMDYQH
UDVYMHWHGDOMLQVNLPQDG]RURPX]PRJXüQRVWUHJXODFLMHRVYMHWOMHQMDLSUDüHQMDVWDQMDVYMHWLOMNL
bitno se poboljšava pouzdanost i sigurnost sustava javne rasvjete.
3ULPMHQMLYDQMHPYHüSRVWRMHüHWHKQRORJLMHNDRãWRMH/('HOHNWURQLþNHSUHGVSRMQHQDSUDYH
ugradnjom fotonaponskih modula na rasvjetne stupove uz dobro upravljan sustav mogla bi se]QDþDMQR VPDQMLWL SRWURãQMD HOHNWULþQH HQHUJLMH L HPLVLMD &22 na globalnoj razini.
Projektiranjem takvog sustava pridonijelo bi se i pouzdanosti javne rasvjete jer bi ista postala
PDQML SRWURãDþ HOHNWULþQH HQHUJLMH L PRJOD EL GMHORPLþQR ULMHãLWL SUREOHP SUHRSWHUHüHQRVWLeOHNWURHQHUJHWVNRJ VXVWDYD X WUHQXFLPD YUãQH SRWURãQMH 0RJXüQRVWL UD]YRMD HQHUJHWVNL
XþLQNRYLWHMDYQHUDVYMHWHVXPQRJREURMQH, a današnja rasvjeta mora prilagoditi racionalnijoj iXþLQNRYLWLMRMSRWURãQMLHOHNWULþQHHQHUJLMH
LITERATURA[1.]Runko Luttenberger, L.; Luttenberger, L., Oživotvorenje energetskih rješenja zaRþXYDQMH PRUVNRJ RNROLãD RG zakiseljavanja i zagrijavanja, Pomorski zbornik.
Posebno izdanje 1 (2016) ; 231-243[2.]Luttenberger, L.: Zahtjevi kod projektiranja suvremenog sustava javne rasvjete,
Seminarski rad, Raspoloživost elektroenergetskih podsustava, doktorski studij)DNXOWHWHOHNWURWHKQLNHLUDþXQDUVWYD6YHXþLOLãWDX=DJUHEX
[3.]P. Van Tichelen, T. Geerken, B. Jansen , M. Vanden Bosch (Laborelec), V. Van Hoof,
L. Vanhooydonck (Kreios), A. Vercalsteren: Final Report Lot 9: Public street
lightingVLMHþDQM9,72
[4.]Kos, M.: Suvremena energetski efikasna rasvjeta, EnergyPlus d.o.o., Rijeka, 12.
studeni 2014.
[5.]*ODYDã + ,YDQRYLü 0 0DQGLü 1 Energy audit of public lighting in the area ofOsijek-Baranja County (Croatia), IEEE, 1144 – 1149, svibanj 2014.
[6.]Narodne novine: =DNRQXR]DãWLWLWLRGVYMHWORVQRJRQHþLãüHQMD, NN 114/11, Zagreb, 5.
listopada 2011.
[7.]Grad Rijeka: Prijedlog Akcijskog plana energetski održivog razvitka Grada Rijeke(SEAP), Rijeka, svibanj 2010.
[8.]Luttenberger, L.: -DYQDUDVYMHWDX*UDGX5LMHFLX]SULMHGORJH]DXQDSUHÿHQMHVXVWDYD,
Seminarski rad, Regulacija u energetici, doktorski studij Fakultet elektrotehnike iUDþXQDUVWYD6YHXþLOLãWDX=DJUHEX.

Energy and the Environment (2016) 315-326

325[9.]Elis Inženjering d.o.o.: ,]YMHãüH R SURYHGHQRP HQHUJHWVNRP SUHJOHGX MDYQH UDVYMHWH
Grad Rijeka, Rijeka, prosinac 2014.
[10.]
Rodrigues, C. ; NIMO - Modern Lighting Res. Group, Fed. Univ. of Juiz deFora (UFJF), Juiz de Fora, Brazil ; Almeida, P.S. ; Soares, G.M.: An experimental
comparison between different technologies arising for public lighting: LEDluminaires replacing high pressure sodium lamps, IEEE, 141 – 146, srpanj 2011.
[11.]
6DYLü 7 Zelena nabava u Europi, Modul: Rasvjeta, www.buy-smart.info,
Regionalna energetska agencija Sjeverozapadne hrvatske[12.]*ODYDã + ,YDQRYLü 0 0DQGLü 1: Energy audit of public lighting in thearea of Osijek-Baranja County (Croatia), IEEE, 1144 – 1149, svibanj 2014.
[13.]
European Comission: Lighting the Cities – Accelerating the Deployment of
Innovative Lighting in Europen Cities, svibanj 2013.

INCREASING THE EFFICIENCY OF STREET LIGHTING
Summary: Local authorities are required to provide a service of street lighting in the area
under their jurisdiction, while reliability of street lighting is ensured through appropriatequality standard, accessibility and efficiency of the service as well as by proper management.
The paper analyses the significance of street lighting from the standpoint of physicalplanning, functionality, reliability and safety. Furthermore, analysis is made of determining
factors in the design of efficient street lighting system which is a major energy consumer, theobligations of energy efficient city in application of effective measures and reduction of CO2
emissions, with particular reference to the reliability of existing street lighting systems. The
paper evaluates the situation in the City of Rijeka, providing an overview of therepresentation of particular light sources as well as the methods of operation and control.
Assessment is made of the critical spots which have an impact on reliability and safety ofstreet lighting system. The costs of electricity consumption and street lighting maintenanceare considered as well as the problems in delimitation of street lighting ownership. The
authors propose the application of currently available technologies such as LED andelectronic ballasts, as well as the installation of photovoltaic modules on lampposts, andemphasizes in particular the significance of good management of the system with the scope of
reducing electricity consumption, thus achieving environmental requirements of CO2
emissions reduction at global level. In author's opinion prior to any refurbishment using
energy efficient lamps, it is necessary to effect measurements that will be comparable with thepost-installation measurements and to provide reliable data on the savings achieved.
Furthermore, it is necessary to single out from combined systems and then integrate IT-and
programme-wise the street lighting system in order to ensure monitoring, analysis of input
parameters, control and regulation for street lighting owner or the local authority.
Keywords: street lighting, energy efficiency, system reliability, energy efficient city,emission reduction

326

L. Luttenberger, L. Runko Luttenberger: 3RYHüDQMHXþLQNRYLWRVWLVXVWDYDMDYQHUDVYMHWH

Energy and the Environment (2016) 327-336

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tel 00385/51/294-189
marikn@fthm.hrSažetak: 7XULVWLþNLREMHNWLVX YHOLNLSRWURãDþLHQHUJLMHšto podrazumijeva i visoke energetske
troškove. Troškovi energije mogu se efikasnije kontrolirati, što XWMHþHQDNRQDþDQILQDQFLMVNL
rezultDWLSRYHüDYDSURfit. Postoji mnogo investicijskih studija i izvedba projekata energetskeXþLQNRYLWRVWL za smanjenje energetskih troškova, no valja ih selektivno tretirati i primijeniti,
QH VSXãWDMXüL pri tome razinu kvalitete usluge i zadovoljstvo gosta. -HGDQ RG QDþLQD ]Dpoticanje energetVNH XþLQNRYLWRVWL L UD]XPQRJ NRULãWHQMD HQHUJLMH X WXULVWLþNLP REMHNWLPD MH
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gosta za RþXYDQMHokoliša. 5DGDQDOL]LUDSULPMHUHPDOLKLVUHGQMLKWXULVWLþNLKSRGX]HüDNDRLYHOLNLK KRWHOVNLK ODQDFD X SULPMHQL PMHUD HQHUJHWVNH XþLQNRYLWRVWL i obnovljivih izvora
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financijske ili tehnološke podloge, manje proaktivni za okoliš od velikih hotelskih lanaca.
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nude manji objekti ili pojedinci, mogu poVOXåLWL NDR SULPMHU VOLþQLP REMHNWLPD X +UYDWVNRM
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korporativne kulture i osviještenosti te reduciranju emisije štetnih plinova što je sve jedini i
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1. UVOD
Turizam s ekonomske strane globalno generira oko 5% BDP-a i stvara oko 8% radnih mjesta[1], a u Europskoj Uniji sudjeluje s oko 5% direktnog doprinosa BDP-u i zapošljavanju radne
snage (10% u BDP-u EU i 12% u radnim mjestima ako se pribroje i sve vezane djelatnosti) te
WUHQXWQR SUHGVWDYOMD WUHüX naM]QDþajQLMX HNRQRPVNX DNWLYQRVW VD ]QDþajnim potencijalom za
daljnji rast i zapošljavanje.[2] U Republici Hrvatskoj 10,4% izravnog udjela u BDP-u s
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strani turisti. [4] 7R XND]XMH QD SRUDVW WXULVWLþNLK GROD]DND ]D  X RGQRVX QD SUHWKRGQX JRGLQX L SRUDVW WXULVWLþNLK QRüHQMD WXULVWD ]D  3HUVSHNWLYD KUYDWVNRJ WXUL]PDSRSULPD LVNOMXþLYR UDVWXüH WUHQGRYH 0HÿXWLP WXUL]DP RVLP VYRMLK HNRQRPVNLK SUHGQRVWL
generirD]QDþDMDQSULWLVDNQDRNROLãLWR]ERJSXWRYDQMDRGQRVQRWUDQVSRUWDWXULVWDNRML ispušta
YHOLNH HPLVLMH VWDNOHQLþNLK SOLQRYD L GUXJLK RQHþLãüXMXüLK WYDUL X ]UDN YRGH L PRUH
Procjenjuje se da turizam na globalnoj razini doprinosi ukupnim svjetskim emisijama
VWDNOHQLþNLK SOLQRYD V RNR  RG þHJD RNR  SULSDGD DYLRQVNRP SURPHWX DXWRPRELOVNRPSURPHWXLWXULVWLþNRPVPMHãWDMX[5] 8SUDYR]ERJWHþLQMHQLFHFLOMUDGDMH
ukazati na važnost XþLQNRYLWRg korištenja energijom X WXULVWLþNLP REMHNWLPD. Rad pokušava
RGJRYRULWLQDLVWUDåLYDþNRSLWDQMHGDOLMHXþLQNRYLWLPNRULãWHQMHPHQHUJLMHPRJXüHVPDQMLWL
troškove, zadovoljiti sve zahtjevnije goste, a sve u svrhu optimizacije korištenja energije,RþXYDQMD RNROLãD L UD]YRMD X RNYLULPD RGUåLYRVWL" 7XULVWLþNL objekti su YHOLNL SRWURãDþLenergije što podrazumijeva i visoke energetske troškove. Troškovi energije mogu se efikasnije
NRQWUROLUDWL ãWR XWMHþH QD NRQDþDQ ILQDQFLMVNL UH]XOWDW L SRYHüDYD SURILW 3RVWRML PQRJR
investicijskih studija i izvedba projekata eQHUJHWVNH XþLQNRYLWRVWL ]D VPDQMHQMH HQHUJHWVNLKWURãNRYDQRYDOMD LK VHOHNWLYQR WUHWLUDWL L SULPLMHQLWLQHVSXãWDMXüL SUL WRPH UD]LQX NYDOLWHWH
usluge i zadovoljstvo gosta. -HGDQRGQDþLQD]DSRWLFDQMHHQHUJHWVNHXþLQNRYLWRVWLLUD]XPQRJ
korištenja enerJLMH X WXULVWLþNLP REMHNWLPD MH SURPRFLMD QDMSULODJRGOMLYLMLK QDMSUDNWLþQLMLK L
QDMLVSODWLYLMLK UMHãHQMD NDNR EL VH XQDSULMHGLOD QMLKRYD HQHUJHWVND XþLQNRYLWRVW XSRWUHEDobnovljivih izvora energije, ali i potaknula VYLMHVW JRVWD ]DRþXYDQMH RNROLãD 8 Qastavku se
GDMH DQDOL]D SULPMHUD PDOLK L VUHGQMLK WXULVWLþNLK SRGX]HüD NDR L YHOLNLK KRWHOVNLK ODQDFD X
SULPMHQLPMHUDHQHUJHWVNHXþLQNRYLWRVWLLREQRYOMLYLKL]YRUDHQHUJLMH
2. (1(5*(76.$8ý,1.29,72678785,=08Europska unija sve više SRWHQFLUDSRGX]HüDQD XYRÿHQMHUREDLXVOXJDHNRORãNLKSHUIRUPDQVL.
[6] Turizam i hotelska industrija jedan su od ]QDþDMQLMLK Dktera u eksploataciji energije,SRþHYãL RG SXWRYDQMD VD mjesta stalnog boravka turista do njegovog odredišta, te se i u
NUDMQMHPWXULVWLþNRPREMHNWXJost služi mnoštvom resursa i energetskih izvora.[7] Suvremeni
gost je ekološki svjestan i traži QDþLQ ]DGRYROMHQja svoMLK SRWUHED LVWRYUHPHQR SD]HüL QD
cijenu te povoljna i „value for money“ rješenja. 9HüLQDSRGX]HüDVPDWUDGDLPSOHPHQWDFLMD
mjera za HQHUJHWVNX XþLQNRYLWRVW L]LVNXMH ]QDþDMQH ILQDQFLMVNH LQYHVWLFLMH 3UHPD .LUNX [8],postoji nekoliko razloga kao razlog odupiranju hotelske industrije u implementaciji zelene
politike. Prvi najvažniji razlog su zahtjevni gosti, koji nisu toliko ekološki educirani i koji pri
GRODVNX X KRWHO RþHNXMX svaki dan svježe opranu posteljinu, tople kupke kao i luksuzne spa
centre, raskošne bazene i kvalitetan prijevoz. Hotelska industrija vidi složenost problema kada
VH JRYRUL R VPDQMHQMX UHVXUVD NRMH üH NRQ]XPHQWL X daljnjim procesima hotelskog prihvata
zasigurno primiMHWLWLWHüHWRSRWDNQXWLX]UXMDQRVW3ULMHWQMDMHWRNDRLUL]LNXVPMHUHQSUHPDKRWHOVNLP NRPSDQLMDPD L ODQFLPD NRML GYRMH RNR XYRÿHQMD HNRORãNLK VWDQGDUGD 7DNRÿHUYHOLNLSUREOHPþLQHL]DSRVOHQLFLNojima zeleni planovi te njihova implementacija predstavlja
QHSRWUHEDQLGRGDWDQSRVDRSDSUXåDMXRWSRUSUL SURYRÿHQMX PMHUD HQHUJHWVNH XþLQNRYLWRVWL
Ipak pojam održivog razvoja je duboko ukorijenjen u svijestLYHüLQHSRWURãDþDNRMLVXVYMHVQL
klimatskih promjena i njenih posljedica na planetu Zemlju. Prema istraživanjima [9],GDQDãQMLWXULVWVYRMHSRWUHEHVYHYLãHQDVWRML]DGRYROMLWLQDHNRORãNLQDþLQDYROMDQMHLYLãH
platiti. [10] 2GUåLYLUD]YRMLXODJDQMHXHQHUJHWVNXXþLQNRYLWRVWQHELWUHEDRYLãH biti pomodni„trend“ YHüVWLOåLYRWDVYDNRJJRVWDRGQRVQRXVWDOMHQDSRQXGDVYDNRJWXULVWLþNRJREMHNWD

Energy and the Environment (2016) 327-336

329

8 RNYLUX LQGXVWULMVNRJ L NRPHUFLMDOQRJ VHNWRUD PRåH VH UHüL GD MH KRWHOLMHUVWYR MHGDQ RG
QDMYHüLK SRWURãDþD HQHUJLMH D VDPLP WLP MH RSWHUHüHQR L V YHlikim energetskim troškovima.
1R þLQMHQLFD MH GD VH VYL WL WURãNRYL PRJX HILNDVQLMH NRQWUROLUDWL RG RSHUDWLYQLK WURãNRYD
1DMYDåQLMH RG VYHJD NROLþLQD UHGXNFLMH WLK WURãNRYD XWMHþH QD NRQDþDQ ILQDQFLMVNL UH]XOWDWSRYHüDYDSURILWLþLQLKRWHOELWQRNRQNXUHQWQLMLPRPRJXüDYDMXüLEROMHXVUHGRWRþHQMHQDJRVWD
LNROLþLQXNDSDFLWHWD
3UHGQRVWLXþLQNRYLWRJNRULãWHQMDHQHUJLMHRþLWXMXVHXx unaprHÿHQMX zadovoljstva gostiju,
x dodatku na estetici sadržaja,x reduciranju troškova održavanja i kvarova na sustavima,x poboljšanju vrijednosti opreme i zgrada,
x XQDSUHÿHQMX korporativne kulture i osviještenosti,
x reduciranju HPLVLMHãWHWQLKSOLQRYDNRMLXWMHþXQDNOLPDWVNHSURPMHQH
S ovim bi svakako trebali biti upoznati menadžeri svih razina u WXULVWLþNLPREMHNWLPD. A oni
bi u]SRPRüVYRMLKWHKQLþNLKUXNRYRGLWHOMDWUHEDOLznati kako [11]:x L]UDþXQDWLSRWURãQMXHQHUJLMHNRGVYLKKRWHOVNLKVDGUåDMDLSRVWURMHQMD
x XVSRUHGLWLLKVDVOLþQLPPRGHORPREMHNWDX]HPOMLLVYLMHWX
x usvojiti mjere i akcijski plan (Plan upravljanja energijom) u pravcu uštede i energije itroškova,
x L]UDþXQDWLSRWHQFLMDOQHXãWHGH
2.1. Upravljanje energijom u hotelima
Upravljanje energijom u hotelskoj industriji podrazumijeva zahtjeve VSHFLILþQH]DRYXJUDQX
poslovanja. VHOLNLLPDOLKRWHOLSRVOXMXGDQRQRüQRUXWLQVNLL]YUãDYDMXQL]UD]OLþLWLKXVOXJDL
to kroz niz odjela koji mogu biti raspodijeljeni u više zgrada: npr. uz sobe hoteli imaju
restorane i sale za posluživanje hrane, barove, centre za rekreaciju i salone ljepote,
konferencijske sale, trgovine, zatim administrativne urede, kuhinje, praonice i sobe zaodržavanje. Sve nabrojeno otežava proces upravljanja energijom u hotelu. Bez obzira što
cijene opreme za pojedine sustave hotela stalno rastu mnogi hotelijeri i upravitelji ne želetrošiti sredstva i vrijeme za zamjenu takve opreme koja se još uvijek može servisirati.
6UHüRPSRVWRMHPQRJHWDNWLNHNRMHVHODNRüRPPRJXLQNRUSRULUDWLXGQHYQHSRVORYHDNRMH
ne zahtijevaju kapitalna sredstva [12]:xMjere bez troškova uNOMXþXMX: optimizaciju temperature za grijanje prostorija i vode,kontrolu i prilagodbu operabilnog vremena sve opreme energetskog sustava, kontrolu iprilagodbu osvjetljenja, gašenje opreme kada nije potrebna, izbjegavanje simultanog
JULMDQMD L KODÿHQMD SURVWRULMD JDãHQMH VXVWDYD JULMDQMD KODÿHQMH L RVYMHWOMDYDQMD X
nezauzetim prostorijama.

x

Mjere s malim do umjerenim troškovima su LQVWDODFLMD EROMLK NRQWUROQLK XUHÿDMD
WHUPRVWDWLþQDUHEUDUDGLMDWRUDIRWRüHOLMH« LQVWDOLUDQMHSUR]LUQLK]DVORQDLOLVMHQila usobama, instaliranje štedljivih žarulja u sobama i društvenim prostorijama, brtvljenje
starijih vrata i prozora, poboljšavanje uporabe topline u praonici i bazenu, zamjena
stare opreme s efikasnijim alternativama i što više ako MHPRJXüHNRULVWLWLREnovljive
izvore energije.

330

0.ULVWLQLü1LåLü: 8þLQNRYLWRNRULãWHQMHHQHUJLMHXWXULVWLþNLPREMHNWLPD

3ULPMHULUDFLRQDOQRJXSUDYOMDQMDHQHUJLMRPXQHNLPVYMHWVNLPKRWHOLPDGDQMHXVOLMHGHüRM
tablici.
Tablica 1. Primjer racionalnog upravljanja energijom u nekim svjetskim hotelima
HOTEL

PRAKSA I UŠTEDA

Renaissance International Solarna energija koristi se za rasvjetu i stropne ventilatore.
hoteli i resorti
Klizni prozori i vrata su povezani s konektorima tako da se pri
RWYDUDQMX NOLPDWVNL XUHÿDML LVNOMXþXMX =DPMHQRP SRVWRMHüLKJULMDþD ERMOHUD HILNDVQLMLPD RVWYDUHQH VX SURVMHþQH uštede od  PMHVHþQR SR JRVWX 1D KRGQLFLPD VH NRULVWH VYMHWOD VD
SUHNLGDþLPDDYDQMVNDUDVYMHWDNRULVWLIRWR-HOHNWULþQHüHOLMH
Intercontinantal Sydney-HGQDND NYDOLWHWD þLVWRüH PRåH VH SRVWLüL SUDQMHP QD &
umjesto na 96°C što je rezultiralo prosMHþQRP JRGLãQMRP
uštedom plina od oko 24.000 $.

Intercontinental, Miami

Energetska ušteda procjenjuje se na 400.000 kWh godišnje štoiznosi 2.400 $.

Boston Park Plaza

Instalirano je 1.686 termo izolacijskih prozora, a svaki prozor
godišnje uštedi hotelu 75 $ u troškovima energije.

,]YRU3HWULü/³'HVWLQDFLMVNLPHQDGåPHQW´(NRQRPVNLIDNXOWHW6YHXþLOLãWDX6SOLWX6SOLW
2006., str. 60-62. [13]8YHüLQLVOXþDMHYDSURJUDPuspješne energetske efikasnosti zahtijeva neke bazne promjene uQDþLQX NRULãWHQMD WHKQRORJLMH QDþLQX SRQDãDQMD ]DSRVOHQLK WH QDþLQX QD NRML VX SRVWDYOMHQLpolLWLND LOL SURFHGXUH SRGX]HüD X WRP VPMHUX 7H SURPMHQH QH PRUDMX ELWL GUDVWLþQH MHU X
PQRJR VOXþDMHYD PDOD XQDSUHÿHQMD GRQRVH ]QDþDMQH UH]XOWDWH 2QR ãWR MH QDMYDåQLMH je danijedna promjena ako nije u interakciji s drugima, QHüH VDPD ]D VHEH SROXþLWL ]QDþDMQLML
rezultat. Uz sve to neophodna je potpora top menadžmenta u implementaciji kroz sve hotelske
procese i operacije, a to je u primjerima iz tablice br.1. postignuto
2.2. Investiranje u energetske troškove(QHUJHWVNLWURãNRYLSRGLMHOMHQLVXSRSRMHGLQLPRGMHOLPDKRWHODXVOMHGHüLPRPMHULPD [14]:
x
x
x
x
x

JULMDQMHLKODÿHQMH 43%
topla voda
15%
kuhinja10%
rasvjeta
22%
ostalo10%

Kako bi se QDYHGHQLPWURãNRYLPDPRJORXSUDYOMDWLQDQDþLQGDVHRQLUHGXFLUDMXSRWUHEQRMH
provesti niz promjena poput [15]:Energy and the Environment (2016) 327-336

331

Tehnološke promjene : UDVYMHWDVWURMHYL+9$& JULMDQMHR]UDþLYDQMHNOLPDWL]DFLMD voda,
NRQWURODHQHUJLMHUHJHQHUDFLMVNLXUHÿDMLL]RODFLMDX]JUDGLLPQRJLGUXJLVXVWDYNHQDNRMLPD
VHRþHNXMXWUDMQDXQDSUHÿHQMDLSREROMãDQMDXVPLVOXHfikasnijeg korištenja energije.
Promjene u ponašanju: energiju troše i gosti i zaposlenici, tako da njihove navike i ponašanje
imaju veliki XWMHFDM =D HILNDVQX XãWHGX HQHUJLMH WDNRÿHU MH SRWUHEQR XNOMXþLWi zaposlenike igoste hotela, utjecati na njihovo ponašanje te unaprijediti njihove vještine i znanje.
Organizacijske promjene: podrška višeg menadžmenta je neophodna. Primjerice, uspostava
povjerenstva ili energetskog tima XNOMXþXMH FLOMHYH UHGXNFLMH HQHUJLMH X REOLNX SRVORYQLKzaduženja i odgovornosti, prikazivanje izvještaja o napretku smanjenja energetskih troškova
na sastancima sa zaposlenima i redRYQR SUDüHQMH UHåLMVNLK WURãNRYD L SULSDGDMXüLK UDþXQD uodjelu knjigovodstva.
8JUDGQMD RSUHPH L XUHÿDMD NRML ãWHGH HQHUJLMX QH GRQRVL VDPR financijsku uštedu YHü
SRYHüDYD vrijednost samog objekta WH VWYDUD HNRORãNL LPLGå WXULVWLþNRJ REMHNWD DOL L FLMHOH
destinacije. Kod pristupanja ugradnji takYH RSUHPH L XUHÿDMD ELWQR WR þLQLWL postupno
IDYRUL]LUDMXüL RQH NRML LPDMX QDMNUDüL SHULRG SRYUDWD XORåHQRJ SD\EDFN  'UXJLP ULMHþLPD
sposobnost investiranja u poEROMãDQMD HQHUJHWVNH XþLQNRYLWRVWL VD GXJRURþQLMLP vremenom
povrata ulaganja temelji se na brzim uštedama zasnovanima na ulaganju u opremu iste
QDPMHQH VD NUDüLP YUHPHQRP SRYUDWD XODJDQMD 7DEOLFD EU SULND]XMH YULMHPH SRYUDWD
ulaganja za najvažnije stavke i SR]LFLMHHQHUJHWVNHXþLQNRYLWRVWLTablica 2. 2NYLUQLSHULRGSRYUDWD]DXþLQNRYLWRNRULãWHQMHHQHUJLMH
Sistem (pozicija)
Rasvjeta
Strojarska oprema+9$& JULMDQMHLKODÿHQMH
Potrošnja vode8UHÿDMLNRQWUROH
Izolacija objekta

Procijenjena energetska
ušteda0,06 GJ/m2
0,02 GJ/m2
0,20 GJ/m2
0,09 GJ/m2
0,07 GJ/m2
0,03 GJ/m2

Okvirni period povrata
4 godine
5 godina
6 godina
4 godine
5 godina
8 godina

Izvor: Office of Energy Efficiency - Natural Resources Canada: Saving Energy Dollars in
Hotels, Motels and Restaurants [16]Iz tablice 2 je vidljivo da okvirni period povrata u energetski efikasniju opremu iznosi od 4 do
8 godina. Navedene mjere donose poboljšanja u estetici sadržaja i nivoa komfora kojiohrabruje goste na ponovni posjet, što naravno donosi SRQRYQR QRYH SULKRGH L SRYHüDQMH
ekoORãNRJLPLGåDWXULVWLþNRJREMHNWD
3. (1(5*(76., 8ý,1.29,7$ 5-(â(1-$ 35,./$'1$ =$ 83275(BU U
0$/,0,65('1-,0785,67,ý.,032'8=(û,0$U nastavku rada daje se pregled energetsNLXþLQNRYLWLK UMHãHQMD GRVWXSQLK ]D PDOD L VUHGQMDSRGX]HüD NRMD VH SRMHGLQDþQR Pogu odabrati za implementaciju. Rješenja za energetskuXþLQNRYLWRVWGRVWXSQDPDOLPLVUHGQMLPSRGX]HüLPDVXNODVLILFLUDQDXWULUD]OLþLWHVNXSLQH332

0.ULVWLQLü1LåLü: 8þLQNRYLWRNRULãWHQMHHQHUJLMHXWXULVWLþNLPREMHNWLPDxxxÝXSUDYOMDQMH HQHUJLMRPÝ VNXSLQD VH VDVWRML RG UMHãHQMD NRML VH RGQRVH QD KRWHOVNX
energetsku politiku kao i DQJDåPDQRVREOMDLJRVWLMXVPMHUDPDRþXYDQMDHQHUJLMHÝVPDQMHQMH SRWUHED ]D JULMDQMHP L UDVKODÿLYDQMHPÝ VDGUåL WHKQLþND UMHãHQMD ]Drenovaciju eksterijera zgrade, kako bi se smanjila potreba za grijanjem i
UDVKODÿLYDQMHPÝHILNDVQRVWRSUHPHÝVHVDVWRMLRG WHKQLþNLKUMHãHQMDVDVYUKRPSREROMãDQMDHILNDVQRVWLKRWHOVNHRSUHPHELORSRPRüXEROMHJRSHUDFLMVNRJVXVWDYD NUR]NRQWUROXLUHJXODFLMX
opreme) ili zamjenom opreme

7DEOLFDEU(QHUJHWVNLXþLQNRYLWDUMHãHQMD]DPDODLVUHGQMDSRGX]HüD
Upravljanje energijom¾ Procijeniti energetski profil hotela¾ Izraditi jednostavnu energetsku politiku¾ 8VYRMLWLGREUXSUDNVXYRÿHQMDGRPDüLQVWYD¾ Osigurati reguliranje održavanja i servisiranja opreme¾ 8QDSULMHGLWLXSUDYOMDQMHHQHUJLMRPLQIRUPLUDMXüLRVREOMHLJRVWH
6PDQMHQMHSRWUHEDJULMDQMDLUDVKODÿLYDQMD¾ Poboljšati toplinsku izolaciju zgrade¾ 6SULMHþLWLQHNRQWUROLUDQXOD]DN]UDND¾ 8QDSULMHGLWLPLNURNOLPXL]DãWLWX]JUDGHRGOMHWQLKYUXüLQD
Efikasnost opreme¾ Bolja operativna upotreba trenutne opreme (kroz regulaciju i kontrolu opreme)¾ Poboljšati efikasnost grijanja (grijanje prostora i proizvodnja tople vode)¾ Poboljšati efikasnost rashlade prostora¾ 3REROMãDWLXþLQNRYLWRVWYHQWLODFLMH
¾ Unaprijediti efikasnost osvjetljenja¾ 8QDSULMHGLWL GUXJX HOHNWULþQX opremu
Mnogi strani autori poput Chana [17@DOLLVWRWDNRLGRPDüLDXWRULSRSXW3HWULü[18] slažu seda hoteli u sklopu velikih hotelskih lanaca više i brže primjenjuju mjere energetskeXþLQNRYLWRVWL WH SRVOXMX X VNODGX VD SURSLVDQLP NRGHNVLPD ]DãWLWH okoliša, društvene
odgovornosti i održivog razvoja. Razlog tomu, osim jednostavnih mjera racionalizacije, jestãWR YHüLQD DNWLYQRVWL ]DKWLMHYD ]QDþDMQR SRþHWQR XODJDQMH ,DNR MH SRYUDW QD WR XODJDQMH
relativno brz, hoteli koji posluju bez sigurne i stabilnH ILQDQFLMVNH L XSUDYOMDþNH SRGUãNH VL
takav vid investicije teže mogu priuštiti 0HÿXWLP L PDOL VDPRVWDOQL WXULVWLþNL REMHNWL åHOH
SUDWLWLYHüHNRQNXUHQWHWHGDXWRPHLXVSLMHYDMXSRND]XMHVOLMHGHüHLVWUDåLYDQMH,VWUDåLYDQMHBest Practices Guide-Successful EET Integration in SME Hotels [19] predstavlja najbolje i
QDMLVWDNQXWLMH SULPMHUH X KRWHOVNRP VHNWRUX X VPLVOX LQWHJULUDQMD HQHUJHWVNH XþLQNRYLWRVWL
Istraživanje je provedeno u okviru HES-a [20], te se daje 18 primjera malih i srednjih hotela
NRMXVXXVYRMXSUDNVXXYHOLSURJUDPHRþXYDQMDHQHUJLMH=DVYDNLKRWHOGDQHVXLQIRUPDFLMH
NRMH VH WLþX PRWLYDFLMH ]D LPSOHPHQWDFLMX SURMHNWD NRML SRPDåH RþXvanju energije te
informacije o povijesnoj pozadini hotela. Uz obradu motiva hotelijera za implementaciju,WDNRÿHUVXREUDÿHQHLSRWHãNRüHVNRMLPDVXVHVXVUHWDOLNUR]LPSOHPHQWDFLMXWHNOMXþni faktori
koji su pomogli u ovom procesu. [21] Od spomenutih 18 primjera u ovom radu dana jeanaliza samo izabrana dva hotela sa kojima mogu QDüL VOLþQRVWL PDQML KUYDWVNL WXULVWLþNL
objekti.

Energy and the Environment (2016) 327-336

333

HOTEL “LA PEROUSE” je manji hotel u Francuskoj, u centru Nantesa sa 3 zvjezdice. U
SULYDWQRPMHYODVQLãWYXLL]JUDÿHQMHJRGLQH
Ekološke karakteristike: Ekološke oznake koje ovaj hotel posjeduje su: Green key, EU
Ecolabel. [22] [23]*RGLãQMDSRWURãQMDHQHUJLMHMHN:KPVDVWRSRPRNXSLUDQRVWL3RWURãQMDHOHNWULþQHenergije po gostu je 14 to 16 kWh.
PRISTUP HOTELIJERA: Želja direktora hotela bila je stvoriti ekološki održivi hotel uz
potpuno zDGRYROMVWYR L ]DSRVOHQLND L JRVWD 'LUHNWRU MH RGOXþLR X]HWL X RE]LU HNRQRPVNH
]QDþDMNHWHWDNRÿHUQH]DQHPDULWL VRFLMDOQHLHNRORãNH]QDþDMNHX]LPDMXüLXRE]LU zabrinutost
oko klimatskih promjena åHOHüLVPDQMLWLXWMHFDMnjegovog hotela na okoliš. Tada se upustio u
jednogodišnje istraživanje eko oznaka te je hotel ostvario oznake Green key i EU Ecolabel.
Ove dvije oznake vidno su poboljšale kvalitetu usluge pružane u ovom hotelu.
23,6 0-(5$ 2ý89$1-$ (1(5*,-(: Poduzete su mjere X VYUKX RGUåLYRVWL L RþXYDQMD
energije. Postavljene su naprave za mjerenje potrošnje energije u hotelskim sobama i izvan
QMLKNDNRELVHPRJOREROMHXWYUGLWLNROLNRHQHUJLMHVHWURãLLQDãWR2QRãWRVXWDNRÿHUXþLnili
MHDNWLYDFLMDRVREOMDýHVWLPVDVWDQFLPDSRGL]DODVH VYLMHVWRRþXvanju okoliša i informiranostosoblja NDNRRQLPRJXSRPRüLXRþXYDQMXHQHUJLMH7DNRÿHUVHUDGLlo i na informiranju gosta
RPMHUDPDHQHUJHWVNHXþLQNRYLWRVWLWHNDNRRQLVDPL PRJXWRPHSULGRQLMHWL*RVWLYHüLQRPSRGUåDYDMX RYDM VXVWDY UDGD WH SULKYDüDju uvjHWH V ODNRüRP %LWQR MH informirati i goste iosoblje, gdje se najviše troši HQHUJLMHWHSUHSRUXþLWL]LPVNHLOMHWQHVREQHWHPSHUDWXUH unutar
hotela.
+27(/ Ä/(6 25$1*(5,(6³ MH PLUDQ VHRVNL KRWHO X )UDQFXVNRM 2VREOMH þLQL 
zaposlenika. Hotel nudi bazen, ugodne sobe te prostor za sastanke. Ima 3 zvjezdice i uprivatnom je vlasništvu.
Ekološke karakteristike: oznaka EU Eco-label od 2007.godine.
35,6783 +27(/,-(5$ ³/HV 2UDQJHULHV´ MH UHODWLYQR QRY KRWHO WH YODVQLN LVWLþH NDNR MHNOMXþQMLKRYRJXVSMHKDVWDOan rad na poboljšanju i stalna implementacija novih tehnologija u
VYUKXRþXYDQMDHQHUJLMH9ODVQLNWYUGLNDNRPXMHR]QDND(FR-ODEHO(8GRQLMHODQHVDPRYHüL
uspjeh nego i želju i volju za stalnim poboljšanjem.
23,60-(5$ 2ý89$1-$(1(5*,-(6YDND  PMHVHFa mjeri se stopa potrošnje energije
koja se prezentira osoblju te se radi na osmišljavanju plana kako je reducirati. Vlasnici ovog
KRWHODQDãOLVXYUORMHGQRVWDYDQQDþLQLQIRUPLUDQMDJRVWLMXRNRRþXYDQMDHQHUJLMHQDXOD]XX
hotel, na recepciji se nalaze lHWFLNRMHJRVWPRåHX]HWLWHVHLQIRUPLUDWLRQDþLQXSRVORYDQMDKRWHODLãWRRQVDPPRåHXþLQLWLNDNRELVHHQHUJLMDRþXYDODâWRVHWLþHLQIRUPLUDQMDRVREOMDQDMYLãHSDåQMHVHSRVYHüXMHNXKLQMLLNXKLQMVNRPRVREOMXMHUSRVWRMLXYMHUHQMHGDVHXRGMHOX
kuhinje troši najviše energije, iako prema istraženoj literaturi ta tvrdnja ne stoji. Na
sastancima se osoblje informira o potrošnji energijeDWRQDMþHãüHRYLVLRJRGLãQMHPGREXMHU
se potrošnja energije prati s obzirom na period. Neke jednostavne mjere koje vlasnici hotela
UDGH X VYUKX RþXYDQMD HQHUJLMH VX QSU NRULãWHQMH WUDNLFD QD YUDWLPD L SUR]RULPD NDNR EL VH
VSULMHþLo prodor hladnog/toplog zraka.
35('1267, .DR SUHGQRVWL RYRJ SULVWXSD QDYRGL VH HNRQRPVND XþLQNRYLWRVW QH VDPRHNRORãNDDRþXYDQMHHQHUJLMHSRGLJORVH]D7DNRÿHU(8(FR-ODEHOMHRGOLþQDR]QDND]D
PDUNHWLQãNLLPLGåMHUGDMHKRWHOXYHüXYLGOMLYRVWQDWUåLãWXLEROMXNRQNXUHQWQRVWâWR VH WLþH KRWHOD X 5HSXEOLFL +UYDWVNRM nekolicina ih posluje po principu zelenog
hotelijerstva, te analizom sadašnjeg stanja 2016.godini 41 hotel ima certifikat o održivom
poslovanju "Sustainable Hotel Certificate by UPUHH",[25] koji im je dodijelila Udruga
poslodavaca u hotelijerstvu Hrvatske (UPUHH) od 2014. do 2016. godine. Certifikat

334

0.ULVWLQLü1LåLü: 8þLQNRYLWRNRULãWHQMHHQHUJLMHXWXULVWLþNLPREMHNWLPD„Sustainable Hotel“ MDPþL GD REMHNWL X VYRP SRVORYDQMX VOLMHGH VYMHWVNH WUHQGRYH RGUåLYRJSRVORYDQMDSRSXWXVSMHãQRJXSUDYOMDQMDRGUåLYRãüXXVYDNRGQHYQRPKRWHOVNRPSRVORYDQMX
]DãWLWL RNROLãD L VWDOQRP UD]YLMDQMX VYLMHVWL R WRM ]DãWLWL HQHUJHWVNH XþLQNRYLWRVWL HGXNDFLje
zaposlenika, uštede energije i vode, nabave, prodaje, marketinga i PR-a, kao i kontroleispuštanja emisije CO2. Plan je da do kraja 2018. koncept zelenog poslovanja usvoje i ostali
KRWHOLXþODQVWYX838++-DNRMLKMHEOL]XLþLQHRNRSRVWRXXNXSnom hotelijerstvu
Hrvatske, kao i da se projektu pridruže i ostale strukovne udruge - NDPSLQJD QDXWLþNRJ
WXUL]PD L GUXJLK VHJPHQDWD WXULVWLþNH SRQXGH Troškove tog projekta snosi UPUHH uz
sufinanciranje Ministarstva turizma i drugih partnera, a njegov strateški cilj oslanja se na
ciljeve iz Strategije razvoja hrvatskog turizma do 2020. koji se temelje QDXYRÿHQMXSUDNVH
zelenog poslovanja, što podrazumijeva sinergiju ekonomske dobiti, brige za okoliš u najširemVPLVOXWHVRFLMDOQHXNOMXþHQRVWLXãLUX]ajednicu. [26]4. =$./-8ý$.
7XULVWLþNLREMHNWLVYLKWLSRYDVXRþHQLVXVQL]RPL]D]RYDMHUJlobalizacija uzrokuje pojavu sve
više novih destinacija, kao i ulazak novih brendova na tržišteþLPHVH]DRãWUDYDNRQNXUHQFLMD
Kako komponenta cijene osoblja teško dolazi u pitanje (pokazatelji UNWTO-a govore ostalnom rastu) uz neke druge manje racionalizacije, poboljšanje energetske XþLQNRYLWRVWL isamim tim sniženje troškova, QDPHüHVHNDRQXåDQL]ERUWLPYLãHãWRWRPRåHSROXþLWLLQHNH
dodatne pozitivne efekte. Najdirektniji je pozitivan utjecaj na okoliš, odnosno prostor, a on je
u svoj svojoj ukupnosti najinteresantniji upravo turizmu EXGXüL GD VX QD QMHJD NDR QD
SULPDUQL UHVXUV GRPLQDQWQR QDVORQMHQL L QDGRJUDÿHQL Vrlo je bitno smanjiti energetske
potrebe pri projektiranju, L]JUDGQML UHNRQVWUXNFLML WXULVWLþNLK REMHNDWD WH JUDGLWL SDVLYQH
objekte i objekte nulte emisije po uzoru na zero energy hotele. [27] Primjeri hotela iz ovog
UDGD SRND]XMX NDNR HGXNDWLYQLP L WHKQLþNLP PMHUDPD smanjiti potrošnju energije, te kako
XNOMXþLYDQMHP RVREOMD L JRVWLMX SRYHüDWL XãWHGX energije. Iz tih primjera vidljiva je važnost
uklanjaQMDEDULMHUDXXYRÿHQMXPMHUDHQHUJHWVNHXþLQNRYLWRVWLXSRVWRMHüHREMHNWH, te važnost
XYRÿHQMD REQRYOMLYLK L]YRUD HQHUJLMH L HQHUJHWVNL XþLQNRYLWLK tehnologija. =DNOMXþXMH VH GD
usprkos što veliki hotelski lanci raspolažu znatnim financijskim sredstvima, koja mogu
LQYHVWLUDWL X VNXSH WHKQRORJLMH LSDN ]QDWQD SREROMãDQMD SRND]XMX L PDOD L VUHGQMD SRGX]HüD
Primjeri dokazuju da je upravo vlasnik ili menaGåHU REMHNWD NOMXþQD RVRED SUL GRQRãHQMXWDNYLKRGOXNDDOLX]HGXNDFLMXLSRWSRUXVYLK]DSRVOHQLNDQDRSüXNRULVWQMLKVDPLKJRVWLMXLFLMHOH WXULVWLþNH GHVWLQDFLMH 8þLQNRYLWLMH NRULãWHQMH HQHUJLMH SRYHüDYD  L XNXSQX RGUåLYRVWWXULVWLþNHGHVWLQDFLMH.
LITERATURA[1] UNEP&UNWTO, Tourism in the Green Economy – BackgroundReport, 2012.
http://www.unep.org/greeneconomy (01.07.2016.)[2] EC (European Commission), Guide on EU Funding for the TourismSector, 2014.
http://ec.europa.eu/enterprise/sectors/tourism/index_en.htm(01.07.2016.)[3] 6DWHOLWVNLUDþXQWXUL]PD5+]DJRGLQXLL]UDþXQQHL]UDYQLKXNXSQLKXþinaka turizma
u RH, Institut za turizam, 2014.
[4] Državni zavod za statistiku, www.dzs.hr[5] UNWTO&UNEP (2008) Climate Change and Tourism,
http://sdt.unwto.org/sites/all/files/docpdf/climate2008.pdf (05.07.2016.)

Energy and the Environment (2016) 327-336

335[6] Zografakis, N., Sifaki, E., Assessment of public acceptance and willingess to pay forrenewable energy sources in Crete, Renewable and Sustainable Energy Reviews Elsevier,Vol. 14 , 2010., 1088
[7] Marunda, E., Judias, P., Blessing, M., Challenges facing use of energy in the tourism andhospitality industry in Zimbabwe and policies that can promote the sustainable use ofrenewable energy and tourism development, International Journal of Developmet andSustainability, Vol. 2,2013., 475[8] Kirk, D., Environmental management in hotels, International Journal of Contemporary
Hospitality Management, Vol. 7., 1995., 3[9] Kostakis, I., Sardianou, E., Which factors affect the willingness of tourists to pay forrenewable energy?, Renewable Energy an International Journal, Vol. 38, 2012., 172[10] Graci, S., Dodds, R., Why go green? The business case for enviromental commitment in
the Canadian hotel industry, Anatolia, Vol. 19, 2008., 261[11] 3DYORYLü'Energetska efikasnost u hotelskoj industriji- SXWXNRUSRUDWLYQRJUDÿDQVWYR,
Acta Turistica nova, Vol.2, No2, 2008., 155-179.
>@5DGLü/DNRã7LGUNorma ISO 14000 u hrvatskim hotelima,
https://bib.irb.hr/datoteka/582662.Norma_ISO_14000_u_hrvatskim_hotelima.pdf(05.07.2016.)[13] 3HWULü/³Destinacijski menadžment´(NRQRPVNLIDNXOWHW6YHXþLOLãWDu Splitu, Split,
2006., str. 60-62.
[14] U.S. Environmental Protection Agency and the U.S. Department of Energy: Energy Star
for Hospitality 2006.
[15] 3DYORYLü'Energetska efikasnost u hotelskoj industriji- SXWXNRUSRUDWLYQRJUDÿDQVWYR,
Acta Turistica nova, Vol.2, No2, 2008., 155-179.
[16] Office of Energy Efficiency - Natural Resources Canada: Saving Energy Dollars in
Hotels, Motels and Restaurants[17] Chan, E.S.W., Barriers to EMS in the hotel industry. International Journal of Hospitality
management, 27(2), 2008., 187-196.
[18] PHWULü/ 3UDQLü/MCroatian hoteliers’ attitudes towards environmental
management, CD-ROM with Proceedings of the Eight International Conference: “Challengesof Europe: Financial Crisis and Climate Change.” ISSN 1847-4497, Ekonomski fakultet,
Split, 2009.
[19] Best Practices Guide – Successful EET Integration in SME Hotels
http://hes.unwto.org/sites/all/files/docpdf/bestpracticesguidesuccessfuleetintegrationinsmehot
elsaugustfinalversion2.pdf (15.06.2016.)[20] Hotel Energy Solution www.hes.unwto.org (15.07.2016.)[21] Key Energy Efficiency Solutions for SME Hotels
http://hes.unwto.org/sites/all/files/docpdf/keyenergyefficiencysolutionsaugustfinalversion.pdf(05.07.2016.)[22] Green Key http://www.greenkey.global/[23] European Commission EU Ecolabel http://ec.europa.eu/environment/ecolabel/(01.07.2016.)[24] Ministarstvo turizma http://www.mint.hr/default.aspx?id=15069 (10.07.2016.)[25] Udruga poslodavaca u hotelijerstvu Hrvatske http://www.upuhh.hr/hr/vijesti/dodjelasustainable-hotel-certificate-by-upuhh/ (15.07.2016.)[26] Strategija razvoja turizma Republike Hrvatske do 2020. godine
http://www.mint.hr/UserDocsImages/Strategija-turizam-2020-editfinal.pdf (01.07.2016.)[27] Nearly Zero Energy Hotels http://www.nezeh.eu/home/index.html (05.07.2016

336

0.ULVWLQLü1LåLü: 8þLQNRYLWRNRULãWHQMHHQHUJLMHXWXULVWLþNLPREMHNWLPDENERGY EFFICIENCY SOLUTIONS IN TOURIST FACILITIESAbstract: Tourist facilities are large consumers of energy, which implies high energy costs.
Energy costs can be more efficiently controlled, which affects the final financial results andincreases profits. There are many investment studies and implementation of energy efficiency
projects to reduce energy costs, but they should be treated and applied selectively, while notdropping the level of service quality and guest satisfaction. One way to encourage energy
efficiency and the rational use of energy in tourist facilities is to promote the most flexible,
most practical and most cost-effective solutions, in order to improve their energy efficiency,
use of renewable energy sources, but also to raise the guest’s awareness of environmental
preservation. The paper analyses the examples of small and medium-sized tourism enterprises
as well as large hotel chains in the implementation of energy efficiency measures andrenewable energy sources. Research shows that small independent tourist facilities, due tolack of financial and technological basis, less proactive on the environment than large hotel
chains. Nonetheless, driven by its own investments, effort, enthusiasm and faith, theecological solutions offered by smaller objects or individuals, can serve as an example tosimilar facilities in Croatia. The achieved results are reflected in the improvement of guest
satisfaction, reduction of maintenance costs and system failures, raised value of equipment
and facilities, improvement of corporate culture and awareness, and reduced emissions, all ofwhich are the only and correct way to sustainable development.
Key words: energy efficiency, tourist facilities, energy saving, sustainable development

Energy and the Environment (2016) 337-348

337

FUNCTIONAL DEPENDENCIES OF THE SIZE OF CERTAIN PARTS
OF THE ENERGETICALLY AND HYDRAULICALLY SUSTAINABLE
URBAN WATER SUPPLY SYSTEM DRIVEN BY SOLAR
PHOTOVOLTAIC ENERGY

1%RMDQĈXULQ*1/XFLMD%DLü1
Faculty of Geotechnical Engineering, University of Zagreb, Varaždin, Croatia.
Tel: 0038(5)42408933, Fax: 0038(5)42313587, Email: bojan.djurin@gfv.hr

Abstract: The use of solar photovoltaic cells in electric energy production for the operation ofpumping stations that pump water is a well known and established technology. However, theiruse and integration into the work of urban water supply system has not been fully explored.
So far, simplified procedures and methodologies have been used that partially solved theissues of reliability and efficiency of such systems, where ultimately such systems were notenergetically and hydraulically sustainable. This paper describes the Critical Period Method
which eliminates these deficiencies, where functional dependences of the size of certain partsof hydraulically and energetically sustainable urban water supply system will be explored anddefined. This will give a more detailed insight into the work of this system.
Keywords: solar photovoltaic energy, water supply system, energetic and hydraulicsustainability, Critical Period Method, functional dependencies

1. INTRODUCTION
The use of solar photovoltaic (PV) energy in the water supply system is an already known
technology [1-3]. This paper presents and explains functional dependencies between
individual parts of the Urban Water Supply System (UWSS) driven by PV energy. The
analysis of this dependence is necessary to fully understand the operation of such system.
This analysis was performed for the case of an open reservoir from where water is pumped
using a PV generator [3], where functional dependence between the power of the PV
subsystem and reservoir volume was established. However, this hasn't been done for the caseof water reservoir of a urban settlement, i.e. for the water supply system.
In addition, this paper explains the scientifically innovative and, in view of engineering,
applicable methodology for dimensioning the sustainable urban water supply system driven
by PV energy, which then becomes Energy Sustainable Urban Water Supply System(ESUWSS). This methodology is called the Critical Period Method (CPM) and is elaborated
in detail and explained in [2] and [3]. The analyzed system consists of three main parts(Figure 1). These are: PV plant - solar photovoltaic generator and inverter with corresponding338%ĈXULQ/%DLü: Functional dependencies of the size…

equipment - subsystem PV, pumping station with related equipment - subsystem PS andreservoir with related equipment - subsystem V. These subsystems make up an integrated
technological system and are functionally interconnected. This system basically turns solar
energy from the environment during solar radiation into electrical energy in the subsystem
PV, which is used for pumping water (mechanical energy) into the water reservoir.

ES
Reservoir
V
Users

PV
generator

HPS
Hg
VPS

Pump
stationEel, PV

Invertor

To otherusers

Water intake

Figure 1. Urban Water Supply System (UWSS) driven by solar photovoltaic (PV) energy
Solar energy is of stochastic nature in view of intensity and duration of solar radiation,.
Therefore, the role of water reservoir as a container of water, i.e. energy, in conjunction withpossible electric energy production from the subsystem PV, is crucial in providing thecontinuity and safety of water supply. Therefore, the system must be appropriately plannedand dimensioned, i.e. the methodology described in this paper must be applied. Given thescope and purpose of this study, the procedures and terms for dimensioning individual partsof the system will not be explained, but they can be found in [2] and [3].

2. METHODOLOGY FOR DIMENSIONING AND SELECTING THE SOLUTION
2.1. Critical Period Method
Novelty or the difference between the previous ways of dimensioning and dimensioning using
the CPM is that instead of one critical period which relates to the maximum daily
consumption of water, the CPM considers three critical periods. In the case of using PV
energy for UWSS, these critical periods are: critical period for sizing the subsystem PV (PVgenerator and inverter) t *Pel ( i ) , critical period for sizing the subsystem PS (pumping station)t *PS ( i ) and critical period for sizing the subsystem V (water reservoir) tV* ( i ) [3]. This provides
security of the operation of each subsystem, since the sizing is performed with respect to theEnergy and the Environment (2016) 337-348

339

critical period/periods of each subsystem, which allows operating integrity of the entire
ESUWSS.
The first critical period t *Pel ( i ) is defined for determining sufficient power of subsystem PV
Pel,PV, which will provide enough electric energy for pumping water into the reservoir every
day of the analyzed year, in accordance with the regime of daily water consumption in asettlement. This is the period (periods) in which the difference ¨9Pel(i) between the dailyrequired water for population needs Vdaily(i) and daily pumped water VPS(i) is minimum forevery day of the year with regard to the balancing period tb :'VPel ( i )Vdaily ( i )  VPS ( i ) , i = 1, 2,..., 365 => min 'VPel ( i )  t *Pel ( i )(1)where ¨9Pel(i) is acceptable difference in practical application, which is normally 0.
The duration of daily solar radiation Ts(i) determines the possible operating period of thepumping station. This introduces the second critical period (periods) t *PS ( i ) for determining thecapacity or power of the pumping station. t *PS ( i ) is the critical period (periods) in which therelationship between the daily consumption of water in a settlement Vdaily (i) and duration ofdaily solar radiation Ts(i) is minimum:
max Qdaily

Vdaily ( i )Ts( i )

 t *PS ( i )(2)

It is understood that adequate PV subsystem power Pel,PV is provided, with respect to thecorresponding critical period t *Pel ( i ) . Thus, in accordance with the rules of the profession, thecapacity of the pumping station is determined that can pump the required quantity of water
Qhour(t) (m3/h), which in fact represents the highest flow per hour during a typical year in theplanning period.
The critical period (periods) tV* ( i ) for determining the reservoir volume V is the period inwhich maximum daily water consumption in a settlement Vdaily(i) for each day i is maximum
during the year, where the intensity of solar radiation Es(i) and its duration Ts(i) is satisfactory,
so that subsystem PV can produce sufficient electricity to drive the main pumping station. It is
understood that adequate PV subsystem power Pel,PV is provided with respect to thecorresponding critical period t *Pel ( i ) and sufficient subsystem PS capacity QPS, also withrespect to the corresponding critical period t *PS ( i ) :max Vdaily ( i )  tV* ( i )

(3)

340

%ĈXULQ/%DLü: Functional dependencies of the size…

Each of the three critical periods is determined with regard to a certain balancing period(periods) tb, i.e. equalization periods of the required and pumped water or equalization periodsof the required and produced energy. The shortest possible balancing period tb is one day.
When the balancing period tb is longer the solution is in principle safer, because longer
balancing period reduces the impact of extreme low insolation Es on the required power of thesubsystem PV, Pel,PV. In addition, the system is more efficient with regard to the possibility ofusing solar radiation, since the sum of the total available solar insolation is greater when tb islonger, because it eliminates the impact of extreme maximum individual daily duration andintensity of solar radiation. Therefore, the solution is safer and more rational in view ofdimensioning the subsystem PV. This means that the required water can be pumped with alower installed power of the subsystem PV.

2.2. Forming time series elements for the pumped and required quantity of water
The CPM uses time series in the planning period according to the chosen length of thebalancing period. In the balancing period tb longer than one day there are two possible waysof forming the elements of time series. Time series can be formed in two ways: (i) as sets of tb
days in which elements of the sequence don't overlap, i.e. sets are added to each other without
overlapping of days; (ii) as sets of tb days in which the elements of the sequence move for ǻt= 1 day along the planning (calculation) period. So, in this case, elements of the sequence
overlap in a number of days equal to tb - 1. [3] shows that the first method generates
discontinuous values from the sequence of available values. Due to overlapping, the second
method forms continuous values similar to the set (original) sequence. It is also shown that in
the first method (because certain days don't overlap) leaps in values of certain elements oftime series may occur, which ultimately can result in discrepancies in values of certain partsof ESUWSS, i.e. subsystems PV, PS and V. In the second method leaps in values of certain
elements will not occur, or they will be lower than in the first method. For these reasons, thefirst method will not be considered, but the presented CPM will be applied using the second
method of forming time series (CPM-2). Figure 2 shows the process of forming the timeseries for the balancing period tb = 2 days.

Energy and the Environment (2016) 337-348

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Figure 2. Schematic presentation of forming the time series elements for the balancing period
tb = 2 days

3. EXAMPLE
In this section values of all parts of the analyzed ESUWSS are calculated in accordance withthe proposed methodology, namely: power of the subsystem PV (PV generator and inverter)
Pel,PV, capacity QPS, i.e. power PPS of the subsystem PS (pumping station) and volume of thesubsystem V (water reservoir), together with the associated critical period (periods) for sizing**
the said subsystems, t *Pel ( i ) , t PS(i ) i tV ( i ) . The above is done for the second method for times
series formation, CPM-2, for balancing period tb from 1 till 5 days. The example in whichelectric energy needed to operate the pumping station is provided from the subsystems PV isanalyzed. It is a settlement of 8970 inhabitants and is located in the Mediterranean part of
Croatia on a hilly area. Specific water consumption is qspec = 160 l/capita/day. The adopted
maximum coefficient of daily unevenness is KD,max = 1.65, while the maximum coefficient ofhourly unevenness is KH,max = 2.52. The regime of daily consumption Qdaily(i) for each day i ofthe year is shown in Figure 3. The regime of hourly water consumption is shown in Figure 4.

%ĈXULQ/%DLü: Functional dependencies of the size…

Daily water consuption Qdaily (m3/day)

342

2400
2200
2000
1800
1600
1436
1400
1200
1000
800 676
600
400
200
0
1

2366

2366

1436

676

74

147
220
Time i (days)

365

293

12.00
11.00
10.00
9.00
8.00
7.00
6.00
5.00
4.00
3.00
2.00
1.00
0.00

10.50
Consumption

Average

8.00

9.00
8.00

7.50
7.00

6.00
4.00 4.00

4.17

4,00
3.00 3.00

3.00 3.00
2.00

2.00
1.00 0.50
0.50 0.50

4.50

4.00 4.17
3.00
2.00

0-1
1-2
2-3
3-4
4-5
5-6
6-7
7-8
8-9
9-10
10-11
11-12
12-13
13-14
14-15
15-16
16-17
17-18
18-19
19-20
20-21
21-22
22-23
23-24

Hourly water consumption (% of daily
flow)

Figure 3. Daily water consumption regime during the year [5]Time (h)Figure 4. Hourly water consumption regime during the day [5]For the observed location, the calculated average manometer height HPS is 82.41 m, average
efficiency of the inverter is ȘI = 0.83, while the average efficiency of the pump station is ȘPS =0.90. Average efficiency of the inverter and the pump is ȘPSI = 0.75, while the temperature
coefficient of solar cell is ĮC = 0.005 °C-1. The adopted efficiency of the PV subsystem is ȘPV= 0.15. Average daily intensity of the global solar radiation Es(i) on a horizontal plane andaverage duration of solar radiation Ts(i) are shown in Figure 5.

Energy and the Environment (2016) 337-348

343

8,000

18

7,000

16

6,000

14

5,000

12
10

4,000

8

3,000

6

2,000

4
Average daily insolation period
Average daily global radiation

2

1,000

0

Average daily global radiation ES(i) (Wh/m2)

Average daily insolation period TS(i) (h)

20

0
0

73

146
219
Time i (days)

292

365

Figure 5. Average daily intensity and duration of solar radiation, [3]Figure 6 presents the average daily air temperature Ta(i) (°C) [3] and average daily temperatureof solar cells Tcel(i) (°C), calculated using the standard methodology from [3].
50.0
45.0
40.0

Temperature (°C)

35.0
30.0
25.0
20.0
15.0
10.0
Average daily ambient air temperature

5.0

Average daily cell temperature

0.0
0

73

146
219
Time i (days)

292

Figure 6. Average daily air temperature and solar cells, [4]

365

344

%ĈXULQ/%DLü: Functional dependencies of the size…

4. THE OBTAINED RESULTS
Critical days for all balancing periods tb, obtained by Eq. (1-3) are shown in Table 1.
Table 1. Critical days for all balancing periods tb
Balancing periods tb (days)
Critical period(s) for
CPM-1

1

2

3

4

5

352

349-350

343-345349-352346-350subsystem PV, t *Pel ( i ) (days)

CPM-2

352

344-345344-346349-352348-352

Critical period(s) for

CPM -1

352

345-346343-345349-352341-345subsystem PS, t *PS ( i ) (days)

CPM -2

352

344-345344-346344-347

343-347

Critical period(s) for

CPM -1

244

243-244244-246241-244241-245*subsystem V, tVop
( i ) (days)

CPM -2244

244-245

243-245

243-246242-246

Power of PV generator and inverter
Pel,PV (kW)Due to the methodology, it will be analyzed the dependence of system values as a function ofbalancing period tb, in order to determine their possible functional connection. Based on theobtained results of the size of subsystem PV and the size of subsystem V, in order to ensure
the water supply, the functional dependence of these two values is determined based on thebalancing period tb, Figure 7.
600,00550,00500,00450,00Pel,PV = 86562,012Vop -0,735
R² = 0,977
tb =1
tb =2
tb =3

400,00tb =4350,00300,00

tb =5

CPM-2

250,00200,001050 1100 1150 1200 1250 1300 1350 1400 1450 1500 1550
Operative volume of water reservoir Vop (m3 )Figure 7. Functional dependence of PV generator and inverter power Pel,PV and operative
volume of the water reservoir Vop for CPM-2
In the second case of forming time series CPM-2, the dependence is obvious as well as
continuity, which is shown by determination coefficient R, i.e. the square of its value R2 =0.977. It is evident that with the extension of the balancing period the size of the required
power of PV generator and inverter, Pel,PV, decreases and the size of the required volume ofEnergy and the Environment (2016) 337-348

345

water reservoir Vop increases. The trend of changes grows smaller and tends to the final valuethat would be obtained if the balancing period tb was equal to the analyzed period (one year ormore). However, it should be borne in mind that the obtained pairs of variables Pel,PV and Vop
for tb are discrete values in function of discrete value tb, not continuous, so that the establishedfunctional dependence is only indicative, but not entirely accurate.

Power of PV generator and inverter Pel,PV(kW)

In subsystem PS or in the capacity of the pumping station QPS (and thus the associated powerof the pumping station PPS) there is no continuity of value order of pairs of power Pel,PV andcapacity QPS, Figure 8. Therefore, there is no need to analyze the trend.
550,00525,00

CPM-2

tb =1

500,00tb =2475,00450,00tb =3425,00400,00375,00

tb =5

tb =4

350,00
325,00300,00110 112 114 116 118 120 122 124 126 128 130 132 134
Pumping station capacity QPS (l/s)

Figure 8. Functional dependence of PV generator and inverter power Pel,PV and pumping
station capacity QPS for CPM-2
However, the presented results show basic and logical lawfulness between power Pel,PV andcapacity QPS, resulting from the pumping station function in the system. This dependence is
proportional. Greater power Pel,PV means larger capacity QPS, i.e. longer balancing period tbmeans smaller power Pel,PV, and therefore less required power QPS.
Similar conclusions can be drawn for the connection between the reservoir operating volume
Vop and pumping station capacity QPS (and thus associated pumping station power PPS). Thereis no continuity in value order of pairs of the two values, Figure 9, so there is no need toanalyze the trend, i.e. correlation between these two values.

%ĈXULQ/%DLü: Functional dependencies of the size…

Operative volume of water reservoir Vop
(m3 )

346

1600
1500

CPM-2
tb =5

tb =4

1400
1300
tb =3
1200
1100

tb =2
tb =1

1000
110 112 114 116 118 120 122 124 126 128 130 132 134
Pumping station capacity QPS (l/s)

Figure 9. Functional dependence of reservoir operating volume Vop and pumping station
capacity QPS for CPM-2

5. CONCLUSION
The resulting functional dependences of certain parts of ESUWSS show significant
correlation between the PV subsystem power and reservoir volume, while such functional
dependence does not exist between other parts. It is clear that the exponential dependence best
connects the pairs of value Pel,PV and Vop, which was determined in previous studies related toopen reservoirs, although it is basically not the same type of problem [4].
This proves that the reservoir with its usual hydraulic role of storing water also has thefunction of energy reservoir through the proven functional connection with the source ofenergy, which is in this case subsystem PV. This relationship between stochastic input energy
and deterministic output energy is expected, because larger reservoir volume reduces theinfluence of some extreme time series values of the input solar radiation intensity (solar
energy).
The second method of forming the time series, CPM-2, is apparently more natural and thus
more correct and provides more realistic results in the function of the balancing period tb. The
resulting functional dependency allows empirical extrapolation and the analysis of possible
results for longer tb. No functional dependences were obtained among other values, as wasobserved between subsystem PV and water reservoir. However, the obtained results show
basic and logical lawfulness between the reservoir operating volume Vop and pumping station
capacity QPS, which stems from the function of the pumping station in the system ofconnection between the capacity QPS and power Pel,PV. Greater capacity QPS means smaller

Energy and the Environment (2016) 337-348

347

operating volume Vop, i.e. longer balancing period tb means larger operating volume Vop, andtherefore lower required power Pel,PV. All previously analyzed and obtained can also be
expected in the case of different climatic regions, but with different input values. Therefore,
the presented results are a good indicator of behaviour of the system and system dimensioning
method.

REFERENCES[1] Kenna, J., Gillett, B.: Solar Water Pumping: A Handbook, Intermediate Technology
Publications, London, United Kingdom, 1985.
[2] ĈXULQ%0DUJHWD-Analysis of the Possible Use of Solar Photovoltaic Energy in Urban
Water Supply Systems, Water, 6(6), 2014, 1546-1561.
[3] ĈXULQ % Sustainability of the urban water supply system operating, PhD thesis (inCroatian), Faculty of Civil Engineering, Architecture and Geodesy, University of Split, Split,
Croatia, 2014.
[4] *ODVQRYLü=0DUJHWD-: Vision of total renewable electricity scenario, Renewable andSustainable Energy Reviews, 2011, 15, 1873-1884.
[5] Margeta, J.: Water Supply: Planning, Design, Management and Water Purification, (inCroatian), Faculty of Civil Engineering and Architecture, University of Split, Split, Croatia,
2010.

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Energy and the Environment (2016) 349-358

349

IMPLEMENTATION OF INNOVATIVE ENERGY RETROFITTINGMEASURES IN HERITAGE BUILDINGS – A REVIEWŽiva Kristl
European faculty of law, Delpinova 18 b, 5000 Nova Gorica, Slovenia
ziva.kristl@evro-pf.si

Abstract: Statistical data show that around a quarter of the existing building stock in Europe
was built prior to the middle of the last century and that they have low energy performance.
Many of these buildings are valued for their cultural, architectural and historic significanceand at the same time present essential infrastructure for housing and public buildings. Even
though energy retrofitting of historical and heritage buildings is exempt from EU
requirements, a number of examples show, that energy retrofitting of heritage buildings is an
issue that has to be taken into consideration. The aim of this study is to carry out a systematicand comprehensive literature review in the field of efficient implementation of innovative
energy retrofitting measures in heritage buildings. The measures are divided into three maingroups, e.g. interventions into the building tissue, installation of mechanical equipment andoperation control. The results show that in the recent years the number of projects andpublished papers in the field of energy retrofitting of heritage buildings has substantially
increased. A well covered topic is architectural integration of thermal insulation.
Implementation of HVAC equipment is a much debated topic, usually limited to non-invasive
and discrete solutions. The role of management, monitoring and feedback of building
operation has not been widely recognised as one of the important potentials for energy use
reduction in heritage buildings.
Keywords: heritage buildings, energy retrofit, energy efficiency, user comfort, control
systems
1.

INTRODUCTION

In the following years energy retrofitting of the existing buildings will be one of the maintasks in EU [1]. As the November 2008 Commission Communication for the original proposalof the EPBDr [2] states, “buildings have significant untapped potential for cost effectiveenergy savings“, however, heritage buildings are exempt from these requirements. Statistical
data show, that existing buildings are far more numerous than new buildings and also havesignificantly inferior energy performance. Around a quarter of the existing building stock in
Europe was built prior to the middle of the last century. Many such buildings are valued fortheir cultural, architectural and historic significance and at the same time present essential
infrastructure for housing and public buildings [3]. These buildings often contain energyconsuming systems to provide building services, many of which are elderly, inefficient, or
neglected. This presents a considerable potential for renovation. Energy retrofitting of
heritage buildings however, requires a special approach because these buildings are usuallysubmitted to a set of protective requirements which inevitably restrict the use of viable energy
retrofitting measures. This is understandable, because potentially, good energy performancecan be achieved by using modern building materials and techniques, but there is a risk of
irreparable change of WKHDSSHDUDQFHRIDKHULWDJHEXLOGLQJ3HQLüD et.al. [4] acknowledge that
there is a need to preserve architectural heritage and at the same time to upgrade historicalbuildings to modern requirements. Filippi [5] draws attention to another important fact:
refurbishment works and renovated buildings can take on an interesting market value,350

Ž. Kristl: Implementation of innovative energy retrofitting measures…

however, cultural heritage buildings require a specific design approach, and green retrofitting
is often not attractive from an economic point of view.
This paper investigates the effects of various energy efficiency approaches on energy
performance of cultural heritage buildings. The goal of the study is to carry out a systematicand comprehensive review of the efficient implementation of innovative energy retrofitting
measures in heritage buildings. The measures are divided into three main groups, e.g.
interventions into the building tissue, efficient mechanical equipment and operation control.
Findings of the study are intended to define the main advances associated with the heritagebuildings retrofitting measures, energy use reduction, and are the basis for further researchand development of improved strategies for energy retrofitting of heritage buildings.
2.

STUDY SETUP

In the paper a systematic and comprehensive review of scientific literature dealing withefficient implementation of innovative energy retrofitting measures in heritage buildings was
carried out. Two main groups of publications were reviewed, the EU funded FP and
Horizon2020 Project reports and Science Direct and World Wide Science databases. The
databases were searched for peer-reviewed publications written in English from 1990 to 2016,
with the keywords “heritage building”, „historic building“, “listed building“, “energy use”,„energy efficiency“, “energy retrofitting“ „deep renovation“, and „refurbishment“ together
with, “thermal insulation”, “new material”, “HVAC”, “PV”, “solar” and “control”. The
collected data was edited and further analysed.
It was anticipated, that the measures could be categorised into three main groups:- Interventions into the building tissue (e.g. implementation of innovative thermal
insulation materials, efficient windows etc.);- Efficient mechanical equipment (e.g. heating, ventilation, air-conditioning, PV andsolar thermal);- Operation control (e.g. automatic control, building management system);
3.

RESULTS AND DISCUSSION

Generally, the literature review shows that despite the fact that heritage buildings are
excluded from national and EU regulations concerning the energy performance of buildings,
the debate about this issue has intensified in the recent years. Such an increase of interest isamong other the consequence of the EU policy, starting with the EED [1] and EPBDr [2], andEU supported research programmes, such as in 2013 launched EU RIA Research andInnovation action, TOPIC EE-03-2014: Energy strategies and solutions for deep renovation ofhistoric buildings [6] and URBACT II [7].

Energy and the Environment (2016) 349-358

351

Figure 1: Number of published papers on World Wide Science (WWS) and Science Direct(SD) databases (keywords “energy retrofit” and “heritage building”).
The increased importance of the topic is also reflected in the number of published papers. In
Figure 1 is presented an example of paper search on the above mentioned databases withkeywords “energy retrofit” and “heritage building”. It can be seen that after 2009 the numberof published papers rapidly began to increase and in 2014 and 2015 reached a number ofpublished research that doubled the numbers in previous years. The study by Martínez-Molina
et.al. [8] reveal that residential, religious and museum building types, especially from the lasttwo centuries, have been most often used as case studies. Moreover, Europe, particularly
Italy, is leading the research in this field. This is not surprising, since, as Giombini et.al. [9]state, Italy accounts for 40% of the European historical heritage.
3.2.

Innovative materials

Among the most simple and cost-effective measures for increasing of energy efficiency inbuildings is the implementation of thermal insulation. In buildings with massive walls,
thermal insulation is generally installed at the external side of the building envelope in orderto take advantage of the buildings’ thermal mass and its influence on heat accumulation andtemperature regulation within the building. In heritage buildings, however, thermal insulation
is usually mounted on the inner side of the wall [10, 11, 12] to retain the original building
appearance. Walker et.al. [13] in their work propose a selection of insulation materials
suitable for historic buildings. Balaras [14] stresses that buildings with high thermal mass
have smaller variations of interior air temperature, better thermal comfort, and reduced peakheating and cooling loads than buildings with low thermal mass. A study by Kolaitis et al.
[15] shows that external insulation outperforms internal insulation on average by 8%. The
study by Blecich et.al. [16] corresponds with the conclusions of the previously cited works,
confirming the benefits of thermal mass on energy consumption.
The consequence of inner thermal insulation with classical materials are also reduction ofavailable space and higher risk of moisture accumulation in the building envelope. Zagorskas
et.al. [17] discuss the problems of moisture in brick wall construction, losing space andpresents a method for selecting the best insulation option. Murgul and Pukhkal [10] draw up

352

Ž. Kristl: Implementation of innovative energy retrofitting measures…

recommendations for the selection of construction of the inner insulation of the external wallsin the historical buildings for Saint-Petersburg. The required thickness of insulation material
based on extrusion-type polystyrene foam panels is determined, and humidity regime ofinsulated and non-insulated exterior walls is considered. Walker and Pavía [13] also point out
that the in-situ insulations underperform when compared to their manufacturer's specified
properties (wall U-value is higher by 13–25% with the exception of cork lime). This is
attributed to real in-situ environments compared to ideal testing laboratory conditions. That is
why efforts have been oriented toward development of thermal insulation materials thatwould retain the appearance of the heritage buildings and reversibility of interventions.
Currently in the majority of cases internal implementation of thermal insulating plaster issuggested, mainly containing aerogel [18, 19, 20, 21, 22]. Some studies also propose foamglass and aerogel panels [23, 21].
Stazi et al. [24] however stress that large-thickness thermal insulation coupled with highthermal mass can cause overheating problems. This was anticipated in the project of amuseum energy retrofit [25], where the existing thermal mass was excluded from the building
by internal thermal insulation and partially replaced by concrete heating/cooling panels
mounted on the walls. The application of the described system resulted in substantial
reduction of energy consumption, better internal thermal conditions and lower investment
costs for the heating, ventilation and air conditioning (HVAC) system of the entire building.
AndjelkovLüHWDO>] found that buildings with high thermal mass in Belgrade (Serbia) havelower heating and cooling energy demands than buildings with lightweight construction. On
the basis of the findings presented in the studies can be concluded that due to heritage
protection measures compromises regarding the most efficient thermal insulation position
have to be made and as a consequence somewhat higher energy consumption can be expected.
It can also be established that an effort should be made to look for solutions that retain at least
some active thermal mass within the building.
A large group of studies devote the attention to detailing, especially to thermal bridges andmoisture accumulation in external walls. Paper presented by Walker and Pavía [13]investigate the in-situ thermal performance of seven internal insulation options on a historicbrick wall using heat flux sensors, thermal imaging survey and internal wall temperature. In
the study presented by Harrestrup and Svendsen [27] measurements of the temperature andrelative humidity were performed in the wooden beams-ends embedded in the masonry brickwall, which is a common constructional solution in historical buildings. The study by
Arumägi et.al. [28] also concentrates on the structure junctions and energy performance of thehistoric wooden buildings that usually have strongest influence on visual character of thebuilding There is a general agreement that the phenomenon of thermal bridges and moistureaccumulation is a problem often encountered in historic and heritage buildings and has to beapproached analytically (calculation and testing of solutions should be implemented).
The number of studies dealing with the impact of windows on energy use, air tightness,daylighting and artificial illuminatin is substantially lower. Mainly high performance glazing
is suggested [21, 29]. Likewise, just a few studies on the roofs and the roof structures withregard to energy consumption are published [30, 31].
3.3.

Solar technologies

Architectural integration of HVAC plants, PV and solar panels in historic buildings has
always been a much debated topic. As pointed out by Polo Lopez and Frontini [32] a retrofit

Energy and the Environment (2016) 349-358

353

project aiming to improve the energy performance of a cultural heritage building needs tocarefully weigh different aspects such as energy efficiency, modernization and comfort. Theenergy improvements are desirable, but are not always possible without compromises.
Maahsen and Fabbri [33] draw attention to the problem of technical plant installation impact,which is a major challenge in restoration and retrofit projects, especially due to the fastdevelopment of the HVAC solutions. This is why Milone et.al. [34] point out that sometimes
the best available technologies are not the only viable for energy interventions in historicalbuildings. As pointed out by Filippi [5], newly installed HVAC systems come from a different
dwelling and technical culture and inevitably influence the building structure. Therefore,
HVAC should be installed only if absolutely necessary. Fabbri et.al. [35] suggest that in somecases heritage building functions better without the HVAC technology.
The installation of energy efficient HVAC and renewable energy systems in cultural heritagebuildings is usually restricted by various cultural preservation regulations that result in aconservative approach. The Moschella et. al. study [36] deals with the theme of integration ofsolar technologies in heritage buildings and focuses on difficult and problematic relationshipbetween the physical conformity of the plant and the cultural values of the building itself. Oneof the problems that inhibits the use of these technologies is again the reversibility ofinterventions. On the other hand, a group of authors [32, 37, 38, 39,] have a significantly
different approach suggesting a less reserved attitude towards installation of PV and solar
panels. Moran and Natarajan [39] argue that a different approach is needed to ensuresignificant savings delivered by the historic stock whilst balancing the need to maintain thebuilt heritage. An intriguing conclusion of their research is that PV modules mounted on theroof of heritage buildings result in far higher CO2 reduction than changes of the building
fabric: “Results indicate that in ordinary energy use patterns, without additional demand
management, an average of 56% of electricity generated from a roof mounted PV system isused within the dwelling, reducing CO2 emissions by an average of 19%. In contrast, typical“actual” savings from changes to the building fabric, which are difficult to implement andoften not realised in practice, are around 9%.“ Similar approach in used in several research
projects, planning to use PV and solar thermal technologies in heritage buildings [21, 23, 40,
41].
With the emergence of new LED technologies, considerable energy savings can also be
achieved by new lighting installation. E.g. Ciampi and Rosato [42] evaluate the potential
energy saving achievable by replacing the existing lighting system in a historical building, theinfluence of various actions, such as different types, different arrangement and different
mounting height of luminaires and different walls reflectance values. Efficient lighting
systems are also proposed in other works [e.g. 21].
3.4.

Control systems

A building management system (BMS), known also as a building automation system (BAS),is a computer-based control system installed in buildings that controls and monitors thebuilding’s mechanical and electrical equipment such as ventilation, lighting, power systems,
fire systems, and security systems. The use of automated control in buildings is mostcommonly implemented in large public buildings [43, 44]. It has been shown to have a great
deal of potential for reducing the energy consumption of HVAC systems as well as for
artificial illumination. Building automation can also greatly enhance the quality of the indoor
environment and in this way increase the performance and enhance the comfort of theoccupants. Recent developments in building-management systems (BMSs) have been
predominantly driven by the advances in computers and telecommunications technology [45,354

Ž. Kristl: Implementation of innovative energy retrofitting measures…

46]. As pointed out by Rocha et.al. [47], building energy management systems (BEMS) withdynamic temperature set points results in greater reduction in energy consumption than aconventional BEMS with policy measures. However, being a relatively recent technology,
operation control is not widely studied in heritage building retrofitting [48].
The role of monitoring and feedback has not been yet widely recognised as one of theimportant options for a successful energy retrofit of heritage buildings. One of few publishedexamples of BMS implementation in heritage buildings was executed in the Research project
MUSEUMS NNE5-1999-20, 2000-2004 Energy Efficiency & Sustainability In Retrofitted &New Museums Buildings [26] and demonstrated that energy efficient and sustainable museum
buildings can satisfy architectural, functional, comfort, control and safety requirements.
Recently solutions using wireless sensor monitoring, ICT-based monitoring and intelligent
building control have been proposed [21, 49].
4.

CONCLUSIONSThe European existing building stock presents a great opportunity for reduction of energy
consumption, which makes the energy retrofitting of heritage buildings a very relevant issue
despite the fact that these buildings are excluded from national and EU regulations concerning
the energy performance of buildings. The interest in energy retrofitting of heritage buildings
has substantially grown in the recent years. Such an increase of interest is among other theconsequence of the EU policy which supports the research in this field.
A well covered topic is architectural integration of thermal insulation, which is usually limited
to internal application. Although buildings with high thermal mass (external thermal
insulation) use somewhat less energy, have smaller variations of interior air temperature andbetter thermal comfort, in heritage buildings compromises have to be made to retain theoriginal appearance. Some of the studied cases prove that although protected, heritagebuildings can achieve good energy efficiency levels. Even though sometimes not optimal,
these measures still offer substantial energy use reductions and ensure sustainable building
operation. The consequence of inner thermal insulation with classical materials are also
reduction of available space and higher risk of moisture accumulation in the building
envelope. This is why efforts have been oriented toward development of insulative plasters
mainly containing aerogel and perlite that allow preservation of the original appearance andenable reversibility. A large group of studies devote the attention to detailing, especially tothermal bridges and moisture accumulation in external walls and junctions. There is a generalagreement that the phenomenon of thermal bridges and moisture accumulation is a problem
often encountered in historic and heritage buildings and that it has to be approachedanalytically.
Implementation of HVAC equipment in historic buildings has always been somewhat
controversial. In EU member countries the installation of energy efficient HVAC andrenewable energy systems in cultural heritage buildings is usually restricted by various
cultural preservation measures. In majority of cases such installation is limited to non or lowinvasive solutions, especially because integration of larger plants can irreversibly damage thebuilding heritage. The integration of solar technologies in buildings manifests itself in adifficult and problematic relationship between the physical conformity of the plant and thecultural values of the building. One of the problems that inhibits the use of these technologies
is again the reversibility of interventions and change of appearance. A group of authors
however suggests that the attitude towards installation of PV and solar panels should be lessrestrictive, pointing out the energy efficiency of such systems.

Energy and the Environment (2016) 349-358

355

The role of management, monitoring and feedback of building operation has not been widely
recognised as one of the important features in heritage buildings, although building
management systems (BMS) have a substantial potential for reducing the energy consumptionof HVAC systems as well as for artificial illumination. Building automation can also greatly
enhance the quality of the indoor environment.
The review shows that there is a number of areas that have a significant impact on energy
consumption and preservation of cultural heritage. The use of innovative materials andtechnologies open up new possibilities. Due to the importance of the field it is essential toacquire a common unified scientific approach to preservation and conservation of the cultural
heritage property through standardisation activity.
LITERATURE[1] Energy efficiency directive 2012/27/EU (EED)[2] Directive on energy performance of buildings - recast 2010/31/EU (EPBD Recast)[3] EE-03-2014 - Energy strategies and solutions for deep renovation of historic buildings,
http://cordis.europa.eu/programme/rcn/664681_en.html, (accessed 08. 09. 2016)[4] 3HQLüD0*RORYLQD60XUJXO9Revitalization of Historic Buildings as an Approach to
Preserve Cultural and Historical Heritage, Procedia Engineering, Volume 117, 2015,
Pages 883-890[5] Filippi M., Remarks on the green retrofitting of historic buildings in Italy, Energy and
Buildings, Volume 95, 15 May 2015, Pages 15-22[6] EU research participants portal, TOPIC: Energy strategies and solutions for deep
renovation of historic buildings, EE-03-2014,
https://ec.europa.eu/research/participants/portal/desktop/en/opportunities/h2020/topics/50
4-ee-03-2014.html, (accessed 30.06.2016)[7] Lewis J.O., Hógáin S.N., Borghi A., Cities of Tomorrow – Action Today. URBACT II
Capitalisation. Building energy efficiency in European cities, published by URBACT,
2013,
http://urbact.eu/sites/default/files/import/general_library/19765_Urbact_WS6_ENERGY_
low_FINAL.pdf (accessed 08. 09. 2016)[8] Martínez-Molina A., Tort-Ausina I., Cho S., Vivancos J.L., Energy efficiency and thermal
comfort in historic buildings: A review, Renewable and Sustainable Energy Reviews,
Volume 61, August 2016, Pages 70-85.
[9] Giombini M., Pinchi E.M., Energy Functional Retrofitting of Historic Residential
Buildings: The Case Study of the Historic Center of Perugia, Energy Procedia, Volume
82, December 2015, Pages 1009-1016.
[10] Murgul V., Pukhkal V., Saving the Architectural Appearance of the Historical Buildings
due to Heat Insulation of their External Walls, Procedia Engineering, Volume 117, 2015,
Pages 891-899.
[11] Bjarløv S.P., Finken G.R., Odgaard T., Retrofit with Interior Insulation on Solid
Masonry Walls in Cool Temperate Climates – An Evaluation of the influence of Interior
Insulation Materials on Moisture Condition in the Building Envelope, Energy Procedia,
Volume 78, November 2015, Pages 1461-1466.
[12] RIBuild, Robust Internal Thermal Insulation of Historic Buildings,
http://cordis.europa.eu/project/rcn/193477_en.html (accessed 08. 09. 2016)[13] Walker R., Pavía S., Thermal performance of a selection of insulation materials suitablefor historic buildings, Building and Environment, Volume 94, Part 1, December 2015,
Pages 155-165.

356

Ž. Kristl: Implementation of innovative energy retrofitting measures…

[14] Balaras C.A., The role of thermal mass on the cooling load of buildings: an overview ofcomputational methods, Energy and Buildings 24 (1996) Pages 1-10.
[15] Kolaitis D.I., Malliotakis E., Kontogeorgos D.A., Mandilaras I., Katsourinis D.I., Founti
M.A., Comparative assessment of internal and external thermal insulation systems forenergy efficient retrofitting of residential buildings, Energy and Buildings 64 (2013)
Pages 123-131.
[16] Blecich P., FraQNRYLü0.ULVWOäEnergy retrofit of the Krsan Castle: Fromsustainable to responsible design—A case study, Energy and Buildings, Volume 122, 15June 2016, Pages 23-33.
>@=DJRUVNDV-=DYDGVNDV(.7XUVNLV=%XULQVNLHQơ0%OXPEHUJD$%OXPEerga
D., Thermal insulation alternatives of historic brick buildings in Baltic Sea Region,
Energy and Buildings, Volume 78, August 2014, Pages 35-42.
[18] Wakili G., Stahl Th., Heiduk E., Schuss M., Vonbank R., Pont U., Sustr C., Wolosiuk D.,
Mahdavi A., High Performance Aerogel Containing Plaster for Historic Buildings with
Structured Façades, Energy Procedia, Volume 78, November 2015, Pages 949-954.
[19] Bianco L., Serra V., Fantucci S., Dutto M., Massolino M., Thermal insulating plaster asa solution for refurbishing historic building envelopes: First experimental results, Energy
and Buildings, Volume 95, 15 May 2015, Pages 86-91.
[20] Galliano R., Ghazi Wakili K., Stahl Th., Binder B., Daniotti B., Performance evaluationof aerogel-based and perlite-based prototyped insulations for internal thermal
retrofitting: HMT model validation by monitoring at demo scale, Energy and Buildings,
Volume 126, 15 August 2016, Pages 275-286.
[21] 3encult, Efficient energy for EU cultural heritage,
http://www.3encult.eu/en/project/welcome/default.html, (accessed 08. 09. 2016)[22] Effesus, Energy efficiency for EU historic districts’ sustainability, http://www.effesus.eu(accessed 08. 09. 2016)[23] Resseepe, Retrofitting Solutions and Services for the enhancement of Energy Efficiency
in Public Edification, http://www.resseepe-project.eu/, (accessed 08. 09. 2016)[24] Stazi F., Vegliò A., Di Perna C., Munafò P., Experimental comparison between 3
different traditional wall constructions and dynamic simulations to identify optimal
thermal insulation strategies, Energy and Buildings 60 (2013) 429-441.
[25] Košir M., Krainer A., Dovjak M., Perdan R., Kristl Ž., Alternative to the Conventional
Heating and Cooling Systems in Public Buildings, Journal of Mechanical Engineering
56(2010)9, Pages 575-583.
>@$QGMHONRYLü%9%96WRMDQRYLü006WRMLOMNRYLü-1-DQHYVNL0%6WRMDQRYLü
Thermal mass impact on energy performance of a low, medium and heavy mass building
in Belgrade, Thermal Science 16(2) (2012) 447-459.
[27] Harrestrup M., Svendsen S., Full-scale test of an old heritage multi-storey building
undergoing energy retrofitting with focus on internal insulation and moisture, Building
and Environment, Volume 85, February 2015, Pages 123-133.
[28] Arumägi E., Mändel M., Kalamees T., Method for Assessment of Energy Retrofit
Measures in Milieu Valuable Buildings, Energy Procedia, Volume 78, November 2015,
Pages 1027-1032.
[29] Nunes de Freitas P., Correia Guedes M., The use of windows as environmental control in“Baixa Pombalina's” heritage buildings, Renewable Energy, Volume 73, January 2015,
Pages 92-98.
[30] Pisello A.L., Thermal-energy analysis of roof cool clay tiles for application in historicbuildings and cities, Sustainable Cities and Society, Volume 19, December 2015, Pages
271-280.

Energy and the Environment (2016) 349-358

357[31] Renerpath, Eenergy rehabilitation methodology based on new and non- intrusivetechniques for the energy analysis, http://www.cartif.com/en/internationalprojects/european/interreg/item/989-renerpath.html (accessed 08. 09. 2016)[32] Polo López C.S., Frontini F., Energy efficiency and renewable solar energy integrationin heritage historic buildings, Energy Procedia 48 (2014) Pages 1493-1502.
[33] Maahsen-Milan A., Fabbri K., Energy restoration and retrofitting. Rethinking
restoration projects by means of a reversibility/sustainability assessment, Journal of
Cultural Heritage 14(3) (2013) Pages 41-44.
[34] Milone D., Peri G., Pitruzzella S, Rizzo G. (2015): Are the Best Available Technologies
the only viable for energy interventions in historical buildings? Energy and Buildings 95
Pages 39-46.
[35] Fabbri K., Pretelli M., Heritage buildings and historic microclimate without HVAC
technology: Malatestiana Library in Cesena, Italy, UNESCO Memory of the World,
Energy and Buildings, Volume 76, June 2014, Pages 15-31.
[36] Moschella A., Salemi A., Lo Faro A, G. Sanfilippo, M. Detommaso, A. Privitera.,
Historic Buildings in Mediterranean Area and Solar Thermal Technologies: Architectural
Integration vs Preservation Criteria, Energy Procedia, Volume 42, 2013, Pages 416-425.
[37] Dabaieh M., Makhlouf N.N., Hosny O.M., Roof top PV retrofitting: A rehabilitationassessment towards nearly zero energy buildings in remote off-grid vernacular
settlements in Egypt, Solar Energy, Volume 123, January 2016, Pages 160-173.
[38] Sibley M., Sibley M., Hybrid Green Technologies for Retrofitting Heritage Buildings inNorth African Medinas: Combining Vernacular and High-tech Solutions for an
Innovative Solar Powered Lighting System for Hammam Buildings, Energy Procedia,
Volume 42, 2013, Pages 718-725.
[39] Moran F., Natarajan S., PV in historic dwellings: The potential to reduce domestic CO2
emissions, Journal of Building Engineering, Volume 3, September 2015, Pages 70-78.
[40] New4old, New energy for old buildings - Promoting the integration of RES & RUE
measures in historic buildings,
http://ec.europa.eu/energy/intelligent/projects/en/projects/new4old, (accessed 08. 09.
2016)[41] New4old, New energies for old buildings,
https://nachhaltigwirtschaften.at/en/hdz/projects/new4old-new-energies-for-oldbuildings.php, (accessed 08. 09. 2016)[42] Ciampi G., Scorpio A.M., Sibilio S., Retrofitting Solutions for Energy Saving in a
Historical Building Lighting System, Energy Procedia, Volume 78, November 2015,
Pages 2669-2674.
[43] Semprini G., Marinosci C., Ferrante A., Predari G., Mochi G., Garai M., Gulli R., Energy
management in public institutional and educational buildings: The case of the school ofengineering and architecture in Bologna, Energy and Buildings, Volume 126, 15 August
2016, Pages 365-374.
[44] Virgone A.J., Fracastoro G.V., Pellegrino A., Blaso L., Savoyat J., Johannes K.,
Management and monitoring of public buildings through ICT based systems: Control
rules for energy saving with lighting and HVAC services, Frontiers of Architectural
Research, Volume 2, Issue 2, June 2013, Pages 147-161.
[45] Logar V., Kristl Ž., Škrjanc I., Using a fuzzy black-box model to estimate the indoor
illuminance in buildings, Energy and Buildings, Volume 70, February 2014, Pages 343351.
[46] Jáñez Morán A., Profaizer P., Zapater M.H., Valdavida M.A., Bribián I.Z., Information
and Communications Technologies (ICTs) for energy efficiency in buildings: Review andanalysis of results from EU pilot projects, Energy and Buildings, Volume 127, 1
September 2016, Pages 128-137.

358

Ž. Kristl: Implementation of innovative energy retrofitting measures…

[47] Rocha P., Siddiqui A., Stadler M., Improving energy efficiency via smart building energy
management systems: A comparison with policy measures, Energy and Buildings,
Volume 88, 1 February 2015, Pages 203-213.
[48] Wang B., Xia X., Optimal maintenance planning for building energy efficiency
retrofitting from optimization and control system perspectives, Energy and Buildings,
Volume 96, 1 June 2015, Pages 299-308.
[49] SEEMPUBS, Smart Energy Efficient Middleware for Public Spaces,
http://cordis.europa.eu/project/rcn/95583_en.html, (accessed 08. 09. 2016)

PROVEDBA MJERA ENERGETSKE PRILAGODBE U ZGRADAMABAŠTINE - PREGLEDSažetak: 6WDWLVWLþNLSRGDFLSRND]XMXGDMHRNRþHWYUWLQDSRVWRMHüLK]JUDGDX(XURSLVDJUDÿHQDSULMHVUHGLQHSURãORJVWROMHüDWHGDWLREMHNWLLPDMX]QDWQRVODELMXHQHUJHWVNX
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Energy and the Environment (2016) 359-368

359

SMART CITY THROUGH SYNERGIES WITH INDUSTRY
Katharina Karner
FH JOANNEUM GmbH, Werk-VI-Strasse 46a, +43 3862 33600 8364 / 8381,
katharina.karner@fh-joanneum.at
Abstract: Generally waste heat, waste water and waste streams are available as industrial
energy resources in industrial plants and their roof areas for solar energy use. In Austria, until
now, only waste heat has been used in small parts for heat supply of towns. The application ofwaste heat has so far been largely taken for internal heat recovery only. A holistic approachconsidering all available energy resources by the industry in synergetic connection with thesurrounding urban areas is yet to feature. Only a few projects in terms of waste heat usage for
district heating have been implemented. At international level, the utilization of industrial energy
has also hardly been considered in a synergistic combination with the municipal authorities.
Numerous legal requirements determine conditions for industrial companies in terms of theirenvironmental performance and energy savings etc. With the help of other energy efficiency
methods it is hardly possible to achieve the required energy efficiency savings without
influencing the production process. Therefore, the energetic linking of industrial companies andurban areas through the usage of industrial energy, to cover the energy demand of the towns
offers an energy efficiency measure for industries without biasing their economic behaviour.
Additionally, this approach represents an opportunity for energy enhancing independency ofspecific regions. The potentials for synergies were examined based on four project regions inAustria with a population between 7,000 and 12,000 inhabitants and a more or less strong
penetration of industrial companies. It was found that in total, up to 35% of the total energy
demand of the surveyed towns could be covered. This means also a saving of the primary energy
demand for the towns in the same extent. For electricity, coverage of up to 46%, and for heat,coverage of up to 32%, are possible. The recovery and exploitation of the so far unemployedindustrial energy leads to a significant increase of efficiency for the industrial companies.
Key words: industrial energy, synergy potential, energetic coupling, energy efficiency
1. INTRODUCTION

From a global and EU-wide perspective, improved energy efficiency is essential to achievegreenhouse gas savings, reductions in primary energy consumption and a secure energy supply.
Requirements like the EU 20-20-20 goals are already being transferred into (national) legal
frameworks. Other White Papers have already been published to offer an orientation for future
development. In the target agreements of EU 20-20-20, a reduction of 20% greenhouse gases, anincrease of renewable energy use (20%) and of energy efficiency (20%) based on the year 1990
have been set. [1] The roadmap 2050 still forces the reduction of greenhouse gases but underheavy emphasis on economic growth. [2]In Austria, the promotion of energy efficiency is, besides the security of supply and thedevelopment of renewable energies, one of the three pillars of the Austrian energy strategy.
Additionally in the government program the federal government committed an efficient,affordable and socially responsible energy system for a liveable environment. The aim of the2014 Energy Efficiency Act is to force the reduction of energy consumption through energy

360

K. Karner: Smart city through synergies with industry

efficiency measures to 292 TWh (energy consumption 2014: 298 TWh), an ambitious target inview of an expected economic and population growth until 2020. [1]Industrial companies are usually characterized by a high energy input. This goes hand in handwith residual energy which cannot be consumed within the company. That includes the mostwidely known energy source waste heat, but also waste and waste water (waste heat bound inwater). Additionally these companies have large unused roof space, which serve as sites for the
production of renewable PV-power. As far as (economically) feasible, these energy pathways are
already exploited within the companies’ processes. [3]The excess energy, however, is normally available for external applications. Here, the energy
can cover a part of the energy demand of nearby towns or urban regions. As a new definition, theterm “industrial energy” is introduced for the energy resources which are described above.
In this paper industrial enterprises are not considered as energy consumers but as energy
suppliers. This approach links for the first time industries (energy suppliers) with neighbouring
cities (energy consumers). Main goal of the paper is the evaluation of the synergy potential forindustrial energy. Waste heat is not only considered in the classical way (temperature level
above 90°C), but also waste heat streams below 90°C and waste water streams. Both can be usedby means of heat pump technology. In addition, waste streams and roof surfaces for solar use aretaken into account. The combined exploitation of all industrial energy streams for an energetic
connection to neighbouring urban areas is one opportunity to fulfil the claimed (legal)
requirements. The shown path represents an option for increasing the energy efficiency ofindustrial companies, without compromising their processes and their profitability. Thisapproach will not only improve the energy efficiency of the industries but also the overall energy
performance of the region.
2. STATE OF THE ART
The real gross domestic product (GDP) and total energy consumption are grown in Austria from1990 to 2013 by more than 50% and more than 30%. The energy consumption has not increased
at the pace extent as economic growth. A reduction in energy intensity was achieved by 14%,
but a complete decoupling of energy demand and economic performance could not be achieved
yet like in most industrialized nations. [4]Today more than 24% of all Austrian households are heated by district heating systems. In
comparison to other European countries Austria is in the centre but far behind Baltic andNorthern European states, where supply with district heating is more than 60%. Less than 7% of
the heat supply to district heating systems is from industrial waste heat. [4] This was determinedby a study of Kommunalkredit Public Consulting documenting a waste heat potential of
15,000 GWh per year (which could be used to cover around 15% of the Austrian heating
demand) [5]. One of the main reasons why this potential is not exploited is the lack of synergy
between towns and industries. It is supposed that waste heat with its transient characteristics
could not be fed in district heating systems without compromising the stability and safety of the
network and without huge efforts in system controlling and timing or storage. Furthermore, theamount of waste heat extraction is not variable to a huge extent. To achieve a high covering
during the winter months it is likely to oversupply during summer months. Hence, there is anapparent requirement for large storage facilities to achieve a high waste heat extraction and ahigh degree of utilization. [3]A synopsis of already implemented projects concerning industrial energy usage is presented
below. These selected projects are at the leading edge in their field of application. Although allEnergy and the Environment (2016) 359-368

361

of them are innovative, but none of them follows a holistic approach nor includes the synergetic
effects of industry and urban area in their implementation.
x Solar sourced district heating: in Marstal (Denmark) the district heating system is supplied withsolar energy. In total more than 1400 consumers are connected to the grid and consume around 19
GWh / a. A collector area of 18000 m² has a thermal capacity of 13 MWth. Also interseasonal
storage facilities are included in the DH grid and offering a capacity of 18 MW (14000 m³). [6]x Heat recovery with ORC: the ORC plant with the highest capacity (4,967 kW) is applied for theheat recovery in the cement industry in Slovakia, followed by two ORC plants in Bulgaria and
Italy with 4,000 kW each. The recovered energy is exploited for the companies energy demand.
[7]
x Heat storage: the district heating water storage tank in Theiss (Austria) has a thermal capacity of 2
GWh (50,000 m³) and is applied in combination with the nearby thermal power plant (800 MW).
[8]x Heat pumps for district heating: 75% of the heat for the district heating system in Drammen(Norway) is supplied by ammonia heat pumps. 8°C cold water from the fjord is used to be heated
up to 90°C. The heat pumps deliver 13.2 MW with a COP of 3.05. [9]x Industrial waste heat for district heating: in Austria different companies supply district heating
systems with their waste heat e.g. Heinzel Pulp Zellstoff Pöls AG (80 GWh), Sandoz GmbH (18GWh/a), Kaindl (25 GWh/a), Henkel Austria (19.4 GWh/a), voestalpine Donawitz (32 GWh/a).
[10]Besides these examples, other projects could also be named, which apply industrial energy. But
none of these projects show the holistic approach elaborated in this paper.
The state of the art shows, that industrial waste energy was already surveyed in numerous
studies. The focus was on heat; other industrial energy sources were not mentioned.
Furthermore, the synergetic link between industries and urban areas is novel. The purpose of thepaper is therefore to provide an overview of the possible synergies and between industries andurban areas to underline the advantages of the usage of industrial energy e.g. raised energy
efficiency for industrial companies and urban areas, decreased CO2 emissions and dependency
on fossil and non-regional energy sources, etc.
3. INTEGRATION OF INDUSTRIAL ENERGY
In industrial processes, both the desired product and emissions are generated. Emissions can be
air pollutants, greenhouse gases, but also carriers of energy. Heat streams (discharged via air orwater) and waste streams act as energy carriers, too. Furthermore, large roof areas of industrial
plants are available for generating PV-electricity.
3.1. Available routes
Waste heat
Industrial processes often produce large amounts of waste heat streams, which are often not
utilized. They are discharged via sophisticated cooling devices or directly emitted to theenvironment. Typical sources of waste heat in industrial plants are for instance flue gases,
streams from structural cooling of heat treatment plants and product and cooling units, which are
incurred either in continuous processes or in batch processes. These differ according to their
supply characteristics and their temperature levels. The temperature level of hot exhaust gas
streams reach from several hundred degrees to low temperature waste heat in the range of 40 to
60 °C. In addition, waste heat streams are dependent on their processes and underlie strong
short-term but also long-term variation (transient heat generation). [3]Waste water

362

K. Karner: Smart city through synergies with industry

With the non-use of warm waste water (waste heat discharged via waste water) a large quantityof low temperature (30-45°C) energy gets lost. Particularly water-intensive industries such as thepulp and paper industry and the food industry would provide wastewater in large quantities andwith interesting temperature levels. [11]Waste heat in waste water can be used directly from the sewer or from the waste water treatment
plant. For recovery of waste heat from industrial wastewater only the first two possibilities are ofimportance. The usage of heat from the wastewater treatment plants is of minor importance
except for companies which have their own wastewater treatment plant or the plant can be easily
implemented into the DH-grid. [12]The effectiveness of wastewater treatment plants is not influenced by the recovery of heat. On
the other side, many industrial companies have to cool their wastewater before they candischarge it. They mix it with fresh water so that the high temperatures of the waste water do noharm to the necessary bacteria in the purification process of the wastewater treatment plants. The
discharged heat potential thus remains unutilized in many cases and thermally stresses rivers etc.
[11]
Waste
Waste can be subject to different treatments. Depending on requirements, waste must be
conditioned before its treatment. With thermal waste treatment the energy content of the waste is
exploited. In addition, the hazardous potential and the mass and volume will reduce. Calorificfractions from the mechanical treatment of waste, residues from wood processing and waste
wood, sewage sludge and other slurries; residues from pulp and paper production, plastics andpackaging materials, old tires and other rubber waste, hazardous waste and waste oils, meat andbone meal and animal fat and shredder residues are fed to a thermal treatment. [13]Roof areas
Industrial enterprises provide large unemployed roof areas for energetic applications. Much of
the industrial roves are flat roves, which allow through a small angle a degree of flexibility inelevation, erection and alignment of the modules. Gabled roofs have an angle between 20° to 50°
and the orientation of the modules is predetermined to the conditions of the gable roof. An
advantage for the use of the free roof areas for electricity generation using photovoltaic
technology is the application of existing infrastructure. In general, the connection to the medium
voltage network already exists, and can be applied for the PV system. This results in lower costs.
[14]
3.2. Technological aspects
The following factors are essential for integration into the urban power network:x temporal availability
x temperature levelx medium of the energy flow.

Table 1 shows the industrial energy carriers and their integration possibilities into the urban
energy network. Free roof surfaces are generally suitable for the exploitation of solar thermalenergy. However, they are omitted in favour of electricity in this way and therefore notconsidered further. Waste is also suitable for the production of electricity, but due to the highheating demand this option is not considered further.
Table 1: An overview of industrial energy carriers, their usage possibilities and technologies.

Energy carrier
Waste heat

Usage possibility Technology
Heat, electricity, Heat pump (heating / cooling)coolingHeat exchanger

Temperature level< 90 °C> 90 °C

Energy and the Environment (2016) 359-368

Wastewater

Heat

Waste

Heat, electricity

Roof areas

Electricity

Variants of the Rankine cycle
Heat pump (heating)
Heat exchanger
Heating Plant(CHP and other variants of the
Rankine cycle)
Photovoltaic(Solar thermal)

363> 90 °C
35 – 90 °C> 90 °C> 90 °C> 90 °C

Industrial energy sources can be exploited for heat, power and cooling. The choice of usage
possibility depends on the amount of the occurrence and the temperature level. If both conditions
are met even a combined use is possible.
Heat production
In table 1, all industrial energy sources can be exploited to generate heat. Heat in form of waste
heat (bound in water or air) is transferred by heat exchanger to a secondary circuit. Is the heatalready available at an appropriate temperature level (depending on the design, about 90 °C), it
can be fed directly into a district heating network. If a temperature increase is necessary, a heatpump must be arranged in-between. Waste is burned in waste incineration plants or co-fired inindustrial furnaces and also fed into a district heating network. [3]Electricity production
Free roof surfaces are available for photovoltaic systems and can be exploited to generate
electricity. Irradiation levels, efficiencies and the characteristics of the module also have thegreatest impact on energy yield.
Waste heat streams in large amounts and high temperature levels are also usable for the
production of electricity. Here, only the ORC technology is considered in more detail, since thisis a proven technology for the use of low-temperature waste heat. The ORC technology is
specifically developed for low temperature applications and is particularly suitable for theelectricity generation of industrial waste heat (temperatures above 90 °C). In addition, waste heatfrom steam turbines can be fed in the district heating network if the temperature level of the
back-pressure steam is above 90°C. [10]Waste may be burned in heating plants or in CHP plants. Again heat and electricity can begenerated. The yield depends on the composition of the waste (calorific value) and on theefficiency of the plant.
Cold production
Waste heat can be exploited for cooling during the summer months if appropriate subjects areavailable. If industrial heat should be applied for cold production absorption cooling machines
are used. In contrast to conventional compressor based refrigeration, the cooling effect is notproduced by means of mechanical energy but with thermal energy. Thus any heat source with thenecessary temperature level can be applied. The produced cold is then fed into district cooling
networks which work analogue to district heating systems. [15]4. METHOD
Identification of energy intensive industrial branches
Annual data of Austria’s energy demand over the last 30 years is the basis for the identificationof industrial branches with high energy demand. We can deduce that companies with a high364

K. Karner: Smart city through synergies with industry

energy input also have a higher amount of unexploited industrial energy which is available forthe supply of towns.
Choice of project regions
As project regions, four urban regions in Austria with a population of 7,000 -12,000 inhabitants
each were chosen. Three of them are characterized by a high energy demand of industrial
companies. The production sector is of minor importance for the fourth town, but it is includedin the consideration, because all four towns provide necessary infrastructure (district heating
system). Especially the availability of data in a high quality was crucial for the choice of the
project regions. Furthermore the effect of a high industrial penetration can be highlighted. The
results can exemplarily be used for projections for towns with the same size and characterization.
In Austria there are 70 further towns and 2,300 - 4,000 in Europe of the same size.
Data acquisition and preparation
In the preparation, the supply- (industry) and the demand- (city) side are separately examined
and further divided into space heat and electricity considerations. Generally, data is provided byindustries and towns and completed by load profiles and statistical data. Data is based on hourly
values.
The gathering of industry related data is based on a bottom-up approach. The majority of data isbased on directly measured values from industrial companies which are combined to load
profiles. Data which was available only as absolute annual values are refined using specific load
profiles. Additionally comparisons and completion with statistical data were done. Heat supply
curves are determined by the industrial behaviour. Industrial processes can be either divided into
non-steady processes or continuous processes. Electricity supply curves are based on standard
profiles for solar irradiation from PV GIS for the region. Electricity demand curves are based on
published standard load profiles for households and absolute annual values for the electricity
demand of a city. Heat demand curves are based on load profiles gained from measured values of
districted heating systems.
Model development and setup
The technical feasibility of integrating industrial energy in urban areas is evaluated by means ofa simulation model. The model is equation oriented and consists of components, which aredescribed as black boxes.
The relationship of the model components and the relevant data inputs can be seen in figure 1.
Red symbols mark heat-relevant areas, blue symbols are related to electricity and green symbols
characterize necessary additional input data.
The component model “industry 1-n” symbolizes industrial companies in the city, dependent on
the number of those, the number of component models vary from 1 to n. Here, the component
serves as a simple input interface for all industry related data. The data is collected andassembled to load profiles. During that step, the assembling to load profiles is only done forwaste heat, waste water and waste.

Energy and the Environment (2016) 359-368

365

Figure 1: A schematic layout of the information flow in the simulation model.

The component “waste storage” adds all waste streams and provides average values of calorificvalues and the amount of waste. These values serve as input parameters for the “waste heatplant” component, where the waste gets burned at a certain thermal efficiency.
)LQDOO\ WKH FRPSRQHQW ³Ȉ LQGXVWU\ -n” sums up all heat related load profiles from the single
companies to one heat supply curve and all electricity related load curves to one electricity
supply curve. The heat supply curve is connected to a district heating system to supply heat tothe “city”. The input and output streams of electricity and heat converge in the component “city”
which is characterized by electricity and heat demand.
The components “+/- heat” and “+/- electricity” show the surplus of industrial energy or the
additionally required energy to cover the energy demand of the city. If the component displays apositive value, than a surplus of industrial energy is available and the need of a storage facility isgiven. If the component displays a negative value, then the city is under supplied and additionalenergy is needed; preferably renewable energy.
The structure of the model allows for a high degree of flexibility. It can be adapted to different
industrial profiles and to different sizes of towns. The model can be easily extended with adding
more “industry 1-n” components, ZKLFKDUHODWHUFROOHFWHGDQGVXPPHGXSLQWKHFRPSRQHQW³Ȉindustry 1-n”.
5. RESULTS
A summary of the results can be found in table 2. Town A shows a low contribution of industrial
energy demand with 12% compared to the total energy demand of the town. Industrial energy
occurs only as waste and as electricity from PV. This results in a low coverage of energy demandwith industrial energy (3%). Significant coverage of the electricity demand can be achieved
during the summer months due to the high availability of solar irradiation and the lower
electricity demand of the city compared to the rest of the year.
More than two third of the energy demand of town B is caused by industry (67%). Waste heat,
waste, waste water and electricity from PV serve as potential industrial energy sources for
supplying the town. Accordingly coverage of up to 24% of the total energy demand of town B is
possible. Over supply with industrial heat arise during the summer months because the heating
demand of the town is lower compared to the rest of the year. The high coverage of the366

K. Karner: Smart city through synergies with industry

electricity demand leads to oversupply with industrial electricity for around 500 hours a year, butmainly during the summer months.
Although town C shows a relatively high share of industrial energy demand (53%), the synergy
effect with the town is quite low. This is because of the existing industrial branches in the city.
Most of the industrial energy is available as waste and electricity from PV. Similar to town A, asignificant coverage of the electricity demand can be achieved from spring to autumn.
Table 2: A summary of the results of industrial energy integration in four Austrian towns.

Energy demand industry (% of total energy demand of the
town)
Waste heat (% of total industrial energy supply)
Waste water (% of total industrial energy supply)
Waste (% of total industrial energy supply)
PV electricity production (% of total industrial energy
supply)Heat coverage (% of total heat demand )Electricity coverage (% of total electricity demand)
Total coverage (% of total energy demand)

Town A Town B Town C Town D
12
67
53
71
0
0
100
100

28
70
2
100

42
0
58
100

98
0
2
100

2
6
3

22
30
24

3
16
5

32
46
35

Town D shows a high contribution of industrial energy demand to the total energy demand of thetowns with 71%. Waste heat, waste water and electricity from PV serve as industrial energy
streams which can be exploited for the coverage of the energy demand of the city.
6. DISCUSSION AND CONCLUSIONSIn this paper a new approach concerning energy efficiency for industries is presented. Here,
industrial enterprises are presented as energy suppliers for neighbouring cities. All industrial
energy streams are considered in a holistic approach and high synergy potentials between
industries and cities are achieved. Besides high temperature waste heat (temperature level above90°C), also waste heat below 90°C, waste water, waste and roof areas for PV use are taken into
account.
It was found that in total, up to 35% of the total energy demand of the surveyed towns could becovered by means of industrial energy. This leads to a reduction in maximum capacity for heatand electricity production. Furthermore, also savings of primary energy for the towns in the same
extent can be recorded. Depending on the energy supply mix, fossil fuels can be replaced byindustrial energy. That lowers the CO2 emissions, the dependency on external energy supplierand therefore increases the security of supply.
The coverage of electricity with industrial electricity ranges in the observed urban regions from
6 to 46%. The implementation of PV plants is linked with minor efforts, so there is thepossibility that even for town A, which shows the lowest synergy effects, the implementation
could be profitable. It is likely that an implementation of industrial heat usage is profitable for all
four towns because the main parts of investment costs for the infrastructure (district heating
system) have already been made.
In any case, town B and town D should be surveyed further, because of the relatively highsynergy effects. Especially a detailed economic consideration and the development of suitablemodels for operations which offer fair prices for all system participants should be done.
The recovery and usage of industrial energy leads to a significant increase of efficiency for theindustrial companies. Key figures need to be developed that the savings in CO2 emissions andthe improvement in energy efficiency can be appropriately calculated.

Energy and the Environment (2016) 359-368

367

Although none of the analysed studies pursuing the holistic approach of this paper, an overlap
with some studies and a need for an increased usage of industrial energy could be identified. E.g.
in the research work of ([16] the industrial excess heat potential is mapped for EU27; ([17]compared amongst others excess heat from industrial processes with the regional heat demand.
The studies of ([18] and (Connolly and Mathiesen, 2014) are regarded to 4th generation districted
heated grids. Both papers underline the importance of industrial waste heat in future energy
systems.
ACKNOWLEDGEMENTS
This work was carried out as part of the project entitled “Paradigm shift in urban energy systemthrough potential synergies with industry” (Paradigmenwechsel im urbanen Energiesystem durch
Synergiepotenziale mit der Industrie, project number: 845219), which was funded by Austrian
Research Promotion Agency (FFG).
The author would like to extend their gratitude to the Energieagentur Obersteiermark, Universityof Applied Sciences JOANNEUM and Montanuniversität Leoben for supporting the project.
REFERENCES[1] European Parliament. Directive 2012/27/EU of the European Parliament and of the Councilof 25 October 2012 on energy efficiency. Off J Eur Union Dir 2012:1–56.
doi:10.3000/19770677.L_2012.315.eng.
[2] European Commission. 2050 Energy strategy 2016.
https://ec.europa.eu/energy/en/topics/energy-strategy/2050-energy-strategy (accessed
January 5, 2016).
[3] Theissing M, Schloffer M, Tragner M, Wanek M, Theißing-Brauhart I. Instationarity ofindustrial waste heat as a limiting factor in the use and integration in heat distribution andheat recovery systems (Instationarität von industrieller Abwärme als limitierender Faktor bei
der Nutzung und Integration in Wärmeverteil- und. Kapfenberg: 2009.
[4] FGW. Facts and figures natural gas and district heating Austria 2014 (Erdgas undFernwärme in Österreich - Zahlenspiegel 2014). Vienna: 2014.
[5] Niedermair M. Waste heat potential 2012 (Abwärmepotenzialerhebung 2012). Vienna:
2012.
[6] Renewable Energy House. Marstal District heating n.d.
http://www.solarge.org/index.php?id=1235& (accessed August 19, 2015).
[7] Turboden. Turboden: References - Heat Recovery 2015.
http://www.turboden.eu/en/references/references.php?country=all&application=1&power=4000 (accessed August 19, 2015).
[8] EVN. Power Plant Theiß (Kraftwerk Theiß) 2015. https://www.evn.at/EVN-Group/EnergieZukunft/Energie-aus-Niederosterreich/Gas-und-Kohle.aspx (accessed August 19, 2015).
[9] European Heat Pump Association. Drammen District Heating n.d.
http://www.ehpa.org/technology/best-practices/large-heat-pumps/drammen-district-heatingnorway/ (accessed August 19, 2015).
[10] BIOS-BIOENERGY. Description of the ORC technology for biomass Combined Heat andPower plants as well as further possibilities for process integration n.d.
[11] Mauz H. Plants for Wastewater Usage (Abwasserwärmenutzungsanlagen). Graz: 2007.
[12] Grazer Energieagentur. Wastewater Usage (Abwasserwärmenutzung). Graz: 2007.
[13] Gara S, Schrimpf S. Treatment of waste materials in the iron and steel industry (Behandlung

368

K. Karner: Smart city through synergies with industry

von Reststoffen und Abfällen in der Eisen-und Stahlindustrie). 1998.
[14] bmwfw. Status of Energy Austria (Energiestatus Österreich). vol. 2013. 2013.
[15] Lambeuer J, Fahl U, Ohl M, Blesl M, Voß A. Industrial HeatPumps (Industrielle
Großwärmepumpen). Suttgart: 2008.
[16] Connolly D, Lund H, Mathiesen B V., Werner S, Möller B, Persson U, et al. Heat roadmap
Europe: Combining district heating with heat savings to decarbonise the EU energy system.
Energy Policy 2014;65:475–89. doi:10.1016/j.enpol.2013.10.035.
[17] Persson U, Moller B, Werner S. Heat Roadmap Europe: Identifying strategic heat synergy
regions. Energy Policy 2014;74:663–81. doi:10.1016/j.enpol.2014.07.015.
[18] Lund H, Werner S, Wiltshire R, Svendsen S, Thorsen JE, Hvelplund F, et al. 4th Generation
District Heating (4GDH). Integrating smart thermal grids into future sustainable energy
systems. Energy 2014;68:1–11. doi:10.1016/j.energy.2014.02.089.
[19] Connolly D, Mathiesen BV. A technical and economic analysis of one potential pathway to
a 100 % renewable energy system. Int J Sustain Energy Plan Manag 2014;01:7–28.

PAMETNI GRAD KROZ SINERGIJU S INDUSTRIJOMSažetak,QGXVWULMVNHWYUWNHRELþQRNDUDNWHUL]LUDYLVRNDSRWURãQMDHQHUJLMH7RLGHUXNXSRGUXNX
s proizvodnjom viška energije, npr. u obliku otpadne topline, otpadne vode i otpada. Dodatno,
industrijske tvrtke imaju velike neiskorištene površine koje se mogu koristiti za proizvodnju
energije iz obnovljivih izvora (npr. krovna površina za korištenje solarne energije). KorištenjeYLãNRYDHQHUJLMHYHüVHXJUDQLFDPDPRJXüHJRGYLMDXQXWDUWYRUQLFD1HLVNRULVWLYLGLRPHÿXWLPRELþQRMHGRVWXSDQ]DYDQMVNXXSRrabu. Gradovi ili urbane regije u blizini mogu tada poslužiti
kao "energijska spužva" i apsorbirati taj višak energije. Dodatno, uz integraciju industrijske
energije, cilj je i opskrba gradova kroz regionalne obnovljive izvora energije.
U prvom koraku, analizirano je kako se isprepletenost energetike s industrijom i integracija
drugih regionalnih, obnovljivih izvora energije podudara s ciljevima i putevima regionalnih ilokalnih razvojnih planova. Na temelju raspoloživih potencijala industrijske energije i
UHJLRQDOQLK REQRYOMLYLK L]YRUD HQHUJLMH LGHQWLILFLUDQL VX FLOMHYL WH VX SRVWDYOMHQL UD]OLþLWL
VFHQDULML UD]YRMD HQHUJHWLNH 3UDNWLþQRVW LQWHJUDFLMH LQGXVWULMVNH HQHUJLMH L REQRYOMLYLK L]YRUDHQHUJLMHELWLüHSULND]DQLNUR]RSVHåQHVLPXODFLMH7HKQLþNDRJUDQLþHQMDVXYDåDQGLRVLPXODFLMH
L SR]QDYDQMH LVWLK PRåH ELWQR SREROMãDWL ]QDþDM UH]XOWDWD SURMHNWD 1D WHPHOMX RGDELUDWHKQRORJLMHXþLQMHQDMHHNRQRPVNDSURFMHQD'RELYHQLUH]XOWDWLVHNRULVWHNDRXOD]L]DVWYDUDQMH
smjernica za implementaciju.
Rezultati pokazuju da je integracija industrijske energije izvediva i može pokriti dio potrošnje
HQHUJLMH X XUEDQLP SRGUXþMLPD 8] SRPRü GUXJLK UHJLRQDOQLK REQRYOMLYLK L]YRUD HQHUJLMH
SRYUHPHQRMHPRJXüDLSRWSXQDRSVNUEDJUDGDVUHJLRQDOQLPREQRYOMLYLPL]YRULPDHnergije.
.OMXþQHULMHþLEnergija, sinergijski potencijal, energetski spoj, energetska efikasnost

Energy and the Environment (2016) 369-380

369

THERMODYNAMIC PROPERTY ANALYSIS OF OPERATINGSUBSTANCES IN DIESEL ENGINE CYLINDER PROCESS
Vedran Mrzljak, Tomislav Senčić, Igor Poljak
Faculty of Engineering, University of Rijeka, Vukovarska 58, 51000 Rijeka, Croatia,
vedran.mrzljak@riteh.hr, tomislav.sencic@riteh.hr, Tel/Fax: +385-51-651-551
Abstract: The paper presents a thermodynamic property analysis of four essential operating
substances in diesel engine cylinder process: air, liquid fuel, fuel vapour and combustion
products. Only the most important thermodynamic properties of each operating substancewere taken into consideration. It was observed that the most of the thermodynamic properties
are highly dependent on the operating substance temperature. Due to lack of equations forthe calculation of some operating substance’s properties, separate approximation
polynomials were presented. Polynomial coefficients were calculated by using theindividually developed numerical program. Changing of thermodynamic properties for all
operating substances was compared with measurements from the available literature, anddeveloped polynomial errors were displayed. For each thermodynamic property a separate
sub-program was developed, and it is possible to use these sub-programs directly in diesel
engine numerical simulations. The accuracy of the diesel engine numerical simulation
primarily depends on the exact calculation of the operating media thermodynamic properties,
what ensures high applicability of the conducted analysis.
Keywords: diesel engine, operating substance, thermodynamic property, numericalsimulation

1. INTRODUCTION
The main intention of this article is to determine the equations which describe properties ofimportant substances in the diesel engine cylinder operating conditions. Equations are suitable
for application in computer numerical models. Observed substances are air, combustion
products, liquid fuel and fuel vapour. In this article, properties of the diesel fuels No 1 and No
2 were observed. The fuels above correspond well to the Croatian diesel fuels labelled D1 andD2.
Properties of the observed substances are obtained by analysing diagrams and nomogramsfrom existing literature. Diagrams and nomograms are not suited for application in computer
numerical models. Therefore, they are digitized and interpolated using the software
ENGAUGE. Interpolated data from diagrams is described with polynomial equations, usuallywith one variable.
All values are in SI units. All labels and corresponding units are listed and described at theend of this paper
2. THERMODYNAMIC PROPERTIES OF AIR

370

V. Mrzljak, T. Senčić, I. Poljak: Thermodynamic property…

Dynamic viscosity of air is determined according to the Sutherland equation [1]:ߤୟ ൌͳǤͶ͸ʹ ή ͳͲି଺ ή ඥܶୟ
ͳ൅

ଵଵଶ

(1)

்౗

Values achieved by using equation (1) are validated by comparing with the table data from [2]and [3], which display a dynamic viscosity of air at ambient pressure and temperatures
between 0 °C and 1200 °C.
Heywood [4] proposes another equation for dynamic viscosity of air:ߤୟ ൌ ͵Ǥ͵ ή ͳͲି଻ ή ܶୟ଴Ǥ଻

(2)

Thermal conductivity of air has specific dependence on pressure. It is almost independent ofpressure at temperatures below 2000 K. From the temperatures of 2000 K and above, thermal
conductivity is significantly dependent on pressure. Lower pressure has a stronger impact onthermal conductivity.
Two types of interpolation are considered; polynomial and linear (equations (3) and (4)). The
polynomial equation shows lower error (up to 5% when below 1273 K). Thus the polynomial
equation is considered more suitable.
Data from [5] is used for validation of calculated values. Literature [5] contains values of airthermal conductivity for a wide range of pressures (10 – 101.3 bar) and temperatures (500 –
15000 K).
݇ୟǡ୪୧୬ ൌ ͳǤ͸͹Ͳ ή ͳͲିଶ ൅ ͶǤʹͻ͵ ή ͳͲିହ ή ܶୟ(3)݇ୟǡ୮୭୪୷ ൌ ʹǤͲ͵͸ ή ͳͲିଶ ൅ ͷǤ͹ͻ͵ ή ͳͲି଺ ή ܶୟ ൅ ͺǤ͵͹͸ ή ͳͲି଼ ή ܶୟଶ െ ͸Ǥ͸Ͳʹ ή ͳͲିଵଵή ܶୟଷ ൅ ʹǤͲ͸ͻ ή ͳͲିଵସ ή ܶୟସ െ ʹǤʹͲʹ ή ͳͲିଵ଼ ή ܶୟହ(4)Prandtl number of air shows similar dependence on pressure and temperature as thermal
conductivity does [5]. At temperatures below 2000 K Prandtl number is almost independentof pressure, while above 2000 K lower pressure has a stronger impact on Prandtl number.
Polynomial interpolation of the fifth order, Fig.1, has shown the best fit with the data from[5]:ܲ‫ݎ‬ୟ ൌ ͲǤ͸͸ͷ ൅ ʹǤ͸ͺͺ ή ͳͲିସ ή ܶୟ െ ͵ǤͶ͵͹ ή ͳͲି଻ ή ܶୟଶ ൅ ʹǤ͵Ͳ͹ ή ͳͲିଵ଴ ή ܶୟଷെ ͹Ǥ͵͵͵ ή ͳͲିଵସ ή ܶୟସ ൅ ͺǤͷ͵͵ ή ͳͲିଵ଼ ή ܶୟହ(5)

Pra [-]

Energy and the Environment (2016) 369-380

371

0.78
0.76
0.74
0.72
0.70
0.68
0.66
0

500

1000

1500

2000

2500

3000

Ta [K]
Fig. 1 Interpolation of the Prandtl number of air in dependence on the temperatureSpecific heat capacity of air at constant pressure can be determined according to the following
equation [6]:ܿ୔ୟ ൌ ͳͲͲͲ ή ሾͻͻʹǤͶ ൅ ͲǤͳͻͲ͹ͻ ή ሺܶୟ െ ʹ͹͵Ǥͳͷሻሿ(6)In the temperature range between 0°C and 1000°C the results from the equation (6) deviateless than 1% from available table data. The Prandtl number value is usually adopted as aconstant.
3. THERMODYNAMIC PROPERTIES OF COMBUSTION PRODUCTS
Dynamic viscosity of the combustion products was determined according to Heywood [4]:
ߤ୥ ൌ

ߤୟ
(7)

ଵ

ͳ ൅ ͲǤͲʹ͹ ή

ఒౝValues calculated by using equation (7) deviate from available table data for less than 4% [4].
Prandtl number of combustion products is defined separately for lean and rich mixtures
respectively [4]:ܲ‫ݎ‬୥ ൌ ͲǤͲͷ ൅ ͶǤʹ ή ൫ߢ୥ െ ͳ൯ െ ͸Ǥ͹ ή ൫ߢ୥ െ ͳ൯ܲ‫ݎ‬୥ ൌͲǤͲͷ ൅ ͶǤʹ ή ൫ߢ୥ െ ͳ൯ െ ͸Ǥ͹ ή ൫ߢ୥ െ ͳ൯ଶ்ౝͳ ൅ ͲǤͲͳͷ ή ͳͲି଺ ή ൬ఒ ൰ౝଶ

, when ߣ୥ ൒ ͳ(8), when ͲǤʹͷ ൑ ߣ୥ ൑ ͳ andܶ୥ ൒ ʹͲͲͲ

(9)

ଶ

Values calculated by using equation (8) deviate from available table data for less than 5% [4],while the values calculated using equation (9) deviate for less than 8% [6].
ߢ୥ ൌ ͳ ൅

ܴ୥
ܿ୚୥

(10)

372

V. Mrzljak, T. Senčić, I. Poljak: Thermodynamic property…

ܴ୥ ൌͺ͵ͳͶǤ͵ͺʹͺǤͺͻͺ ൅ ͲǤͲ͸ ή ‫ݎ‬(11)ߣ୥ െ ͳ
ͲǤͲ͸ͻͺ ൅ ߣ୥

(12)

Air content, according to Zacharias [7]:‫ݎ‬ൌSpecific heat capacity at constant volume of the combustion products is defined by thefollowing equation:ͲǤͲͶͺͷ͵Ǥ͵͸ଶି଺൅ ʹ ή ቆ͹Ǥ͹͸ͺ ൅ ଴Ǥ଼ ቇ଴Ǥ଻ହ ቇ ή ൫ܶ୥ െ ܶ଴ ൯ ή ͳͲ
ߣ୥
ߣ୥
ͲǤͶ͸Ͷ
ή ൫ܶ୥ െ ܶ଴ ൯ ή ͳͲିସ ൅ ቆͶǤͺͻ͸ ൅ ଴Ǥଽଷ ቇ቉ߣ୥ܿ୚୥ ൌ ͳͶͶǤͷ ή ቈെ͵ ή ቆͲǤͲͻ͹ͷ ൅(13)

In equation (13), ܶ଴ ൌ ʹ͹͵Ǥͳͷ is the reference temperature.
Thermal conductivity of combustion products is determined on the basis of Prandtl number
and dynamic viscosity for combustion products:݇୥ ൌܿ୔୥ ή ߤ୥
ܲ‫ݎ‬୥

(14)

Specific heat capacity at constant pressure of combustion products:ܿ୔୥ ൌ ܿ୚୥ ൅ ܴ୥

(15)

4. THERMODYNAMIC PROPERTIES OF LIQUID FUEL
A lot of data about different fuels can be found in [8]. Diesel fuel is labelled as No 1, No 2
and No 4. Croatian labels for the corresponding diesel fuels are D1 and D2. Fuel labelled No
4 appeals to heavier fuel fraction, so it is omitted from this article. Fuel and fuel vapour
properties dependence on the temperature is described in [9]. Basic characteristics of diesel
fuels No 1 and No 2 are shown in Table 1.
In numerical models it is important to know the dependence of the fuel properties (density,
viscosity, latent heat, surface tension, specific heat capacity, thermal conductivity, etc.) on thetemperature. Liquid fuel properties usually vary from sample to sample. Thus a large numberof fuel samples must be examined. Literature [8] shows the results of examination of morethan 60 samples of each fuel.

Energy and the Environment (2016) 369-380

373

Liquid fuel density, at high pressure, at which the fuel is injected into the engine cylinder,
does not depend only on temperature, but also on the pressure:ߩ୤ ൌ ߩ୤଴ ή ൬ͳ ൅‫݌‬୤െ ߙ ή οܶ୤ ൰
‫ܧ‬୤

(16)

Diesel fuel elastic modulus ‫ܧ‬୤ ൌ ͳͻǤ͸ ή ͳͲଶ  is defined as a mean of kerosene andlubricating oil elastic modulus [10]. Diesel fuel thermal expansion coefficient has a value ߙ ൌ͹ǤͶͲ͹ ή ͳͲିସ  ିଵ. οܶ୤ stands for the temperature difference between the actual fueltemperature and 25°C.
Diesel fuel examined in [10] has density ߩ୤଴ ൌ ͲǤͺ͸ͶȀ ଷ at 20°C, while diesel fuel D2 hasa very similar density ߩ୤଴ ൌ ͲǤͺͶͷȀ ଷ at the same temperature. Higher pressure causes thefuel density to rise, but the temperature has a much stronger impact.
Table 1 Main characteristics of diesel fuels No 1 and No 2
Fuel characteristics
Unit
No 1 - D1
No 2 - D2
Boiling point
°C
226
266
Angle of A.S.T.M. distillation curve°C / %
point 10%
1.44
2.22
0.67
0.89
(Θ70 - Θ10) / 60
Molar mass
kg/kmol
174
198
Critical temperature°C (K)
410 (683)
453 (726)
Critical pressure
bar
22.6
20.9
Factor of characterization, K
11.8
11.7
The following data are average values achieved through thorough examination of a great
number of diesel-fuel samples.
A.S.T.M. distillation curve
°C
start
177
189
point 10%196
225
point 50%223
263
point 90%
259
308
end
282
338
Pour point°C- 40.5- 21.6
Cloud point°C- 37.7- 15
Sulphur content% mass0.13
0.3
Fuel density (60° / 60°F, i.e. 15.5°C)
kg/m3
813
842
Fuel kinematic viscosity at 38°C
m2/s
1.72 · 10-6
2.8 · 10-6
Flash point°C
60
75
Aniline point
°C
64.4
71.7
Dynamic viscosity of the diesel fuel is determined in a wide pressure (1 to 830 bar) andtemperature range (20 to 120 °C) [10]. The dependence of the diesel fuel dynamic viscosity
on pressure and temperature can be expressed with the second degree polynomial, Fig. 2:
ߤ୤ ൌ ‫ܣ‬ሺߐ୤ ሻ ൅ ‫ܤ‬ଵ ሺߐ୤ ሻ ή ሺ‫݌‬୤ ή ͳͲሻ ൅ ‫ܤ‬ଶ ሺߐ୤ ሻ ή ሺ‫݌‬୤ ή ͳͲሻଶ

(17)

374

V. Mrzljak, T. Senčić, I. Poljak: Thermodynamic property…

The coefficients are expressed in the following equations:‫ܣ‬ሺߐ୤ ሻ ൌ ͷǤͻʹ͹ʹ͵ ή ͳͲିହ ൅ ͲǤͲͲ͵ͲͺͲ͵ ή  ൬െή  ൬െߐ୤ െ ͳ͹ǤͶͷ͹ͺͻ൰͹͹Ǥ͹͹ߐ୤ െ ͳ͹ǤͶͷ͹ͺͻ൰ ൅ ͲǤͲͲ͵͸͹͸ͳͳ͵Ǥͻͺ͵ͷͳ‫ܤ‬ଵ ሺߐ୤ ሻ ൌ ͺǤͲʹͻ͸Ͷ ή ͳͲି଺ െ ͳǤͳ͹ʹͷ͸ ή ͳͲି଻ ή ߐ୤ ൅ ͵Ǥͺʹͳʹͻ ή ͳͲିଵ଴ ή ߐ୤ଶ൅ ͳǤ͵ͲͲ͵ͷ ή ͳͲିଵଶ ή ߐ୤ଷ‫ܤ‬ଶ ሺߐ୤ ሻ ൌ ʹǤʹͳ͹ͷ͸ ή ͳͲି଼ ή  ൬െή  ൬െ0.0300

(19)

(20)

20°C
30°C
40°C
60°C
80°C

0.0250μf [kg/(m∙s)]ߐ୤ െ ʹͲ൰ͷͳǤͶͷ͵ߐ୤ െ ʹͲ൰ ൅ ͷǤͺͷ͵ͳͺ ή ͳͲିଽͻǤͳʹ͸ͺʹͻ

(18)

0.02000.01500.01000.00500.0000
0

10

20

30

40

pf [MPa]

50

60

70

80

Fig. 2 Diesel fuel (D2) dynamic viscosity dependence on the pressure and temperatureaccording to the equation (17)
According to the [8] and [9], the liquid fuel kinematic viscosity depends only on thetemperature:ͻ ሺ߭୤ ή ͳͲ଺ ൅ ͲǤ͸͵͸͹ሻ ൌ െͶǤ͵͵Ͷ ή  ൬ ή ܶ୤ ൰ ൅ ͳͳǤ͸ͶͶͷ

(21)

The results of equation (21) correspond very closely to the measured values from [9]. The
relative error is very small, except in the very high temperature range.
The evaporation latent heat of the liquid fuel, like most other liquid fuel properties,
depends primarily on the temperature, Fig. 3. The diagram describing this dependency [8] istranslated to the fifth degree polynomial, Table 2:ܳ୐୤ ൌ ‫ ܣ‬൅ ‫ܤ‬ଵ ή ߐ୤ ൅ ‫ܤ‬ଶ ή ߐ୤ଶ ൅ ‫ܤ‬ଷ ή ߐ୤ଷ ൅ ‫ܤ‬ସ ή ߐ୤ସ ൅ ‫ܤ‬ହ ή ߐ୤ହ
Table 2 Constants for equation (22)(22)

QLf [kJ/kg]

Energy and the Environment (2016) 369-380

375

Parameter
‫ܣ‬
‫ܤ‬ଵ
‫ܤ‬ଶ
‫ܤ‬ଷ
‫ܤ‬ସ
‫ܤ‬ହ

Value
3.62720 ∙ 102- 5.89170 ∙ 10-1
3.39630 ∙ 10-3
- 2.41520 ∙ 10-5
7.55997 ∙ 10-8
- 9.05488 ∙ 10-11

0

200

400
350
300
250
200
150
100
50
0
100

300

400

500

ߐf [°C]
Fig. 3 Diesel fuel No 2 (D2) evaporation latent heat dependence on the fuel temperature
The surface tension of the liquid fuel is calculated according to the Ramsay and Shields [8]:మ‫ܯ‬୤ యߪ୤ ൬ͳͲͲͲ ή ൰ ൌ ʹǤͳʹ ή ͳͲିଷ ή ൫ܶ୤ǡୡ୰ െ ͸ െ ܶ୤ ൯
ߩ୤

(23)

At critical temperature, both evaporation latent heat and surface tension have a value of zero.
Values calculated by using equation (23) differ from the values given by [8] and [9] for lessthan 5% in the whole temperature range of the liquid fuel.
Saturated vapour pressure can be determined according to the known fuel temperature andboiling temperature, Fig. 4, by using nomograms from [9]. The saturated vapour pressure isdetermined by utilizing pressure function A [8]:ሺͳǤͶͷͲ͵͹͹ ή ͳͲെͶ ή ‫ ୴݌‬ሻൌ ͳǤͳ͸͹ͳͻͻ ൅ ͷǤʹͷͷ͵ ή ሺͳ െ ͲǤͲͲ͸ͺ͹ͻͳ͹ ή ‫ܣ‬ሻ‫ܣ‬ൌܾήͻ ή ൫ܶ୤ǡ୆୔ െ ܶ୤ ൯ͷ

Factor ܾ can be determined according to both of the following equations:

(24)
(25)

376

V. Mrzljak, T. Senčić, I. Poljak: Thermodynamic property…

ܾ ൌ ͲǤͳͶʹ ൅ ଽ
ହ

ܾൌଽ
ହ

ʹͳʹ
ή ܶ୤ǡ୆୔െ ͲǤͲͶඨܵଵ଴Ψ ή

ͻ
ͷ

(26)

ͺ͸Ǥͷ

(27)

ή ൫ܶ୤ǡ୆୔ െ ܶ୤ǡ୊୔ ൯

In the above equations ܵଵ଴Ψ represents the slope of the A.S.T.M. curve of the fuel distillation
at the point where 10% of the fuel already evaporated.
1.00E+07

pv [Pa]1.00E+06
1.00E+05
1.00E+04
1.00E+03
1.00E+02
50

150

250

350

450

ߐf [°C]
Fig. 4 Diesel fuel No 2 (D2) saturated vapour pressure dependence on the fuel temperature
Necessary values for Fig. 4 are obtained by including the equation (27) in equation (25). Thus
the pressure function A depends only on characteristic temperatures for observing fuel. The
boiling point temperature and flash point temperature are determined from Table 1. Pressurefunction A is included in the equation (24), where the only unknown variable is now liquid
fuel temperature, which is varied in a range ߠ୤ ൌ ͸ͷ ǥ Ͷ͸ͷι.
The results of the equation (24) slightly differ from values determined by using nomogramsfrom [9]. The difference is noticeable in the low temperature range. At high temperatures theresults correspond very well.
The specific heat capacity at constant pressure for the liquid fuels, obtained by processing
crude oil, can be determined according to the following formula [8]:ܿ୔୤ ൌͳ͵ʹǤ͵ͻͺʹͶඥߩ୤଴ͻ ή ߐ୤ή ൤ͲǤ͵ͺͺ ൅ ͲǤͲͲͲͶͷ ή ൬൅ ͵ʹ൰൨
ͷ(28)

Specific heat capacity values determined by equation (28) deviate from available literature [9]for less than 5%.

Liquid fuel thermal conductivity can be determined according to the linear equation:݇୤ ൌ ͲǤͳͳ͸ͷͶ െ ͳǤͲͷͻͲͻ ή ͳͲିସ ή ߐ୤

(29)

Energy and the Environment (2016) 369-380

377

5. THERMODYNAMIC PROPERTIES OF FUEL VAPOUR
All characteristics and properties of the fuel vapour are determined according to the diagramsfrom [9].
Specific heat capacity at constant pressure for diesel fuel vapour, mostly depend on thevapour temperature, and can be described by a linear equation:ܿ୔୴ ൌ ʹǤͲͶͻͺͷ ή ͳͲଷ ൅ ͳǤ͸͹ͳͲ͸ ή ߐ୴

(30)

Dynamic viscosity of the fuel vapour depends on the vapour temperature, and can be
described by a linear equation:ߤ୴ ൌ ʹǤʹͳͳͶͷ ή ͳͲି଻ ൅ ͶǤͶ͵͵ͺ͹ ή ͳͲି଼ ή ߐ୴

(31)

Fuel vapour thermal conductivity dependence on the vapour temperature is almost linear.
Therefore the interpolation is done in two ways – by using linear and by using exponentialfunctions:݇୴ ൌ ͻǤ͵ͻͳͲͳ ή ͳͲିସ ൅ ͳǤʹͳͻ͵͹ ή ͳͲିସ ή ߐ୴(32)ߐ୴ െ ߐ୴଴݇୴ ൌ ݇୴଴ ൅ ‫ ܣ‬ή  ൬
൰
‫ܤ‬

(33)

Parameters for the equation (33) are given in the Table 3.
Table 3 Constants for equation (33)
Parameter
݇୴଴
ߐ୴଴
‫ܣ‬
‫ܤ‬

Value
- 0.04029- 418.55628
0.02398
611.52836

Exponential function (33) is better suited for the approximation of the temperature range
below 600 °C. In that range difference between results of using equations (32) and (33) isvery low. Therefore, it is recommended to use linear function (32) on the whole temperature
range, Fig. 5.

378

V. Mrzljak, T. Senčić, I. Poljak: Thermodynamic property…

0.09

Linear interpolation
Exponential interpolation

kv [W/(m∙K)]

0.08
0.07
0.06
0.05
0.04
0.03
0.02
200

250

300

350

400

ߐv [°C]

450

500

550

600

Fig. 5 Fuel vapour thermal conductivity dependence on the vapour temperature
The diffusion coefficient of the fuel vapour has a big dissipation of its values. Equation (34)
determines the lower limit of the dissipation. Equation (35) determines upper limit. The
arithmetic mean value of those functions is determined by equation (36), Fig. 6.
‫ ୴ܦ‬ൌ െ͹Ǥ͹ͳͻͳͻ ή ͳͲି଺ ൅ ͳǤͲ͵͸͹ ή ͳͲିହ ή  ൬ߐ୴൰Ͷ͸͹Ǥʹͻͻͳ(34)‫ ୴ܦ‬ൌ െ͸ǤͳͻͷͻͶ ή ͳͲି଺ ൅ ͻǤͻʹ͹͹ͳ ή ͳͲି଺ ή  ൬ߐ୴൰͵͸ͺǤ͵ͺ͵͸͸(35)ߐ୴‫ ୴ܦ‬ൌ െ͸Ǥ͸͸ͳͳ ή ͳͲି଺ ൅ ͻǤͺͷ͹ͳ ή ͳͲି଺ ή  ൬൰ͶͲʹǤͺͲ͸ͻͻ(36)

Upper limit
Arithmetic mean
Lower limit

4.00E-05

Dv [m2/s]

3.00E-05
2.00E-05
1.00E-05

0.00E+00
0

100

200

300

ߐv [°C]

400

500

600

Fig. 6 Diffusion coefficient of the diesel fuel vapour dependence on the vapour temperature

6. CONCLUSION
Available data in the form of diagrams and nomograms were digitized and interpolated toacquire polynomial equations. Established equations are well suited for application in any
numerical simulation of diesel engine, usually in the form of subroutines.

Energy and the Environment (2016) 369-380

379

Data in the literature is acquired through experimentation on many diesel fuel samples.
Despite large numbers of samples, some properties show great dispersion of values at thesame conditions.
The most values calculated according to the established equations differ from available data
for less than 5% in the given range, but there are some exceptions. Calculated values ofPrandtl number for combustion products in rich mixtures deviate up to 8%. The diffusion
coefficient of the fuel vapour shows the great dispersion. Thus, upper and lower limits of thedispersion have to be defined.
7. LIST OF SYMBOLS
Alphabetical symbols
A[-]
pressure functionb[-]factor for determining pressure function
cP[kJ/(kg·K)] specific heat capacity at constant pressurecV[kJ/( kg·K)] specific heat capacity at constant volume
D[m2/s]
diffusion coefficientE[MPa]elastic modulusk[W/(m∙K)] thermal conductivity
M[kg/kmol]molar massp[MPa]pressurePr[-]
Prandtl number
Q[kJ/kg]evaporation latent heatR
[kJ/(kg·K)] gas constantr[-]
air content
S[K/%]
slope of the A.S.T.M. curve of the fuel distillationT[K]
temperature
Greek symbols[K-1]
thermal expansion coefficientα[°C]temperatureߐ[-]
adiabatic exponent
κ[-]
air-fuel equivalence ratioλμ[kg/(m∙s)]
dynamic viscosity
3[kg/m ]
densityρ[N/m]surface tensionσ[m2/s]
kinematic viscosity߭Indexes0
atmospheric conditionsaair
BPboiling point
cr
critical point
f
fuel
FP
flash pointgcombustion productsL
evaporation latent heatlinlinear function

380

poly
v

V. Mrzljak, T. Senčić, I. Poljak: Thermodynamic property…

polynomial function
fuel vapour

8. LITERATURE[1][2]Voronjec, K., Obradović, N.: Mehanika fluida, Građevinska knjiga, Beograd, 1976.
Isachenko, V. P., Osipova, V. A., Sukomel, A. S.: Heat Transfer, MIR Publishers,
Moscow, 1977.
[3] Kreith, F., Black, W. Z.: Basic Heat Transfer, MIR Publishers, Moscow, 1983.
[4] Heywood, J. B.: Internal Combustion Engine Fundamentals, McGraw-Hill, New York,1988.
[5] Hansen, C.F.: Approximation for the thermodynamic and transport properties of hightemperature air, NASA TN 4150, 1958.
[6] Malić, D., Đorđević, D.: Termodinamika i termotehnika (poglavlje: Međunarodni
sustav jedinica i tablice), Građevinska knjiga, Beograd, 1977.
[7] Zacharias, F.: Mollier –I,S-Diagramme für Verbrennungsgase in Datenverarbeitung,
MTZ 31, 1970.
[8] Barnett, H. C., Hibbard, R. R.: Properties of aircraft fuels, NASA TN 3276, 1956.
[9] Sitkei, G.: Kraftstoffaufbereitung und Verbrennung bei Dieselmotoren, Springer-Verlag,
Berlin, 1964.
[10] Hersey, M. D.: Viscosity of diesel engine fuel oil under pressure, NASA TN 315, 1929.

ANALIZA TERMODINAMIČKIH SVOJSTAVA RADNIH TVARI U
CILINDRU DIZELSKOG MOTORASažetak: Rad prikazuje analizu termodinamičkih svojstava četiri esencijalne radne tvari u
procesu unutar cilindra dizelskog motora: zraka, tekućeg goriva, pare goriva i produkata
izgaranja. U razmatranje su uzeta samo najbitnija termodinamička svojstva svake navedene
radne tvari. Tijekom provedene analize uočeno je da većina termodinamičkih svojstava
promatranih radnih tvari izrazito ovisi o temperaturi svake pojedine radne tvari. Zbog
nedostatka točnih jednadžbi za izračun nekih bitnih svojstava radnih tvari, predstavljeni su
polinomi koji aproksimiraju navedena svojstava. Koeficijenti dobivenih polinoma računati su
korištenjem individualno razvijenog numeričkog programa. Kretanje termodinamičkih
svojstava svih razmatranih radnih tvari uspoređeno je sa mjerenjima iz dostupne literature, tesu prikazane pogreške dobivenih aproksimacijskih polinoma. Za svako termodinamičko
svojstvo svake promatrane radne tvari izrađen je zaseban numerički podprogram, te jemoguća direktna primjena razvijenih podprograma u numeričkim simulacijama dizelskih
motora. Točnost numeričke simulacije dizelskog motora primarno ovisi o preciznom izračunu
termodinamičkih svojstava radnih tvari, što omogućuje visoku primjenjivost provedene
analize.
Ključne riječi: dizelski motor, radne tvari, termodinamička svojstva, numerička simulacija

Energy and the Environment (2016) 381-394

381

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1. UVOD+LEULGQR HOHNWULþQR YR]LOR +(9  MH WLS YR]LOD NRMH za pogon koristi motor sa unutarnjim
izgaranjem (SUI motor), WH MHGDQ LOL YLãH HOHNWULþQLK VWURMHYD. Umjesto elektULþQLK VWURMHYDPRJXVHNRULVWLWLUD]OLþLWLKLGUDXOLþNLLOLSQHXPDWVNLPRWRUL]DMHGQRVDSULSDGQLPVSUHPQLFLPD
energije. Primarna svrha ovakvih vozila jest smanjenje potrošnje goriva i emisije štetnih
plinova u odnosu na konvencionalna vozila. Osim toga, dodatna prednost HEV nad
NRQYHQFLRQDOQLPYR]LOLPDMH]QDWQRQLåDUD]LQDEXNHXJUDGVNRMYRåQMLJGMH+(9WLSLþQRUDGLNDRþLVWRHOHNWULþQRYR]LOR,DNRMHQDRYDMQDþLQUHDOL]LUDQD]QDþDMQLMDXãWHGDJRULYDRQRMHL
dalje primarni izvor energije u vozilu. ViVRNRM XþLQNRYLWRVWL +(9 ]QDþDMQR GRSULQRVLPRJXüQRVW UHJHQHUDWLYQRJNRþHQMDNRMLPVHNLQHWLþNDHQHUJLMDYR]LODSUHWYDUDXHOHNWULþQXWH
se pohranjuje u bateriju. Osim toga, znatno smanjenoj potrošnji goriva HEV pridonosi i
LVNOMXþLYDQMH 68, PRWRUD NRG PLUovanja vozila, kao i pri malim brzinama vozila kad se za
SRJRQ YR]LOD NRULVWL LVNOMXþLYR HOHNWULþQL SRJRQ .DNR EL VH UHDOL]LUDOH RYH SUHGQRVWL +(9SRWUHEQR MH XQXWDU YR]LOD LPSOHPHQWLUDWL XSUDYOMDþNX VWUDWHJLMX NRMD SUHFL]QR XSUDYOMD
tokovima energije iz više izvora.
U ovom radu je kao alternativa konvencionalnom gradskom autobusu (Volvo 8900)
predstavljen hibridni autobus (Volvo 7900) sa paralelnom konfiguracijom pogona. Paralelnakonfiguracija pogona podrazumijeva da oba izvora energije (SUI motor i elHNWULþQL VWURM)
PRJX SUHNR PHKDQLþNH VWD]H LVWRYUHPHQR LVSRUXþLYDWL VQDJX ]D SRJRQ YR]LOD Od tehnika
upravljanja pogonom korištene VX VOMHGHüH GYLMH tehnike: empirijski podesivi regulator
1

mentor diplomskog rada: prof.dr.sc. Joško Deur, asistent: mag.ing. Branimir Škugor

382

D. Perliü: 0RGHOLUDQMHLXSUDYOMDQMHKLEULGQLPHOHNWULþQLP«zasnovan na bazi pravila (RB) i minimizacija ekvivalentne potrošnje goriva (ECMS). Za
upravljanje tokovima energije, tehnike koriste trenutne informacije o ruti kojom se vozi.
2. VOZNI CIKLUSI
6QLPDQMHUHDOLVWLþQLKYR]QLKFLNOXVDSURYHGHQRMHX'XEURYQLNXQDNUXåQRMUXWL%DELQ.XN–Pile – Babin Kuk u prosincu 2014. godine. Snimanje je provedeno GPS opremom za
konvencionalni autobus MAN LION S CITY, model NL 323, koji ujedno i prometuje na toj
liniji gradskog prijevoza. Duljina rute za vrijeme snimanja iznosila je približno 12 kilometara,
te je zbog radova bila za 2 kilometra duža od linije kojom se prometuje za vrijeme ljetne
sezone. Tijekom 24 – VDWQHYRåQMHDXWREXVSULMHÿHGRWLþQXNUXåQXUXWXSXWDDRGWRJDMH
]D VQLPDQMH SRGDWDND RGDEUDQR QMLK  L] UD]OLþLWLK GLMHORYD GDQD NDNR EL VH REXKYDWLOi svi
uvjeti vožnje.
3RGDFL VX VQLPOMHQL SUHFL]QLP *36 SULMHPQLNRP 6QLPOMHQL SRGDFL XNOMXþXMX YULMHPH
geografsku duljinu i širinu, nadmorsku visinu, te horizontalnu i vertikalnu komponentu brzine
vozila. Nakon što su podaci snimljeni bilo ih je potrebnR REUDGLWL L QD WDM QDþLQ SULODJRGLWL
potrebama simulacija. 2EUDGRP VX GRELYHQL VOMHGHüL SRGDFL WUDMHNWRULMH JLEDQMD YUHPHQVNL
profili horizontalne komponente brzine, mase putnika i nagib ceste.
3. KONVENCIONALNI AUTOBUS
Kao osnova za modeliranje i simulaciju konvencionalnog autobusa uzet je niskopodni autobus
WYUWNH9ROYRPRGHO2YDMNRQYHQFLRQDOQLDXWREXVX]HWMHL]UD]ORJDãWRLPDVOLþQHRSüH
karakteristike kao i hibridni autobus modeliran kasnije u radu, te tako predstavlja temelj za
usporedbu potrošnje.
3.1. Opis konvencionalnog autobusa$XWREXVSRNUHüH– FLOLQGULþQLGLHVHORY68,motor radnog volumena 7.7 L, snage 206 kW sa
maksimalnim momentom od 1050 Nm [2]. Transmisija je 12 – stupanjska automatska [3]. U
tablici 1 mogu se vidjeti ostali zQDþDMQLMLSDUDPHWULDXWREXVD9HüLQDSDUDPHWDUDSUHX]HWDMHL]
> @ GRN VX SUHGQMD SRYUãLQD YR]LOD L HIHNWLYQL SROXPMHU NRWDþD L]UDþXQDWL QD WHPHOMX
podataka iz navedene literature.
Tablica 1=QDþDMQLMLSDUDPHWULDXWREXVDVolvo 8900 [4, 5]
Parametar
OznakaVrijednost
Mjerna jedinica
Duljina12mlPrednja površina vozila
8.364
m2
Af
Tip gume
275/70 R22.5''(IHNWLYQLSROXPMHUNRWDþD
0.441
m
r
Prijenosni omjer
4.72
ioUkupna dopuštena masa
19000
kg
mu
Masa praznog vozila
12700
kg
mpr

Energy and the Environment (2016) 381-394

383

3.2. Opis uzdužne dinamike8]GXåQDGLQDPLNDRSLVDQDMHMHGQDGåERP]DSRJRQVNLPRPHQWQDNRWDþLPD W kot ):W kotr ª¬ mv ( dvv / dt  g (sin D  P kotr cos D ))  0.5 U zrak Cd Afvv2 º¼(1)

U jednadžbi (1  QDOD]H VH QHNL SDUDPHWUL þLMH YULMHGQRVWL VX SR]QDWH L QHNL NRML VX RGUHÿHQL
SULEOLåQRX]LPDMXüLXRE]LUQHNHNDUDNWHULVWLNHDXWREXVDYDULMDELOQDPDVDYR]LOD mv) koja jeRGUHÿHQD PDVRP SUD]QRJ DXWREXVD XYHüDQRP ]D YDULMDELOQX PDVX SXWQLND DNFHOHUDFLMD
slobodnog pada (g) vrijednosti 9.81 m/s2, koeficijent trenja kotrljanja (μkotr) vrijednosti 0.012>@]DYULMHGQRVWJXVWRüH]UDND ȡzrak VHXYHüLQLVOXþDMHYDX]LPDNJP3, pa je uzeta i u
RYRP UDGX WH NRHILFLMHQW DHURGLQDPLþQRJ RWSRUD Cd) vrijednosti 0.7 [6], vv je brzina
autobusa.
3.3. Modeliranje pogona konvencionalnog autobusa
Pogonska struktura konvencionalnog autobusa prikazana je na slici 1. SUI motor dobiva
gorivo kao izvor energije. U SUI motoru se energija goriYDSUHWYDUDXPHKDQLþNX. Na vratilu
SUI PRWRUD NRMH VH YUWL RGUHÿHQRP EU]LQRP VWYDUD VH RNUHWQL PRPHQW %U]LQD L PRPHQW
prenose se do transmisije gdje se moment množi, a brzina dijeli prijenosnom omjeromRGUHÿHQRJ VWXSQMD SULMHQRVD 1D WUDQVPLVLMX VH QDGRYH]XMH GLIHUHQFLMDO NRML VYRMLP
prijenosnLP RPMHURP GRGDWQR VPDQMXMH EU]LQX L SRYHüDYD PRPHQW 3ROXRVRYLQDPD VH WDMPRPHQWLEU]LQDSUHQRVHQDNRWDþH

Slika 1. Shema pogona konvencionalnog autobusa

3.3.1. Motor s unutarnjim izgaranjem
SUI motor opisan je mapom masenog protoka goriva ( m f ) i krivuljom maksimalnog momentau koordinatnoj ravnini sa brzinom vrtnje na apscisi i okretnim momentom na ordinati (slika
2). Mapa je dobivena skaliranjem preuzete mape dieselovog motora snage 176 kW i
maksimalnog momenta 900 Nm [7] . Skaliranje je izvršeno Willansovom linijskom metodom[8] i dobivene su približno karakteristike dieselovog SUI motora kakve ima Volvo 8900
autobus.

384

D. Perliü: 0RGHOLUDQMHLXSUDYOMDQMHKLEULGQLPHOHNWULþQLP«Slika 2. Mapa masenog protoka goriva sa krivuljom maksimalnog momenta
0RPHQWLNXWQDEU]LQD68,PRWRUDUDþXQDMXVHL]SRJRQVNRJPRPHQWDLNXWQHEU]LQHQD
NRWDþLPDVOMHGHüLPNLQHPDWLþNLPMHGQDGåEDPD

W kot
Kt i0 h(2)

Zm Zkot i0 h

(3)

Wm

SRPRüXNRULVQRVWLWUDQVPLVLMH Șt), prijenosnog omjera diferencijala (io)i prijenosnog omjera
stupnja prijenosa transmisije (h).
3.3.2. Transmisija
7UDQVPLVLMD RVLP YHü VSRPHQXWLK  VWXSQMHYD ]D SRJRQ SUHPD QDSULMHG LPD L  VWXSQMD ]DSRJRQXVXSURWQRPVPMHUX2YDNRYHOLNEURMVWXSQMHYDSULMHQRVDRPRJXüXMHYLVRNXNRULVQRVW
i efikasnost. Modelirana je kao mapa optimalnih stupnjeva prijenosa i može se vidjeti na slici
0DSDMHQDSUDYOMHQDQDQDþLQGDVH]DVYDNXNRPELQDFLMXPRPHQWDQDNRWDþLPDLEU]LQH
vozila ispitivala potrošnja goriva za pojedini stupanj prijenosa, a odabirao se onaj stupanj zakoji je potrošnja bila minimalna. Crnim linijama prikazan je maksimalni izlazni moment naNRWDþLPD X RYLVQRVWL R EU]LQL YR]LOD NRML MH GRELYHQ QD WHPHOMX NULYXOMH PDNVLPDOQRJ
momenta SUI motora sa slike 2, NRULVWHüL YULMHGQRVWL NRULVQRVWL WUDQVPLVLMH SULjenosnog
omjera diferencijala, vrijednosti pojedinih stupnjeva prijenosa, te jednadžbi (2) i (3).

Energy and the Environment (2016) 381-394

385

Slika 3. Mapa optimalnih stupnjeva prijenosa

4. +,%5,'1,(/(.75,ý1,$872%86
Kao osnova za modeliranje i simulaciju hibridnog autobusa uzet je autobus tvrtke Volvo,
model 7900. Autobus LPD SXQR VOLþQRVWL VD NRQYHQFLRQDOQLP DXWREXVRP RSLVDQLP X
SUHWKRGQRPSRJODYOMX,PDMXLVWXNDURVHULMXLGRLGHQWLþQLKNRPSRQHQWL
4.1. 2SLVKLEULGQRJHOHNWULþQRJDXWREXVD
Paralelna hibridna konfiguracija pogona autobusa VDGUåLþHWYHURFLOLQGULþQL litreni dieselov
SUI motor maksimalne snage 179 kW i maksimalnog momenta 918 Nm, WH HOHNWULþQL VWURM
maksimalne snage 120 kW i maksimalnog momenta 800 Nm. 7UDQVPLVLMDMHLGHQWLþQDNDRL
kod konvencionalnog autobusa opisanog u prethodnom poglavlju. Izvor eOHNWULþQH HQHUJLMH
DXWREXVDMHEDWHULMDNDSDFLWHWDN:K2VWDOL]QDþDMQLMLSDUDPHWULKLEULGQRJDXWREXVD9ROYRLGHQWLþQLVXNDR]DVOXþDMNRQYHQFLRQDOQRJDXWREXVDLSULND]DQLVXXWDEOLFL
4.2. 0RGHOLUDQMHSRJRQDKLEULGQRJHOHNWULþQRJDXWREXVD
Pogonska struktura hibridnog autobusa prikazana je na slici 4. SUI motor dobiva gorivo kao
izvor energije. U SUI motoru se enerJLMDJRULYDSUHWYDUDXPHKDQLþNX. Na vratilu SUI motora
NRMHVHYUWLRGUHÿHQRPEU]LQRPVWYDUDVHPRPHQW68,PRWRUMHVSRMNRPNRMDVHXNOMXþXMH
SRSRWUHELVSRMHQVDHOHNWULþQLPVWURMHP(OHNWULþQLVWURMGRELYDHOHNWULþQXHQHUJLMXL]EDWHULMH
L SUHWYDUD MH X PHKDQLþNX .DR L NRG 68, PRWRUD QD YUDWLOX HOHNWULþQRJ VWURMD NRMH VH YUWLRGUHÿHQRP EU]LQRP VWYDUD VH PRPHQW %U]LQD L PRPHQW Srenose se do transmisije gdje se
PRPHQW PQRåL D EU]LQD GLMHOL SULMHQRVQRP RPMHURP RGUHÿHQRJ VWXSQMD SULMHQRVD 1D
transmisiju se nadovezuje diferencijal koji svojim prijenosnim omjerom dalje smanjuje brzinu
LSRYHüDYDPRPHQW3ROXRVRYLQDPDVHWDMPRPHQWL EU]LQDSUHQRVHQDNRWDþH=DFMHORNXSQXorganizaciju rada prethodno spomenutih komponenti pogona, te za tokove energije zaduženaMHXSUDYOMDþNDMHGLQLFD386

D. Perliü: 0RGHOLUDQMHLXSUDYOMDQMHKLEULGQLPHOHNWULþQLP«Slika 4. Shema pogona hibridnog autobusa
4.2.1. Motor s unutarnjim izgaranjem
68, PRWRU RSLVDQ MH PDSRP VSHFLILþQH SRWURãQMH gs) i krivuljom maksimalnog momenta, a]ERJQHPRJXüQRVWLSULEDYOMDQMDLQIRUPDFLMDRPDSLRULJLQDOQRJ9ROYR68,PRWRUDSUHX]HWD
MH LGHQWLþQD PDSD NDR L ]D VOXþDM NRQYHQFLRQDOQRJ DXWREXVD L SULND]DQD MH QD slici 5. Po
karakteristikama se ispostavilo da je mapa preuzetog motora adekvatna i da nije potrebno
VNDOLUDQMHPDSHNDRãWRMHELRVOXþDMNRGNRQYHQFLRQDOQRJDXWREXVD

Slika 50DSDVSHFLILþQHSRWURãQMHJRULYDVDNULYXOMRPmaksimalnog momenta preuzeta iz [7]4.2.2. (OHNWULþQLVWURM%XGXüL GD GHWDOMQLMH NDUDNWHULVWLNH RULJLQDOQRJ 9ROYR HOHNWULþQRJ VWURMD QLVX ELOH QD
UDVSRODJDQMXNDRDGHNYDWQD]DPMHQDX]HWMHHOHNWULþQLVWURMWYUWNH5HP\VHULMH+9+ [9].
(OHNWULþQLVWURMRSisan je mapom korisnosti i krivuljom maksimalnog momenta u koordinatnoj
ravnini sa brzinom vrtnje na apscisi, te momentom na ordinati (slika 6). Mapa korisnosti i
NULYXOMD PDNVLPDOQRJ PRPHQWD QH]QDWQR VX UXþQR L]PLMHQMHQL X RGQRVX QD RULginal.
Izmijenjeni su za potrebe implementacije tako da bi se približilo osnovnim karakteristikama
Volvo HOHNWULþQRJVWURM

Energy and the Environment (2016) 381-394

387

Slika 60DSDNRULVQRVWLHOHNWULþQRJVWURMDVDNULYXOMRPPDNVLPDOQRJPRPHQWD
4.2.3. Baterija
Uz gorivo, baterija je dodatan izvor energije za pogon vozila. Baterija je litij – ionska vršne
snage 120 kW. Na slici 7 a) prikazana je ovisnost napona otvorenog kruga o SoC – u.

a)b)Slika 7. Ovisnost napona otvorenog kruga (Uoc) o stanju napunjenosti baterije (engl. State ofCharge (SoC)) a) i pojednostavljeni shematski prikaz baterije [6]0RGHO EDWHULMH GDMH LQIRUPDFLMX R 6R& ED]LUDQX QD LVNRULãWHQMX HOHNWULþQH HQHUJLMH EDWHULMH
Vrijednosti SoC-D NUHüX VH X JUDQLFDPa 0 d SoC d 1 . Na slici 7 b) prikazan je
pojednostavljeni shematski prikaz baterije koji je primijenjen u modeliranju. Na temelju
shematskog prikaza dobiva se jednadžba modela baterije [6]:

SoC

2
U OC
(SoC)  4 R(sgn(i )) Pbat  U OC (SoC)
2Qmax R (sgn(i ))

(4)

388

D. Perliü: 0RGHOLUDQMHLXSUDYOMDQMHKLEULGQLPHOHNWULþQLP«iz koje se vidi da SoC ovisi o Uoc, otporu baterije(R), snazi baterije (Pbat) i njenom kapacitetu(Qmax).
-HGQDGåEDNRMDSRYH]XMHHOHNWULþQXVQDJXVDPHKDQLþNRPLJXELFLPDJODVLPbat

PesKes  sgn( Pes )W esZesKes  sgn( Pes )(5)gdje je Pes VQDJD HOHNWULþQRJ VWURMD K es korisnost stroja, a Ĳes i Ȧes moment i kutna brzina
HOHNWULþQRJVWURMDIz jednadžbe se vidi da ako je Pes pozitivna da se vozilo pogoni i da je Pbat
YHüDQHJRPes, a ako je Pes QHJDWLYQDYR]LORNRþLLPbat je manja nego Pes [6].
4.2.4. Transmisija
7UDQVPLVLMD MH PRGHOLUDQD QD QDþLQ GD VX QDSUDYOMHQH PDSH RSWLPDOQLK VWXSQMHYD SULMHQRVDNDR L ]D VOXþDM NRQYHQFLRQDOQRJDXWREXVD1DSUDYOMHQD MH SRVHEQR PDSD ]D HOHNWULþQL QDþLQ
UDGDDXWREXVDDSRVHEQR]DKLEULGQLQDþLQ=DKLEULGQLQDþLQUDGDYR]LODPDSDMHQDSUDYOMHQD
QD QDþLQ LGHQWLþDQ NDR NRG NRQYHQFLRQDOQRJ DXWREXVD, a za HOHNWULþQL QDþLQ UDGD DXWREXVD
napravljHQD MH QD QDþLQ GD VH ]D VYDNX NRPELQDFLMX PRPHQWD QD NRWDþLPD L EU]LQH YR]LODLVSLWLYDODNRULVQRVWHOHNWULþQRJVWURMD]DSojedini stupanj prijenosa, a odabran je onaj stupanj]DNRMLMHNRULVQRVWHOHNWULþQRJVWURMDPDNVLPDOQD
4.3. 8SUDYOMDþNDVWUDWHJLMD
8SUDYOMDþNDMHGLQLFDRGUHÿXMHKRüHOLYR]LORYR]LWLXHOHNWULþQRPLOLKLEULGQRPQDþLQXUDGD
=DGXåHQDMH]DXNOMXþLYDQMHLLVNOMXþLYDQMH68,PRWRUDSRSRWUHEL7DNRÿHURGUHÿXMHVWXSDQM
prijenosa transmisije, te regulira punjenje baterije po potrebi ili prilikom regenerativnog
NRþHQMD 8SUDYOMDþND MHGLQLFD WR VYH RGUHÿXMH QD RVQRYX XSUDYOMDþNLK VWUDWHJLMD NRMH VX
implementirane u nju.
1DVOLFLSULND]DQMHFMHORNXSQLXSUDYOMDþNLVXVWDYXNRMHPVXXOD]LXXSUDYOMDþNXMHGLQLFXvv,
Ĳkot i SoCDL]OD]LL]XSUDYOMDþNHMHGLQLFHVXUDGQHWRþNH68,PRWRUD PRPHQWĲm i brzina Ȧm)
LUDGQHWRþNHHOHNWULþQRJVWURMD PRPHQWĲes i brzina Ȧes) [10].

Slika 8)XQNFLRQDOQLEORNGLMDJUDPFMHORNXSQRJXSUDYOMDþNRJVXVWDYD [10]Energy and the Environment (2016) 381-394

389

4.3.1. Regulator zasnovan na bazi pravila (RB)Blok dijagram RB regulatora [10] prikazan je na slici 9. Može se vidjeti da RB regulator
XNOMXþXMH L EDWHULMVNL 6RC UHJXODWRU NRML ]D RGUHÿHQR RGVWXSDQMH 6R&-a od referentne
vrijednosti SoC (SoCR), odnosno za neku regulacijsku grešku (eSoC) na izlazu daje snagu –Pbat 6R& UHJXODWRU MH SURSRUFLRQDOQRJ WLSD V PUWYRP ]RQRP L ]DVLüHQMHP WH V YULMHGQRVWLSRMDþDQMDGRVWDWQRPGDRGUåLeSoC XUD]PMHUQRPDOLPJUDQLFDPDDX]HWDYULMHGQRVWSRMDþDQMD
je K = 105. RB regulator snazi –Pbat GRGDMHSRWUHEQXVQDJX]DSRJRQYR]LODWM]DKWMHYYR]DþD(Pkot  WH WDNR UDþXQD VQDJX 68, PRWRUD Pm). Nakon što je definirana vrijednost Pm slijediUDþXQDQMH UHIHUHQWQLK UDGQLK WRþDND 68, PRWRUD /RJLND XNOMXþLYDQMDLVNOMXþLYDQMD 68,PRWRUD RGUHÿXMH NDGD üH VH XNOMXþLYDWL RGQRVQR LVNOMXþLYDWL 68, PRWRU X RYLVQRVWL R WRPH
prelazi li Pm SUHGRGUHÿHQLSUDJ Pprag). Pprag MHSUDJNRMLVHRGDELUHSURL]YROMQRQDQDþLQGDVH
L]EMHJQHSRGUXþMHUDGD68,PRWRUDVDYLVRNRPSRWURãQMom goriva i odabrana vrijednost je 53
kW. Pm PRåHSULMHüLPprag XVOMHGHüDGYDVOXþDMDNDGDVHSRYHüDPkot ili kada SoC regulator
zahtjeva punjenje baterije (Pbat < 0).

Slika 9%ORNGLMDJUDP5%UHJXODWRUDXNOMXþXMXüLJUDQXVDSoC regulatorom [10]4.3.2. Regulator zasnovan na bazi pravila kombiniran s trenutnom optimizacijom (RB +ECMS).DNRMHYHüVSRPHQXWRQDVWRMDQMHP]DGRGDWQLPVPDQMHQMHPSRWURãQMHJRULYDSRVWRMHüL5%
regulator kombiniran je s trenutnom ECMS optimizacijom [10]. Cilj ECMS-a je minimizirati
 ek (NYLYDOHQWQDSRWURãQMDJRULYDXNOMXþXMH m f itakozvanu ekvivalentnu potrošnju goriva ( mekvivalentnu potrošnju goriva iz baterije ( m bat ) koja uzima u obzir tok snage u bateriji, a dana
MHVOMHGHüRPMHGQDGåERPm ek

m f  m bat ( Pbat , K bat , g s )(6)

gdje je K bat korisnost baterije.

 ek u svakom diskretnom koraku. Pretraživanje optimalne
ECMS algoritam minimizira m
UDGQH WRþNH 68, PRWRUD SURYHGHQR MH MHGQRVWDYQLP MHGQRGLPHQ]LRQDOQLP SUHWUDåLYDQMHP

390

D. Perliü: 0RGHOLUDQMHLXSUDYOMDQMHKLEULGQLPHOHNWULþQLP«Pretraživanje je provedeno po liniji konstantne brzine vrtnje SUI motora koja je za danu
paralelnu konfiguraciju pogona RGUHÿHQD L] EU]LQH YR]LOD GHILQLUDQH YR]QLP FLNOXVRP WH MX
QLMH PRJXüH PRGLILFLUDWL 7R ]QDþL GD MH RVWDR VDPR MHGDQ VWXSDQM VORERGH ]D RGDELU
RSWLPDOQH UDGQH WRþNH ]D UD]OLNX RG VHULMVNR – paralelne konfiguracije pogona gdje postoje
dva stupnja slobodH ]D RGDELU RSWLPDOQH UDGQH WRþNH WM SUHWUDåLYDQMH SR EU]LQL L PRPHQWX
[10@ 3UYD WRþND SUHWUDåLYDQMD MH  UDGQD WRþND NRMD MH RGUHÿHQD RG VWUDQH 5% UHJXODWRUD L]
zahtjeva za snagom SUI motora prema:

Wm

Pm

(7)

Zm

L]UD]ORJDãWRELEDãWDUDGQDWRþNDPRJODELWLRSWLPDOQDDOLQHDUQLPSUHWUDåLYDQMHPSRVWRMLYHOLND PRJXüQRVW GD VH WD WRþND SUHVNRþL 1DGDOMH VOLMHGL SUHWUDåLYDQMH RG PLQLPDOQH
YULMHGQRVWLLVSLWLYDQMDUDGQHWRþNHNRMDVHQDOD]LQDNULYXOMLVQDJHPprag, pa sve do maksimalne
UDGQH WRþNH NRMD VH QDOD]L QD NULYXOML PDNVLPDOQRJ PRPHQWD 1DYHGHQR SUHWUDåLYDQMH
provedeno je sa dovoljno finim korakom od 1 Nm. Nakon što je definirana optimalna radnaWRþND68,PRWRUDSRWUHEQRMHRGUHGLWLUDGQXWRþNXHOHNWULþQRJVtroja. Kako je brzina vrtnje
stroja, kao i kod SUI motora, definirana voznim ciklusom, potrebno je još odrediti moment
HOHNWULþQRJVWURMDSUHPD

W es

W kot
hio

(8)

W m

5. SIMULACIJSKI REZULTATI
Slika 11 prikazuje usporedbu potrošnje goriva i ispuštanja CO2 na 100 km za RB i RB+ECMS
XSUDYOMDþNHVWUDWHJLMH3ULND]DQHVXSURVMHþQHYULMHGQRVWLza svih 7 voznih ciklusa i varijabilnu
masu putnika u autobusu. Na litru potrošenog dizel goriva ispusti se 2.68 kg CO2 [11].
Ispuštanje CO2 na 100 km [kg]Potrošnja goriva na 100 km [L]
20

18,47

18,38

100
50

10

49,4

49,25

RB

RB+ECMS

00
RB

RB+ECMS

Slika 10. Usporedba potrošnje goriva i ispuštanja CO2 na 100 km za RB i RB+ECMS
XSUDYOMDþNHVWUDWHJLMH
6OLNDSULND]XMHUDGQHWRþNH68,PRWRUDGRELYHQH]DMHGQRPRGYRåHQFLNOXVLYDULMDELOQX
masu putnika u autobusu. Usporedno su prikazDQHUDGQHWRþNH]D5%L5%(&06

Energy and the Environment (2016) 381-394

391

Slika 11. UsporHGQHUDGQHWRþNH]D5%L5%(&06 XSUDYOMDþNHVWUDWHJLMH.DR ãWR VH PRåH YLGMHWL QD VOLFL UDGQH WRþNH ]D 5%(&06 VX QH]QDWQR SRPDNQXWH SUHPD
krivulji maksimalnog momenta SUI motora X RGQRVX QD 5% ãWR XSXüXMH QD QHãWR QLåX
YULMHGQRVW XNXSQH VSHFLILþQH SRWURãQMH gs  7D QH]QDWQD SRPDNQXWRVW WRþDND L]PHÿX GYLMH
strategije razlog je neznatnoj razlici u potrošnji goriva prikazanoj na slici 11. Navedeno
XSXüXMH QD WR GD VX RSWLPDOQH UDGQH WRþNH MDNR EOL]X UDGQLP WRþNDPD NRMH VX GRELYHQH ]DRB.
Slika  SULND]XMH XVSRUHGQR SURVMHþQH YULMHGQRVWL SRWURãQMH JRULYD L LVSXãWDQMD &22 za 26
puta odvožene cikluse. Prikazana je usporedba za konvencionalni autobus kojim su snimljeni
podaci MAN LION S CITY, modelirani konvencionalni autobus Volvo 8900 i za modelirani
KLEULGQL DXWREXV 9ROYR  VD 5%(&06 XSUDYOMDþNRP VWUDWHJLMRP Usporedba je
SURYHGHQDQDED]LRGRGYRåHQLKFLNOXVDRGQRVQRL]PHÿXSXQMHQMDUH]HUYRDUDMHUMHQD
tDMQDþLQVQLPOMHna potrošnja Man-ovim autobusom. Kako je snimljeno samo 7 kružnih ruta,
estimirana je potrošnja goriva i ispuštanje CO2 za svih 26 kružnih ruta. Estimacija je
SURYHGHQDQDQDþLQGDMHX]HWDDULWPHWLþNDVUHGLQDYULMHGQRVWL]DSULMHÿHQLKLVWLKFLNOXVD
Ispuštanje CO2 za 26xciklus [kg]Potrošnja goriva za 26xciklus [L]
150
100

127

400

102,9
55,7

200

340,4

275,8
149,3

50
0

0
MAN LION S CITY
Volvo 8900
Volvo 7900 (RB+ECMS)

MAN LION S CITY
Volvo 8900
Volvo 7900 (RB+ECMS)

Slika 12. Usporedba potrošnje goriva i ispuštanja CO2 za 26xciklus za RB i RB+ECMS
XSUDYOMDþNHVWUDWHJLMH

392

D. Perliü: 0RGHOLUDQMHLXSUDYOMDQMHKLEULGQLPHOHNWULþQLP«6. =$./-8ý$.
Opisan je, modeliran i simuliran konvencionalni autobus Volvo 8900, a simulacija je izvršena
na snimljenim voznim ciklusima. Dobiveni simulacijski rezultati pokazali su da je potrošnja
Volvo autobusa niža za otprilike 20 % u odnosu na potrošnju Man autobusa što je rezultat
UD]OLþLWLKNDUDNWHULVWLNDRYDGYDDXWREXVDDGLMHORPLRGUHÿHQLKSRJUHãNLPRGHOLUDQMD Potom
je opisan, modeliran i simuliran hibridni autobus. 3UHGVWDYOMHQD MH XSUDYOMDþND VWUDWHJLMD
]DVQRYDQDQD5%UHJXODWRUXNRMLXNOMXþXMHL6R&UHJXODWRUD]DWLPVWUDWHJLMDNRMDNRPELQLUD
5% L (&06 UHJXODWRUH 6LPXODFLMVNL UH]XOWDWL SRND]XMX NDNR ]D VOXþDj RB+ECMS postoji
WHQGHQFLMD SRVWDYOMDQMD UDGQLK WRþDND 68, PRWRUD QD QLåH YULMHGQRVWL VSHFLILþQH SRWURãQMH
JRULYDXRGQRVXQD5%DOLQHGRYROMQRGDELVH]QDþDMQLMHVPDQMLODSRWURãQMD7RLPSOLFLUDGD
VXRSWLPDOQHUDGQHWRþNHEOL]XUDGQLKWRþDNDGHILQLUDQLK5%UHJXODWRURPLGD]DVOXþDMYR]LODVD SDUDOHOQRP KLEULGQRP NRQILJXUDFLMRP SRJRQD QHPD ]QDþDMQLMH NRULVWL GRGDYDQMH (&06
algoritama. Dobiveni rezultati pokazuju da je smanjenje potrošnje goriva hibridnog autobusa
u odnosu na modelirani konvencionalni autobus približno 45 %, dok smanjenje potrošnje
goriva u odnosu na Manov autobus kojim su snimani podaci iznosi 56 %.

7. POPIS OZNAKA
Oznaka
l
Af
r
io
mu
mpr

Ĳkot

mv
vv
t
g
Į
μkotr
ȡzrak
Cd

Ȧkot
Ĳm
Ȧm
Ĳd
Ȧd
m f
Șt
h

Ĳes

Ȧes
gs

Opis
Duljina autobusa
Prednja površina autobusa(IHNWLYQLSROXPMHUNRWDþD
Prijenosni omjer diferncijala
Ukupna dopuštena masa autobusa
masa praznog vozila
3RJRQVNLPRPHQWQDNRWDþLPD
Varijabilna masa vozila
Brzina vozila
VrijemeAkceleracija slobodnog pada
Nagib ceste
Koeficijent trenja kotrljanja*XVWRüD]UDND.RHILFLMHQWDHURGLQDPLþNRJRWSRUD.XWQDEU]LQDNRWDþD
Moment motora sa unutarnjim izgaranjem
Kutna brzina motora sa unutarnjim izgaranjem
Moment diferencijala
Kutna brzina diferencijala
Maseni protok goriva
Korisnost transmisije
Prijenosni omjer stupnja prijenosa transmisije
0RPHQWHOHNWULþQRJVWURMD
Kutna brzina vrtnje HOHNWULþQRJVWURMD
6SHFLILþQDSRWURãQMDJRULYD

Jedinica
m
m2
m
kg
kg
Nm
kg
m/s
s
m/s2
º
kg/m3
rad/s
Nm
Nm
Nm
rad/s
g/s
Nm
rad/s
g/Ws

Energy and the Environment (2016) 381-394

nm
nes
Șes
Uoc
SoC
R
i
Ubat
Qmax
Pbat
Pes
SoCR
eSoC
K
Pm
Pkot
Pprag

ĲmR
ȦmR

Pon
Poff
Mu/i
ǻSoC

Ĳm,max
 ek
m
 bat
m
Șbat

Brzina vrtnje motora sa unutarnjim izgaranjem%U]LQDYUWQMHHOHNWULþQRJVWURMD.RULVQRVWHOHNWULþQRJVWURMD
Napon otvorenog kruga
Stanje napunjenosti baterije
Otpor baterije
Jakost struje punjenja/pražnjenja baterije
Napon baterije
Maksimalni kapacitet baterije(OHNWULþQDVQDJDEDWHULMH
6QDJDHOHNWULþQRJVWURMD
Referentna vrijednost SoC – a
Regulacijsko odstupanje SoC regulatora3RMDþDQMH6R&UHJXODWRUD
Snaga motora sa unutarnjim izgaranjem
Snaga za pogon vozila
3UDJVQDJHXNOMXþLYDQMDLVNOMXþLYDQMDPRWRUD
Referentna vrijednost momenta motora
Referentna vrijednost kutne brzine motora
6QDJDNRMDGHILQLUDXNOMXþLYDQMHPRWRUD Pprag)
6QDJDNRMDGHILQLUDLVNOMXþLYDQMHPRWRUD Pprag)
8NOMXþLYDQMHLVNOMXþLYDQMHPRWora sa unutarnjim izgaranjem
Odstupanje SoC
Maksimalna vrijednost momenta motora
Ekvivalentna potrošnja goriva
Ekvivalentna potrošnja goriva iz baterije
Korisnost baterije

393

o/min
o/min
V
ȍ
A
V
C
W
W
W
W
W
Nm
rad/s
W
W
Nm
g/s
g/s
-

Literatura[1] âNXJRU%+UJHWLü0'HXU-*36PHDVXUHPHQW– based road grade reconstruction withapplication to electric vehicle simulation and analysis. In: 10th Conference on Sustainable
Development of Energy, Water and Environment Systems, Dubrovnik, Croatia, 2015.
[2] „Karakteristike SUI motora Volvo D8K280 EU6“;
http://euro6.volvobuses.com/pdf/Volvo-D8K-Euro6-Fact-Sheet-EN.pdf[3] „Volvo I – shift transmisija“;
http://productinfo.vtc.volvo.se/files/pdf/hi/AT2412D_Eng_01_953860.pdf[4] „Parametri autobusa Volvo 8900 1/2“;
http://www.volvobuses.com/SiteCollectionDocuments/VBC/Downloads/Volvo-8900-Euro6Brochure-EN.pdf[5] „Parametri autobusa Volvo 8900 2/2“;
http://www.hyperbus.se/download/18.52b58bdf14510b15162b4bba/1396356737766/Hyperbu
s-Report+on+3+buses+built-DataSheet-Volvo7900-Hybrid-Euro-5,Appen....pdf

394

D. Perliü: 0RGHOLUDQMHLXSUDYOMDQMHKLEULGQLPHOHNWULþQLP«>@3HUOLü'(OHNWULþQRGRVWDYQRYR]LOR– završni projekt preddiplomskog studija,
6YHXþLOLãWHX=DJUHEX)DNXOWHWVWURMDUVWYDLEURGRJUDGQMH
[7] Yuan Zou; Hou Shi – jie; Li Dong – ge; Gao Wei; Xiao – song Hu: Optimal Energy
Control Strategy Design for a Hybrid Electric Vehicle. Discrete Dynamics in Nature andSociety Volume 2013, Article ID 132064[8] Zuurendonk B.: Advanced Fuel Consumption and Emission Modeling using Willans line
scaling techniques for engines. 33 p. Eindhoven: Technische Universitet Eindhoven, June 3,2005.
[9] Ä.DUDNWHULVWLNHHOHNWULþQRJVWURMD+9+³
http://www.remyinc.com/docs/HVH410R2.pdf[10] Škugor %'HXU-&LSHN03DYNRYLü''HVLJQRIDSRZHU– split hybrid electricvehicle control system utilizing a rule – based controller and an equivalent consumption
minimization strategy, Journal of Automobile Engineering, Vol. 228 (6), pp. 631 – 648, 2014.
[11] „Ispuštanje CO2 po litri dizel goriva“;
http://people.exeter.ac.uk/TWDavies/energy_conversion/Calculation%20of%20CO2%20emis
sions%20from%20fuels.htm, 31.1.2016.

MODELING AND CONTROL OF A HYBRID ELECTRIC CITY BUS
Summary: In this thesis a procedure of collecting and processing data related to driving
cycles of a considered city bus route is described. The data are intended for the usage insimulations of various vehicle models. A model of existing conventional bus is developed andvalidated with respect to recorded cumulative fuel consumption data. In order to examine thepossibilities for electrification of existing conventional buses that operate on the consideredroute, a hybrid electric bus model is developed, as well as an accompanying hybrid
powertrain control strategy. Finally, simulations of developed models are conducted overrecorded driving cycles and comparative fuel consumption and CO2 emission results are
given.
Keywords: Conventional Bus, Hybrid Electric Bus, Driving Cycles, Modeling, Control,
Simulation

Energy and the Environment (2016) 395-408

395

SIMULACIJA POTROŠNJE GORIVA I EMISIJA U REALNIMUVJETIMA CESTOVNOG PROMETA
7RPLVODY6HQþLü/XND6ODYLþHN7HR*XELü
7HKQLþNLIDNXOWHW6YHXþLOLãWDX5LMHFL9XNRYDUVND5LMHNDWVHQFLF#ULWHKKU
Sažetak: 3RVWRMH PQRJH PHWRGH PMHUHQMD L L]UDþXQD potrošnje goriva motora u ustaljenim
XYMHWLPD0HÿXWLPUHDOQLXYMHWLXFHVWRYQRPSURPHWXSRGUD]XPLMHYDMXSURPMHQXSDUDPHWDUD
kao što su brzina vožnje i nagib koji je potrebno svladati što rezultira kontinuiranom
promjenom zahtjevane snage. Velik utjecaj iPDMXLVYRMVWYDYR]LOD,]PHÿXPRWRUDLSRJRQVNLKNRWDþDVWRMLWUDQVPLVLMDLPMHQMDþNRMLWDNRÿHULPDMXYHOLNLXWMHFDMQDSRWURãQMXJRULYD
8 UDGX MH SUHGVWDYOMHQ SURJUDP ]D SURUDþXQ SRWURãQMH JRULYD L HPLVLMD ãWHWQLK SOLQRYD
Advisor. Temelji se na odabiru trenutne potrošnje i emisija iz mape dobivene mjerenjima na
probnom stolu ili u stvarnim uvjetima. Potrošnja i emisije ovise o nizu parametara: u prvom
UHGX NRQILJXUDFLML WHUHQD L SURPMHQL EU]LQH WLMHNRP YRåQMH NRMH VX QDMþHãüH ]DPLMHQMHQH
standardnim vo]QLP FLNOXVRP DOL L NDUDNWHULVWLNDPD PRWRUD YR]LOD L PMHQMDþD *ODYQLSDUDPHWDU PRWRUD MH PDSD VSHFLILþQH SRWURãQMH JRULYD NRMX MH ]D UD]QH PRWRUH PRJXüH
SURQDüLXOLWHUDWXULDOLLGRELWLSRPRüXUD]OLþLWLKVLPXODFLMVNLKVRIWYHUD
Prikazana je usporedba ]DLVWRYR]LORVDGYDUD]OLþLWDPRWRUDUD]OLþLWRPPDVRPWHUD]OLþLWRPYUVWRP PMHQMDþD ,]UDþXQ MH L]YUãHQ QD VWDQGDUGL]LUDQLP YR]DþNRP FLNOXVX *UDILþNL MH
SULND]DQD HPLVLMD ãWHWQLK SOLQRYD WH SURPMHQD UDGQH WRþNH PRWRUD ]D YULMHPH YRåQMH ]D
UD]OLþLWH VOXþDMHYH 7DEOLþQR MH SULND]DQD SRWURãQMD JRULYD HPLVLMD XJOMLþQRJ GLRNVLGD
GXãLNRYLKRNVLGDXJOMLþQRJPRQRNVLGDLQHL]JRUHQLKXJOMLNRYRGLND]DUD]OLþLWHNRQILJXUDFLMH
YR]LOD7DNRÿHUMHVLPXOLUDQRXEU]DQMHYR]LODQDUD]OLþLWLPGLRQLFDPD8]DNOMXþQRPGijelu su
SURNRPHQWLUDQHPRJXüQRVWLNRULãWHQRJSURJUDPDLGRELYHQLUH]XOWDWL.OMXþQHULMHþL: simulacija potrošnje goriva, program Advisor, realni uvjeti prometa
1. UVOD)RVLOQDJRULYDVXGUDVWLþQRSURPLMHQLODOLFHVYLMHWDX]DGQMLKSDUVWROMHüD7RSOLQski strojevi su
RPRJXüLOL QHVOXüHQL SRUDVW åLYRWQRJ VWDQGDUGD 0RWRUQD YR]LOD RPRJXüXMX ODNãH SXWRYDQMH
SURQDOD]DN ]DSRVOHQMD QD YHüLP XGDOMHQRVWLPD WH QDURþLWR WUDQVSRUW UD]OLþLWLK GREDUD L]
SRGUXþMDJGMHVXMHIWLQLMD2YDPDVRYQDHNVSORDWDFLMDIRVLOQLKgoriva, osim blagodati, donosi i
brojne probleme. Prije svega, nastanak fosilnih goriva je veoma spor proces za koji su
SRWUHEQHWLVXüHJRGLQDSDVHVPDWUDGDüHGRüLGRVPDQMHQMDQMLKRYHNROLþLQHQDSODQHWX7R
SRYODþL ]D VRERP L  SURPMHQX FLMHQD 2VLP Woga cijene goriva su tijesno povezane sa
SROLWLþNR-HNRQRPVNRP VLWXDFLMRP L GL]EDODQVRP ILQDQFLMVNH PRüL RQLK NRML LPDMX QD
raspolaganju gorivo i onih koji ga nemaju. Ovakvi dizbalansi mogu uzrokovati i sukobe koji
SRNUHüXPLJUDFLMXVWDQRYQLãWYD
Osim spomeQXWLK SUREOHPD NRML EL VH PRJOL SRMDþDWL QHVWDãLFRP JRULYD WX VX L HNRORãNL
SUREOHPL 6SDOMLYDQMH IRVLOQLK JRULYD QRVL VD VRERP HPLVLMX QHNLK ãWHWQLK WYDUL 0HÿXQDMãWHWQLMLPDVXGXãLNRYLRNVLGLQHL]JRUHQLXJOMLNRYRGLFLXJOMLþQLPRQRNVLGVXSRUQLRNVLGL
WH NUXWH þHVWLFH  2VLP RYLK WYDUL LVSRVWDYOMD VH GD MH L XJOMLþQL GLRNVLG QHL]EMHåQL SURGXNWL]JDUDQMD YUOR ãWHWDQ ]DWR ãWR GMHOXMH VWYDUDMXüL QD ]HPOML HIHNW VWDNOHQLND ãWR LPD ]Dposljedicu globalno zagrijavanje i nepovoljne klimatske promjene. Kako EL VH RJUDQLþLOH

396

76HQþLü/6ODYLþHN7*XELü: Simulacija potrošnje goriva i emisija u realnim …

emisije štetnih plinova provode se razne kampanje i organiziraju se svjetski kongresi te se]DNRQRGDYVWYRXVPMHUDYDNDRJUDQLþDYDQMXPDNVLPDOQLKGRSXãWHQLKHPLVLMD>@-HGQR RG JODYQLK SRGUXþMD OMXGVNRJ GMHORYDQMD VD YLVRNRP HPLVLMRP ãWHtnih tvari zbog
L]JDUDQMDMHFHVWRYQLSURPHWãWRMHQDURþLWR]QDþDMQRMHUVHRGYLMDSRJRWRYRXJUDGRYLPDLX
SRGUXþMLPD YLVRNH QDVHOMHQRVWL 3URL]YRÿDþL FHVWRYQLK YR]LOD VH QDVWRMH SULODJRGLWL
novonastaloj situaciji raznim tehnikama kojima nastoje smanjiti potrošnju goriva. Nekeosnovne prilagodbe su poboljšanje aerodinamike karoserije, smanjenje mase vozila te
VPDQMHQMH RWSRUDNRWUOMDQMDNRWDþD6FLOMHPVPDQMHQMD SRWURãQMHLHPLVLMD VHRSWLPLUDMX VYHNRPSRQHQWH YR]LOD RG NRWDþD SUHNR NDURVHULMH L WUDQVPLsije, ali najutjecajniji faktor je
SRJRQVNL PRWRU >@ >@ >@ >@ >@ 1DMþHãüH VH XJUDÿXMH EHQ]LQVNL LOL GL]HOVNL PRWRU
1DVWRML VH VPDQMLWL JXELWNH L PDVD NDNR EL VH X NRQDþQLFL VPDQMLOD SRWURãQMD 2YH WHKQLNH
smanjenja motora su poznate pod nazivom GRZQVL]LQJSULþHPXVHSULPMHULFHVWDULMLPRWRUL
VDþHWLULFLOLQGUDREXMPDRNRO]DPMHQMXMXPRGHUQLMLPWURFLOLQGULþQLPVDSUHGQDELMDQMHPNRMLQXGHSUHGQRVWLPDQMHGMHORYDPDQMHPDVHPDQMHPHKDQLþNLKJXELWDNDDOLNDNRELQXGLOLjednaku snagu su opremljeni prednabijanjem. Nadalje, motore na fosilna goriva se nastoji]DPLMHQLWLHOHNWULþQLPPRWRULPD9LVRNDFLMHQDLPDVDEDWHULMH]DSRKUDQXSRWUHEQHHQHUJLMH>@SUHGVWDYOMDMXSUREOHPSDVHRYDNDYSRJRQVNLVNORSþHVWR]DPMHQMXMHKLEULGQLPSRJRQRP
koji može biti serijski ili paralelni [8].
'HEDWDRNRWRJDNRMDMHWHKQLNDHILNDVQLMD]DNRMXXSRWUHEXMHDNWXDOQDLQHPDMHGQR]QDþQRJ
odgovora. Zapravo sama primjena vozila ima veliki utjecaj na to koji je pogonski sklop
RSWLPDODQ =DWR VH UD]YLMDMX UD]OLþLWL YR]QL FLNOXVL >@ NRML RPRJXüXMX VWDQGDUGL]LUDQXXVSRUHGEXUD]OLþLWLKYR]LODLUMHãHQMDXLVWLPXYMHWLPD.DNRELVHXEU]DRUD]YRMLRSWLPL]DFLMD
vozila i komponenti te olakšao odabir za pojedinu namjenu, u razvojnom procesu vozila
uvelike se koriste kompMXWRUVNH VLPXODFLMH 3RVWRMH QDMUD]OLþLWLMH VLPXODFLMH SRMHGLQLKNRPSRQHQWL YR]LOD NRMH VOXåH ]D DQDOL]X VWUXNWXUH GMHORYDQMD WUDQVPLVLMH L]UDþXQ
WHUPRGLQDPLþNLK SURFHVD X PRWRUX L GLQDPLþNRJ SRQDãDQMD FLMHORJ YR]LOD9UOR MH YDåQR GD
simulacija uzima u RE]LUVYHSDUDPHWUHYR]LODLWRþQHXYMHWHRNROLQHXNRMRMVHYR]LORNRULVWL
8SUDYRWRQDPRPRJXüXMH SURJUDP$GYLVRU NRMLMHSULPMHQMHQXRYRP UDGX>@ >@ >@[12].
2. 0$7(0$7,ý.,02'(/
7HPHOML]UDþXQDSRWURãQMHJRULYDMHWDNR]YDQDX]GXåQDGLQDPLNDYR]LOD>@SRPRüXNRMHVH
RGUHÿXMHVLODSRWUHEQD]DVYODGDYDQMHRWSRUDJLEDQMXLLQHUFLMHYR]LODVOLND
Sila otpora gibanju vozila jednaka je:
Ftr Ȝ. (m . a) + Far + Fslope + Froll(1)

SULþHPXMHȜ  . (gr . grf)2(2)

faktor utjecaja inercije rotacijskih masa [14], gr i grf su prijenosni omjer i završni prijenosni
omjer u diferencijalu, m je masa vozila, a je ubrzanje.
$HURGLQDPLþNDVLODRWSRUDVHUDþXQDSUHPD
Faero  ȡair/2) . A . CD . v2

(3)

Energy and the Environment (2016) 395-408

397

SULþHPXMHȡair JXVWRüD]UDNDA SRYUãLQDSRSUHþQRJSUHVMHNDYR]LODCD koeficijent otpora
zraka v brzina.
Otpor kotrljanja je
Froll = m. croll . g(4)croll = 0.015 je koeficijent otpora kotrljanja, g = 9.81ms-2 je ubrzanje sile gravitacije.
Sila koju je potrebno svladati zbog nagiba je:
Fsl = m . g . sin(n)(5)

SULþHPXMHDNXWXVSRQD

Slika 1. Skica vozila sa komponentama otpora gibanju [15]%U]LQDYUWQMHNRWDþDVHUDþXQDL]EU]LQH
nkot = YʌUkot(6)

SULþHPXMHUkot SROXPMHUNRWDþD
3RWUHEQLPRPHQWQDNRWDþX]DVYODGDYDQMHVLOHJLEDQMDMH
Mkot = Ftr . rkot

(7)

Moment koji treba dobaviti motor je umanjen za ukupni prijenosni omjer:
Mmot = Mkot/ (gr . grf)

(8)

Snaga koju mora proizvesti motor je umnožak potrebnog momenta i kutne brzine:
P = Mkot . 2 . ʌ. nkot = Mmot . 2 . ʌ. nmot

(9)

Srednji efektivni tlak potreban da bi se ostvario moment Mmot na koljenastom vratilu ovisi o
WDNWQRVWLĲLUDGQRPREXMPX9H:
peff = (Mmot . t/2 . 2 . ʌ 9H(10)

6SHFLILþQDSRWURãQMDJRULYD%6)&NDRLPQRJDGUXJDVYRMVWYDPRWRUDNDRãWRVXHPLVLMHštetnih plinova se na probnom stolu mjere i upisuju u tablice. Ovaj program koristi takve
WDEOLFHQDQDþLQGDL]QMLKYDGLWUHnutnu vrijednost u funkciji trenutne brzine vrtnje motora iokretnog momenta, koji je proporcionalan srednem efektivnom tlaku, kao što je prikazano na

398

76HQþLü/6ODYLþHN7*XELü: Simulacija potrošnje goriva i emisija u realnim …

slici 2:
(11)

Slika 2. Dijagram efektivnog stupnja korisnosti u zavisnosti o momentu i brzini vrtnje motora
7UHQXWQDSRWURãQMDJRULYDVHUDþXQDL]VSHFLILþQHSRWURãQMH]DWUHQXWQXVQDJX
g = BSFC . P [kg/h](12)-RãMH]QDþDMQDSRWURãQMDL]UDåHQDNDR
b = (BSFC . P)/(v . ȡfuel) [l/100km](13)(PLVLMH ãWHWQLK SOLQRYD VH YDGH L] VOLþQLK WDEOLFD NDR L SRWURãQMD JRULYD 7DNR ]D HPLVLMX
dušikovih oksida imamo tablicu,(14)]DHPLVLMXXJOMLþQRJPRQRNVLGD,(15)za emisiju neizgorenih ugljikovodika,(16)WH]DHPLVLMXNUXWLKþHVWLFDNRGGL]HOVNLKPRWRUD.

(17)

Ulazni parametri modela su vrijednosti trenutne brzine v, nadmorske visine h za svaki
vremenski korak dt3XWVHL]UDþXQDYDL]EU]LQH
ds = v . dt, s = GV

(18)

Energy and the Environment (2016) 395-408

399

3. OPIS PROGRAMA
6LPXODFLMD SRWURãQMH JRULYD YR]LOD REDYOMHQD MH SRPRüX UDþXQDOQRJ SURJUDPD $GYDQFHG
Vehicle SimulatoU ãWR X SULMHYRGX ]QDþL QDSUHGQD VLPXODFLMD YR]LOD NUDüHJ QD]LYDADVISOR. Program se sastoji od skupa kodova koji u cijelini rade u Matlab/SimulinkRNUXåHQMX 0DWODE MH NRULãWHQ ]D ODJDQR PDWULþQR SURJUDPLUDQMH SURUDþXQD GRN MH 6LPXOLQN
korišten za jednoVWDYQRJUDILþNRSULND]LYDQMHRGQRVDXQXWDUNRPSOHNVQLKVXVWDYD%HVSODWDQ
je i dostupan putem interneta od 1998. godine. Program je prvobitno razvijen u studenom
1994. godine od strane nacionalnog laboratorija za obnovljive izvore energije Sjedinjenih
AmerLþNLK'UåDYD 1DWLRQDO5HQHZDEOH(QHUJ\/DERUDWRU\- NREL). Prvotno je razvijen je u
FLOMX DODWD NRML RODNãDYD UD]YLMDQMH UD]XPLMHYDQMH WH NRQVWUXLUDQMH KLEULGQLK HOHNWULþQRSRJRQMHQLKYR]LODDOLXEU]RSRVWDMHSXQRQDSUHGQLMLLIOHNVLELOQLMLUDþXQDOQLSUogram. Osnova
UDGD SURJUDPD MH DQDOL]D SRJRQVNRJ VNORSD YR]LOD WH SULMHQRVD VQDJH L]PHÿX NRPSRQHQWD
NRMH VXGMHOXMX X SRJRQX YR]LOD NROMHQDVWR YUDWLOR VSRMND PMHQMDþ VWXSQMHYD SULMHQRVDGLIHUHQFLMDO  6LPXODFLMD SRGUåDYD WUL UD]OLþLWD REOLND L]YRUD Hnergije: motor s unutarnjim
L]JDUDQMHPVXVWDYJRULYLKüHOLMDWHVXVWDYSRKUDQHHOHNWLþQHHQHUJLMH
3URJUDPMHPRGXODUDQãWR]QDþLGDMHVYDNDNRPSRQHQWDLVSURJUDPLUDQDX0DWODERNUXåHQMX
te joj je pridružena ikona u Simulink okruženju. Pojedine komponente se tako spajaju u sustav
vozila. Primjer takvodg sustava prikazan je na slici 3.

Slika 3. Primjer Advisor modela vozila u Simulink okruženju
$GYLVRU LPD WUL JODYQD JUDILþND VXþHOMD 3UYR VXþHOMH MH 9HKLFOH ,QSXW WH VOXåL ]D XQRVparametara vezanih ]D YR]LOR 6OLMHGL VXþHOMH ]D XQRV SDUDPHWDUD VLPXODFLMH 6LPXODWLRQ3DUDPHWHUV=DGQMHJUDILþNRVXþHOMHVOXåL]DSULND]UH]XOWDWD5HVXOWV9HKLFOH LQSXW VXþHOMH SULND]DQR QD VOLFL  GR]YROMDYD RGDELU L PRGLILNDFLMX SDUDPHWDUD
vozila korištenog za VLPXODFLMX 6D OLMHYH VWUDQH QD YUKX QDOD]L VH SRMHGQRVWDYOMHQL JUDILþNL
SULND] NRQILJXUDFLMH SRJRQVNRJ VXVWDYD 7DM MH JUDILþNL SULND] LQWHUDNWLYDQ WH VH SULWLVNRP
miša na bilo koji prikazani dio vozila otvara poseban prozor za modifikaciju te komponente.
,VSRG WRJ JUDILþNRJ SULND]D YR]LOD QDOD]L VH JUDI SHUIRUPDQVL .RULVQLN PRåH ELUDWL L]PHÿX
VOLMHGHüLK þHWLUL NRPSRQHQWH SRJRQVNL VWURM IXHOBFRQYHUWHU  XSUDYOMDþ PRWRUDPRWRUBFRQWUROOHU  SRKUDQD HQHUJLMH HQHUJ\BVWRUDJH  LOL PMHQMDþ VWXSQMHYD SULMHQRVa
WUDQVPLVVLRQ  =D VYDNX QDYHGHQX NRPSRQHQWX SRVWRML YLãH PRJXüLK JUDIRYD SHUIRUPDQVL
NRMH MH PRJXüH RGDEUDWL SULWLVNRP PLãD QD SDGDMXüL L]ERUQLN 7L JUDIRYL SUDWH VYHPRGLILNDFLMH SD üH VH SURPMHQRP ELOR NRMHJ SDUDPHWUD YH]DQRJ ]D SHUIRUPDQVH SRJRQVNRJ
stroja istovremeno ažurirati i adekvatni graf performansi. Na desnoj strani prozora nalaze se
SDGDMXüL L]ERUQLFL SRPRüX NRMLK NRULVQLN PRåH RGDEUDWL VYH SDUDPHWUH YH]DQH ]D YR]LOR3ULPMHULFHSULWLVNRPQDSDGDMXüLL]ERUQLN9HKLFOHRWYDUDVHPRJXüQRVWRGabira svih vozila
NRMD VH QDOD]H X NQMLåQLFL SURJUDPD$GYLVRU 1HNL RG SDUDPHWDUD NRMH MH PRJXüH RGDEUDWLSDGDMXüLP L]ERUQLFLPD XNOMXþXMX YUVWX YR]LOD YUVWX SRJRQVNRJ VWURMD WUHWLUDQMH GLPQLK400

76HQþLü/6ODYLþHN7*XELü: Simulacija potrošnje goriva i emisija u realnim …

SOLQRYDWHVXVWDYPMHQMDþDVWXSQMHYDSULMHQRVD,VSRG SDGDMXüLh izbornika odabire se vrsta pogona vozila (prednji pogon, stražnji pogon,
pogon
QD VYD þHWLUL NRWDþD  D LVSRG QMHJD PRJXüH MH RWYRULWL 6LPXOLQN EORNRYVNX VKHPX WRND
informacija za zadani pogonski sustav pritiskom na gumb "View Block Diagram". Na dnupro]RUDQDOD]HVHGYDSDGDMXüDL]ERUQLNDVQDVORYRP9DULDEOH/LVWNRMLVOXåH]DSURPMHQX
bilo kojeg skalarnog parametra kojeg Advisor definira u radnom prostoru Matlaba kroz listu
varijabli.
1HNHRGSDUDPHWDUDNRMLVHþHãüHPLMHQMDMXNDRãWRMHPDNVLPDOQD snaga pogonskog stroja ili
PDVD WHUHWD PRJXüH MH GLUHNWQR PRGLILFLUDWL X SUYRP JODYQRP JUDILþNRP VXþHOMX 3RãWR MH
program vektoriziran, promjenu bilo koje vrijednosti prati promjena svih parametara vezanih]D WX YULMHGQRVW ãWR HOLPLQLUD SRMDYX NRULVQLþNH greške [4]. Kod programa je otvoren i
GRVWXSDQ]DUD]OLþLWHPRGLILNDFLMHWHVWLUDQMHQRYLKIL]LþNLKPRGHODPRGHODYR]LODLOLYR]QLK
ciklusa.

6OLND*UDILþNRVXþHOMH]DXQRVSDUDPHWDUDYR]LOD
4. SIMULACIJEU radu je izvršena serija simulacija. Kao baza je poslužio model automobila "Ford Focus" iz
2003. godine koji se nalazi u standardnoj biblioteci programa Advisor.
Osnovnekarakteristike prikazane su u tablici 1.
Tablica 1. Osnovna svojstva vozila
Model

Ford Focus 2003. g

Duljina

4152 mmŠirina1698 mm0HÿXRVRYLQVNLUD]PDN

2615 mmEnergy and the Environment (2016) 395-408

401

Frontalna površina

2.06 m2.RHILFLMHQWDHURGLQDPLþNRJRWSRUD&'

0.312

Maksimalna masa

1570 kg

Kako bi rezultati bili usporedivi, sve su simulacije provedene na voznom ciklusu NEDC (New
EuURSHDQ'ULYLQJ&\FOH 7DMFLNOXVMHXYHGHQJRGLQH'L]DMQLUDQMH]DRFMHQXNROLþLQH
emisija ispušnih plinova automobilskog motora i potrošnje goriva u osobnim automobilima.
3UYLGLRFLNOXVDWUDMHVHNXQGLLSUHGYLÿDJUDGVNXYRåQMXGRNGUXJLGLRod 780 do 1180
VHNXQGHSUHGYLÿDSULJUDGVNXYRåQMX*UDGVNDYRåQMDMHNDUDNWHUL]LUDQDQLVNLPRSWHUHüHQMLPD
motora, niskom temperaturom ispušnih plinova te maksimalnom brzinom od 50 km/h.
3ULJUDGVND YRåQMD MH GL]DMQLUDQD YLãH DJUHVLYQLMD V YHüRP EU]LQRP >@ NEDC vozni ciklus
prikazan je na slici 5.

Slika 5. NEDC (New European Driving Cycle) vozni ciklus
8VSRUHÿLYDQH VX UD]OLþLWH YHU]LMH YR]LOD 2VQRYQL VOXþDM MH YR]LOR VD VWDQGDUGQLP PRWRURPVQDJH  N: PDVH YR]LOD VD SXWQLFLPD L WHUHWRP RG  NJ VD UXþQLP PMHQMDþHP VD EU]LQD 8 GUXJRP VOXþDMX MH SUHWSRVWDYOMHQR GD MH ]D VYODGDYDQMH XRELþDMHQLK JUDGVkih iprigradskih brzina iz NEDC ciklusa dovoljan i manji motor. Pretpostavljena je ugradnja
motora od 53 kw te je provjereno može li vozilo pratiti zadani tempo NEDC voznim ciklusom
WH NDNR VH WR RGUDåDYD QD SRWURãQMX L QD HPLVLMH 8 WUHüHP VOXþDMX MH SUHtpostavljen pravi
GRZQVL]LQJ NRML RVLP VPDQMHQMD PRWRUD XNOMXþXMH L ODNãX VWUXNWXUX YR]LOD WH MH VWRJDRGUHÿHQD PDVD RG  NJ 7UHED QDSRPHQXWL GD X RYRP VOXþDMX QLMH ELOD SR]QDWD PDSDHILNDVQRVWL YR]LOD QHNRJ VXYUHPHQRJ PRWRUD NRML EL GRQLR L SRYHüDQX HILNDVQRVW YHü MHNRULãWHQ VDPR VNDOLUDQ SRþHWQL PRWRU 8 þHWYUWRP VOXþDMX VH SDN YUãL DQDOL]D XWMHFDMD
SULMHQRVQRJRPMHUDQDSRWURãQMXLHPLVLMH6WRJDMHRGDEUDQPMHQMDþVDEHVNRQDþQLPEURMHP
prijenosnih omjera ili CVT (Continuosly Variable Transmission). Osnovni parametri vozila
koji su varirani prikazani su u tablici 2.
Tablica 2. Osnovni varirani parametri vozila
6OXþDM
Maks. snaga
Masa vozila

0MHQMDþ

1 - Osnovni

63 kW

1514

5XþQLEU]LQD

2 - Manji motor

53 kW

1486

5XþQLEU]LQD

3 - Manji motor i masa

53 kW

1200

5XþQLEU]LQD

4 - &97PMHQMDþ

63 kW

1507

CVT

402

76HQþLü/6ODYLþHN7*XELü: Simulacija potrošnje goriva i emisija u realnim …

8 QDVWDYNX QD VOLNDPD  GR  SULND]DQH VX WUHQXWQH HPLVLMH ãWHWQLK SOLQRYD ]D  REUDÿHQDVOXþDMD 3ULND]DQD MH HPLVLMD QHL]JRUHQLK XJOMLNRYRGLND R]QDþHQR VD KF GXãLNRYLK RNVLGD
R]QDþHQRVDQR[XJOMLþQRJPRQRNVLGDR]QDþHQRJVDFRLþHVWLFDR]QDþHQLKVDSPXJNP8
cijelom rasponu vremena najgornja je krivulja za hc, pa co/10 pa nox. Vrijednost za pm jecijelo vrijeme jednaka 0.

6OLND(PLVLMH]DVOXþDM- Osnovni

Slika 7. (PLVLMH]DVOXþDM- Manji motor

6OLND(PLVLMH]DVOXþDM- Manji motor i masa

6OLND(PLVLMH]DVOXþDM- &97PMHQMDþ

0RåH VH SULPMHWLWL NDNR VH GLMDJUDPL ]D VOXþDMHYH VD UXþQLP PMHQMDþHP SRQDãDMX VDVYLPEnergy and the Environment (2016) 395-408

403VOLþQRRVLPãWRVHSURSRUFLRQDOQRsmanjuju emisije svih polutanata sa smanjenjem motora imase (Slike 6, 7 i 8.) 1DGDOMHPRåHPRXRþLWLNDNRPRGHOX]LPDXRE]LUSRYHüDQHHPLVLMHX
prvom dijelu vožnje, dok je motor hladan, u prvih 300 s. Nakon što katalizator postigne radnu
temperaturu, nDNRQPLQXWDHPLVLMHVH]QDWQRVPDQMXMX(PLVLMDþHVWLFD SP MHNRQVWDQWQR
 NDNR VH UDGL R EHQ]LQVNRP PRWRUX 1HRþHNLYDQR VOXþDM VD PMHQMDþHP VD NRQWLQXLUDQRP
SURPMHQRP SULMHQRVQRJ RPMHUD &97 MH UH]XOWLUDR VD ]QDWQR XYHüDQLP HPLVLMDPD ãWHWQLKplinova, VOLND  0RJXüH REMDãQMHQMH MH GD SULOLNRP UDGD X NRPELQDFLML VD RYDNYLPPMHQMDþHP PRWRU PRåH ELWL RSWLPL]LUDQ LOL ]D VPDQMHQMH SRWURãQMH LOL ]D VPDQMHQMH HPLVLMD[16].
U tablici 3 su izneseni zbirni rezultati potrošnje goriva i emisije štetnih plinova. Smanjenje
SRWURãQMHSULOLNRPNRULãWHQMDPDQMHJPRWRUDLVPDQMHQMDPDVHYR]LODMHRþHNLYDQR9R]LORVD
XJUDÿHQLP&97PMHQMDþHPGDMHMRãEROMHUH]XOWDWH7RMHPRJXüH]DWRãWRPRWRUQDWDNYRPYR]LOXUDGLFLMHORYULMHPHXSRGUXþMXPDNVLPDOQRJ VWXSQMD GMHORYDnja, kao što je vidljivo iz
VOLNHG 1DUDYQRLRYDNDYPMHQMDþLPDVYRMD RJUDQLþHQMD7DNR MH SRQHNDG RJUDQLþHQDPDNVLPDOQDVQDJDNRMDVHPRåHSUHQLMHWLDSRQHNDGVXSRYHüDQLPHKDQLþNLJXELFL(PLVLMDXJOMLþQRJGLRNVLGDMHGLUHNWQRSURSRUFLRQDOQDSRWrošnji goriva.
âWRVHWLþHHPLVLMDRVWDOLKSURGXNDWDL]JDUDQMDUH]XOWDWLVXPDQMHRþHNLYDQL,]QHQDÿXMHSRUDVWHPLVLMH QHL]JRUHQLK XJOMLNRYRGLND L XJOMLþQRJ PRQRNVLGD ]D YR]LOR VD VPDQMHQRP PDVRP
1DURþLWR VX QHRþHNLYDQH YLVRNH HPLVLMH VYLK ãWHWQLK SOLQRYD VD YR]LORP VD XJUDÿHQLP &97
prijenosom.

Tablica 3. Zbirni rezultati potrošnje i emisija
1
2OsnovniManji motor

3 Manji mot. i 4
masa
CVT

Potrošnja (l/100km)

7

6.4

5

4.4

CO2 (g/km)

162.4

148.5

116

102.1

HC (g/km)

0.276

0.246

0.253

0.35

CO (g/km)

1.289

1.18

1.187

1.648

NOx (g/km)

0.107

0.112

0.099

0.318

404

a)

76HQþLü/6ODYLþHN7*XELü: Simulacija potrošnje goriva i emisija u realnim …

b)

c)
d)
6OLND3ULND]UDGQRJSRGUXþMDPRWRUD]DUD]OLþLWHVOXþDMHYHD - Osnovni, b) 2 - Manji
motor, c) 3 - Manji motor i lakše vozilo, d) 4 - 9R]LORVD&97PMHQMDþHP

Na slici 10 prikazana je mapa stupnja djelovanja motora zavisno o brzini vrtnje i momentu zaUD]OLþLWHVOXþDMHYH8PDSLVXR]QDþHQHWRþNHXNRMLPDMHPRWRUUDGLR0RåHVHXRþLWLGDMH
VKHPD SR NRMRM VX UDGQH WRþNH UD]EDFDQH VOLþQD ]D VOXþDMHYH VD UXþQLP PMHQMDþHP 5D]ORJ
WRPHMHþLQMHQLFDGDVHUDGLRLVWRPPMHQMDþXLORJLFLSURPMHQHSULMHQRVQRJRPMHUD0HÿXWLPPRåH VH XRþLWL GD ]D VOXþDM E  ]D PRWRU PDQMH VQDJH L GLPHQ]LMD UDGQH WRþNH SDGDMX EOLåHSRGUXþMXPDNVLPDOQHLVNRULVWLYRVWLSDþDNLXVDPRWRXVNRSRGUXþMH=DODNãHYR]LORVOXþDMF  ]DKWLMHYD VH QHãWR PDQML PRPHQW ]D SRJRQ YR]LOD 6DVYLP MHUD]OLþLWD VLWXDFLMD ]D YR]LORRSUHPOMHQR&97PMHQMDþHPVOXþDMG 6YHVXUDGQHWRþNHNRQFHQWULUDQHXSRGUXþMXQDMYHüH
efikasnosti osim jedne skupine kRMD VH QDOD]L X SRGUXþMX PDNVLPDOQRJ PRPHQWD L QHNROLNRL]QLPNLNRGPLQLPDOQRJPRPHQWD2YHVXWRþNHYMHURYDWQRUH]XOWDW]DXVWDYOMDQMDLNUHWDQMD
vozila iz stajanja.
2VLP SRWURãQMH JRULYD L HPLVLMH ãWHWQLK SOLQRYD L XåLWDN X YRåQML MH þHVWR YDåDQ SDUDPHtar.
-HGDQ YDåDQ SRND]DWHOM MH VYDNDNR XEU]DQMH$GYLVRU QDP RPRJXüXMH L VLPXODFLMX XEU]DQMD]DYLVQRR]DGDQLPVYRMVWYLPDYR]LOD5H]XOWDWLXEU]DQMD]DVLPXOLUDQHVOXþDMHYHSULND]DQLVX
u tablici 4.

Energy and the Environment (2016) 395-408

405

Tablica 4. Simulacija ubrzanja
1
Osnovni2
Manji motor

3 Manji mot. i masa

4CVT

0-96.6 km/h

7.8

8.2

7.5

13.3

64.4 - 96.6 km/h

3.6

3.9

3.4

7.3

0 - 137 km/h

15

16.1

14.3

32.8

0RåHPR YLGMHWL GD VPDQMHQMH PDVH GRQRVL YHOLND SREROMãDQMD XEU]DQMD XQDWRþ VODELMHP
motoru. Rezultati ubrzanja vozila sa ovdje SULPMHQMHQLP&97SRJRQRPVXUD]RþDUDYDMXüLMHU
]D SRVWL]DQMH RGUHÿHQH EU]LQH WUHED JRWRYR GYRVWUXNR YLãH YUHPHQD QHJR VD NODVLþQLP
PMHQMDþHP
=$./-8ý$.
Provedena je analiza potrošnje goriva i emisije štetnih plinova za standardan osobni
automobil oprHPOMHQ UD]OLþLWLP PRWRULPD L VXVWDYLPD SULMHQRVD VQDJH QD 1('& YR]QRP
ciklusu. Korišten je program Advisor.
$GYLVRU MH RGOLþDQ SURJUDP NRML RPRJXüXMH SURFMHQX SHUIRUPDQVL SRWURãQMH L HPLVLMDFHVWRYQLK YR]LOD QD ]DGDQRM SXWDQML ,PD YUOR LQWXLWLYQR JUDILþNR VXþHOMH NRMH RPRJXüXMHVLPXODFLMXQDMUD]OLþLWLMLKNRQFHSDWDYR]LODXNOMXþXMXüLHOHNWULþQDLKLEULGQDYR]LOD.RULVWDQMHMHURPRJXüXMHRSWLPL]DFLMXYR]LODNDRVXVWDYDQDPLMHQMHQRJ]DLVSXQMDYDQMHWRþQRRGUHÿHQLKzahtjeva. U tom kontekstu, osim odabira moWRUDRPRJXüXMHRGDELUVXVWDYDSULMHQRVDVQDJHLVWUDWHJLMH L]PMHQH SULMHQRVQLK RPMHUD 1DURþLWR NRG KLEULGQLK YR]LOD RPRJXüXMH MRã L
GLPHQ]LRQLUDQMHHOHNWULþQRJPRWRUDEDWHULMDLRSWLPLUDQMHVWUDWHJLMHUDGDVXVWDYD.DNRMHNRG
otvoren i temeljen na sveprLVXWQRP 0DWODEX PRJXüH MH LQWHUYHQLUDWL X SRVWRMHüH PRGHOH L
UD]YLWLQRYH2YRJDþLQLYUORSULNODGQLP]DLVWUDåLYDQMDLREUD]RYDQMH7DNRÿHUSURJUDPMHWHPHOMLWRYDOLGLUDQWHLPD]DGRYROMDYDMXüXGRNXPHQWDFLMXNRMDRODNãDYDUDG
Vozni ciklus NEDC je odabran jer zadnjih godina predstavlja standard za provjeru potrošnje
JRULYDLQDURþLWRHPLVLMDVWHWQLKSOLQRYD3UREOHPMHãWRSUHWSRVWDYOMDWHUHQEH]X]EUGLFDãWRnije adekvatno za mnoge gradove.
5H]XOWDWLVLPXODFLMDVXLVSDOLRþHNLYDQRãWRVHWLþHSRWURãQje goriva u zavisnosti o instaliranoj
VQD]L PRWRUD L R PDVL YR]LOD 1DURþLWR QLVND MH LVSDOD SRWURãQMD JRULYD NRG DXWRPRELOD VD
EH]VWXSDQMVNLPPMHQMDþHP,]PDSHYR]LODVDR]QDþHQLPUDGQLPWRþNDPDPRåHPR]DNOMXþLWL
GDMHUD]ORJWRPHãWRPRWRU]DVOXþDMHYHVDQLåRPSRWURãQMRPUDGLYLãHXSRGUXþMXVDYHüRPNRULVQRãüXâWRVHWLþHHPLVLMDãWHWQLKSOLQRYDUH]XOWDWLVXPDQMHRþHNLYDQLRVLPXJOMLþQRJGLRNVLGDNRMLMH
SURSRUFLRQDODQ SRWURãQML JRULYD 'XãLNRYL RNVLGL QHL]JRUHQL XJOMLNRYRGLFL L XJOMLþQL
monoksid sXXQHNLPVOXþDMHYLPDYLãLNRGPDQMHJPRWRUDLODNãHJYR]LODQHJRNRGRVQRYQRJPRWRUD 7R VH PRåH SURWXPDþLWL QD QDþLQ GD MH PDQML PRWRU YLãH RSWHUHüHQ X QHNLPVLWXDFLMDPDNDRãWRVXNUHWDQMHL]PMHVWDLXEU]DQMH3ULPMHüXMHVHGDPRWRULPD]QDWQRYLãHemiVLMH X SUYLK  V RGQRVQR GRN VH PRWRU L NDWDOL]DWRU QH ]DJULMX ãWR YMHUQR GRþDUDYD
stvaru situaciju. U tu svrhu su u ulazne podatke Advisora spremljene dvije mape emisija,
jedna za hladan motor i jedna za stanje postignute radne temperature. Osim potrošnje i406

76HQþLü/6ODYLþHN7*XELü: Simulacija potrošnje goriva i emisija u realnim …

HPLVLMD$GYLVRU QDP RPRJXüXMH L VLPXODFLMX XEU]DQMD YR]LOD NRMH MH YDåQR ]D VYODGDYDQMHQHNLKVLWXDFLMDXSURPHWX SUHWMHFDQMH WHþHVWRYDåDQNULWHULMNRGNXSQMHYR]LOD5H]XOWDWLQDP
pokazuju kako smanjenje mase može imati velik utjecaj pa je sa VOXþDMHP VD VPDQMHQRPPDVRP SRVWLJQXWR EROMH XEU]DQMH XQDWRþ VODELMHP PRWRUX X RGQRVX QD RVQRYQL VOXþDM$XWRPRELO VD EH]VWXSDQMVNLP PMHQMDþHP QD RYRP SRGUXþMX SRVWLåH YUOR VODEH UH]XOWDWH MHU
mu za ubrzanja treba otprilike dvostruko više vremena nego ostalim automobilima. Razlog
WRPHMHãWRMHVXVWDYQDãWLPDQGDXSUDYOMDPRWRUGDUDGLXJODYQRPXSRGUXþMXPDNVLPDOQRJVWXSQMD GMHORYDQMD 2YDNYL VXVWDYL þHVWR LPDMX UD]OLþLWH SURJUDPH UDGD SULPMHULFH
HNRQRPLþDQ VWDQGDUGQL L VSRUWVNL WDNR GD EL VH GUXJDþLMRP logikom upravljanja sigurno
SRVWLJOLEROMLUH]XOWDWL&97PMHQMDþLQXGHãLURNHPRJXüQRVWLDOLWDWHPDQDGLOD]LRYDMUDG
U radu je dokazana efikasnost programa Advisor kao alata za odabir i optimizaciju
NRPSRQHQWL YR]LOD NRMH þLQH RVQRYQH XYMHWH ]D SRVWLzanje efikasnosti na zadanoj putanji.
Smanjenje mase vozila i dimenzija motora su najdirektnije strategije za postizanje cilja.
$OWHUQDWLYQH WHKQRORJLMH NDR ãWR VX &97 PMHQMDþL LOL KLEULGL]DFLMD ]DKWLMHYDMX SXQR GXEOMH
analize.

LITERATURA[1] Casper, J. K. : Energy - Powering the Past, Present, and Future, Chelsea House , New
York, 2007.
>@0DKDOHF,/XOLü=.R]DUDF'Motori s unutarnjim izgaranjem , FSB Zagreb, 2010.
[3] http://www.mce-5.com/english/pop_up/resultats_cles/Key_results.html - rezultati tehnologije
promjenjivog omjera kompresije (VCR) firme MCE-5, 10.9.2016.
>@*XELü7Simulacija potrošnje goriva vozila=DYUãQLUDG7HKQLþNLIDNXOWHW 6YHXþLOLãWDX
Rijeci, 2016.
[5] Committee on the Assessment of Technologies for Improving Light-Duty Vehicle Fuel
Economy: Assessment of Fuel Economy Technologies for Light-Duty Vehicles; The National
Academies Press, Washington, D.C. (www.nap.edu), 2011.
[6] Police, G., Diana, S., Giglio, V., Iorio, B., Rispoli, N.: Downsizing of SI engines by turbocharging; Instituto Motori, Consiglio Nazionale delle Ricerche, 2006.
[7] Larminie, J., Lowry J.: Electric Vehicle Technology Explained , John Wiley & Sons Ltd ,West Sussex, England, 2003.
[8] Katrašnik, T.: Hybridization of powertrain and downsizing of IC engine : a way to reduce
fuel consumption and pollutant emissions : Part 1., Energy convers. manage., 2007, 48, 5,1411-1423.
[9] http://www.car-engineer.com/the-different-driving-cycles/ - Opis raznih voznih ciklusa,
10.9.2016.
[10] Wipke, K.; i dr.: Advisor 2.0: A Second-Generation Advanced Vehicle Simulator for
System Analysis, National Renewable Energy Laboratory, Colorado, 1999.
[11] Markel, T.; i dr.: ADVISOR: a system analyisis tool for advanced vehicle modeling,
Journal of Power Sources 110, pp. 255-266, 2002.
>@6ODYLþHN/Simulacija utjecaja smanjenja motora vozila=DYUãQLUDG7HKQLþNLIDNXOWHW
6YHXþLOLãWDX5LMHFL
[13] Meywerk, M.: Vehicle Dynamics, John Wiley & Sons Ltd , 2015.
[14] http://hpwizard.com/rotational-inertia.html - opis procjene utjecaja rotacijske inercije,
10.9.2016.
>@6HQþLü7.LULQþLü9/HQLü.Electric vehicle modelling for real application,

Energy and the Environment (2016) 395-408

407

Energija i okoliš, Opatija, 2012.
[16] Deacon, M., Brace, C. J., Vaughan, N. D., Burrows C. R. i Horrocks, R. W. :Impact ofalternative controller strategies on exhaust emissions from an integrated diesel/continuously
variable transmission powertrain, Proceedings of the Institution of Mechanical Engineers,
Volume 213, Part D, 1999.

408

76HQþLü/6ODYLþHN7*XELü: Simulacija potrošnje goriva i emisija u realnim …

FUEL CONSUMPTION AND EMISSIONS SIMUALATION IN REAL
ROAD TRAFFIC CONDITIONS
Abstract: There are many experimental and calculation methods for engine fuel consumption
in steady state conditions. However, real road traffic conditions mean the variation ofparameters such as speed and slope which results in continuous variation of required power.
There is a big influence on vehicle parameters too. Between the engine and the wheels there is
the transmission with the gearbox which has a great influence on the fuel consumption too.
The paper presents a program for fuel consumption and emission calculation Advisor. It isbased on picking the current consumption and emission rate from a map obtained on a test
bench or in real conditions. Consumption and emission depend on various parameters: in firstorder on the terrain configuration and speed variation which are mostly replaced bystandardized driving cycles, but also on the engine, vehicle and transmission characteristics.
The main engine parameter is the break specific fuel consumption map which can be found inliterature for various engines, but can also be obtained with simulation softwares.
A comparison is performed for the same vehicle with two different engines, two different
masses and two different gearbox types. The calculation is done on a standard driving cycle.
The emissions and the variation of the working point during the raid is presented graphicallyfor different cases. The integral amounts for the emission of the consumption, emission ofcarbon dioxide, nitrogen oxides, carbon monoxide and unburned hydrocarbons are presented
in a table for different vehicle configurations. The vehicle acceleration is also simulated on
several distances. The performances of the used program and of the vehicle are commented in
the conclusion part of the paper.
Key words: fuel consumption and emission simulation, real traffic conditions, Advisor

Energy and the Environment (2016) 409-414

409

NUMERICAL SIMULATION OF A PARALLEL HYDRAULIC HYBRIDSYSTEM FOR A DELIVERY VAN'%UQþLü**UHJRYUniversity of Rijeka, Faculty of Engineering,
Vukovarska 58, 51000 Rijeka, Croatia,
Phone: +385-(0)51-651528, fax: +385-(0)51-651416,
e-mail: gregovg@riteh.hr
Abstract: Main aims of modern delivery vans development are the decrease of the fuelconsumption and environmental pollution, which is achieved with optimisation of the internal
combustion engine. Apart from internal combustion engine optimisation, more attention has
been devoted to the design of hybrid vehicle drivetrain systems. The hybrid vehicle is avehicle that can use two or more systems to create, store and reuse energy. It is usuallyrealised with a regenerative braking principle, which stores and reuses the energy that is lost
during the braking, thus increasing the overall efficiency of the vehicle. Depending on thedesign of storing and reusing energy, the hybrids are divided into electrical, hydraulic andmechanical. In this paper an analysis of the hydraulic hybrid system with parallelarchitecture is carried out to determine fuel saving in comparison with delivery van with theclassical drivetrain. Based on the different delivery van driving regimes a calculation of thevan hydraulic hybrid system is conducted and standard hydraulic components are chosen.
After that a numerical model of the parallel hydraulic hybrid system is developed using the
Matlab/Simulink software. Using a developed numerical model, simulations for breaking andstarting modes of the vehicle are performed.
Key words: parallel hydraulic hybrid vehicle, numerical simulation, delivery van
1. INTRODUCTION
The idea of a hybrid vehicle is the result of the need to increase the efficiency of aconventional vehicle thus it is necessary to incorporate additional systems into it. This createsa vehicle with primary and secondary systems. The primary system is used to power thevehicle and this is always the internal combustion engine (IC engine). The task of thesecondary system is to produce, store and reuse energy which would be irrevocably lost in theenvironment [1]. Losses in conventional vehicles such as losses in the IC engine, powertransmission, as well as losses due to air resistance and rolling are inevitable. However, theenergy that is lost during braking can be stored and reused, thus increasing the overall
efficiency of the vehicle. This principle of the braking energy utilization is called regenerative
braking.
Depending on the design of the secondary system, hybrids are divided into electrical,
hydraulic and mechanical hybrids. Hybrid electric vehicles are the most known hybrid
vehicles because of the application of the electric hybrid technology in passenger cars. The
main components of the hybrid electric vehicle are the generator, electric motor and electric
battery. The main components of hydraulic hybrid systems are the hydraulic pump, hydraulicmotor and hydraulic accumulator, which are equivalent to the generator, electric motor andelectric battery in electric hybrids. The main advantage of hydraulic hybrids compared to410'%UQþLü**UHJRY: Numerical simulation of a parallel hydraulic…

electric hybrids is the greater amount of stored energy density which is up to five times higher[2]. Another advantage of the hydraulic hybrid is great efficiency in cases of frequent braking
and the starting of vehicles.
The basic division of the hydraulic hybrid is into serial and parallel hybrids (Figure 1).
Typical serial hybrids are mounted on vehicles that already have a hydrostatic transmission.
The lack of a serial hybrid is the inability to achieve high speeds, making it ideal for use on
heavy vehicles, but not on vehicles in intercity traffic e.g. delivery vans. For such vehicles it
is more convenient to use a parallel hydraulic hybrid system, because it allows the storage ofenergy during braking, but when it needs to achieve higher speeds it uses the primary system.
High pressure
accumulator

High pressure
accumulator

Hydraulicpump
Hydraulicmotor

Hydraulicpump/motor
Low pressure
accumulator

Low pressure
accumulatora)b)
Figure 1. a) Parallel hydraulic hybrid vehicle, b) Serial hydraulic hybrid vehicle
2. CALCULATION OF A PARALLEL HYDRAULIC HYBRID SYSTEM FOR A
DELIVERY VAN
Calculation of the parallel hydraulic hybrid system is carried out for the delivery van“Volkswagen Crafter TDI400.” Calculation has been carried out for two regimes of driving
which are defined by the inclination of the road, vehicle driving speed and percentage ofvehicle payload. The first step in the calculation is to estimate all the resistances that occur
when the delivery van is driving: rolling friction force, air resistance force, resistanceacceleration force and gravitational force. The sum of all resistance forces results with a dragforce which the vehicle must overcome. By knowing the value of the drag force, vehicle
driving speed and dimensions of the wheel we are be able to calculate the maximum torqueand the rotational speed on the vehicle wheels. Assuming the pressure drop 400 bar and thehydro-mechanical efficiency 0.98 it follows that the displacement of the hydraulicpump/motor is 159.4 cm3. According to the obtained value for displacement, the axial piston
hydraulic pump/motor Bosch Rexroth A6VM [3] has been chosen.
The calculation of the high pressure accumulator is based on the ability to absorb asufficiently kinetic energy during the regenerative braking. It is assumed that the highpressure accumulator will be fully charged during the vehicle braking from 70 km/h to 10
km/h [4]. Supposing the losses in the hydraulic system, 60% of the kinetic energy which canbe absorbed during the braking is 389 kJ. The high pressure accumulator with a nominal
volume 50 l and the minimum operating pressure of 200 bar has been chosen as a preliminary.
The maximum stored energy in the chosen high pressure accumulator has been calculated tobe 392 kJ. The number of high pressure accumulators have been calculated on way that the
maximum kinetic energy attained during the vehicle braking was divided with the maximum
stored energy in the high pressure accumulator, which is 0.99 accumulators. Therefore, theEnergy and the Environment (2016) 409-414

411

Bosch Rexroth HAB 50-414 bladder type accumulator [3] has been chosen. The low pressure
accumulator has not been calculated because it is chosen according to the minimum operatingpressure of the high pressure accumulator. The Bosch Rexroth HAB 50-207 bladder type
accumulator has been selected [3].
3. NUMERICAL MODELLING OF A PARALLEL HYDRAULIC HYBRID SYSTEM
Based on the mathematical model [5], the numerical model of the parallel hydraulic hybrid
system can be developed. The white-box modelling has been applied for numerical modelling,using the Matlab/Simulink software. Two numerical models have been carried out, thenumerical model for the vehicle braking mode and the vehicle starting mode. Both numericalmodels are composed of the numerical model of the hydraulic pump/motor and the numericalmodel of the high pressure accumulator. The input value in the numerical model for thevehicle braking mode is the rotational speed of the hydraulic pump i.e. rotational speed of thevehicle wheels, and output value is the pressure of the working fluid in the high pressure
accumulator. The numerical model of the parallel hydraulic hybrid system for vehicle starting
mode is shown in Figure 2. The Coulomb friction and static friction have been neglected in
the numerical model of the hydraulic motor, only the viscosity friction has been taken into
account [6]. The input value in the numerical model is the pressure drop between the low andhigh pressure accumulators and output values are the pressure in the high pressure
accumulator and the hydraulic motor torque and rotational speed.

Figure 2. The numerical model of the parallel hydraulic hybrid system for vehicle startingmode
4. SIMULATION OF DEVELOPED NUMERICAL MODEL OF A PARALLELHYDRAULIC HYBRID SYSTEM
The aim of the simulation results is to prove the accuracy of the developed numerical model.
Simulations have been carried out for the numerical model of the vehicle braking mode andthe numerical model of the vehicle starting mode. Ten seconds of simulation duration havebeen chosen for all simulations. From the previous assumption it follows the high pressure
accumulator will be fully charged during the vehicle braking from 70 km/h to 10 km/h. The
rotational speed of the hydraulic pump has been calculated as a linear decrease of therotational speed from 44 s-1 to 6 s-1 during 10 seconds. Decrease of the vehicle speed during
the breaking mode is a result of the fluid that enters into the hydraulic accumulator and must412

'%UQþLü**UHJRY: Numerical simulation of a parallel hydraulic…

overcome gas pressure in the high pressure accumulator. The compressed gas creates
resistance to the flow of the fluid in the accumulator, which creates a decrease of the pumprotational speed.
The simulation results of the pressure in the high pressure accumulator (Figure 3) show that at
the beginning of the simulation the pressure is equal to the pre-charged pressure in theaccumulator, 180 bar. During vehicle breaking, the hydraulic pump achieves a flow of theworking fluid from the low to high pressure accumulator, which results in the increase of thepressure in the high pressure accumulator. After 3.5 seconds the maximum pressure of theselected accumulator bar has been achieved. It can be concluded that the results indicate to thereal behaviour of the developed numerical model.
400
380
360
340

p / bar

320
300
280
260
240
220
200
180
0

1

2

3

4

5

6

7

8

9

10

t/s
Figure 3. Simulation results of pressure in the high pressure accumulator during vehicle
braking mode
When the vehicle begins to accelerate, the working fluid is flowing from the high to low
pressure accumulator. The simulation results of the pressure in the high pressure accumulator(Figure 4) show that at the beginning of the simulation the accumulator is fully charged andthe pressure has maximum value. After the first second the pressure begins increase, which is
the result of accumulator discharging.
400
390

p / bar

380
370
360
350
340
330
320
0

1

2

3

4

5

t/s

6

7

8

9

10

Energy and the Environment (2016) 409-414

413

Figure 4. Simulation results of pressure in the high pressure accumulator during vehicle
starting mode

THM / Nm

During the starting mode, the pump is acting as a hydraulic motor. The hydraulic motor has tobe able to overcome the maximum torque which is needed to start the vehicle. The mostunfavourable situation is when the vehicle is driving on an inclined road with the maximum
payload where it is necessary to overcome the load torque of 920 Nm. The mentioned value of
torque has been used for the simulation of the vehicle starting mode during the wholesimulation. Although in real vehicles the value of load torque is decreases after starting thevehicles. The simulation results of the torque of hydraulic motor shaft (Figure 5) show thatthe hydraulic motor is able to overcome the torque necessary for starting the vehicle during
the whole simulation.
1120
1100
1080
1060
1040
1020
1000
980
960
940
920
900
0

1

2

3

4

5

6

7

8

9

10

Figure 5. Simulation results of hydraulic motor torque during vehicle starting mode
/ sthe hydraulic motor (Figure 6) show that at
The simulation results of the rotational speed tof
the beginning of the simulation the rotational speed increases to 1580 min-1 and thendecreases as a result of decreasing the pressure in the high pressure accumulator. From thesimulation results it can be observed that after two seconds the rotational speed decreases
under the minimum value of the hydraulic motor rotational speed 476 min-1, which is definedby the driving regime. Therefore, when the hydraulic motor rotational speed decreases to theminimum value the hydraulic hybrid systems switch to the primary IC engine.
1600
1400
1200

nHM / min-1

1000
800
600
400
200
0
0

1

2

3

4

5

6

7

8

9

10

Figure 6. Simulation results of hydraulic motor rotational speed during vehicle starting mode
t/s

414

'%UQþLü**UHJRY: Numerical simulation of a parallel hydraulic…

6. CONCLUSION
The main objective of this research was to develop a numerical model of the parallel
hydraulic hybrid system for the delivery van. Based on the different driving regimes acalculation of the van hydraulic hybrid system was conducted and standard hydrauliccomponents were chosen. The numerical model of the parallel hydraulic hybrid system wasdeveloped using the Matlab/Simulink software. Simulation results of the developed numericalmodel for the vehicle braking mode have shown that during vehicle braking the high pressure
accumulator was fully charged. Simulation results of the developed numerical model for thevehicle starting mode have shown that the hydraulic motor is able to overcome the maximum
torque i.e. the stored energy in the high pressure accumulator is sufficiently for starting thevehicle. Simulation results have proven the real behaviour of the developed numerical model.
REFERENCES
[1]
[2]
[3]
[4]
[5]
[6]

%UQþLü ' Project of Hydraulic Hybrid System for Commercial vehicle. Diploma
thesis, University of Rijeka, Faculty of Engineering, Croatia, (in Croatian), 2016.
Rydberg, K.E., Energy Efficient Hydraulic Hybrid Drives, The 11th Scandinavian
International Conference on Fluid Power, SICFP’09, Linköping, Sweden, 2009.
http://www.boschrexroth.com/en/xc/11.07.2016.
%HUWRYLü'*UHJRY*6LPLQLDWL'Modelling and Simulation of a Serial HydraulicHybrid Drive Train for a Forklift Truck. Advanced Engineering: International Journal,8(2014), Rijeka, Croatia, 2014, pp 5-12.
Jelali, M., Kroll, A.: Hydraulic Servo-systems, Modelling, Identification and Control,
Springer, London, 2003.
Gregov, G.: Contribution to Research Modelling of the Hydrostatic Transmission
Applied to the Forest Vehicle. Doctoral thesis, University of Rijeka, Faculty ofEngineering, Croatia (in Croatian), 2012.
180(5,ý.$6,08/$&,-$3$5$/(/12*+,'5$8/,ý.2*+,%5,'12*
SUSTAVA ZA DOSTAVNO VOZILO

Sažetak: Glavni ciljevi razvoja današnjih dostavnih vozila je smanjenje potrošnje goriva i]DJDÿHQja okoliša, što se QDMþHãüH postiže optimizacijom motora s unutrašnjim izgaranjem.
Osim razvoja motora s unutrašnjim izgaranjem sve se više SDåQMHSRVYHüXMHUD]YRMX hibridnih
sustavi za pogon vozila. Hibridno vozilo je vozilo koje koristi dva ili više sustava za
proizvodnju, skladištenje te naknadno korištenje energije. To se QDMþHãüHRVWYDUXMHprincipom
UHJHQHUDWLYQRJNRþHQMDSULþHPXVHHQHUJLMDNRMDELVHL]JXELODWLMHNRPNRþHQMDSULNXSOMD ipohranjuje za naknadno korištenje, te se QD WDM QDþLQ SRYHüDYD VWXSDQM LVNRULVWLYRVW YR]LOD
2YLVQR R QDþLQX skladištenja i ponovnog iskorištavanja energije, UD]OLNXMHPR HOHNWULþQHKLGUDXOLþNH WH PHKDQLþNH KLEULGQH VXVWDYH 8 RYRP UDGX MH SURYHGHQDDQDOL]D KLGUDXOLþNRJ
KLEULGQRJ VXVWDYD SDUDOHOQH DUKLWHNWXUH V FLOMHP XWYUÿLYDQMH XãWHGH JRULYD X XVSRUHGEL V
NODVLþQLP SRJRQRP GRVWDYQRJ YR]LOD 1D WHPHOMX UD]OLþLWLK režima vožnje dostavnog vozila
provedHQMHSURUDþXQKLGUDXOLþNRJKLEULGQRJVXVWDYDWHVXRGDEUDQHVWDQGDUGQHKLGUDXOLþNH
NRPSRQHQWH 1DNRQ WRJD MH L]UDÿHQ QXPHULþNL PRGHO paralelnog KLGUDXOLþNRJ hibridnog
VXVWDYDNRULVWHüL0DWODE6LPXOLQN Provedene su simulacije L]UDÿHQRJQXPHULþNRJPRGHOD]aUHåLPHNRþHQMDpokretanja vozila.
.OMXþQHULMHþL: SDUDOHOQRKLGUDXOLþNRKLEULGQRYR]LOR, QXPHULþNDVLPXODFLMD, dostavno vozilo

Energy and the Environment (2016) 415-424

415

HIGH HEAT EFFICIENT HEATER CORE
AND EXPERIMENTAL STUDIES
Ahmet C A 1 *|UNHPø1.h1 0HWLQ%$ù3,1$5*) Prof. Dr.-,QJ'HDQ)DFXOW\RI(QJLQHHULQJDQG$UFKLWHFWXUHøVWDQEXO$UHO
University Türkoba Mah. Erguvan Sokak No:26/K TepekenW%\NoHNPHFHøVWDQEXOTurkey(QJLQHHU'÷PHFLOHU0DK$NDV\D%ORNODUÕ%%ORN1R(\SøVWDQEXO
ahmetcan1952@gmail.com; gorkeminkun@gmail.com; mbpinar@gmail.com
Abstract: Energy is an important factor in terms of social and economic development ofcountries and environmental protection. Reducing energy consumption is the basic way toincrease energy efficiency.
Buildings are classified according to primary energy consumption and comprising (CO2)emissions. In this manner, the heating of buildings according to the minimum energy
performance is awakened great interest. In addition, some countries have been implemented
legal requirements in the world.
In the current research, a new experimental equipment was used for a new operating
principle of radiator and heating systems utilized in the determination of efficacy for using inindoor heating that was developed with an innovative approach.
For this purpose, the experiment equipment was designed and automatic control at a specificvalue between 30 °C to 90 °C of the radiator core water temperatures is achieved. The
experimental studies were carried out according to the current standards in Europe andaround the world that measured by the circulating water flow rate and temperature. Finally,
the heating efficiency of the radiator is determined. The results were evaluated for optimal
performance conditions.
Key words: energy efficiency, heating efficiency, radiator core, optimal performance
1. INTRODUCTION
Honeycomb radiator heaters are frequently utilized in volume heating due to their well known
functionality and manufacturing processes. There are several number of studies in theliterature to enhance heating performances of these volume heaters and to locate the bestplace in the heated volume [1], [2], which give rise to high heating performance and to create
acceptable temperature asymmetry.
Nowadays, most honeycomb radiator heater studies in the literature are on reaching highheating performance with less energy and reducing the carbon dioxide emission. Additionally,
there are some other efforts to design heat transfer fluid having minimum friction loss and to
decrease the manufacturing cost.
The way of heating in the volume of heat transfer and the homogeneity of temperature
distribution in radiator cores have particular importance in terms of thermodynamic
irreversibility. In the first heating cycle, utilization of one of the types of renewable energy
sources instead of fossil fuel as heat transfer fluid is also very important in terms ofenvironmental protection sustainability and conservation of natural resources.

416

A. Can, G. Inkun, M. Baspinar: High heat efficient heater core…

2. ADVANCED METHOD
A honeycomb radiator heater filled with porous polymeric material which does not allow thepassaJHRIKHDWFDUULHUIOXLGKDVEHHQGHYHORSHGE\øQNQYH%DúSÕQDU7KHZRUNLQJSULQFLSOH
of the newly developed radiator heater is illustrated by Figure 1. The developed honeycomb
radiator heaters have been tested as in the requirements of national and international standards
by Professor Can and the test results were delivered to the ARC company, which
manufactures the radiator heaters [3]. Experimental studies and reports, TSE - Water Cooled
Radiator Test System Specification, Document Number: 16.10.03.TS.09, Publication Date:
09.05.20111 were tested according to the standards EN 442-1, EN 442-2, EN 442-3. Water
Cooled Radiator System is designed and all of the requirements of TS EN 442-2 standard (inparticular Articles 5 and 6 ) are fulfilled [4].
Heater operation of the radiator cores; Water does not fill the radiator, it enters from the lower
radiator pipe and leaves.

Figure 1. The Heat Radiator Filled With Porous Polymeric Material.
Immediately after the introduction of water into the pipes, the transportation take place on apolymeric material which locate at the beginning of the pipe and ending just before the exit
hole. This novel polymeric material provides ionization and allow electron emission. In otherwords, the superconductor material in the radiator core, generates heat in contact with waterand the generated heat subsequently, is conducted to the surrounding through the radiator. The
temperature loss of water between the inlet and the outlet of radiator core is in the range of 23° C.
Outer armor material which is used during production of radiator core may vary, this does notaffect the operation and heating efficiency of radiator core. As a result, it can be concluded
that radiators can be made of aluminum, sheet metal or even steel.
The material used in the radiator is chemically inert so, there is no chemical reaction during
heat transfer or no harm to human or to the environment. The material is not flammable,
explosive or toxic. Also there is no half-life for the utilized material. Unless heater cell ispierced radiator always runs continuously with a constant performance. The polymeric fillingmaterial never runs out. Moreover, components are easily supplied in most places whole over
the world.
Heating radiator is designed, manufactured and an average value of 156% heating efficiency
was determined for the system by Professor Can in Istanbul Arel University Thermodynamics
Laboratory. This heating efficiency value can be evaluated as in conventional, well-known
heat pump heating effect in thermodynamics. Scientific equivalent of heat transfer phenomenain the system can be explained with "electron mobility – (electron ionization) ionization andspin movement". So the heating system thermodynamically does not transfer the heat energy

Energy and the Environment (2016) 415-424

417(not on the basis of molecular oscillation), but it can be explained as the transfer of thermalenergy with (electron ionization) ionization and spin movement.
2.1. Experiment Design and Experimental Findings
Test equipment, water flow circuit and electrical circuit diagram which are designed for ARK
T1 BOILER
Radiator efficiency and performance experiments shown in Figure 2.
WATER
TEMPERATURE
METER

ELECTRICWATER HEATER
220 V 50 Hz

T4

T5

RADIATORREAR SURFACETEMPERATURE
METERRADIATORPRE
SURFACETEMPERATURE
METERWATER BOILER

T3 RADIATOR

OUTLET WATERTEMPERATURE
METER

T2

RADIATOR
INLET
WATER
TEMPERATURE
METERWATER FLOW
and THERMAL
POWER METERCIRCULATION
PUMP

Figure 2. ARK RADIATOR equipment for efficiency and performance experiment
Test reports and measurement protocols of Ark heating radiator cores have been completedwith 30 ° C constant boiler water temperature as starting point.
It was incremented 10° C by 10° C between 30° C and 90° C which are boiler water
guidelines temperatures. Related calculations were made by using the data written on eachexperiment protocol. Ark heater to heat transfer media from the honeycomb radiator takes
place by natural convection. Heat transfer from radiator core to environment is done bynatural convection. The heat flow with natural convection can be calculated.
Q

Aradiatorsurface .D convectionnummer . 'Ttempaturedifferent(1)

Ark Radiator Thermal Yield K and Ark Radiator Heating Number Effect E1
Thermal Yield K
Continuous flow of the thermodynamic system for converting energy efficiency is defined asfollows. Thermal efficiency becomes 100% as the highest value.
Q reulting earnings
transfered to environment with natural convection(2)K
QspentMultiplied by specific heat Input  output temperature difference

water flow from the radiator
Heating Effect Number E1
which is transferred from ARK Radiator Core to environment with naturalQ
resulting earnings

convention, Lspent by pump  Q water boiler which continuously checks the power of the circulation
pump and discontinuously(open-close control) checks the total power of the electric water
heater in the boiler water express the total power.

418

E1

A. Can, G. Inkun, M. Baspinar: High heat efficient heater core…

Q resulting earnings
 Q

Lspent by pump

Given electrical powertransfered to environment with natural convection
He took power of the pump electric water heater drawn by power(3)

EXPERIMENT NO : 01 According to the calculations of measurement protocol
MEASUREMENT PROTOCOL – Table 1
Experiment No:01
Date:12 June 2015Time
:10 30
Ambient Temperature: 23 oC
boiler water temperature value: 30 oC
Range of Measurement: 5 second
Potency time of Open Close Control : 20 second Downtime:10 x 60 =600 second
Temperature and Circulation Water Flow Measured
Values According to figure 1
T1 oC
T2 oC
T3 oC
T4 oC
T5 oC
31
26.5
25.5
24.0
24.4
30
27.7
26.7
24.8
25.2
30
28.6
27.7
26.0
26.4
29
28.5
27.7
26.4
27.1
30
28.6
27.8
26.7
27.6
30
29.0
28.2
27.2
27.4
31
28.7
27.9
27.5
27.5
30
29.0
28.2
27.7
28.1
30
28.6
27.9
27.4
27.8
30
28.5
27.7
27.2
27.6

Voltage applied to Electric
Kettle, Current and Powermeasurement values
U Volt I Amper N Watt
222.450.17
24221.980.17
24222.670.17
24222.33
10.25
2059
222.590.17
24222.800.17
24221.550.17
24222.440.17
24221.520.17
24221.8410.27
2059

The electric heater was activated for 20 seconds and reactivated after 12 minutes. In
experiment, when electric heater deactivated, values measured by the thermometer wereobtained according to figure 1.
T1 = 23.0 oC T2 = 22.8 oC T3 = 22.3oC T4 = 22.4 oC T5 = 22.5oC
When the electric heater deactivated, circulation pump and power drawn by the thermometer
equals to N = 24 Watt and when the electric heater activated, power drawn by thethermometer equals to N = 2059 Watt.
Circulation pump rate of flow measuring instruments was measured as Vwater = 0.457 m3/h .
Ark heating radiator cores calculations based on the geometry of the heat transfer
surface
Length = 100 cm, Height = 60 cm, Width = 6 cm
4 grid surface = 0,05 x 1 x 4= 0,012 m2
4 grid surface (2 front + 2 back) surface: 0,06 x 1 x 4= 0,2 m2
2
28 vertical lamella (14 front + 14 back) surface= 0,84 m
Ark Radiator total heat transfer surface = 0,012+0,2+0,84 = Acore surface= 1,05 m2
Calculation of Natural convection number ĮT was determined by measuring the ambient temperature. The temperature TES is calculated.
The number of natural convection is found in the following equation:

Energy and the Environment (2016) 415-424

419

TES

T4  T5
2(4)

D

Nu . kl(5)

105 < Gr . Pr < 1011 range and for Laminer Flow Nu

D .l

1/5

is used,.
kwhere Nu: Nusselt number, Ra: Rayleigh number (Ra = Gr . Pr), Gr: Grashof number, Pr
Prandatl number. Following values were measured; heat transfer capability of air k = 0.02685
W/ m oC, Prandtl number Pr = 0.695, kinematic viscosity of air Ȟ  .5 x 10-6 m2/s,
respectively. Gr.Pr = 2.62 x 1011
Nu is calculated as 720.
Nu . k 720 . 0, 02685
Watt
(6)
D
32 2
l
m K
0, 6
0, 60 Gr.Pr

Temperature of medium was measured as To = 23 oC. The difference between average surface
temperatures of Ark radiator core, measured front (T4) and back (T5) surfaces, and medium
temperature is calculated as TES = 27.5 oC.
The heat flow from Ark radiator core to medium with natural convection can be calculated.
ǻT = 27.5 – 23 = 4.5 oC
Q

(7)A .D . 'T 5, 7(1, 05 ). 32 . 4,5 820,8(151, 2) Watt(8)

It was observed that after water heater boiler temperature is set to a reference temperature
value, it operates according to the principle of discontinuous two-position (on-off) automatic
control. Electric water heater consumed power for 20 seconds during the experiment. Powerconsumed by circulation pump was constant and measured as 24 Watt. After electric water
heater being activated for 20 seconds, electrical current did not pass through water heater for
about 12 minutes (720 seconds). Power consumed by the electric water heater and the pumpat the same time was measured as 2059 Watt.
It was observed that after water heater boiler temperature is set to a reference temperature
value, it operates as shown in Figure 3 according to the principle of discontinuous twoposition (on-off) automatic control.

Q Electric
Heatingpower

N ort eff

L Pump power
20 s

720 s

t time s420

A. Can, G. Inkun, M. Baspinar: High heat efficient heater core…

Figure 3. Water Heater Boiler Temperature Two-Position Automatic Control Average
Effective PowerThe number of Ark heater radiator core heating effect was calculated as below;

E1

L pumpQ The resulting
 Q

Water heating boiler(9)aAs control size electrical power was not continuous at the two-position automatic control
effective power value was determined to cover the duration of the experiment. A unit of 20
second was accepted temporarily. Total duration where electric water heater was inactive wasdetermined as second. Total duration where electric water heater was inactive was determinedas 12 minutes (720 seconds). In Figure 2 two-position (on-off control) control corresponds 37
units, each one is 20 seconds and 720 seconds. During the experiment, total duration isdetermined as 740 seconds calculated as three times reference 20 seconds. Here, 1x20
seconds=20 seconds, 2059 Watt and 36x20 = 720 seconds 24 Watt values were found. The
electrical power value (1x720 seconds + 1x20 seconds = 740 seconds) was found to be bydividing 720 seconds by 20 seconds. Average effective power value was calculated as 59,2
Watt by dividing 1x20159 + 36x24 = 2923 Watt value by 79 Watt (24+55) was calculated byadding constant electrical power value 37 units to power value 24 Watt consumed by thepump during the unit experiment.

E1

820,8(151, 2)
10,39(1,91)
24  55 79(9)bȕ2 heating effect number is defined as a separate single unit of the system shown below;

E2

Q The resulting
Q

(10)

transferred

The heat flow from heater radiator core to medium with natural convection was calculated
before, it was not changed Q The resulting .
Hot water heat flow transferred to the core by circulation pumpQtransferredQ transferredm water .cwater .(T2  T3 )Measured circulating water flow Vwater

0, 457

457
3600

0,127

m water

0, 457.1000

457

kg
h

T2 = 28.6 oC, T3 = 27.6 oC.

m3, m suh(11)Vsu .Ukg
csu specific heat of water = 4186 J/kg.oC,sEnergy and the Environment (2016) 415-424

421

Q transferred(12)m water . cwater .(T2  T3 ) 0,127 . 4186 .1 531, 4 Watt

For the calculation of E 2 heating effect number Ark radiator core was considered as a single
unit.

E2

820,8(151, 2)
1,54(0, 28)
531, 4(13)

These calculated values were described as heating effect number of arc radiator core. It was
higher than 100 %. Higher value than the value carried by the hot water to the Ark radiator
cores is transferred to the medium to be heated. The difference is the energy given by polymer
filled in Are radiator core in contact with hot water.
Heating effect numbers calculated according to the measurements performed at othertemperatures are given in the table.
2.2. Additional Information of Results
Experiment designed in different places and regions of Turkey proved that at least 50% fuelsaving was possible. Six liters of water inlets in a standard normal radiator and the sauce
amount outlets with a temperature difference of 6-7 oC between incoming and outgoing water.
However, the amount of incoming water into an Ark radiator is 175 mililiters, which means
26 folds lees than that of a normal eating radiator with only 2-3 oC drop in outgoing watertemperature. Additionally, heat transfer is very fast and temperature distribution on theradiator surface is almost homogen.
The image of temperature distribution an a working heating radiator by a thermal camera isshow in Figure 4.

Figure 4. Distribution of Temperature an a working heating radiator

422

A. Can, G. Inkun, M. Baspinar: High heat efficient heater core…

3. CONCLUSION
In order to calculate and evaluate heat efficiency and performance of Arc Radiator Core, anexperiment set is designed and produced (in accordance with TS EN 442-1, TS EN 442-2, TS
EN 442-3 standards) as shown in Figure-2. The experiments are conducted from 30 oC to 90o
C at each ten degrees interval.
Arc Radiator Core sample is made from aluminum materials that are provided by thecompany particularly for this experimentation. Company acknowledged that radiator core
may also be made from steel or a better heat transferring material.
Values of the heat conveying fluid water that is flowed thorough radiator with constanttemperature are calculated with Pt100 pressure thermometer at boiler exit point, core entrance
and exit points. The water flow values of water circulation pump (with a constant electrical
power) out of radiator core are also calculated.
Under normal conditions with radiator cores water flows through the whole radiator howeverwith Arc Radiator Core water enters with the lower channel pipe and flows through radiator
as shown in Figure-1. This procedure is especially economic and advantageous in terms of
running costs as compared with the conventional hot water radiators. A conventional hot
water radiator contains 4.5 liters of water. Since Arc Radiator Core is not filled with water it
only contains 175ml. of water inside lower channel. Heat energy of hot water that is carriedout from tank is transferred into whole radiator core with a super conductive chemically noreactive, harmless material that is not poisonous to human and nature. Thermal camera images
provided in Figure-3 shows that heat values are distributed evenly throughout the surface of
the water arc radiator core.
Based on the definitions provided by the company; chemical polymer used inside the Arc
Radiator Core is a locally available, easy to obtain, pure material that has no half-life.
As observed from current applications this material can provide equal performance until theradiator core is breached or broken. Heat transfer inside the arc radiator core is not based on
the conventional heated water molecules’ movements. According to submitted copyrighted of
the Company product is an innovative new product which transfers heat by the “electron
ionization and spin off movement”. A major advantage of this operational difference can beseen when temperatures of heat transferring water is calculated at the entrance and exit pointsof the radiator. There exist 6-7 co temperature differences on the conventional whereas thisdifference drops to 2 co at the Arc Radiator Core. Based on the preliminary findings of theCompany this drop in the temperature differences may save up to %50 energy.
Heat Effective Numerical Values that are defined at the beginning of this thermodynamics
report of the Arc Radiator Core are calculated as; 9.8 at 30 oC, 5.7 m2 (1,05 m2 geometrical)
actual heat surface <1 m2 actual heat surface accepted 1.8 (% 180)>, 6.7 at 40 oC <1.23>,
7.3 at 50 oC <1,40>, 4.5 at 60 oC <0.82>, 5.5 at 70 oC <1.01>, 4.5 at 80 oC <0,92> and 4.3 at
90 oC <0,80>. High performance, extra comfort and high energy savings can be achieved
especially under low water temperatures when 18 oC-24 oC cabin temperatures are considered,based on these heat effective numerical values. Moreover these savings can be seen as aconcrete example of lowering CO2 emissions by using less energy for the Europe and theWorld.

Energy and the Environment (2016) 415-424

423

4. LIST OF SYMBOLS
Q
A
D
k

Heat flow
surface of radiator
Convection mummer
heat transfer capability
K
Thermal yieldT
temperaturettimePower of pumpL
Rate of volume
Vm water Rate of mass flow
Nu
Nusselt numberRa
Rayleigh number
Gr
Grashof numberPr
Prandtl number
Kinematic viscosity
Q
N
power
Heating effect number
E

Watt
m2
W/m2 oC
W/m oCoCs second
Watt
m3/s
kg/s
m2/s
Watt
-

REFERENCES[1] CAN, A., BABADAGLI, A: Importance of Form and Placement of Heating Elementsfrom the Aspect of Comfort, Environment, Health and Economy, Strojarstvo 50(1)(2008)43-50[2] ,1&523(5$)3'(:ø77'3Fundamentals of Heat and Mass Transfer, Second
Edition, by John Wiley & Sons, Inc. Printed in the Republic of Singapore, 1985.
[3] CAN, A., “Ark Radiator Verim ve Performans Deneyleri Raporu´ øVWDQEXO $UHO
hQLYHUVLWHVL 0KHQGLVOLN 0LPDUOÕN )DNOWHVL 7HUPRGLQDPLN /DERUDWXDUÕ  6D\ID 
7HPPX]øVWDQEXO
[4] TS EN 442-1, TS EN 442-2, TS EN 442-6WDQGDUWODUÕ[5]CAN, A. ,VÕYH0DGGH7UDQVIHUL6FULSW%LULQFL%DVNÕøVWDQEXO$UHOhQLYHUsitesi 2016.

424

A. Can, G. Inkun, M. Baspinar: High heat efficient heater core…

9,62.28ý,1.29,7$-(=*5$*5,-$û(*7,-(/$,
EKSPERIMENTALNE STUDIJE
Sažetak: (QHUJLMDMHYDåDQþLPEHQLNXVPLVOXVRFLMDOQRJLHNRQRPVNRJUD]YRMD]HPOMHL]DãWLWHRNROLãD6PDQMHQMHSRWURãQMHHQHUJLMHRVQRYQLMHQDþLQ]DSRYHüDQMHHQHUJHWVNHXþLQNRYLWRVWLZgrade su klasificirane prema primarnoj potrošnji energije i emisijama (CO2 1DWDMQDþLQgrijanje zgrada u skladu s minimalnim energetskim karakteristikama budi veliko zanimanje.
Uz spomenuto, neke zemlje u svijetu primjenjuju i zakonske uvjete.
U trenutnom istraživanju, nova eksperimentalna oprema korištena je za novi operativni
SULQFLSUDGLMDWRUDLVXVWDYDJULMDQMDNRULãWHQLKXRGUHÿLYDQMXXþLQNRYLWRVWLSULOLNRPJULMDQMD
u zatvorenom prostoru, a koja je razvijena inovativnim pristupom.
Za ovu svrhu, eksperimentalna oprema je projektirana te je ostvarena automatska regulacija
temperature vode jezgre radiatora od 30 °C do 90 °C. Eksperimentalna mjerenja protoka
FLUNXODFLMHYRGHLQMHQHWHPSHUDWXUHSURYHGHQDVXXVNODGXVYDåHüLPVWDQGDUGLPDX(XURSLL
diljem sYLMHWD.RQDþQRXþLQNRYLWRVWJULMDQMDUDGLMDWRUDMHRGUHÿHQD5H]XOWDWLVXRFLMHQMHQLza optimalne uvjete rada.
.OMXþQH ULMHþL HQHUJHWVND XþLQNRYLWRVW XþLQNRYLWRVW JULMDQMD jezgra radijatora, optimalne
performanseEnergy and the Environment (2016) 425-434

425

7(502',1$0,ý.$$1$/,=$3/2ý$672*,=0-(1-,9$ý$723/,1(
6WLSH9XOHWLü3DROR%OHFLFK%HUQDUG)UDQNRYLü
7HKQLþNLIDNXOWHW6YHXþLOLãWDX5LMHFL9XNRYDUVND5LMHND
E-mail: stipe.vuletic.ri@gmail.com, pblecich@riteh.hr, bernardf@riteh.hrSažetak: u UDGX VH DQDOL]LUD SULMHOD] WRSOLQH L VWUXMDQMH IOXLGD X SORþDVWRP L]PMHQMLYDþX
topline. 5H]XOWDWLREXKYDüDMXSULND]H raspodjela temperatura, vektore brzina strujanja i padatlaka unutar SORþDVWRJL]PMHQMLYDþD WRSOLQHXNRMHPXMHVWUXMDQMHL]PHÿXWRSOHLKODGQHYRGHSURWXVPMHUQR1XPHULþNRPRGHOLUDQMHSRVOXåLORMH]DDQDOL]XSORþDVWRJL]PMHQMLYDþDWRSOLQH
te uz ispravno odabrane modele i parametre QXPHULþNRJ PRGHOLUDnja, krajnji su rezultati
zadovoljili postavljene kriterije.
3RVWDYOMHQL PDWHPDWLþNL PRGHO VDVWRML VH RG GRPHQH MHGQDGåEL RþXYDQMD L UXEQLK XYMHWD
3RGUXþMH SURUDþXQD GRPHQD  GLVNUHWL]LUDQD MH PHWRGRP NRQWUROQLK YROXPHQD 2SLVDQL VX
odabrani modeli, fizikalna svojstva fluida i materijala stijenki, rubni uvjeti, sheme
GLVNUHWL]DFLMH L DOJRULWDP ]D UMHãDYDQMH SROMD WODNRYD L EU]LQD =D SRWUHEH QXPHULþNRJ
PRGHOLUDQMDSULMHOD]DWRSOLQHLVWUXMDQMDIOXLGDXQXWDUSORþDVWRJL]PMHQMLYDþDWRSOLQHXUDGXVX NRULãWHQL UDþXQDOQL SURJUDPL: Gambit (za geometriju domene) i ANSYS Fluent (zaUDþXQDOQXGLQDPLNXIOXLGD 
Rezultati VXSULND]DQLXUDVSRQXEURMHYD5H\QROGVRYH]QDþDMNHRGGRWMXSRGUXþMXlaminarnog i turbulentnog strujanja fluida. Iz rezultata se može zakljuþLWL GD VH SURPMHQRP
Reynoldsovog broja odnosno režima strujanja fluida, mijenjaju i karakteristike strujanja
IOXLGD WM NRHILFLMHQWL SULMHOD]D WRSOLQH L SDG WODND XQXWDU L]PMHQMLYDþD WRSOLQH 7DNRÿHU
SRYHüDQMH5H\QROGVRYRJEURMDX]URNXMHVPDQMHQMHLVNRULVWLYRVWLWRSOLQHXL]PMHQMLYDþX, kojeMH]QDþDMQLMHL]UDåHQRNRGODPLQDUQRJVWUXMDQMDQHJRNRGWXUEXOHQWQRJVWUXMDQMDIOXLGD.OMXþQH ULMHþL SORþDVWL L]PMHQMLYDþ WRSOLQH QXPHULþNR PRGHOLUDQMH NRHILFLMHQW SULMHOD]Dtopline, pad tlaka, iskoristivost topline
1.

UVOD

U radu je izvršena WHUPRGLQDPLþND DQDOL]D SORþDVWRJ L]PMHQMLYDþD WRSOLQH SRPRüX NRMH su
XVWDQRYOMHQH PRJXüQRVWL SORþDVWRJ L]PMHQMLYDþD topline kao i QMHJRYR SRGUXþMH UDGD.
3URPMHQRPSRþHWQLKrubnih uvjeta miMHQMDMXVHLNUDMQMLUH]XOWDWLWHVHSRPRüXQMLKdobivaju
radne karakteristike SORþDVWRJL]PMHQMLYDþDWRSOLQH>@
THUPRGLQDPLþNDDQDOL]DVDGUåDYDSULND]raspodjele temperatura XQXWDUL]PMHQMLYDþD topline,
raspodjele brzina VWUXMDQMD IOXLGD SDGRYH WODND L L]UDþXQ toplinskog stupnja djelovanja. Uz
navedeno, opisani su i QDþLQLSULMHOD]DWRSOLQH XL]PMHQMLYDþXWRSOLQHRVQRYQHNDUDNWHULVWLNH
SORþDVWLK L]PMHQMLYDþD topline, definiran je PDWHPDWLþNL PRGHO NDR L korištene sheme
diskretizacije i algoritmi za rješavanje polja tlaka i brzina [1].

426

69XOHWLü3%OHFLFK%)UDQNRYLü: 7HUPRGLQDPLþNDDQDOL]DSORþDVWRJL]PMHQMLYDþDWRSOLQH=D SRWUHEH QXPHULþNH DQDOL]H SULMHOD]D WRSOLQH L VWUXMDQMD IOXLGD X L]PMHQMLYDþX WRSOLQH
NRULãWHQLVXUDþXQDOQLSURJUDPL*DPELW]DFUWDQMHJHRPHWULMHLXPUHåDYDQMDGRPHQHRGQRVQR
ANSYS Fluent za numeriþNLSURUDþXQLSULND]UH]XOWDWD
I]PMHQMLYDþL WRSOLQH VX WRSOLQVNL XUHÿDML X NRMLPD VH toplina izmjenjuje L]PHÿu dva ili više
fluida s ciljem zagrLMDYDQMD LOL RKODÿLYDQMD IOXLGD [2]. 1DOD]H ãLURNX SULPMHQX X UD]OLþLWLPSRGUXþMLPDXVXVWDYLPDFHQWUDOQRJJULMDQMDLNOLPDWL]DFLMHNRGSULSUHme potrošne tople vode,XWHKQLFLKODÿHQMDXSURFHVQRMHQHUJHWVNRMLQGXVWULMLXDXWRPRELOVNRMLQGXVWULML XUDþXQDOQRM
industriji, u prehrambenoj industriji, itd.
8RVQRYQRMSRGMHOLL]PMHQMLYDþDWRSOLQH UD]OLNXMXVHWULYUVWHL]PMHQMLYDþD UHNXSHUDWRUi –IOXLGLVXIL]LþNLRGYRMHQLLizmjenjuju toplinu SURYRÿHQMHPNUR]NUXWXVWLMHQNXLNRQYHNFLMRP
s površine stijenke na fluid; 2) regeneratori - izmjena topline odvija se posredstvom
akumulacijske mase koja se prvo zagrijava toplom strujom fluida, a nakon toga predaje
toplinu hladnoj struji fluida; 3) dLUHNWQL L]PMHQMLYDþL WRSOLQH - izmjena topline odvija sedirektnim dodirom struja u prostoru mješališta. U rekuperatore topline spadaju lamelni
L]PMHQMLYDþL WRSOLQH SORþDVWL L]PMHQMLYDþL WRSOLQH FLMHYQL L]PMHQMLYDþL WRSOLQH L]PMHQMLYDþL
WRSOLQHVFLMHYLPDXSODãWXPLNURNDQDOQLL]PMHQMLYDþLWRSOLQHLWG
PORþDVWLL]PMHQMLYDþLWRSOLQHVDVWRMHVHRGWDQNLKSORþDNRMH IL]LþNLodvajaju fluidHUD]OLþLWLKWHPSHUDWXUDLSUHNRþLMLKVHVWLMHQNLizmjenjuje toplina. 1DGDOMHSORþDVWLL]PMHQMLYDþLWRSOLQH
mogu se podijeliti po YUVWL SORþD gODWNH SORþH oUHEUHQH SORþH  L SR QDþLQX VSDMDQMD
(]DEUWYOMHQHSORþH, zDOHPOMHQHSORþHzDYDUHQHSORþH) [3].
6YDND SORþD LPD þHWLUL UXEQD SULNOMXþND NRML X SDURYLPD RVLJXUDYDMX SURWRþQRVW IOXLGD VD
svake strane SORþH.DGVXSORþH]DEUWYOMHQe, rubni VHSULNOMXþFLSORþDVSRMHLWYRUHNDQDOHX
kojima struje fluidi. 5D]GMHOQH L VDELUQH FLMHYL NRMH VH QDOD]H V YDQMVNH VWUDQH NXüLãWDL]PMHQMLYDþD WRSOLQH SRUDYQDWH sX V SULNOMXþFLPD i povezane na vanjske cjevovode koji
dovode SRWUHEQHNROLþLQHIOXLGDUD]OLþLWLKNDUDNWHULVWLND
=D SORþDVWL L]PMHQMLYDþ WRSOLQH SULND]DQ QD VOLFL  KODGQD VWUXMD IOXLGD XOD]L kroz ulazni
SULNOMXþDN SORþH SURWMHþH X SURVWRUX L]PHÿX SORþD L L]OD]L kroz izlD]QL SULNOMXþDN QD LVWRM
strani, GRNVXGUXJDGYDSULNOMXþND za toplu struju fluida blokirani dvostrukom brtvom. ToplaVWUXMDIOXLGDSURWMHþHXSURVWRULPDL]PHÿXVXVMHGQLKSORþDSURWXVPMHUQRXRGQRVXQDKODGQX
struju fluida, a suprotno postavljene brtve blokiraju strujanje hladne struje fluida.

Slika 1. 6WUXMDQMHIOXLGDXSORþDVWRP L]PMHQMLYDþu topline

Energy and the Environment (2016) 425-434427

2. 0$7(0$7,ý.,02'(/0DWHPDWLþNL PRGHORSLVXMHstacionarno VWUXMDQMH L SULMHOD]WRSOLQH X SORþDVWRP L]PMHQMLYDþX
WRSOLQH V YDORYLWLP VWLMHQNDPD þLMD MH GRPHQD SULND]DQD QD VOLFL  1XPHULþNRP DQDOL]RPREXKYDüHQ MH L dvodimenzijski PRGHO L]PMHQMLYDþD WRSOLQH 'RPHQD VH VDVWRML RG dva
VXVMHGQD SUROD]D L]PHÿX SORþD u kojima protusmjerno struje hladna voda i topla voda,
YDORYLWX SORþX NRMD LK RGYDMD NDR L GYLMH SRORYLFH SORþD NRMH ]DWYDUDMX VSRPHQXWH SUROD]H
6WRJD GRPHQD REXKYDüD SRGGRPHQX KODGQH YRGH   SRGGRPHQX SORþH   L SRGGRPHQX
tople vode (3). Na granicama domene postavljaju se rubni uvjeti: na ulaznim presjecima rubni
uvjet ulazne brzine i temperature vode, na izlaznim presjecima rubni uvjet izlaznog tlaka
kojim se postiže bolja konvergencija rješenja u odnosu na rubni uvjet izobraženog strujanja za
nestaELOQD L WXUEXOHQWQD VWUXMDQMD UXEQL XYMHW SHULRGLþQH VWLMHQNH SRVWDYOMD VH QD ERþQLPstranama domene, adijabatski rubni uvjet postavlja se na ostalim stranama uz pretpostavku daMH L]PMHQMLYDþ WRSOLQH LGHDOQR L]ROLUDQ SUHPD RNROLQL QD NRQWDNWQLP SRYUãLQDPD L]PHÿXIOXLGD L VWLMHQNL SORþD SRVWDYOMD VH UXEQL XYMHW JUDQLþQRJ VORMD X NRMHPX MH EU]LQD VWUXMDQMD
fluida 0 (engl. no slip condition DL]PMHQDWRSOLQHRGYLMDVHþLVWRPGLIX]LMRP

Slika 2. 5DþXQDOQDGRPHQDSORþDVWRJL]PMHQMLYDþDWRSOLQH
6WUXMDQMHLSULMHOD]WRSOLQHXSRGGRPHQDPDRSLVXMHRSüDMHGQDGåEDRþXYDQMD [4] koja glasi
߲(ߩ ή ߶)(1)
+ div(ߩ ή ‫ݓ‬ሬሬԦ ή ߶) = div(߁ ή grad߶) + ܵம
߲‫ݐ‬

428

69XOHWLü3%OHFLFK%)UDQNRYLü: 7HUPRGLQDPLþNDDQDOL]DSORþDVWRJL]PMHQMLYDþDWRSOLQH

6WUXMDQMHLSULMHOD]WRSOLQHUMHãDYDMXVHVWDFLRQDUQLPPRGHORPWDNRGDL]RSüHMHGQDGåEH  
RWSDGD QHVWDFLRQDUQL þODQ 8 SRGGRPHQDPD WRSOH YRGH L KODGQH YRGH RSüD MHGQDGåEDRþXYDQMD REXKYDüD MHGQDGåEX RþXYDQMD PDVH I = 1, * = 0, SI    MHGQDGåEH RþXYDQMD
PRPHQWDNROLþLQHJLEDQMDLWR]Dx-os (I = wx, * = K, SI = – wp/wx), za y-os (I = wy, * = K, SI= – wp/wy) i za z-os (I = wz, * = K, SI = – wp/wz) NDRLMHGQDGåEXRþXYDQMDHQHUJLMH(I = T, * =Of/cf, SI = 0)8SRGGRPHQLSORþHSRVWDYOMDVHMHGLQRMHGQDGåEDRþXYDQMDHQHUJLMH(I = T, * =Op/cp, SI = 0).
8PHWRGLNRQWUROQLKYROXPHQDSRGUXþMHSURUDþXQDRGQRVQRGRPHQD]DPMHQMXMHVHNRQDþQLPbrojem kontrolnih volumenaDQHSR]QDWHYULMHGQRVWLIL]LNDOQLKYHOLþLQDWUDåHVHXþYRURYLPD
kontrolnih volumena [4] 6XVWDY SDUFLMDOQLK GLIHUHQFLMDOQLK MHGQDGåEL X] SRþHWQH L UXEQH
uvjete prevodi se u sustav algebarskih jednadžbi za kontrolne volumene. ,QWHJULUDQMHPRSüH
MHGQDGåEHRþXYDQMDSRNRQWUROQRPYROXPHQXGRELYDVHනେ୚߲(ߩ ή ߶)dܸ + න div(ߩ ή ‫ݓ‬ሬሬԦ ή ߶)dܸ = න div(߁ ή grad߶)dܸ + න ܵథ dܸ
߲‫ݐ‬
େ୚

େ୚

(2)

େ୚

Primjenom Gaussovog teorema, volumni integrali koji sadrže operator divergencije mogu se
L]UD]LWLNDRSRYUãLQVNLLQWHJUDOL=DRGUHÿLYDQMHQHSR]QDWLK tokova varijable I na granicama
kontrolnih volumena korištena je shema diskretizacije drugog reda upwind. KonvektivniþODQRYL u MHGQDGåEL RþXYDQMD ovise i o lokalnom polju brzina i o raspodjeli tlakova. Za
SURUDþXQSROMDWODNRYDLEU]LQDNRULãWHQMH6,03/(DOJRULWDP [5]. To je iteracijski postupak
NRMLXNOMXþXMHpretpostavke i korekcije ]DSURUDþXQ tlakova u pomaknutoj mreži za SURUDþXQpolja brzina.

3. REZULTATI I ANALIZA
Prikazani rezultati dobiveni su za ulaznu temperaturu hladne vode od 283 K (10 °C) i ulaznu
temperaturu topline vode od 353 K (80 °C) dok su ulazne brzine hladne i tople vode odnosno
QMLKRYLPDVHQLSURWRFLUDþXQDWLQDWHPHOMX5H\QROGVRYRJEURMD [6]1DRYDMQDþLQGRELYHQLMHUDVSRQ UH]XOWDWD WUDåHQLK IL]LNDOQLK YHOLþLQD SRSXW L]OD]QLK WHPSHUDWXUD WRSOH L KODdne vode,
NRHILFLMHQDWDSULMHOD]DWRSOLQHLVNRULVWLYRVWLL]PMHQMLYDþDWRSOLQHSDGDWODNDLEU]LQDVWUXMDQMD
0DVHQLSURWRFLL]UDþXQDWLQDWHPHOMX5H\QROGVRYRJEURMDSULND]DQLVXXWDEOLFL
Tablica 1. Maseni protoci hladne i tople vode ovisno o Reynoldsovom broju
Hladna voda, Topla voda,
Hladna voda, Topla voda,
ReRe‫ۦ‬hv [kg/s]‫ۦ‬tv [kg/s]‫ۦ‬hv [kg/s]‫ۦ‬tv [kg/s]
100
0.078
0.021
3000
2.351
0.640
500
0.392
0.107
3500
2.743
0.747
1000
0.784
0.213
4000
3.135
0.853
1500
1.175
0.320
4500
3.526
0.960
2000
1.567
0.427
5000
3.918
1.067
2500
1.959
0.533

Energy and the Environment (2016) 425-434

429

Rezultati su prikazani za poglede presjeka A, B i C odnosno za ulazni, izlazni i srednji presjeku L]PMHQMLYDþX WRSOLQH VOLND 3. Pogled A prikazuje raspodjelu temperatura na ulazu hladne
vode i izlazu tople vode. Pogled B pokazuje raspodjelu temperatura u VUHGLQL L]PMHQMLYDþD
topline, a pogled C prikazuje temperature na izlazu hladne vode i ulazu tople vode. Slika 4.
prikazuje raspodjelu temperatura tRSOH L KODGQH YRGH X SORþDVWRP L]PMHQMLYDþX WRSOLQH ]Dpoglede A, B i C. Strujanje fluida modelirano je laminarnim modelom, a Reynoldsov broj za
obje struje iznosi 1500. Slika 5. prikazuje raspodjelu temperatura tople i hladne vode uSORþDVWRP L]PMHQMLYDþX za poglede A, B i C. Strujanje je opisano laminarnim modelom, aReynoldsov broj iznosi 5000.

Slika 3. 3RJOHGLXYHüDQLKSUHVMHNDNRULãWHQLNRGSULND]DUH]XOWDWD

Slika 4. Raspodjela temperatura za laminarni model strujanja pri Re = 1500

Slika 5. Raspodjela temperatura za laminarni model strujanja pri Re = 5000

430

69XOHWLü3%OHFLFK%)UDQNRYLü: 7HUPRGLQDPLþNDDQDOL]DSORþDVWRJL]PMHQMLYDþDWRSOLQH,VNRULVWLYRVW SORþDVWRJ L]PMHQMLYDþD WRSOLQH UDþXQD VH NDR RPMHU UD]OLNH XOD]QH L L]OD]QH
temperature tople vode i razlike ulaznih temperatura tople i hladne vode odnosnoI=ܶ୲୴,୳୪ െ ܶ୲୴,୧୸୪
ܶ୲୴,୳୪ െ ܶ୦୴,୳୪

(3)

Kod manjih Reynoldsovih brojeva, SORþDVWL L]PMHQMLYDþ WRSOLQH SRVWLåH YHüX LVNRULVWLYRVWtopline. S druge strane, SRYHüDQMH Reynoldsovog broja rezultira bržim strujanjem, manjim
promjenama temperDWXUDLPDQMRPLVNRULVWLYRãüXWRSOLQH7ablica 2. daje iskoristivost topline
L]UDþXQDWX QD WHPHOMX UH]XOWDWD QXPHULþNH DQDOL]H NRULãWHQMHP ODPLQDUQRJ PRGHOD VWUXMDQMD
(Re =100 – 5000) i standardnog k-ѓ modela turbulentnog strujanja (Re = 1000 – 5000).
Tablica 2. Izlazne temperature tople i KODGQHYRGHLLVNRULVWLYRVWWRSOLQHXL]PMHQMLYDþX
Laminarno strujanje
Turbulentno strujanje
Iturb/IlamThv,izl
Ttv,izl
Thv,izl
Ttv,izl
Re
Ilam
Iturb
100
301.79283.14
0.998
/
/
/
/
500
300.61288.73
0.918
/
/
/
/
1000
299.15294.610.834
301.71
283.94
0.987
1.18
1500
298.21298.580.777
301.22286.02
0.957
1.23
2000
297.47301.500.736
300.88287.32
0.938
1.27
2500
296.84303.800.703
300.23289.55
0.906
1.29
3000
296.29305.76
0.675
299.62291.85
0.874
1.29
3500
295.80307.480.650
299.57292.11
0.870
1.34
4000
295.35308.990.629
299.56292.10
0.870
1.38
4500
294.93
310.390.609
298.78294.99
0.829
1.36
5000
294.56
311.680.590
298.90294.56
0.835
1.42

7XUEXOHQWQLP PRGHORP VWUXMDQMD GRELYD VH YHüD LVNRULVWLYRVW WRSOLQH X SORþDVWRPL]PMHQMLYDþu, u rasponu od 18% kod Re = 1000 do 42% kod Re ãWRMHRþHNLYDQRVRE]LURP GD VH SRYHüDQMHP 5H\QROGVRYRJ EURMD SRYHüDYDMX NRHILFLMHQWL SULMHOD]D WRSOLQH L
WRSOLQVNL WRNRYL XQXWDU L]PMHQMLYDþD WRSOLQH .RHILFLMHQWL SULMHOD]D WRSOLQH X L]PMHQMLYDþX
WRSOLQH UDþXQDMX VH NDR RPMHU L]PHÿX JXVWRüH WRSOLQVNRJ WRND L UD]OLNH L]PHÿX WHPSHUDWXUH
stijenke i referentne temperature fluida [7] SUL þHPX MH UHIHUHQWQD WHPSHUDWXUD XOD]QD
temperatura fluida‫ݍ‬ሶ୲୴
‫ݍ‬ሶ୦୴
D୲୴ =, D୦୴ =
(4)ܶୱ,୲୴ െ ܶ୲୴,୳୪
ܶୱ,୦୴ െ ܶ୦୴,୳୪
5H]XOWDWLQXPHULþNRJSURUDþXQDGRELYHQLVX]DL]PMHQMLYDþWRSOLQHXVWDFLRQDUQRPUDGXWDNRGD MH JXVWRüD WRSOLQVNRJ WRND QD REMH VWUDQH MHGQDND Tլtv = Tլtv GRN VH SORþH L]UDÿXMX L]
DOXPLQLMDNRMLSUXåDPLQLPDOQLRWSRUSURYRÿHQMD WRSOLQHWH VX VWRJDWHPSHUDWXUHVWLMHQNH QD
obje strane približno jednake Ts,tv § Ts,hv. Slika 6. prikazuje koeficijente prijelaza topline za
WRSOXLKODGQXYRGHGRELYHQHVODPLQDUQLPLWXUEXOHQWQLPPRGHORPVWUXMDQMDXSRGUXþMXRe =100-5000. 2þHNLYDQR NRHILFLMHQWL SULMHOD]D WRSOLQH SRYHüDYDMX VH V SRUDVWRP 5H\QROGVRYH
]QDþDMNH 3UHPD WDEOLFL  KODGQD YRGD LPD YHüH PDVHQH SURWRNH L YHüH EU]LQH VWUXMDQMD RG
WRSOHYRGHDOL]DLVWHYULMHGQRVWL5H\QROGVRYH]QDþDMNH=ERJWRJDMHWHPSHUDWXUQDUD]OLNDXEnergy and the Environment (2016) 425-434

431

QD]LYQLNX L]UD]D   PDQMD ]D KODGQX YRGX L YHüD ]D WRSOX YRGX D NRHILFLMHQWL SULMHOD]Dtopline za hlDGQXYRGXVXYHüLRGRQLK]DWRSOXYRGX7XUEXOHQWQLPRGHOVWUXMDQMDSRMDþDYDL]PMHQX WRSOLQH L]PHÿX IOXLGD L VWLMHQNH WH VX NRHILFLMHQWL SULMHOD]D WRSOLQH YHüL QHJR NRGODPLQDUQRJ PRGHOD 5D]OLND L]PHÿX RYD GYD PRGHOD VWUXMDQMD SRYHüDYD VH V SRUDVWRPReynROGVRYH]QDþDMNH

Slika 6. Koeficijenti prijelaza topline za laminarni model (L.M.) i turbulentni model (T.M.)
Slika 7. prikazuje vektore brzine strujanja tople i hladne vode u pogledu B dobivene
ODPLQDUQLPPRGHORPVWUXMDQMD]DWUL5H\QROGVRYH]QDþDMNe: Re = 1500, 3000 i 5000. Za iste
YULMHGQRVWL 5H\QROGVRYH ]QDþDMNH KODGQD YRGD LPD YHüH EU]LQH RG WRSOH YRGH ]ERJ YHüH
YLVNR]QRVWL8OD]QDWHPSHUDWXUDKODGQHYRGHMH&X]GLQDPLþNXYLVNR]QRVWRGPPas
dok je ulazna temperatura tople vode 80 °C uz GLQDPLþNX YLVNR]QRVW RG  PPas [8].
Vektori brzine tople i hladne vode u pogledu B dobiveni k-ѓ modelom turbulencije prikazani
su na slici 8. Usporedbom slika 7. i 8. može se primijetiti da turbulentni model strujanja
rezultira bržim strujanjem vode neposredno uz stijenku, a sporijim strujanjem u sredini
NDQDOD 7R MH L X]URN YHüLP NRHILFLMHQWLPD SULMHOD]D WRSOLQH NRML VH GRELYDMX WXUEXOHQWQLP
modelom strujanja [9].

Slika 7. Vektori brzine strujanja vode u pogledu B za laminarni model strujanja

432

69XOHWLü3%OHFLFK%)UDQNRYLü: 7HUPRGLQDPLþNDDQDOL]DSORþDVWRJL]PMHQMLYDþDWRSOLQH

SliNH  L  SULND]XMX UDVSRGMHOH XNXSQRJ WODND VWDWLþNL  GLQDPLþNL  X VWUXMDPD WRSOH L
KODGQHYRGH]DODPLQDUQLPRGHOVWUXMDQMDL]D5H\QROGVRYH]QDþDMNHRe = 1500 i 5000. Pad
WODND UDþXQD VH NDR UD]OLND L]PHÿX XNXSQRJ WODND QD XOD]X L QD L]OD]X NDQDOD Pad tlaka na
VWUDQLKODGQHYRGHYHüLMHRGSDGDWODNDQDVWUDQLWRSOHYRGH]ERJYHüHEU]LQHVWUXMDQMDKODGQH
vode.

Slika 8. Vektori brzine strujanja vode u pogledu B za turbulentni model strujanja

Slika 9. Raspodjela ukupnog tlaka za laminarni model strujanja pri Re = 1500

Slika 10. Raspodjela ukupnog tlaka za laminarni model strujanja pri Re = 5000

Energy and the Environment (2016) 425-434

433

4. =$./-8ý$.
Cilj ovog UDGD ELOD MH QXPHULþND DQDOL]D SULMHOD]D WRSOLQH L VWUXMDQMD YRGH X SORþDVWRPL]PMHQMLYDþXWRSOLQH6WUXMDQMHL]PHÿXWRSOHLKODGQHYRGHXL]PMHQMLYDþu topline s valovitimSORþDPD je protusmjerno. 1XPHULþNRP DQDOL]RP REXKYDüHQR MH SRGUXþMH 5H\QROGVRYLK
brojeva Re = 100 - 5000, a strujanje vode je modelirano laminarnim modelom i standardnimk-ѓ PRGHORP WXUEXOHQFLMH 5H]XOWDWL QXPHULþNH DQDOL]H REXKYDüDMX UDVSRGMHOH WHPSHUDWXUDKODGQH L WRSOH YRGH YHNWRUH EU]LQD VWUXMDQMD L UDVSRGMHOH XNXSQRJ WODND 8VSRUHÿHni su
rezultati dobiveni za laminarni i turbulentni model strujanja vode. Usporedba vektora brzina
VWUXMDQMD YRGH GRELYHQLK ]D WXUEXOHQWQL L ODPLQDUQL PRGHO VWUXMDQMD RWNULOD MH VOMHGHüH
Turbulentni model strujanja rezultira bržim strujanjem vode neposredno uz stijenku SORþDD
sporijim strujanjem u sredini kanala. S druge strane, laminarni model posjeduje sporije
strujanje vode uz stijenku ali brže strujanje vode u sredini kanala. To objašnjava zašto
tXUEXOHQWQL PRGHO VWUXMDQMD SUHGYLÿD YHüL L]PLMHQMHQL Woplinski tok L]PHÿX WRSOH L KODGQH
vode, YHüH NRHILFLMHQWH SULMHOD]D WRSOLQH L YHüX LVNRULVWLYRVW WRSOLQH X L]PMHQMLYDþD RG
laminarnog modela strujanja. Npr. iskoristivost topline u plRþDVWRP L]PMHQMLYDþX WRSOLQH
dobivena za turbulentni model strujanja YHüa je za 18% kod Re = 1000 odnosno za 42% kod
Re = 5000. Uzrok svemu tome je sama priroda turbulentnog strujanja koje je nestabilno i sL]UDåHQLMLPPLMHãDQMHPL]PHÿXVORMHYDIOXLGD
8 GDOMQMHP UDGX UH]XOWDWH QXPHULþNH DQDOL]H SRWUHEQR MH XVSRUHGLWL V eksperimentalnim
PMHUHQMLPDNDNRELVHSURYMHULODYDOMDQRVWRGDEUDQRJPDWHPDWLþNRJPRGHOD1DGDOMHPRåHVH
LVSLWDWL XWMHFDM JHRPHWULMH RUHEUHQMD L PDWHULMDOD SORþH QD SRVWLJQXWX LVNRULVWLYRVW SORþDVWRJ
L]PMHQMLYDþDWRSOLQH
LITERATURA
[1]
[2]
[3]
[4]
[5]
[6]

[7]
[8]

S. 9XOHWLü: 7HUPRGLQDPLþND DQDOL]D SORþDVWRJ L]PMHQMLYDþD WRSOLQH, diplomski rad,
7HKQLþNLIDNXOWHW6YHXþLOLãWDX5LMHFL5LMHND, 2015.
)%RãQMDNRYLü: Nauka o Toplini, Svezak I., II., III., Graphis d.o.o, Zagreb, 2012.
R.K. Shah, '36HNXOLü: Fundamentals of heat exchanger design, John Wiley & Sons,
Inc. 2003.;
A. Trp, . /HQLü: 1XPHULþNR PRGHOLUDQMH X WHUPRGLQDPLFL, bilješke s predavanja,
7HKQLþNLIDNXOWHW6YHXþLOLãWDX5LMHFL5LMHNDANSYS Fluent 6.3 – Documentation, PA, Pittsburgh, USA, 2009.
P. Blecich: Utjecaj raspodjele zraka na WHUPRKLGUDXOLþND svojstva lamelnog
L]PMHQMLYDþD WRSOLQH, doktorska GLVHUWDFLMD 7HKQLþNL IDNXOWHW 6YHXþLOLãWD u Rijeci,
Rijeka, 2014.
J.E. Hesselgreaves: Compact heat exchangers: selection, design and operations,Elsevier Science Ltd., Oxford, UK, 2001.
. 5DåQMHYLü: 7HUPRGLQDPLþNH WDEOLFH L GLMDJUDPL, 3. izdanje, Narodna Tehnika
Krvatske, Zagreb, 1989.

434

69XOHWLü3%OHFLFK%)UDQNRYLü: 7HUPRGLQDPLþNDDQDOL]DSORþDVWRJL]PMHQMLYDþDWRSOLQH[9]

V. *ODåDU%)UDQNRYLü3%OHFLFKNumerical and experimental analysis of fin andtube heat exchanger, Int. Conference Energy and Environment 291-300, Opatija,
2014.

Popis oznaka/DWLQLþQHR]QDNHVSHFLILþQLWRSOLQVNLNDSDFLWHW-NJ.
ckoeficijent prolaza topline, W/m2K
kmaseni protok, kg/s‫ۦ‬tlak, Pap
toplinski tok, W
4լ
JXVWRüD toplinskog toka, W/m2
Tլ
5H\QROGVRYD]QDþDMND
Re
þODQL]YRUDS
temperatura, KTvrijeme, stbrzina, m/sw
x, y, z osi koordinatnog sustava*UþNHR]QDNH
2
D koeficijent prijelaza topline, W/m K* koeficijent difuzije
iskoristivost topline, I
toplinska vodljivost, W/mKO
2K GLQDPLþNDYLVNR]QRVW1VP
JXVWRüDNJP3
U
Subskripti
CV kontrolni volumen
hv hladna voda
iz izlazni
tv topla voda
ul ulazni

THERMODYNAMIC ANALYSIS OF A
PLATE HEAT EXCHANGER
Abstract: This paper analyzes the heat transfer and fluid flow of a plate heat exchanger. The
results include visualization of temperature distributions, pressure drop and vectors of fluid
flow velocity for the plate heat exchanger in which hot and cold water have counterflow
arrangement. Numerical modeling was used for the analysis of the plate heat exchanger and,after correctly selecting the models and parameters of numerical modeling, the final results
reached the chosen criteria. The mathematical model consists of a domain, the conservation
equations and boundary conditions. The computational domain was discretized with the finite
volume method. Furthermore, the paper describes the selected models, the physical propertiesof the fluid and of the heat exchanger walls, the boundary conditions, the discretization
scheme and algorithm for linking pressure and velocity fields. For the purpose of numericalmodeling of heat transfer and fluid flow inside the plate heat exchanger, the following
computer programs were used: Gambit (for domain geometry and meshing) and ANSYS
Fluent (Computational Fluid Dynamics). The results are given in the range of Reynolds
numbers between 100 and 5000, i.e. for the laminar and the turbulent fluid flow regimes.
From the results it can be concluded that the flow characteristics, that is the heat transfer
coefficients and pressure drops in the plate heat exchanger change with the Reynolds number
and the flow regime. Also, the heat exchanger effectiveness reduces with the increase of the
Reynolds number, an effect that is more pronounced for laminar flow and less for turbulent
flow.
Keywords: plate heat exchanger, numerical modeling, heat transfer coefficient, pressure
drop, heat exchanger effectivenessEnergy and the Environment (2016) 435-446

435(TRO)JEDINSTVO INFORMACIJE, ENERGIJE I MATERIJE 1,JRUýDWLü6YHXþLOLãWHX=DJUHEXFakultet strojarstva i brodogradnje, Zagreb, Hrvatska
01 616 82 22, igor.catic@fsb.hr$OHNVDQGDU.QHåHYLü
Univerzitet modernih znanosti, Mostar, Bosna i HercegovinaSažetak: Preobilje informacija prijeti slomom obrazovnog sustava. Jedno od rješenja
REUD]RYDQMD QRYLK JHQHUDFLMD X ãNROL PRJXüH MH RVWYDULWL VLQWH]RORJLMVNLP SULVWXSRP ,]
SRVWRMHüLK LQIRUPDFLMD VWYDUDWL QRYR RSüHQLWLMH ]QDQMH L VSR]QDMH što rezultira smanjenjem
informacija. Na temelju sintezologijskog pristupa u kojem je temelj RSüDVXVWDYQRVQDWHRULMD
DQDOL]LUDQLVXXOD]LLL]OD]LL]WHKQLþNLKVXVWDYDLQIRUPDFLMDHQHUJLMDLPDWHULMD3RGUREQRVX
analizirane definicije tih izvora (resursD  'RãOR VH GR ]DNOMXþND GD VH VYDNL L]YRU PRåHizraziti u jedinicama ostala dva. Sastavljena je jednadžba navedenih izvora koja ukazuje da
QMLKRYDVXPDQDXOD]XLL]OD]XL]VXVWDYDPRUDELWLNRQVWDQWD'RãORVHGR]DNOMXþNDGDWDWULL]YRUDþLQH WUR MHGinstvo.
.OMXþQH ULMHþL: informacija, energija, materija, sustavnosna teorija, podrijetlo izvora,
suvremeno obrazovanje
1. UVOD
Preobilje najraznolikijih informacija, razna rješenja u proizvodnji energije i sve raznovrsniji
oblici mase na subatomskoj te višim razinama vodi rascjepkavanju znanja. To se posebnoodražava na sve snažnije usitnjavanje znanosti. Stoga se zahtijeva novo promišljanje. Kako to
SUHWYRULWLXQRYR]QDQMHLVSR]QDMHNRMLPDMHFLOMPDNVLPDOQRSRRSüDYDQMH"7RMHQXåQR]DWRšto se živoWQLSDSRVOMHGLþQRLUDGQLYLMHNSURGXOMXMX To zahtijeva obrazovanje i znanje, a ne
L]REUD]EXLVYHNUDüHYDåHüHVWUXþQR]QDQMH2GJRYRUQDWRNDNRVSULMHþLWLWRIUDJPHQWLUDQMH
znanja i spoznaja nudi sintezologijski pristup.[1]Sintezologijski pristup RPRJXüXMH GD VH QDXN QD VYLP UD]LQDPD WHPHOML QD MHGLQVWYX
informacije, energije i materije. Poticaj za takva promišljanja nudi iskaz A. G. Oettingera:»Bez materije ništa ne postoji, bez energije ništa se ne zbiva, bez informacije ništa nema
smisla«.[2] I pridodaje: »informacija je samo jedan od tri temeljnih izvora (resursa) o kojem
mi svi ovisimo, ostala dva su energija i materija«.[2]
7R MH GRYHOR GR ]DNOMXþND R SRWUHEL QDJODãDYDQMD MHGLQVWYHQRVWL PDWHULMH HQHUJLMH L
informacije. Bez obzira na svrhu, svi navedeni temeljni izvori su uvijek prisutni. Tome treba
pridodati ideju da je suma materije, energije i informacije na ulazu i izlazu u sustav
konstanta.[3]1Tekst se temelji na predavanju prvog autora: (Tro)jedinstvo informacije, energije i materije, Festival]QDQRVWL7HKQLþNLPX]HM1LNROD7HVOD=DJUHEWUDYQMD

436,ýDWLü$.QHåHYLü: (Tro)jedinstvo informacije, energije i materije

Temeljni cilj rada je zahtjev da se cjelokupna populacija tijekom školovanja upozna, ali i
spozna tu jedinstvenost i neodvojivost materije, energije i informacije.
2. METODOLOGIJA RADA
5D]PDWUDQMDXRNYLUXRYRJUDGDWUDåLYUORSUHFL]QHGHILQLFLMHSRMPRYDLNRULãWHQMHRGUHÿHQLK
metoda istraživanja. Uz navedena tri osnovna izvora koje treba definirati, korišten je
sintezologijski pristup.[1]2.1 Sintezologija[1]5LMHþ VLQWH]RORJLMD QDVWDOD MH SUHG JRWRYR VWROMHüH 7RP MH ULMHþL WELQJHQãNL SURIHVRUDQDWRPLMH 0DUWLQ +HLGHQKDLQ SRNXãDR VXVWDYQRVQLP QDXNRP RSLVDWL þRYMHþML RUJDQL]DP
(1920.). 8QDWRþUHODWLYQRGXJRPSRVWRMDQMXWRJQDXND QM/HKUH SRGUXþMHVLQWH]RORJLMHQLMH
VHSRVHEQRUD]YLMDOR9DåQHVXSRGORJH]DXVSMHãDQVLQWH]RORJLMVNLSULVWXSRSüDVXVWDYQRVQD
teorija i kulturologija.[1]3RRSüHQD GHILQLFLMD VLQWH]RORJLMH JODVL »Sintezologija je znanost koja integrira znanja
materijalne i duhovne kulture zbog stvaranja novog znanja i spoznaja kada je to potrebno, kao
i pretvaranje tih znanja i spoznaja u umjetnine (artefakte), proizvode, usluge i druga znanja ispoznaje materijalne i duhovne kulture, a koje može prepoznati i priznati društvo.«[1] U doba
preobilja svih informacija sintezologijska istraživanja postaju nužnost.
2SüDVXVWDYQRVQDWHRULMD
Opseg teksta RQHPRJXüXMHpodrobniji opis osnova sustavnosne teorije (e. Theory of Systems,
Systemic Theory, nj. Systemtheorie, f. théorie des systèmes). To je GDQDVMHGQDRGQDMPRüQLMLKLVWUDåLYDþNLK PHWRGD =ERJ VYRMH SULPMHQMLYRVWL QD VYLP SRGUXþMLPD GMHORYDQMD SULURGH L
OMXGVNRJELüDQDPHüHVHNDRQXåQRVWXSR]QDYDQMHVWRPWHRULMRPWLMHNRPãNRORYDQMD
Za potrebe ovog rada, osnovnim izvorom o sustavnosnoj teoriji, temeljenu na teoriji skupova,
smatra se knjiga G. Ropohla: Eine Systemtheorie der Technik.[4,5@ .RULVWHüL VH ]QDQMLPD L
VSR]QDMDPDL]WRJGMHODQDþLQMHQDMHVXVWDYQRVQDDQDOL]DSRVWXSNDLQMHNFLMVNRJSUHãDQMD To
MHRPRJXüLORSRRSüDYDQMHNRMHMHUHzultiralo da se s jednom jedinom definicijom može opisatiYLãH RG  LQDþLFD WRJ SRVWXSDND QHRYLVQR R YUVWL SUHUDÿLYDQH åLYH LOL QHåLYH WYDUL LOLmaterijala.[6] Navedeno djelo poslužilo za kasnije veliki broj radova od koji se izdvaja samo
jedan.[7] Bila MH WR SUYD SULPMHQD VWHþHQLK LVNXVWDYD SUYRJ DXWRUD SUL VXVWDYQRVQRM DQDOL]LLQMHNFLMVNRJSUHãDQMDQDSRGUXþMXKXPDQLVWLþNLK]QDQRVWLMH]LNRVORYOMD,VWRGREQRMHUDG>6]
bio poticaj da se kao sustav analizira trenutak velikog praska (e. Big-Bang) u radu Energy orInformation.[8]Energy and the Environment (2016) 435-446

437

23û,7(+1,ý.,6867$9
8NRQFHSWXRSüHWHKQLNHVOLNDSULND]XMHVKHPXRSüHJWHKQLþNRJVXVWDYD3RWLFDM]DVOLNXSRWMHþHL]>4a].

6OLND2SüLWHKQLþNLVXVWDY SRWLFDM>4a])
Crna kutija (e. Black Box) s ulazima i izlazima te stanjima, a koja djeluju u prostoru i
YUHPHQXMHPRGHORSüHJWHKQLþNRJVXVWDYD
3ROD]HüL RG VOLNH  L LVND]D 2HWWLQJHUD GROD]L VH GR ]DNOMXþND R WUR MHGLQVWYX PDWHULMH
energije i informacije (slika 2). 2

Slika 2 Jedinstvo sustava s nazivima za znanstvenu disciplinu,
gospodarsku djelatnost te prirodne tokove i procese.

2=QDþHQMHQD]LYDPDWHULMDOLVWLNDHQHUJLVWLNDLLQIRUPDWLVWLNDELWüHNDVQLMHGHILQLUDQR438,ýDWLü$.QHåHYLü: (Tro)jedinstvo informacije, energije i materije

3.1 Definicije elemenata sustava
Materija
Materija je objektivna realnost koja postoji neovisno o spoznaji o njoj.[9@ 0DWHULMX MH PRJXüH
definirati i kao jedinstvo þHVWLFD L SURVWRUD X NRP VH þHVWLFH NUHüX L GMHOXMX MHGQD QD GUXJXPLMHQMDMXüL VH WLMHNRP YUHPHQD >0@ 0RJXüD MH SURãLUHQLMD GHILQLFLMD 0DWHULMD MH MHGLQVWYRþHVWLFDLSURVWRUDXNRMHPVHþHVWLFHNUHüX SULbližavaju i udaljavaju) i djeluju jedna na drugu
SULYODþHL RGELMDMXVDVWDYOMDMX LUDVWDYOMDMX  SULþHPXþHVWLFH SURVWRUNUHWDQMHL GMHORYDQMH
imaju prošlost, tj. nastanak (od prethodnoga, starog), razvoj i nestanak (pretvaranje u naredno,novo).[10] 3RVWRMH GYD RVQRYQD REOLND PDWHULMH IL]LþND SROMD YDORYL  L þHVWLFH SRVMHGXMX
masu).
)L]LþNDSROMD QSUHOHNWURPDJQHWVNRSROMH >@HOHPHQWDUQH QSUNYDUNRYLOHSWRQL LVORåHQLMH
þHVWLFH QSU DWRPL  WYDUL L PDWHULMDOL UD]OLþLWL VX REOLFL PDWHULje (tablica 1). Oblik materije
sastavljen od atoma je tvar, a tHKQLþNLXSRWUHEOMLYDWYDUMHmaterijal (tvorivo).[9]Tablica 1 Oblici materije

Oblici materije)L]LþNDSROMD(valovi):
gravitacijsko
HOHNWURVWDWLþNR
magnetsko
elektromagnetsko (npr. fotoni)
informacijsko polje3ýHVWLFH NJ 
elementarne:x kvarkovi
x leptoni (npr. elektroni)složene:x protoni i neutroni
x atomska jezgra
x atomix molekulex makromolekulex tijela (od atoma, molekula imakromolekula):
3
x tvarix materijali (tvoriva) 4
svemirska tijela:
x planeti, planetoidi, kometi, meteoroidi
x VPHÿLSDWXOMFL
x zvijezde
x galaksije
x VXSHUJDODNWLþNDMDWD

Tvar (supstancija) je oblik materije sastavljen od atoma.[6]0DWHULMDO WYRULYR MHWHKQLþNLXSRWUHEOMLYDWYDU>6]

4

Energy and the Environment (2016) 435-446

439

8 WHKQLþNLP VXVWDYLPD VWYDUL XPMHWQD WHKQLND QHåLYRJD  SRMDYQL VX REOLFL PDWHULMH WYDU)ili
materijal (tvorivo).[9@7ULRVQRYQDID]QDVWDQMDPDWHULMHVXþYUVWRNDSOMHYLWRLSOLQRYLWR
7HKQLND NRMD REXKYDüD VYH DNWLYQRVWL ]D SURL]YRGQMX WYDUL L PDWHULMDOD MH materijalika (e.
Material Technology, nj. Materialtechnik  3UHGODåH VH XYRÿHQMH QD]LYD PDWHULMDOLVWLND NDRzDMHGQLþNR LPH ]D ]QDQVWYHQX GLVFLSOLQX JRVSRGDUVNX GMHODWQRVW WH prirodne i društvene
WHKQLþNH WRNRYHPDWHULMDOD WYDULLPDWHULMDOD WHSURFHVHYH]DQHX]WYDULLPDWHULMDOH2VRED
koja se bavi tvarima i materijalima je materijalik.
Energija
8 IL]LþNRP ]QDþHQMX HQHUJLMD R]QDþXMH NDSDFLWHW ]D UDG QHNRJ VXVWDYD (QHUJLMD MH IL]LþNDYHOLþLQDQHPRåHVHL]UDYQRSURPDWUDWLLOLPMHULWL1MHQDNROLþLQDVHPRåHL]UDþXQDWLNRULVWHüL
L]UD]H L] RGJRYDUDMXüLK GLVFLSOLQD IL]LNH Energija prelazi iz jednog oblika u drugi i možeSRSULPLWL UD]OLþLWH REOLNH 3RMDYQH REOLNH HQHUJLMH QD]LYD VH SUHPD UDGX NRML VH SRVWLåHNRULãWHQMHPHQHUJLMHLOLGMHORYDQMHPRGUHÿHQHVLOH[12a,13-15].
3RMDYQL REOLFL HQHUJLMH VX UD]OLþLWL RQD NRMD RYLVL R L]YRUX SR QDþLQX GMHORYDQMD L SR QDþLQX
djelovanja u radnim procesima.
Ovisno o izvoru postoje tri oblika energije [16-18]:
x nuklearna energija MHRQDXMH]JULDWRPDDRVOREDÿDVHWLMHNRPIX]LMHLOLILVLMH
x HQHUJLMD]UDþHQMDMHRQDGLMHORYDDWRPD QSULRQL]XMXüH]UDþHQMH
x energija izgaranja (toplina izgaranja) MHXNXSQDNROLþLQDWRSOLQHSULNRQVWDQWQRP
volumenu, nastale reakcijom pri izgaranju tvari.
3RQDþLQXGMHORYDQMDSRVWRMH>5,16,18]:
x u mehanici, energija koju posjeduje tijelo zbog svojega položaja u prostoru ili
narLQXWLKHODVWLþQLKGHIRUPDFLMDMHpotencijalna energija [18a]x energija tijela u gibanju je NLQHWLþNDHQHUJLMD.[18b]3RQDþLQXGMHORYDQMDXUDGQLPSURFHVLPDHQHUJLMDPRåHELWL[15]:x kemijska energija drži atome ili ione zajedno
x toplinska energija je SRVOMHGLFDXQXWUDãQMHJNUHWDQMDþHVWLFDPDWHULMH
x HOHNWULþQDHQHUJLMD MHVSRVREQRVWHOHNWULþQLKVLODGDVWYRUHUDGSURFHVRPSURPMHQH
SRORåDMDQDERMD QSUNDGDVHHOHNWULþQLQDERMNUHüHXNUXJ 
x svjetlosna energija ili HQHUJLMD]UDþHQMD je ona dijelova DWRPD QSULRQL]XMXüH]UDþHQMH
x gravitacijska energija je rad pod djelovanjem gravitacije.
x PHKDQLþNDHQHUJLMD je rad povezan s kretanjem.
Postoje još dvije vrste energija. To su [15]:x HQHUJLMDHODVWLþQRVWLkoju sadrži savijeno ili uvijeno tijelo u JUDQLFDPDHODVWLþQRVWL
x energija mase može nastati anihilacijom materije u dodiru s antimaterijom.
7HKQLND NRMD REXKYDüD VYH DNWLYQRVWL ]D SURL]YRGQMX HQHUJLMH MH energetika (e. Energy
7HFKQRORJ\QM(QHUJLHWHFKQLN 3UHGODåHVHXYRÿHQMHQD]LYDenergistika NDR]DMHGQLþNRLPH

440,ýDWLü$.QHåHYLü: (Tro)jedinstvo informacije, energije i materije

za znanstvenu disciplinu, gospodarsku djelatnost te SULURGQH WRNRYH L GUXãWYHQH WHKQLþNH 
tokove i procese vezane uz energiju. Osoba koja se bavi energijom je energetik.
Informacija
Promišljanja 1HVWHURYD SRWLþX QD UD]OLNRYQRVW PRJXüLK RSLVD W]Y NROLþLQVNH LQWHUSUHWDFLMH
informacije i toliko potrebne fizikalne definicije informacije.[19,20].ROLþLQVNDGHILQLFLMD 5
Definicija koja slijedi može se nazvati svakodnevnim opisom informacije.[19,20]
Po N. Wieneru, ªLQIRUPDFLMD MH LQIRUPDFLMD QLWL PDWHULMD QLWL HQHUJLMD YHü QHãWRdrugo«.[21,19,20] .XNROHþD QDYRGL WURVWUXNR ]QDþHQMH ULMHþL LQIRUPDFLMD REDYLMHVW L]YMHãWDM
SURXþDYDQMH >12E@ 3RVHEQR GHILQLUD ]QDþHQMH SRMPD LQIRUPDFLMD X WHRULML LQIRUPDFLMD X
materijalnom svijetu i kibernetici. U kibernetici informacija je izlaz (rezultat) iz sustava obradbepodataka koji u istom trenutku postaje ulazu sustav RGOXþLYDQMD, gdje se informacija pretvara u
XSUDYOMDþNX DNFLMX. Po 1RYDNRYLüX [22] LQIRUPDFLMD MH RGUHÿHQR SULRSüHQMH R SURPDWUDQRM
SRMDYL%LWQDVXRELOMHåMDVYDNHLQIRUPDFLMHVYUVLVKRGQRVWSRX]GDQRVWSUDYRGREQRVWNROLþLQDLcijena.[11c@ 5LMHþ LQIRUPDFLMD GROD]L RG latinskog informatio ãWR GRVORYFH ]QDþL SRGDWDN LOL
poruka [14,17,15@ 2YD GHILQLFLMD UD]XPLMHYD LQIRUPDFLMX NDR IUHNYHQFLMX RGUHÿHQH SRMDYQH
SRUXNH NROLþLQD 
8PMHVWRIL]LþNHGHILQLFLMH>4,19]
Nesterov je ukazao na teoriju koja razmatra informaciju kao materijalnu kategoriju,
RWNULYDMXüLIL]LþNXELWLQWHUDNFLMHHQWURSLMVNLKLQIRUPDFLMDLRSLVXMHLQWHUDNFLMXPDVHHQHUJLMHL
informacija unutar sustava. To je teorija kvantne entropijske logike koja postulira:x informacija je materijalna kategorija, jednako kao što su energija i masa nekog sustava
x ]ERJþLQMHQLFHGDMHPDWHULMDOQDVOLMHGL]DNRQRþXYDQMD NRQ]HUYDFLMH ,QIRUPDFLMDQHPRåHQHVWDWLEH]WUDJDLOLVHSRMDYLWLQLRWNXGD8NXSQDNROLþLQDLQIRUPDFLMDX
zatvorenom sustavu (sustav koji ne razmjenjuje masu, energiju i informacije sokolinom) je konstantna vrijednost.
Fundamentalnost informacije [23]
.YDQWQL IL]LþDU 9 9HGUDO X VYRP GMHOX Dekodiranje stvarnosti- Univerzum kao kvantna
informacija SRVHEQX SR]RUQRVW SRVYHüXMH LQIRUPDFLML ª8 VYHPLUX MH informacija puno
fundamentalnija kvantiteta od energije i materije [23a]. Informacija je fundamentalna jer semože uspješno može primijeniti na makroskopske interakcije, poput ekonomskih i društvenih
fenomena kao i objasniti podrijetlo mikroskopskih interakcija poput energije i materije [23b].
Stoga je informacija osnovna nit koja povezuje sve pojave koje vidimo oko sebe. NašaVWYDUQRVW MH VDJUDÿHQD RG LQIRUPDFLMD >3F@ %ULVDQMH LQIRUPDFLMD MH GRND] QMLKRYH IL]LþNHYHOLþLQH >3d]. Osnovna jedinica je bit (0 ili 1) [23e]. Stoga je digitalno kodiranje prirodni
izbor [23f]«.
5

Nesterov ukazuje da Shannonova teorija informacija ne odgovora na pitanje »što je informacija«.[19,20]
2GJRYDUD QD SLWDQMH ªNRMD VH NROLþLQD LQIRUPDFLMH PRåH SUHQRVLWL X MHGLQLFL YUHPHQD RGUHÿHQLP VNXSRP
signala?« [19,20@ =DWR VH RGOXþLOR UD]PDWUDQMH R LQIRUPDFLML SRGLMHOLWL X RQR SUHPD LQIRUPDFLMVNRP WRNX
NROLþLQDLQIRUPDFLMD LIL]LNalnu interpretaciju s pokušajem da se odgovori na pitanje što je informacija. Time seukazuje na dopunski argument o (tro)jedinstvu informacije, energije i materije.

Energy and the Environment (2016) 435-446

441

7UHED QDJODVLWL YDåQX þLQMHQLFX 8OD]QD LQIRUPDFLMD GLMHOL VH QD QDUHGEX L SRGDWNH GRNL]OD]QXLQIRUPDFLMXþLQHVDPRSRGDWFL VOLND 
Informatistika
7HKQLND NRMD REXKYDüD VYH DNWLYQosti za proizvodnju informacija je informatika (e.
,QIRUPDWLRQ 7HFKQRORJ\ ,7  QM ,QIRUPDWLRQWHFKQLN  3UHGODåH VH XYRÿHQMH QD]LYD
informatistika NDR ]DMHGQLþNR LPH ]D ]QDQVWYHQX GLVFLSOLQX JRVSRGDUVNX GMHODWQRVW WH
SULURGQH L GUXãWYHQH WHKQLþNH  WRNRYe i procese vezane uz informaciju. Osoba koja se bavi
informacijama je informatik.
0RJXüMHVOMHGHüL]DNOMXþDN=ELYDQMDna Zemlji opisuju zajedno informatistika, energistika i
PDWHULMDOLVWLND 3UYD UHDNFLMD QD RYR VD]QDQMH MH GD WUHED þRYMHNRYX SR]LFLMX shvatiti kao
XNODSDQMH GUXãWYHQLK WHKQLþNLK  WRNRYD L HOHPHQDWD RUJDQL]DFLMH X SULURGQH ]DNRQLWRVWL L
WRNRYH (QHUJHWLNX ]DãWLWX RNROLQH L VX]ELMDQMH NOLPDWVNLK SURPMHQD GUXãWYHQL WHKQLþNL
sistem), na primjer treba zamijeniti s energistikom.[9,13]
NameüH VH SLWDQMH NDNR VX SRYH]DQH PDWHULMD HQHUJLMD L LQIRUPDFLMD WH UHGRVOLMHG QMLKRYH
pojavnosti?
4. POVEZANOST MATERIJE, ENERGIJE I INFORMACIJE,] GR VDGD QDYHGHQRJ QDPHüH VH SLWDQMH R SRYH]DQRVWL WD WUL WHPHOMQD izvora (resursa) okojima ªPLVYLRYLVLPR©NDNRMHWRUHNDR2HWWLQJHU>@7UHEDQDJODVLWLGDüHVHSUHX]LPDWLL]
OLWHUDWXUQLK L]YRUD LVNOMXþLYR VWDYRYL L ]DNOMXþFL SRMHGLQLK LVWUDåLYDQMD =D SRMHGLQRVWL]DLQWHUHVLUDQLVHXSXüXMXQDL]YRUQHWHNVWRYH
4.1 Korelat energije i mase
Postoji li suodnosna veza, korelatL]PHÿXHQHUJLMHLPDVH"8RGJRYRUXQDWRSLWDQMHWUHEDRELSRPRüLNRQFHSWVMHGLQMHQRVWL6 nedualnosti.[24-26]
Koncept sjedinjenosti temelji se na ideji da je svemir jedna, jedinstvena i zaokružena cjelina
sastavljena od jednog, jedinog i jedinstvenog gradiva - HQHUJLMH 3RVOMHGLþQR QHPD QLNDNYH
IXQGDPHQWDOQH UD]OLNH L]PHÿX PDWHULMH L HQHUJLMH REMHNWLYQRJD L VXEMektivnog,
VYDNRGQHYQRJD L VSLULWXDOQRJ YLGOMLYRJD L QHYLGOMLYRJ YUXüHJD L KODGQRJ þYUVWRJD L
kapljevitoga. [24]Ta je ideja stara više od stotinu godina, a iznio ju je još 1905. godine Albert Einstein svojom
glasovitom formulom
E = mc2(1)

gdje su: E-energija, m-masa i c-brzina svjetlosti.

6

Alternativni prijevod engleskog naziva non-duality, nedualnost, može biti sjedinjenost ili ujedinjenost.[27]442,ýDWLü$.QHåHYLü: (Tro)jedinstvo informacije, energije i materije$NRVH]DQHPDULEU]LQDVYMHWORVWLNDREURMNYDQWLILNDWRUSURL]OD]L]DNOMXþDNGDPDWHULMDMHVW
energija a energija jest materija.[26] 1DPHüHVHSLWDQMHãWRMHELORSUYRPDWHULMDLOLHQHUJLMD"
Odgovor je ponudio Max Planck. »Nema materije kao takve. Sva materija izvire i postoji
VDPR ]DKYDOMXMXüL VLOL NRMD GRYRGL GMHOLüH DWRPD X RGJRYDUDMXüX YLEUDFLMX L GUåL WDMminijaturni, poput solarnog, sustav atoma na okupu. Moramo pretpostaviti kako iza ove silestoji svjestan i inteligentan um. Taj je um matrica sve tvari.« [27,28] 7 M. Planck drugimULMHþLPDNDåHGDMHPDWHULMDVDPRPDQLIHVWDFLMDHQHUJLMHDGDMHVYHPLUVYMHVWDQLLQWHOLJHQWDQ
a ne glupi automat.[27] Može se pridodati, materija je manifestacija energije, materija je
kondenzirana energija.[27]0DVD QHNRJ WLMHOD PRåH VH VPDWUDWL UH]HUYRP HQHUJLMH 6YDNR WLMHOR NRMH RVOREDÿD WRSOLQXSUHGDMH L]YMHVQX NROLþLQX HQHUJLMH LOL NRMH ]UDþL JXEL GLR VYRMH PDVH 2EUDWQR VYDNR WLMHOR
koje prima WRSOLQXLOLNRMHDSVRUELUD]UDþHQMHSRYHüDYDVYRMXPDVX>7,15]
U radu Energy or information [8] na temelju sustavnosnog pristupa postavljeno je pitanje što
je bilo prije, energija ili informacija? Iz opširne analize tog odnosa koja je izostavljena iz
prostornih razloga, odgovor glasi, informacija prethodi energiji.
4.2 Povezanost energije i informacije
Teorija kvantne entropijske logike barata samo s negentropijskim svojstvima informacije i
MHGYD VOLþL RQRP ãWR VH GRåLYOMDYD NDR LQIRUPDFLMX X svakodnevnom životu. To povezuje
informaciju s energijom i materijom.[20]6D VWDMDOLãWD QDYHGHQH WHRULMH LQIRUPDFLMD MH IL]LþNR SROMH L]UDYQR SRYH]DQR V HQHUJLMRP L
masom nekog objekta. Time postaje valnim oblikom materije.
Ako se shvati informacijsko SROMH NDR SRVHEQL REOLN IL]LþNRJ SROMD L] SRVWXODWD NYDQWQH
PHKDQLNH VOLMHGL QXåQRVW SUHQRãHQMD LQIRUPDFLMVNRJ SROMD QHNRP YUVWRP PLNURþHVWLFD NDRãWRQDUD]LQLIXQGDPHQWDOQLKþHVWLFDIRWRQLSUHQRVHHOHNWURPDJQHWVNHVLOH>0]
4.3 Invarijantnost triju izvora
6 PRWULãWDRSüHVXVWDYQRVQHWHRULMHQDPHüHVHSLWDQMHVXPHWULMXL]YRUDHQHUJLMHPDWHULMHL
informacije. Suma navedenih izvora na ulazu i izlazu je konstantna ili invarijantna (jednadžba
2) [29,30].
E+M+I=C(2)
gdje su E, M i I istodimenzijski ekvivalenti energije, mase i informacije a C konstanta.
5D]UMHãHQMHP W]Y SDUDGRNVD 0D[ZHOORYRJ GHPRQD GRãOR MH GR XWYUÿLYDQMD IL]LþNH YH]H
L]PHÿX LQIRUPDFLMHLHQHUJLMH>29] To je omjer ekvivalentnosti informacije i energije, omjer
prirašWDMD NROLþLQH LQIRUPDFLMH L RGJRYDUDMXüHJ QHJDWLYQRJ SULUDãWDMD HQHUJLMVNH HQWURSLMH ,]
RYRJVHPRåH]DNOMXþLWLGDYDåLXQLYHU]DOQLSULQFLSWURVWUXNHHNYLYDOHQFLMHPDWHULMHHQHUJLMH
i informacije, kao i da je ukupna suma ta tri ekvivalenta u nekom autonomnom sustavu
invarijantna (konstantna) [30]. 8
7Na pitanje na tražilici max planck quote intelligent mind odgovor glasi: ima 80 500 tekstova, pristupljeno
21.8.2015.[28]8
Vrlo zanimljiva i opširna rasprava o Maxwelovom demonu, odnosu informacije i energije. objavljena je u [23g].

Energy and the Environment (2016) 435-446

443=D VYDNX RG RYH WUL YHOLþLQH SRVWRMH HNYLYDOHQWL L]UDåHQL X MHGLQLFDPD GUXJD GYD L]YRUD =D
energiju postoji maseni ekvivalent (izražen u jedinicama mase) i informacijski (izražen ubitima); za maseni oblik pRVWRML QMHQ HQHUJLMVNL HNYLYDOHQW L]UDåHQ X MHGLQLFDPD NROLþLQHenergije) i informacijski (izražen u bitima); za informaciju postoji njen maseni ekvivalentL]UDåHQXMHGLQLFDPDPDVH LHQHUJLMVNL L]UDåHQXMHGLQLFDPDNROLþLQHHQHUJLMH ,VWRWDNRL
invarijanta, koja predstavlja ukupnu sumu tri ekvivalenta, može biti izražena bilo kojom od
MHGLQLFDRYHWULYHOLþLQH>29]
Suprotni, antientropijski ili evolucijski procesi, koji se manifestiraju u smanjivanju entropije,
D SRYHüDYDQMX NROLþLQH LQIRUPDFLMH Govode do energijske manifestacije, odnosno do
diferencijacije energijskih potencijala pojedinih elemenata sustava, kao i do povišenja stupnja
QMHJRYHRUJDQL]LUDQRVWL3ULWRPHVHL]YMHVQDNROLþLQDHQHUJLMHWURãL]DYODVWLWXPDQLIHVWDFLMX
odnosno za generiUDQMH RGJRYDUDMXüH NROLþLQH LQIRUPDFLMH NRMD üH VH X VXVWDYX L]UD]LWL
povišenjem stupnja njegove organiziranosti.[28]6WYDU MH KHXULVWLþNRJ L]ERUD PRPHQW LOL VWDQMH RG NRMHJD üH VH NDR SRþHWQRJ UD]PDWUDWL
navedeni transformacijski procesi. Tu nema SUDSRþHWDND X DSVROXWQRP VPLVOX WH ULMHþL ,VWR
WDNR L NDGD VH JRYRUL R SUDREOLNX PDWHULMH WR QLNDNR QH ]QDþL SUYRELWDQ REOLN X QHNRP
apsolutnom vremenskom smislu.
5â7275(%$8ý,7,129(*(1(5$&,-(",VNXVWYRXþLGDRQLNRMHYLGHFMHOLQXRELþQRQLVXGREULVDYMHWRGDYFL]DGHWDOMHâWRWR]QDþL"
2QLNRMLREUD]XMXXãNROLEH]RE]LUDQDVWXSDQMREUD]RYDQMDRELþQRQHYLGHFMHOLQXSRVHEQR
QH RGQRVD VYRJ SUHGPHWD L FMHORNXSQRJ NXULNXOD 0HÿXWLP ]QDMX L]YUVQR NDGD MH SRJRGQR
koje znanje prenositi obzirom na uzrast.
2YDSURPLãOMDQMDSRND]XMXQHNHRGPRJXüLKSXWRYDýLQLVHYUORYDåQim nauk o sustavima tevažnosti razumijevanja osnovnih pojmova poput informacije, energije i materije. U doba
SUHRELOMD LQIRUPDFLMD SRWUHEQD VX SRRSüDYDQMD YLGUDORYVNL, smanjenje broja informacija.
Naveden je primjer injekcijskog prešanja (>  LQDþLFD) NRML VQDåQR VYMHGRþL WX LGHMX 1H
može se i ne treba podXþDYDWLVYHWHSRVWXSNHSDQLQDYLVRNRãNROVNRMUD]LQL
6=$./-8ý$.
2VQRYQDVYUKDRYRJUDGDMHXND]LYDQMHQDPRJXüQRVWSRRSüDYDQMDVYHEURMQLMLKLQIRUPDFLMDL
njihovo pretvaranje u novo znanje i spoznaje. Upravo definiranje osnovnih pojmova kao što
LQIRUPDFLMDHQHUJLMDLPDWHULMDSRND]DORMHNDNRVHQHGRYROMQDSR]RUQRVWSRVYHüXMHQMLKRYRP
preciznom definiranju. .DNRüHWDGDQDXþLWLXþHQLFLXãNROLRþHPXVHUDGL"""
Istodobno je ukazano na (tro)jedinstvo tih osnovnih izvora (resursa). Treba osvijestiti sve koje
VHSRGXþDYDGDVHVYLQDYHGHQLL]YRULPRJXL]UD]LWLXLVWLPMHGLQLFDPD444,ýDWLü$.QHåHYLü: (Tro)jedinstvo informacije, energije i materije

POPIS OZNAKA
E
mc
C
E, M, I

energijamasa
brzina svjetlosti
konstanta
istodimenzijski ekvivalenti energije, mase i informacije

ZahvalaAutori se zahvaljuju svima koji su ih hrabrili u nastojanju da se napiše ovaj tekst. Posebno sezahvaljuju svojih suradnicima koji VX QDYHGHQL X SRSLVX OLWHUDWXUH 1D SR]RUQRP þLWDQMX L
SUHSRUXFLRSUHFL]QRPQD]LYOMX]DKYDOMXMHPRVHGUVF'+UXSLüXLGUVF+=RUFXLiteratura
[1]
[2]

[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]
[14]
[15]

ýDWLü,Sintezologija (http://sintezologija.com.hr/hr/).
Oettinger, A. G.: Knowledge Innovations: The Endless Adventure, plenarno
predavanje 2000 Annual Meeting of the American Society for Information Scienceand Technology, http://ebrap.com.br/pdf/tendencias/knowledgeinnovations.pdf,
pristupljeno 5.8.2015.
Proširenje principa ekvivalentnosti mase i energije na negentropiju
http://singidunumac.info/Izabrani%20radovi%20%20arhiva/Prosirenje%20principa%20ekvivalentnosti.PDF, pristupljeno 5.8..2015.
Ropohl, G.: Eine Systemtheorie der Technik, zur Grundlegung der allgemeinenTechnologie, Carl Hanser Verlag, München Wien, 1979., 169.
Ropohl, G.: Allgemeine Technologie, Eine Systemtheorie der Technik, 3.,überarbeitete Auflage, Universitätverlag Karlsruhe, Karlsruhe, 2009.
ýDWLü,5D]L15DRV3Analiza injekcijskog prešanja polimera teorijom sustava,'UXãWYRSODVWLþDUDL gumaraca, Zagreb, 1991.
ýDWLü,âDULü/MPrilog sustavnosnoj analizi hrvatskog jezika, Rasprave Zavoda za
hrvatski jezik, 20(1994), 19-30.
ýDWLü,5XMQLü-6RNHOH0'DGLü%Energy or Information, Synthesis
Philosophica, 49(1)173–180(2010).
N. N: Polimeri i polimerni materijali, Polimeri, 2(2)74-75(1981).
StoiljkoviüD.: Doprinos Boškoviüeve teorije suvremenog shvaüanju strukturematerije, Anali ogranka SANU u Novom Sadu, broj 7 za 2011.
9UVWHLSRGHODIL]LþNLKSROMD, http://tsmmsnsfizika.weebly.com/sile-i-bezvrtlo382nafizi269ka-polja.html, pristupljeno 11.8.2015.
.XNROHþD6Organizaciono-poslovni leksikon, Rad, Beograd 1986, 15a s.1210, 15b
s. 484, 15c s. 485.
Leksikon Jugoslavenskog leksikografskog zavoda, Zagreb, 1974, s.792.
N. N.: Reference Document on Best Available Techniques for Energy Efficiency,
European Commission, February 2009.
Comparing the comparable, ISO Bulletin, August 1996, 18.

Energy and the Environment (2016) 435-446

[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]
[26]
[27]
[28]
[29]
[30]

445

Heat of combustion, https://en.wikipedia.org/wiki/Heat_of_combustion, pristupljeno
2.4.2016.
Verbrennungsenergie, http://www.gutefrage.net/frage/verbrennungsenergieverbrennungsenthalpie, pristupljeno 2.4.2016.
http://www.enciklopedija.hr, a-Natuknica.aspx?ID=49737, bNatuknica.aspx?ID=31494m, pristupljeno 1.8.2016.
Nesterov, V.: Information in the Structure of the Universe, Academic ResearchInternational, 2(1)11-19 (2012), www.journals.savap.org.pk.
Nesterov, V.: Informacija u strukturi svemira, http://www.molekulazdravlje.com/informacija-u-strukturi-svemira/bigbang/, pristupljeno 1.8.2015(prijevod [19])Hermann & Cie) & Camb: Norbert Wiener Cybernetics: Or Control andCommunication in the Animal and the Machine. Paris, 1948: MIT Press, ISBN
9780262730099.
1RYDNRYLü%Regulacijski sistemi6YHXþLOLãQDQDNODGD/LEHU)6%=DJUHE
Vedral, V.: Dekodiranje stvarnosti - Univerzum kao kvantna informacija, Laguna,
Beograd 2014, [25a, 13], [25b, 21], [25c, 25], [25d, 100]. [25e, 53], [25f, 73], [25g,95-100].
Korelativ, http://www.enciklopedija.hr/natuknica.aspx?id=33165, pristupljeno
18.8.2015.
Korelativ, http://staznaci.com/korelativ, pristupljeno 18.08.2015.
Fizika ne-dualnosti, http://www.manifestiranje.com/uvod/12-tutorial/13-uvod-fizikane-dualnosti, pristupljeno 11.8.2015.
Plank, M.: Das Wesen der Materie [The Nature of Matter], speech at Florence, Italy(1944) (from Archiv zur Geschichte der Max-Planck-Gesellschaft, Abt. Va, Rep. 11
Planck, Nr. 1797).
Planck' units https://en.wikipedia.org/wiki/Planck_units, pristupljeno 18.5.2015.
Maxwell's demon, https://en.wikipedia.org/wiki/Maxwell%27s_demon, pristupljeno
20.8.2015.
http://singidunumac.info/Izabrani%20radovi%20-%20arhiva/Prosirenje%20principa%
20ekvivalentnosti. .PDF pristupljeno 26.5.2013.

TRI(UNI)TY OF INFORMATION, ENERGY AND MATTER
Summary: A plethora of information threatens the collapse of the education system. One of
the solutions the education of new generations in schools can be achieved withsynthesiological approach. From existing information to create a new, more general skills
and knowledge resulting in a reduction of information. Based on synthesiological approach inwhich is the basis the general systemic theory, we analysed inputs and outputs of technicalsystems: information, energy and matter. Based on advanced analyses of mentioned
definitions of mentioned sources has been concluded that any source can be expressed inunits of the other two. Composed equation mentioned sources indicating that their sum at the
inputs and outputs of the system should be constant. It describes the state and the order of
appearance of these sources in the theory of the Big Bang. It has been concluded that thesethree sources make unity.
Keywords: information, energy, matter, systemic theory, the origin of sources, modern
education

446,ýDWLü$.QHåHYLü: (Tro)jedinstvo informacije, energije i materije

Energy and the Environment (2016) 447-456

447

BRINGING DECENTRALIZED ENERGY SOLUTIONS IN CENTRALASIA
7LQD%DXWRYLü, =RUDQ.RUGLü5REHUW3DãLþNR
81'3&URDWLD/RPQLþka 2, Zagreb, Croatia, robert.pasicko@undp.org
Abstract: Tajikistan and Kyrgyzstan are the least developed and poorest countries in Central
Asia with GNI per capita of US$ 1,080 and US$ 1,250 respectively, which is below theaverage for lower middle income countries. The two countries are facing a wide range ofsocio-economic and environmental challenges, particularly affecting the rural areas wheremore than two thirds of Kyrgyzstan’s population and almost three quarters of Tajikistan’s
population reside. Despite nearly universal grid connection rate, approximately 70% of the
Tajik population suffers from extensive shortages of electricity during the winter. Theseelectricity shortages are caused by a combination of a) insufficient winter hydropower output
when river flows are low and b) high demand driven by heating needs in the winter. These
shortages, estimated at about 2,700-4,000 GWh/year impose economic losses at 3% of GDP.
The unmet demand for electricity in Tajikistan, combined with households’ current spendingon alternative fuels in the winter, represent a potentially large market opportunity fordecentralized energy services in rural areas. In order to open this market, UNDP from
Croatia has set up a project “Green Villages in Central Asia” which focuses on providing
electricity and heat energy to households and private sector in Tajikistan and Kyrgyzstan
through improved energy access.
An integral approach in the project focuses on three pillars: a) decentralized technology
solutions; b) innovative financing models; c) setting up of SMEs to unleash the market forbringing energy access (such as RESCO companies, energy cooperatives, DIY technologiesetc). This paper discusses recent innovative finance and business models for green energy,
presents barriers and lessons learned from that process, which proves that decentralizedenergy is a serious alternative to business-as-usual energy system development based on
centralized fossil fuel power plants.
Key words: energy access, energy poverty, RESCO, solar energy, innovative financing,energy cooperatives
1. INTRODUCTION
According to World Development Indicators from 2014 Tajikistan and Kyrgyzstan have GNI
per capita of US$ 1,080 and US$ 1,250 which classify them as the poorest and least
developed countries in Central Asia [1].
Socio-economic problems which are present in both countries are largely related to theunfavorable situation in energy sector causing which causes environmental problems as well.
Population living in the rural areas, where more than two thirds of Kyrgyzstan’s population
and almost three quarters of Tajikistan’s population reside is the most affected by these issues[2]. High percentage lives without reliable or affordable energy access which causes highunemployment rate and high general poverty.
Despite 90% grid connection rate in Tajikistan, almost 70% of the population suffers fromelectricity shortages. Due to high dependence on hydropower, the low river flaws and high448

T. %DXWRYLü=.RUGLü53DãLþNR: Bringing decentralized energy solutions in…

electricity demand cause the most frequent and extensive blackouts during winter period. The
unreliable energy supply brings about further problems regarding economy, development andenvironment which lead to the increase of general poverty which will be dealt with in moredetail in the next chapter. The unreliable energy supply represents a large market opportunity
for decentralized energy services including renewable energy technologies and energy
efficiency that would enhance energy access [3].
Similar electricity shortages occur in Kyrgyzstan during winter as the demand is much higher
than in summer period and the river flows are significantly lower. Those shortages often
occur in rural areas. Currently, less than 1% of renewable energy potential has been usedwhich means that Kyrgyzstan has a serious potential to solve the supply issues which would
help mitigate other problems as well [4].
Future plans for energy access in both countries are heavily relying on business as usualmodel of energy access development – through the new centralized energy production. Thisapproach has shown no or little benefits for local communities that are still lacking electricity
through the large part of the year. There was a need for developing alternative model ofenergy access – one which is based on decentralized energy solutions and based on renewableenergy and community engagement.
Having this in mind, there was a need to develop and test new model of power systemdevelopment that would contribute not only to energy access but also to job creation andenvironmental sustainability. Energy experts from UNDP offices in Croatia, Tajikistan,
Kyrgyzstan and Istanbul regional Hub joined forces to design and pilot new model of energy
access, known as Green Villages model.
This paper represents a new model of integrated rural development approach: Green villages
in Central Asia which has been implemented in pilot areas of rural Tajikistan and Kyrgyzstan.
The model has been introduced in order to reduce energy issues in rural areas and other issues
directly caused by lack of reliable energy access. The paper describes starting assumptions,pilot projects carried out within the model designing, lessons learned from the pilot projects
and scaling up possibilities.
2. INTEGRATED RURAL DEVELOPMENT APPROACH – COMBINING RURALENERGY ACCESS WITH EMPLOYMENT AND ENVIRONMENT BENEFITS
There is a high correlation between energy poverty and issue of general poverty. The inability
to pay for energy or a complete lack of energy access directly influences the four componentsof poverty: health, education, income and environment [5].
Inefficient and technically poorly designed heaters and cookstoves, which are commonly usedin rural areas of Tajikistan and Kyrgyzstan requiring firewood or other biomass, often causeindoor air pollution which could have bad impact on health, primarily among women andchildren. Moreover, as they are usually responsible for biomass collecting, they are also more
exposed to risk of injuries [6] [5]. Due to energy issues, education possibilities for many
school children are very limited; many spend a lot of hours every day collecting biomass
instead of attending school, studying hours are limited due to non-existance of indoor
lighting, conditions within public schools are mostly inadequate in terms of heating andschool equipment and lack of access to modern technologies limits the access to information.

Energy and the Environment (2016) 447-456

449

Development of industry and enterpreneurship is very limited without a reliable andaffordable energy access which, coupled with poor education, results in economic growthstagnation.
Finally, the vast use of biomass leads to serious deforestation problems and the use of
inefficient appliances results in higher energy consumption [5]. Therefore the prerequisite to
mitigate the poverty and foster development in Tajikistan and Kyrgyzstan is to provide
reliable access to energy affordable to the local society [7].
The Integrated Rural Development (IRD) has already been tested in rural areas of Tajikistan
before and it was proved to be a good approach to deal with energy and poverty issues. The
IRD approach is based on combining locally available renewable energy sources, energy
efficiency and fostering income production which is related to either renewable energy
technologies or energy efficiency [6].
For the successful realization of IRD it is important to have the community involved in a
project in order to continue the project management after the set-up phase and to ensure its
operation and maintenance (O&M). It provides the opportunity for the community members
to increase their income through direct work on the mentioned project activities or throughnewly started businesses and activities which setting up becomes possible due to provided
energy access [6]. Moreover, successful realization of the IRD increases living conditions,
reduces health issues and provides opportunities for the whole community but especially for
women and children. Women can dedicate more time to money making activities which
generally result in higher gender equality and children have more time and much better
opportunities and conditions for education. Implemented energy efficient measurements andnew technologies have a positive impact on local environment and they foster sustainable
development [8].
In 2008 United Nations Development Programme started implementation of pilot IRD projectin Jamoat Burunov in Tajikistan. Project included refurbishment of two units in the Nurofar
small hydro power plant, refurbishment of the hospital, school and kindergarten, constructionof mini-dairy, refurbishment of pumping station, construction of a small greenhouse andestablishment of the operator which was responsible for O&M and collecting the fees. It has
been confirmed that the integrated approach improves the living conditions of community andcontributes to poverty eradication much more than simply building an energy source (in thiscase a small hydro power plant). The surveys conducted after the project has shown theimportance of community involvement [6].
However, it was noted that the approach could be further improved by assigning
responsibilities within community for each project activity, by using only locally available,
affordable and replicable technologies (even if they are not the most efficient and reliable), by
involving local experts and by educating local inhabitants about implemented technologies.
[6]
3. PROPOSED GREEN VILLAGES IN CENTRAL ASIA MODEL FOR ENERGYACCESS
Lessons learned from the IRD project were taken into account for developing Green villages
in Central Asia model. Combination of innovative financing and business models,decentralized green technologies and renewable energy and are pillars of the new model.

450

T. %DXWRYLü=.RUGLü53DãLþNR: Bringing decentralized energy solutions in…

Significant role in the project was given to the inclusion of local community and local experts.
Different local NGOs, cooperatives, companies and associations have been fully involved in
the project. The local experts were in-depth familiar with the technologies planned to be
implemented. They were also a valuable source of information about locally available
materials and technologies and their inputs were taken into account while designing pilot
projects technologies as the implemented technologies were supposed to be easily replicableby local communities. Another important contribution of the local experts was easiercommunication with local inhabitants due to lack of language barrier and due to the experts’
deep understanding of local community culture. Finally, local experts were assigned to help
the local communities to accept implemented technologies, to train the people to use them andto help them to overcome any potential barriers. They conducted surveys among inhabitants
after the set-up phase of the pilot projects and provided valuable information.
Another focus in the new model was placed on building capacity and training local people tobe able to produce new technologies themselves. One do-it-yourself workshop on how tobuild solar thermal systems was conducted in the village of Jilikul in Tajikistan. 15 women
were trained during the workshop. Another workshop was carried out in Guzgef village in
Tajikistan, during which 25 participants from all over Tajikistan were trained for a week tobuild a rocket mass heater. Both pilot projects are further described in the following chapter.
General idea of pilot projects which included do-it-yourself workshops or demonstrating
workshops were to build capacity and to transfer technology knowledge in the way that local
inhabitants can easily replicate it themselves. Moreover, that they are able to develop green
energy small and medium enterprises (SMEs) based on the certain activity and technology.
The established green energy SMEs could create jobs, increase income, develop market andplay a significant role in economic development in general.
Finally, an important part of the model is introduction of innovative financial models as
crowdfunding which are supposed to support some project activities mostly regarding
refurbishment of local public buildings but they could be used for various purposes in the
future. The pilot projects have been conducted in 6 villages in Tajikistan and 2 in Kyrgyzstan.
The areas for the pilot projects have been chosen in cooperation with the local experts andtrusted local organizations.
3.1. Small scale decentralized technologies
Enabling women to build solar thermal systems through do-it-yourself workshop. The
objective of the project was tointroduce solar thermal systemdesign to local companies andtrain women in rural households
to build and use solar thermal
systems from locally available
materials thus making womenheaded households more selfsufficient in energy use.
Within the project, three do-ityourself workshops were held:
one was held in Dushanbe for
12 participants from local
companies, technical university
and NGOs and two workshops
Figure 1: Do-it-yourself solar thermal systems workshop in Jilikul

Energy and the Environment (2016) 447-456

451

were performed for 15 women recruited by Women Resource Center in Jilikul village.
Moreover, one of the participants trained during the workshop in Dushanbe organized theworkshop in Pamir region later on which was a great example of further knowledge transfer.
However, it was later recognized how important it is to assign one of local inhabitants aselectrician expert who will help others in maintaining solar systems. In rural areas without
reliable electricity supply this business model could be scaled up in future as SME. If those
SMEs would be led by women, the business will not only enhance the economic development
but also will contribute significantly to women empowerment and gender equality.
Introducing and testing energy efficient cookstoves and solar lamps in un-electrified
households. Cheap EE cookstoves and solar lamps were introduced and tested in six villages(some of which are still without year-round electricity supply) in rural Tajikistan. The
information provided throughsurveys among village users havesuggestedsomedesigninterventions for EE cookstoves
but it has been confirmed that theusers have used less than half of
firewood for cooking, which isvery important for the regions witha lack of biomass due to serious
deforestation. Similar applies forsolar lamps which bring incredible
value in regions without power
supply. Therefore it has beenconcluded that both technologies
could have market value thatwould be recognized by the locals.
Figure 2: Introducing energy efficient cook stoves

Enabling locals for building efficient stoves for indoor heating and cooking. The idea of thepilot project carried out in Guzgef
village in Tajikistan was toeducate and train locals in ruralvillage, where biomass is scarce,
on how to build efficient stove forindoor heating and cooking fromonly locally available materials.
During one week training one
large stove was built in a local
mosque, and two smaller ones in
the local school. This training
attracted people from all around
Tajikistan (20 people) and it
resulted in at least eight people
being fully trained to build theirown mass heater and others who
Figure 3: Rocket mass heater workshop
would follow with morepractice. Several additional designs have been set up, such as integral stoves for cooking andheating, or existing metal stoves adapted to rocket mass heater. Although manual on how tobuild and use rocket mass heater was prepared, the survey has been conducted afterwards

452

T. %DXWRYLü=.RUGLü53DãLþNR: Bringing decentralized energy solutions in…

showing that the stoves have been improperly used by locals at first (it was not 100% dry
before the use) which resulted in limited use of the stove. Consequently, another brief user
manual was prepared with very straightforward instructions on how to use the stoves. It has
been concluded that the manuals provided in areas like rural Tajikistan have to be very clear
and very straightforward and that a local expert should always be engaged to help the local
community to accept and get familiar with new technology after completing official training.
However, more attention needs to be paid in selecting the village as locals were not ready toaccept the new technology. The technology would have the great impact in the places with thelack of biomass, as the stoves can be produced locally by stove masters or local cooperatives.
3.2. Innovative financial models
As mentioned before, innovative financial models implemented in this model are abreakthrough in the IRD approach. They give the community powerful tools to tackle thechanges, improve their living conditions or to start SMEs without relying heavily on current
economic situation or political climate in the country (e.g. subsidies for green technologies).
Within Green Villages’ pilot project portfolio, crowdfunding campaign was carried out inorder to raise the funds for local school building refurbishment. Primary school with 137
children from Guzgef village and surrounding villages, lacks basic conditions as the school is
not connected to electrical grid and has a couple of old, inefficient heating stoves. The
campaign was launched in May 2016 with the initial goal of collecting 8,000 USD. The
refurbishment will include introduction of renewable energy (solar panels), thermal insulationof roof and walls and replacement of windows and wooden floor.
Crowdfunding has proved to be a great tool for the projects contributing to the developmentof local community and as such it can be used in further projects. However, more advanced
innovative financial models have been developed recently that could be implemented forfinancing renewable energy projects: crowdinvesting and crowdlending. Platforms such as
TRINE for crowdinvesting or KIVA for crowdlending have been used successfully for similar
projects in other developing countries. These models have huge potential but they are still tobe implemented and tested within IRD approach.
3.3. Integrated development of green villages on example of Guzgef village
Guzgef is a mountainous village in rural areas of Tajikistan with 350 inhabitants living in 65
households. Due to remote location, 2000 m above sea level the village is not connected to theelectricity grid. With no access to electricity, the inhabitants depend only on coal or firewoodin terms of heating and cooking, on petroleum for lights and generally have very poor living
conditions.
Several pilot projects have been introduced in Guzgef in order to mitigate many issues
regarding lack of energy access and boost further development. First of all, 30 small
photovoltaic systems have been disseminated among households in the village. The projectcontributed to the improvement of living conditions as it enabled the use of indoor lightning
for many families. Secondly, 30 efficient cookstoves have been disseminated which cut therequired amount of firewood used for cooking by half. In the area with serious deforestation
issues, where women and children spend many hours a day collecting biomass, it is asignificant improvement. The other pilot project, which included building of three efficient
stoves for heating in public buildings, contributed as well to the decrease of biomass
consumption in the village and reduction of further deforestation of surrounding areas.

Energy and the Environment (2016) 447-456

453

Moreover, both projects reduced indoor pollution, thus providing better living conditions
which prevent health problems. Thirdly, crowdfunding campaign has been introduced in order
to raise funds for local school refurbishment. Better conditions in local school building,indoor lighting which enables longer studying hours and reduced time required for biomasscollection, provide better education possibilities for school children. Finally, three efficient
stoves (highly efficient rocket stove mass heater design) were built at the workshop attended
by 20 people, from Guzgef, surrounding areas and other parts of Tajikistan. Building capacityand providing locals with knowledge of new technologies is the fundamental step in
economic development. The project can result in starting business: establishing of SMEs orcooperative which will produce and sell the same type of the stove. It can raise the income ofmany village households and initiate further development. In all the projects carried out in
Guzgef, local experts and local NGOs have been included. The local expert played a very
important role in the period right after the efficient stove building workshop. The local people
were not familiar with new technology before it was implemented in their village and evenwith the given instructions on how to use the stoves; they were struggling with it so much thatthey wanted to reject this new technology. However, the local expert that was later visiting
the village helped the local people to overcome all barriers they had regarding the use of theefficient stove. Moreover, great attention was given to the fact that all introduced technologies
are locally replicable which implied that all the materials used are locally provided.
3.4. Upscale of proposed model for energy accessFigure 4: Upscale of Green Villages in Central Asia model

Development of the model started by analyzing the current issues and needs of rural areas of
Tajikistan and Kyrgyzstan in order to develop the model that will be self-sufficient and easily
replicable. As mentioned before, the results and lessons learned from previous IRD projects
were valuable inputs and they were taken into account when designing a new model. The pilot
projects were designed in a way to include as many components as possible, such as: green
technologies, capacity building and innovative financing. The experiences and lessons learned
from pilot projects are now used to develop upscale scenarios.

454

T. %DXWRYLü=.RUGLü53DãLþNR: Bringing decentralized energy solutions in…

RES and EE center. It became clear through capacity building pilot projects carried out inJilikul and Guzgef that the major interest in new technologies exists in Tajikistan. However,through surveys and experts communicating with trainings’ participants, the lack of training
opportunities became evident. One should have in mind that many participants have no accessto modern communications or information providers due to lack of electricity access.
Establishing spots where information can be provided or where trainings could be organizedis essential for further capacity building. Therefore, it was concluded that Renewable energy
and energy efficiency center (RES and EE center) should be set up in at least a couple ofregions. The center should become hub for education and practical demonstration on
renewable energy technologies and energy efficiency. It should also provide information
about equipment, products and services and promote networking among local RES/EE
manufactures and beneficiaries through green-loans initiatives. People interested in starting
their SMEs will be able to attend trainings on green technologies and receive support inbusiness starting, e.g. legal and financial advices (including innovative financial mechanisms
and financing schemes for green energy). Newly established SMEs will have the opportunity
to present their products, find out about market trends, attend workshops and get information
on financial possibilities. Finally, the center will serve for general public education on energy
efficiency and renewable energy technologies. The Renewable energy and energy efficiency
centers should initiate green energy development in the countries.
Role of green energy SMEs. The green energy SMEs could play an important role ineconomic development and they should be encouraged in terms of policy framework andfinancial possibilities. As described, RES and EE centers could serve as a hub for green SMEs
and they can provide information and advice. However, other instruments should beestablished in order to financially help business development. One possibility is a more active
and significant role of national and international financial organizations. They could offerloans and microcredits for establishing SMEs or already existing SMEs. Other possibility
which has huge but unused potential is introducing innovative financial models such as
crowdfunding, crowd lending and crowd investing on a large scale. This potential should be
encouraged by establishing platforms for certain financial model in Tajikistan and Kyrgyzstan(such as Indiegogo, Citizenergy or Solarschool) and at the same time to establish a supporting
center which will provide support and guidance in creating and implementing campaigns.
Through the platforms, the large community of Tajik and Kyrgyz people working abroad will
get a straightforward possibility to invest in green technologies and it will also enable
participation of investors in green energy from around the world.
ESCO model in private companies. As part of the pilot projects energy audits of 10 SMEs in
Tajikistan have been performed. The consultancy and recommendations on improving the
SMEs’ performances in area of sustainable use of natural resources with consideration ofenergy, waste, water saving and environmental aspects were provided for all audited SMEs.
Finally, the principles and approaches for conducting energy efficiency audit in SMEs with anenergy, economic and environmental assessment have been introduced and set up. One of theconclusions of the pilot project is that no major progress could be done regarding energy
efficiency improvement or use of renewable technologies in private companies and industries
without development of Energy Service Companies (ESCO) or Renewable ESCOs (RESCO)on a wider scale. ESCO companies would remove the risk of high capital investments inenergy efficiency and renewable technologies and they could provide services for both SMEs
and for rural households. There are several options for this business model which should beconsidered: leasing model (the client rents a RES system and O&M risks are transferred to
RESCO), hire-purchase model (RESCO retains ownership of the RES system until user has

Energy and the Environment (2016) 447-456

455

completed payments) and concession model (one or more RESCOs are contracted on a feefor-service basis by the government to provide for example energy services to the public
sector facilities).
4. CONCLUSION
Energy planning today needs to go hand in hand with thinking of wider socio-economic
benefits [9] [10]. Model “Green Villages in Central Asia” which was presented in this paper,
proved that the alternative approach for energy access based on decentralized and renewableenergy solutions in rural Tajikistan and rural Kyrgyzstan brings multiple socio-economic
benefits. The main barriers for further development have been recognized: the lack offinances for energy efficiency measurements and renewable technologies implementation, thelack of investments in green technologies due to many barriers and finally, the lack ofknowledge of green technologies, lack of support for green SMEs establishment anddevelopment. Therefore, three main prerequisites for further development have been
proposed: establishment of RES and EE center which would serve as a hub for education on
green technologies and information exchange on market conditions; stronger support for new
or developing green SMEs; and finally, further development of innovative financial models
through establishment of crowdfunding platforms and supporting centers and development of
ESCOs on a wider scale.
LITERATURE[1] World Bank Group, »World Development Indicators,« 2016.
[2] United Nations, »UN data,« http://data.un.org/Default.aspx.
[3] United Nations Development Programme, »Sustainable energy for all: Rapid assessment
and gap analysis,« 2013.
[4] United Nations Development Programme, »Renewable Energy Snapshot: Kyrgyzstan,«
2014.
[5] M. Kanagawa, T.Nakata, »Assessment of access to electricity and the socio-economic
impacts in rural areas of developing countries,« Energy Policy 36, pp. 2016-2029, 2008.
[6] Government of the Republic of Tajikistan and the United Nations Development
Programme, »Socio-Economic and Environmental Benefits of Small Hydro Power in
Tajikistan: Evidence form the Burunov Community,« 2013.
[7] =0RUYDM9%XNDULFD1ýXSLQ'*YR]GHQDF20DUNRYLü65RELüª,QWHUPHGLDWH
Strategy for Renewable Energy Sources Based Integrated Rural Development. Final
draft,« 2011.
[8] =0RUYDM65RELü9%XNDULFDª1DWLRQDO programme for renewable energy sources
based integrated rural development - national scaling up,« 2010.
[9] Z. K. R. P. D. C. Lin Herencic, »Modeling impacts of low-carbon technologies in thecontext of sustainable development in Croatia,« u 7th Dubrovnik Conference on
Sustainable Development of Energy Water and Environment Systems, Dubrovnik, 2013.
[10] R. Pasicko, Optimization of Power System Operation and Development under the
Emission Trading Scheme, University of Zagreb: Disertation, 2014.

456

T. %DXWRYLü=.RUGLü53DãLþNR: Bringing decentralized energy solutions in…

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CENTRALNOJ AZIJI
Sažetak: Dvije najsiromašnije i najmanje razvijene zemlje Centralne Azije, Tadžikistan i
Kirgistan, s bruto nacionalnim dohotcima po stanovniku od 1.080 US$, odnosno 1.250 US$
nalaze se LVSRG SURVMHND ]HPDOMD QLåHJ VUHGQMHJ GRKRWND  2EMH ]HPOMH VXRþDYDMX VH VDširokim spektrom socijalno-HNRQRPVNLK SUREOHPD L L]D]RYRP RþXYDQMD RNROLãD 3RVHEQR VX
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WUL þHWYUWLQH XNXSQRJ VWDQRYQLãWYD ,DNR SULPMHULFH X 7DGåLNLVWDQX YHüLQD VWDQRYQLãWYD LPDSULVWXS HOHNWULþQRM PUHåL RWSULOLNH QMLK  SUHWUSL GXJH SHULRGH EH] VQDEGLMHYDQMD
HOHNWULþQRP HQHUJLMRP WLMHNRP ]LPVNLK PMHVHFL1HSRX]GDQD RSVNUED HOHNWULþQRP energijom]LPL X]URNRYDQD MH NRPELQDFLMRP D  QHGRYROMQH SURL]YRGQMH HOHNWULþQH HQHUJLMH L]
KLGURHOHNWUDQD]ERJVPDQMHQLKULMHþQLKSURWRNDLE SRYHüDQHSRWUDåQMH]DSRWUHEHJULMDQMD3UHNLGL RSVNUEH HOHNWULþQRP HQHUJLMRP X]URNXMX VPDQMHQMH SRWURãQMH HOHNWULþQH HQHUJLMH
L]PHÿX  L  *:K JRGLãQMH ãWR GRYRGL GR HNRQRPVNLK JXELWDND RG  %'3-a.
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energenata tijekom zime, predstavljaju potencijal za stvaranje velikog tržišta distribuiranih
energetskih usluga u ruralnim dijelovima Tadžikistana. Kako bi se potaklo otvaranje tržišta,
UNDP Hrvatska pokrenuo je projekt pod nazivom “Green Villages in Central Asia” s ciljem
RPRJXüDYDQMDSULVWXSDHOHNWULþQRMLWRSOLQVNRMHQHUJLMLNXüDQVWYLPDLSULYDWQRPVHNWRUX
Objedinjenim pristupom projekt je fokusiran na: a) korištenje distribuiranih tehnoloških
sustava; b) primjenu inovativnih financijskih modela; c) poticanje malog i srednjeg
poduzetništva u svrhu otvaranja tržišta usluga za pružanje pristupa energiji (npr. RESCO
tvrtke, energetske zadruge, “napravi sam” tehnološka rješenja itd.).
Ovaj rad daje pregled inovativnih financijskih i poslovnih modela primjenjivih u sektoru
zelene energije te daje pregled dosadašnjih iskustava iz pokrenutih projekata. Nadalje, radpokazuje da je distribuirana proizvodnja energije ozbiljna alternativa dosadašnjem,
konvencionalnom razvoju energetskog sustava koji je bio baziran na centraliziranim
termoelektranama na fosilna goriva; te da su takva rješenja spremna na korištenje uzemljama u razvoju.
.OMXþQH ULMHþL pristup energiji, eneretsko siromaštvo, RESCO, solarna energija, inovativni
financijski modeli, energetske zadruge

Energy and the Environment (2016) 457-466

457

2'5(Ĉ,9$1-(3$5$0(7$5$92'21261,.$=$3275(%(SUSTAVA DIZALICA TOPLINE
Stjepan Strelec, *HRWHKQLþNLIDNXOWHW6YHXþLOLãWDX=DJUHEX+DOOHURYDDOHMD42000
Varaždin, Tel: 042408916; F: 042 313 587
Miroslav Golub, *HRWHKQLþNLIDNXOWHW6YHXþLOLãWDX=DJUHEX+DOOHURYDDOHMD
Varaždin, T: 042 408 900; F: 042 313 587
Kristijan Grabar, SPP d.o.o, Trstenjakova 3, 42 000 Varaždin, T:042 203 302, F: 042
203 306
Marina Marciuš, SPP d.o.o. Trstenjakova 3, 42 000 Varaždin, T:042 203 302, F: 042
203 306Sažetak: 9RGDNDRL]YRUREQRYOMLYHHQHUJLMHMHXþLQNRYLWLHNRORãNLSULKYDWOMLYUDGQLPHGLM za
JULMDQMH L NOLPDWL]DFLMX LQGXVWULMVNLK NRPHUFLMDOQLK VWDPEHQLK  L GUXJLK REMHNDWD RSüH
QDPMHQH 9DUDåGLQVNR SRGUXþMH RELOXMH SRG]HPQRP YRGRP 5HODWLYQR VWDELOQD WHPSHUDWXUDSRG]HPQLK YRGD X SRGUXþMX L]PHÿX  & WLMHNRP FLMHOH JRGLQH QHRYLVQD je o
NROHEDQMLPDNOLPDWVNLKSDUDPHWDUDQDSRYUãLQLSDMHVWRJDSRX]GDQWRSOLQVNLL]YRU3RGUXþMHvaraždinskog vodonosnika, u aluviju dravske terase, nalazi se na plitkim dubinama, što
RPRJXüXMH UHODWLYQR YLVRNX LVNRULVWLYRVW GL]DOLFH WRSOLQH U radu je, u cilju ilustracije
metodološkog postupka, arbitrarno odabran primjer pri projektiranju zdenca za potrebe
klimatizacijskog sustava studentskog restorana u Varaždinu.
.OMXþQHULMHþLYRGDYRGRQRVQLNGL]DOLFHWRSOLQHKLGUDXOLþNDYRGOMLYRVWWUDQVPLVLYQRst
1.

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SULKYDWOMLY QDþLQ ]D JULMDQMH L NOLPDWL]DFLMX LQGXVWULMVNLK komercijalnih, institucionalnih i
VWDPEHQLK REMHNDWD 9DUDåGLQVNR SRGUXþMH QDOD]L VH QD SRGUXþMX ERJDWRP SRG]HPQRP
vodom. Dizajniranje sustava dizalice topline zahtijeva detaljno poznavanje lokalne
KLGURJHRORJLMHLUD]XPLMHYDQMHKLGUDXOLNHNRMDMHXNOMXþHQa u eksploataciju i izmjenu vode pri
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vodonosnika poput poroznosti, hidrauliþNH YRGOMLYRVWL WUDQVPLWLYQRVWL XVNODGLãWHQMD WH
GHEOMLQH YRGRQRVQLND NUR] LVWUDåLYDQMD REMDYOMHQLK UDGRYD QD ORNDOQRP SRGUXþMX WUDåH VH L
SRGDFL L] EOL]LQH SRVWRMHüLK EXQDUD LOL SXWHP SURYRÿHQMD VWYDUQLK WHVWRYD QD WHUHQXParametrima vodonosnika odreÿuje se udaljenost zdenaca kako bi se maksimalno iskoristio
sistem dizalica topline. Crpljenjem podzemne vode iz zdenaca RGUHÿXMX VH KLGUDXOLþNH
karakteristike vodonosnika, a temeljem podataka o izdašnosti zdenaca i o sniženjima razine u
zdencu RGUHÿXMH se NDSDFLWHW ]GHQFD 3UREH WHVWRYL  ]D RGUHÿLYDQMH NDUDNWHULVWLND
vodonosnika izvode se na terenu tako da se prate pijezometarske razine koje nastaju zbog
dodavanja odnosno crpljenja vode iz vodonosnog sloja. Voda u vodonosnom sloju na zadane

458

S. Strelec, M. Golub, K. Grabar, M. Marciuš: 2GUHÿLYDQMHSDUDPHWDUDYRGRQRVQLND«

promjene reagira promjenom razine vodnoga lica. Opažanja je PRJXüH L]YHVWL QD VDPRP
probnom zdencu odnosno na obližnjim pijezometrima.
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prema potrRãDþX.
U ovom radu kao arbitrarni primjer predstavljen je projekt
zdenca za potrebe
klimatizacijskog sustava studentskog restorana u Varaždinu.

2.

MJERENJE VODOPROPUSNOSTI

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solucijskih otvora u konsolidiranom stanju, te o viskoznosti fluida koja je ovisna otemperaturi [5].
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propusne stijene:
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gdje je: k - koeficijeQWKLGUDXOLþNHSURYRGOMLYRVWL>PGDQ], m - debljina propusnog sloja [ m ]Energy and the Environment (2016) 457-466

459

Uz koeficijent transmisivnosti važan parametar vodonosnika je i koeficijent uskladištenja (S)koji predstavlja YROXPHQ YRGH NRMX üH RWSXVWLWL MHGLQLþQL YROXPHQ YRGRQRVQLND pod
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Koeficijent uskladištenja (storage coeff) odnosi se na ukupnu debljinu saturiranog
YRGRQRVQRJKRUL]RQWDãWR]QDþLGDMHMHGQDNXPQRãNXVSHFLILþQHYULMHGQRVWL 6s ) i debljine
horizonta (m) [3].
S = Ss · m [ / ](2)

1HNROLNR MH PHWRGD SR]QDWR ]D RGUHÿLYDQMH vodopropusnosti kao što su pokusno crpljenje,(metoda Lefranc) i metode temeljene na empirijskim formulama uz uporabu podataka ogranulonetrijskom sastavu. .RMD üH VH PHWRGD XSRWULMHELWL RYLVL R FLOMX LVWUDåLYDQMD i
raspoloživim WHKQLþNLP VUHGVWYLPD 0HWRGD SRNXVQRJ FUSOMHQMD MH QDMWRþQLMD PHWRGD Dtemelji se na crpljenju vode iz zdenca kojemu je filtarski dio u vodonosnom sloju koji se želiWHVWLUDWLRGUHÿHQLPNDSDFLWHWRPWLMHNRPRGUHÿHQRJa vremena. Pokusno crpljenje se provodi
glede dva osnova cilja: (a) oGUHÿLYDQMD KLGUDXOLþNLK Narakteristika vodonosnog sloja tetestiranja vodonosnog sloja i dobivanje podataka o izdašnosti zdenca i (b) o sniženjima u]GHQFXQDRVQRYXNRMLKVHRGUHÿXMHNDSDFLWHW]GHQFDLdozvoljeno sniženje kod eksploatacije[4]. Osnova probnog crpljenja sastoji se u opažanju sniženja (pada) vode (w) u zdencu,
odnosno na jednom ili više kontrolnih pijezometara raznih udaljenosti (r) od zdenca. Sniženje
SDG  YRGH PRåH VH SURXþDYDWL NRQVWDntim WHVWRP QHPD SURPMHQH FUSQH NROLþLQH WLMHNRP
vremena) ili „step“ testom, dakle u koracima FUSQDNROLþLQDPLMHQMD se tijekom vremena) [7].

3.
PRIMJER ZDENCA ZA KLIMATIZACIJU STUDENTSKOG RESTORANA UVARAŽDINU
3.1. Probno crpljenje pijezometra
U svrhu dobivanja parametara vodonosnika izbušen je istražno – eksploatacijski zdenac uLVWRþQRP GLMHOX JUDGD 9DUDåGLQD Prikupljeni podaci YULMHPH RG SRþHWND FUSOMHQMD ilizavrãHWNDXVOXþDMXRSRUDYND, udaljenost kontrolnog zdenca i sniženje razine vode izmjerene u
NRQWUROQRP ]GHQFX  SULND]XMX VH JUDILþNL QD dijagramima. Iz njih se tada mogu izvesti
raznovrsni KLGUDXOLþNLSDUDPHWULYRGRQRVQRJa sloja.
Istražnim bušenjem, geološkom prospekcijom do dubine 1 (m) identificirani su prašinastoglinoviti šljunci dok u dubini zaliježu šljunkoviti i šljunkovito-pjeskoviti vodonosni
VHGLPHQWL7HKQLþNDNRQVWUXNFLMD zdenaca, dubine 16 (m)YHüLPVYRMLPGLMHORPQDOD]LVHXãOMXQNRYLWLPVHGLPHQWLPDXNRMLPDVH]DKYDüDMX]QDþDMQLMHNROLþLQHSRG]HPQHYRGHZdenac
je osvajan metodom ispuhivanja (airlift-a),]XWYUÿHQRJJHRORãNRJSURILODWHODERUDWRULMVNLK
granulometrijskih analiza vidljivo je kako su vodopropusnije formacije vodonosQLNDXWYUÿHQH
gotovo od razine terena, dok aluvijalni šljunak zaliježe od 1,0 m dubine. Šljunak odgovara
dobro graduiranim šljuncima (GW), s granulometrijskim koeficijentom vodopropusnosti k >150 (m/dan). [6] 6SHFLILþQLNDSDFLWHWQDMþHãüHMHMHGLQLSRND]DWHOML]GDãQRVWLYRGRQRVQRJVORMDLRELþQRVHL]UDþXQDYDL]SUREQRJFUSOMenja za vrijeme izrade i opremanja zdenca. Prihvatljivo
je dD VH VSHFLILþQL NDSDFLWHW RGUHGL nakon 24- VDWQRJ FUSOMHQMD 0HÿXWLP, u praksi izrada
zdenca pa tako i probno crpljenje ne traju duže od nekoliko sati [5]. Kod ovakvih premisa
PRJXüHMHQDSLVDWLL]UD]]DNROLþLQu crpljenja:

460

S. Strelec, M. Golub, K. Grabar, M. Marciuš: 2GUHÿLYDQMHSDUDPHWDUDYRGRQRVQLND«

q

Q
s

0,022
0,51

>

0,043 m 3 s m@- (cca. 10 sati)(3)

Tablica 1. 'LQDPLþNDUD]LQDUD]LQHSRG]HPQHYRGHXSLMH]RPHWUX6&SULOLNRP.2167$17
TESTA"OZNAKAZDENCAVWDWLþNDUD]LQD
RPV
08.07.2013

stalna crpnaNROLþLQD

eksploatacijski
zdenacSC13,32 m22,0 l/s

GLQDPLþNDUD]LQDSRG]HPQHYRGHDPV(nakon cca. 10 sati)

3,83 msniženje(s)0,51 m-HGDQGLRSRGDWDND R YRGRQRVQRP VORMX PRJXüHMHGRELWLVDPRQDEDzi analiza podataka iz
mjernih pijezometara, dok se drugi SRGDFL PRJX SRVWLüL iz podataka na samom zdencu.
3RNXVQR FUSOMHQMH X VWYDUL þLQi ispitivanje vodonosnog sloja odnosno karakteristike samog
zdenca [4]. Sukladno tome, ukupnR RVWYDUHQR VQLåHQMH UD]LQH HNVSORDWLUDQRJD ]GHQFD þLQH
VOLMHGHüH komponente:sw = BQ + CQ2(4)

gdje su: ‫ݏ‬௪ - sniženje u zdencu [m], ܳ NROLþLQD YRGH NRMRP VH ]GHQDF FUSL >P3/s],‫ ܤ‬parametar otpora sloja [s/m2] i ‫ ܥ‬parametar otpora zdencu [s2/m5].
5MHãHQMHMHGQDGåEHVQLåHQMDGRELYHQRMHJUDILþNLPSXWHPSUHPD-DFRERYRMPHWRGL (slika 2).
9ULMHGQRVWL GLQDPLþNH UD]LQH SRG]HPQH YRGH ]D UD]OLþLWH NDSDFLWHWe crpke prikazane su
tabelarno (tablica 1).
Komponenta BQ predstavlja gubitak u vodonosnom sloju u kojemu je sniženje uzrokovano
otporom laminarnog toka u samom vodonosnom sloju, a komponenta CQ2 predstavlja gubitaku zdencu uzrokovanim turbulentnim tokom vode u filtarskom dijelu konstrukcije zdenca idijelu vodonosnog sloja (slika 1) [4].

Slika 1. Prikaz sniženja na crpljenom zdencu
U tablici 2 L]UDþXQDWH su ]DUD]OLþLWHNROLþLQHFUSOMHQMDYULMHGQRVWLVSHFLILþQRJVQLåHQMDNRMHVXSUHPD-DFRERYRMPHWRGLSRWUHEQH]DL]UDþXQDYDQMHSDUDPHWDUDRWSRUDVORMD(‫ )ܤ‬i otpora

Energy and the Environment (2016) 457-466

461

zdenca (‫ )ܥ‬što je vidljivo na slici 2. 9ULMHGQRVW]D%GRELYHQDMHNDRRGVMHþDNQDRUGLQDWLL
iznosi B = 22,25 s/m2, dok je vrijednost za parametar C dobivena iz omjera C = '(s/Q) / ' Q= 51,41 s2/m5.
Tablica 2. 0MHUHQMDGLQDPLþNHUD]LQHSRG]HPQHYRGHQDSLMH]RPHWUX6&X9DUDåGLQX
Rezultat testa crpljenja u koracima (STEP TEST) "SC1"PoznavanMHP SDUDPHWDUD % L & PRåH VH L]UDþXQDWL VQLåHQMH X ]GHQFX ]D ELOR NRMX NROLþLQX
FUSOMHQMD %XGXüL GD SDUDPHWDU & QLMH RYLVDQ RG YUHPHQD WUDMDQMD FUSOMHQMD NRPSRQHQWD
VQLåHQMDXVOLMHGRWSRUDX]GHQFXNRULVWLVH]DRGUHÿLYDQMHXNXSQRJVQLåHQMDX]GHQFXDNR se
SUHWKRGQRRGUHGLWHRUHWVNRVQLåHQMH]DRGUHÿHQLNDSDFLWHWFUSOMHQMD [3] .
Jednadžba sniženja razine zdenca tada glasi:s

22,25  Q  51,41  Q(5)'REURSURMHNWLUDQMHILOWDUVNRJGLMHODNRQVWUXNFLMHEXQDUDPRåHXYHüRMmjeri smanjiti gubitke,
no ne može ih nikad potpuno HOLPLQLUDWL VOLND 2GQRVL]PHÿXQHOLQHDUQRJSDUDPHWUD
otpora zdenca (C) i konstrukcijskog stanja zdenca dan je prema Waltonu u tablici 3.

6OLND,]UDþXQSDUDPHWDUDJXELWDNDSUHPD-DFRERYRMmetodi, zdenac "SC1".

462

S. Strelec, M. Golub, K. Grabar, M. Marciuš: 2GUHÿLYDQMHSDUDPHWDUDYRGRQRVQLND«

Slika 3: Gubitci u eksploatacijskom zdencu i vodonosnom sloju "SC1".
Tablica 3. Odnos parametra C i stanja bunara
Koeficijent gubitaka na zdencu
C (min2/m5)<0,50,5 do 1.0
1.0 do 4.0> 4.0

Stanje zdenca
Dobro projektiran i osvojen
Blago pogoršano zbog kolmatacije
Ozbiljno pogoršano zbog kolmatacije,]DþHSOMHQMD
Teško se regenerira na prvobitnu izdašnost

8 RYRP UDGX MH REUDÿHQR SUREQR FUSOMHQMH V FLOMHP RGUHÿLYDQMD MHGQDGåEH LVWUDåQReksploatacijskog zdenca "SC1", te optimalnog režima crpljenja, hidrogeoloških parametaravodonosnika s analizom potrebnih XWMHFDMDQDRNROQHJUDÿHYLQHSRVWRMHüHYRGR]DKYDWH kao iprojektiranje crpnih zdenaca u drugoj fazi izgradnje studentskog doma. Crpljenje zdenca
L]YHGHQRMHXNRUDFLPDVDWULUD]OLþLWDNDSDFLWHWDFUSOMHQMDWHNRQWLQXLUDQRXWUDMDQMXRGFFD
10 sati. Maksimalno sniženje razine vode u crpnom zdencu pri kapacitetu od q=22,0 (l/s)
iznosi 51,0 (cm), što ukazuje na povoljne hidrogeološke karakteristike vodonosnika i dobro
izvedenu konstrukciju zdenca. Prilikom probnog crpljenja sniženje u eksploatacijskom]GHQFXSRND]XMHPLQLPDOQDNROHEDQMDGLQDPLþNHUD]LQHYRGHþLPHVHSRVWLåHUHODWLYQREU]R
ravnotežno stanje crpljene koOLþLQHLGRWRND iz vodonosnika [6].

3.2. 2GUHÿLYDQMHKLGURJHRORãNLKSRND]DWHOMDYRGRQRVQLND+LGURJHRORãNL SDUDPHWUL YRGRQRVQLND RGUHÿHQL VX L] SURYHGHQRJ SUREQRJ FUSOMHQMD Vopažanjem sniženja razine podzemne vode na samom crpnom zdencu primjenom metodesuperpozicije za rješenje prema metodi Theis a uz korekciju Jacob-a [7].

Energy and the Environment (2016) 457-466

‫=ݏ‬

463

ܳ
‫ݎ‬ଶ
ቆെ0,5772 െ lnቇ4ߨ ή ܶ
4ήܶή‫ݐ‬(6)

Tablica 4. Hidrogeološki parametri vodonosnika dobiveni probnim crpljenjem.
proba
probnocrpljenje*

KLGUDXOLþNDYRGOMLYRVW– K[m/dan]koeficijent vodoprovodnosti(transmisivnost) – T [m2/dan]koeficijent uskladištenja - S

210

4200

0,003

*Podaci za eksploatacijski zdenac "SC1" - RECOVERY TEST (mjerodavno)+LGURJHRORãNLSDUDPHWULYRGRQRVQLNDRGUHÿHQLVXL]SURYHGHQRJ povrata razine (recovery) na
SRþHWQX UD]LQX RSDåDQRJ QD FUSOMHQRP SLMH]RPHWUX SULPMHQRP PHWRGH VXSHUSR]LFLMH ]D
rješenje "Agarwal + Papadopulos & Cooper" u otvorenom vodonosniku (tablica 4). Metoda
LOXVWULUD SUHWSRVWDYNX GD XJUDÿHQL ILOWDU  ]DKYDüD FLMHOX YLVLQX YRGRQRVQLND $QDOL]D MH
SURYHGHQD XSRWUHERP UDþXQDOQRJ SURJUDPD Ä$TXLIHU7HVW 3UR ³ SURL]YRÿDþD Ä:DWHUORR
Hydrogeologic, Inc. 2004“ [1].
3ULOLNRP NRQVWDQWQRJ FUSOMHQMD XMHGQDþHQRP NROLþLQRP 4   (l/s) u trajanju od cca. 10
VDWL VQLåHQMH X HNVSORDWDFLMVNRP ]GHQFX SRND]XMH PLQLPDOQR NROHEDQMH GLQDPLþNH UD]LQH
YRGH RGQRVQR YUOR EU]R SRVWLåH VH UDYQRWHåQR VWDQMH FUSOMHQH NROLþLQH L SULKUDQH iz
vodonosnika (slika 5).

Slike 4 i 5. Sniženja na zdencu "SC1" za „konstant test“

464

S. Strelec, M. Golub, K. Grabar, M. Marciuš: 2GUHÿLYDQMHSDUDPHWDUDYRGRQRVQLND«

4. RADIJUS UTJECAJA CRPLJENJA
6XNODGQR XWYUÿHQLP NDUDNWHULVWLNDPD YRGRQRVQLND SUHYHGHQH VX VOLMHGHüH DQDOL]H XWMHFDMD
SURMHNWLUDQLKFUSQLKNROLþLQDQDVQLåHQMHUD]LQHSRG]HPQHYRGH
1. Radijus utjecaja sniženja razine podzemne vode za projektirani maksimalni
eksploatacijski režim crpljenja zdenca "SC1" qmax = 5,0 (l/s), te uvjet 10-satnog
neprekidnog crpljenja prikazano je na slici 6.
2. Na lokaciji studentskog centra, u GUXJRMID]LSUHGYLÿDVHizgradnja studentskog doma,]DþLMHSRWUHEHNOLPDWL]DFLMHüHVH]DKYDWLWLGRGDWQLKTmax = 25 (l/s).
Istražno-eksploatacijski zdenac SC1, može se prenamijeniti u eksploatacijski zdenac za
potrebe klimatizacije studentskog restorana. Kapacitet crpljenja izvedenog zdenca u
ODPLQDUQLPXYMHWLPDWHþHQMDL]QRVLTmax = 20 (l/s). Radijus utjecaja sniženja razine podzemne
YRGH]DSURMHNWLUDQXPDNVLPDOQXHNVSORDWDFLMVNXNROLþLQXT (l/s) i neprekidno crpljenje(10 h), je minimalan i iznosi s = 5 (cm) na udaljenosti 30 (m). Zbog eliminacije inetrferencije
izvedenog eksploatacijskog zdenca "SC1" i planirane dodatne NROLþLQH podzemne vode za
potrebe studentskog doma u fazi II. od oko q = 25 (l/s)SUHGODåHVHXJUDGQMDGYLMXPHÿXVREQR
razmaknutih eksploatacijskih zdenaca oznaka "SC2" i "SC3" jednakih konstruktivnih
karakteristika kao i "SC1". Upojni zdenci nalazili bi se u utjecajnoj zoni eksploatacijskog
crpljenja, DRGPDNQXWLPDNVLPDOQRVXNODGQRYHOLþLQLSDUFHOH. Kod toga smjer toka podzemne
vode povoljan je u odnosu na položaj zdenaca u omjeru eksploatacija/upoj. Minimalni razmak
SC1 i U1 iznos 47 (m)GRN]DSUHGYLÿHQHUD]PDNELELRSC3 i U3 = 56 (m) [6].

Energy and the Environment (2016) 457-466

465

Slika 6. Utjecaj na sniženja razine podzemne vode zbog crpljenja istražno-eksploatacijskog
zdenaca SC1, WHEXGXüLK6&L6&PDNVLPDOQRP FUSQRP NROLþLQRP TPD[    
12,5 = 30 l/s. Stacionarna razina podzemne vode za uvjet 10 satnog neprekidnog crpljenja.
5.

=$./-8ý$.

Dizalice topline u sistemu bunarske eksploatacije podzemne vode su pouzdan i HILNDVDQQDþLQKODÿHQMDLJULMDQMDWHPRJXELWLNRULãWHQHXãLURNRPVSHNWUXSULPMHQH9DUDåGLQVNRSRGUXþMH
SULURGQR MH ERJDWR SRG]HPQRP YRGRP WH VH SRWLþH XSRWUHED QDYHGHQRJ  NOLPDWL]DFLMVNRJ
sistema. Dobrim projektiranjem može se u potpunosti iskoristiti podzemna voda kao
REQRYOMLYLL]YRUHQHUJLMHWHWLPHGXJRURþQRRVWYDULWLL]QDWQHXãWHGHXQDWRþSRþHWnim visokim
financijskim ulaganjima.
&USOMHQMHPRGUHÿHQHNROLþLQHYRGHL]]GHQFDLPMHUHQMHPVQLåHQMDUD]LQDSRG]HPQHYRGHX
]GHQFXLSULSDGDMXüLPSLMH]RPHWULPDRGUHÿXMXVHKLGUDXOLþNHNDUDNWHULVWLNHYRGRQRVQRJVORMD
Kod bušenja istražnih bušotina za zdenac iz pijezometra se uzimaju uzorci iz svake nove
geološke formacije. 3RVHEQD SDåQMD RGQRVL VH QD YHOLþLQX ]UQD SRMHGLQLK PDWHULMDOD ,] WLK
podataka razabiUH VH KLGUDXOLþND SURYRGOMLYRVW VORMHYD NRML WYRUH vodonosni sloj. Broj
pokusnih crpljenja, konstruktivne karakteristike zdenaca i zahtjevi korisnika ishodišne su
premise za primjenu metoda koje su ovdje predstavljene.
7HPHOMHPYHüSURMHNWLUDQRJ zdenca oznake "SC1", odnosno rezultatima probnog crpljenja za
definirane hidrogeološke karakteristike vodonosnika, prišlo bi se uskoro projektiranju
dodatnih eksploatacijskih zdenaca za potrebe klimatizacije studentskog doma planiranog za
izgradnju u fazi II, dok bi se zdenac "SC1" prenamijenio u eksploatacijski LVNOMXþLYR za
potrebe klimatizacije studentskog restorana.
0RåH VH ]DNOMXþLWL GD se istražnim radovima X SRGUXþMX LQåHQMHUVWYD RNROLãD D NRMHQDVWDYQLPSODQRPLSURJUDPRPREXKYDüD*HRWHKQLþNLIDNXOWHW6YHXþLOLãWDX=DJUHEX, mogu
znanstveno i VWUXþQR YDORUL]LUDWL SRG]HPQH vode kao obnovljivi izvor energije u sustavu
dizalica topline, kako je ovim radom ilustrirano.

Literatura:[1] AQTESOLV for Windows, developed by Glenn M. Duffield, HydroSOLVE Inc.
[2] %DþDQL$9ODKRYLü7: Hidrogeologija primjena u graditeljstvu6YHXþLOLãWHX6SOLWXIDNXOWHWJUDÿHYLQVUVWYDDUKLWHNWXUHLJHRGH]LMH6SOLW
[3] Grdjan, D.7HRULMDILOWUDFLMHSRG]HPQLKYRGDLSULPMHQD VNULSWD *HRWHKQLþNL)DNXOWHWVaUDåGLQ6YHXþLOLãWDX=DJUHEX9DUDåGLQ
[4] 0LOHWLü 3 0LOHWLü +HLQULFK 0 : Uvod u kvantitativnu hidrogeologiju, RGN-FakultetVYHXþLOLãWDX=DJUHEXVaraždin 1981.
[5] Pollak, Z. +LGURJHRORJLMD ]D JUDÿHYLQDUH *UDÿHYLQVNL IDNXOWHW 6YHXþLOLãWD X =DJUHEX
Zagreb 1995.

466

S. Strelec, M. Golub, K. Grabar, M. Marciuš: 2GUHÿLYDQMHSDUDPHWDUDYRGRQRVQLND«[6] 6WUHOHF 6 *UDEDU . )LOLSRYLü $ ,]YMHãüH R L]YHGEL L SUREQRP FUSOMHQMX LVWUDåQReksploatacijskog zdenca "SC1" u sustavu dizalica topline za potrebe studentskog restorana idoma u Varaždinu, SPP d.o.o., Varaždin, 2013.
[7] Todd K. , Ground water hydrology, John Wiley & Sons, Inc., USA, 1959.

AQUIFER PARAMETERS FOR THE PURPOSES OF HEATING PUMPSYSTEM
Summary: Water as a renewable source of energy is efficient and ecology acceptableworking media for heating and acclimatization of industrial, commercial, living and similar
objects. Varaždin territory is reach with underground water. Relatively stable temperature ofunderground water through the year that is between +12/ +15 °C is independent of climatechange on the surface so it represents a reliable heating source. Relatively high usability ofheating pumps we can thank to shallow position of a Varaždin aquifer. Purpose of this paper
is to illustrate methodological procedure at the example of projecting heating pump well forStudent restaurant in Varaždin .
Keywords : water, aquifer, heat pumps, hydraulic conductivity, transmissivity

Energy and the Environment (2016) 467-482

467

EXERGY AS MEASURE OF SUSTAINABILITY OF ENERGY SYSTEMProf Dr. Peter Novak
Faculty for Technology and System, Novo mesto, Slovenia, +38641678120,
peter.novak@energotech.si
Abstract: Do we need energy or exergy? Amount of exergy in energy carriers is very different
and price includes only the value of quantity and not the quality of energy. Exergy is measurefor quality of energy, because the only part of energy available to do work is exergy. For
different purposes we need energy with different amount of exergy: for heating and coolingenergy mixture between small amount of the exergy and large part anergy is needed.
Transition to sustainable energy system, without GHG emissions, based on RE, open thequestions how to evaluate exergy from solar energy. Solar energy in all form (irradiation,water flows, wind, and biomass) consists from nearly 100% of exergy. Solar energy is for
free, conversion systems are not. To exploit at maximum the present infrastructure there iscommon agreement that we need sustainable energy system with four main energy carriers:
electricity, gaseous, liquid and solid fuels.

Our vision is the new Sustainable Energy System (SES) based on the biomass carbon
recycling using solar and planetary energy for electricity and hydrogen production. SES isbased on the existing infrastructure and known chemical processes. With regards toavailability of renewable energy resources (RES) it is unrestricted in comparison to present
fossil fuels use. The proposed SES consists of the three main energy carriers: electricity,synthetic methane (CH4) and synthetic methanol (CH3OH).
Key words: energy, exergy, evaluation, energy system, sustainability

1. INTRODUCTION
In last year’s EU has adopted many regulations and decision with regard energy management[1] including EU Council decision on 40% GHG reduction and 27% RE in FE until 2030 andParis Agreement. Common goal of this regulation is to change present energy system tosustainable one. In Energy Union document is one of most important statement: “To reachour goal, we have to move away from an economy driven by fossil fuels, an economy whereenergy is based on a centralized, supply-side approach and which relies on old technologies
and outdated business models.”[2]There are different ways and timing to achieve proposed goals. One possibility is to integrate
all those activities in to Circular Economy [3]. What should be a “sustainable development”
in the case of energy supply, distribution and use? How we can measure the sustainability ofenergy system?

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Can we have a sustainable energy system with circulation of organic carbon, going away fromexpression low carbon society to carbon recycling economy?
We presented one of possible solution including tools for evaluation of their sustainability.
Based on previous research results and proposals [4, 5, 6, 7, 8) we find, that one of the best
criterion for measure the sustainability of energy system is exergy approach.
Normally we are selling fuels, electricity, heat and cold. Amount of exergy in these energy
carriers is very different and in theirs prices is included only the quantity and not the qualityof energy. This means the value or amount of exergy in it is not always included in the price.
But in real life we need energy with different amount of exergy: for heating and coolingenergy mixture between small amount of the exergy and large part anergy is needed. For workand lighting the 100% of exergy is needed.
Transition to sustainable energy system, without GHG emissions, based on RE, open thequestions how to evaluate exergy from solar energy. How important are the irreversibility’s of
our processes in solar energy conversion system. Answer is only possible if we know what
type of processes will be used. There is common agreement that we need in practicesustainable energy system with four main energy carriers: electricity, gaseous, liquid and solid
fuels to exploit at maximum the present infrastructure.
2. EXERGY
The word “exergy” was introduced by Zoran Rant [9] and present common definition is:“exergy of a system in a certain environment is the amount of mechanical work that can be
maximally extracted from the system in this environment”.
According Rant the energy W is a sum of exergy E and anergy A (~energy of environment)
W=E+A

1

Exergy is a measure of quality of energy. Energy is always conserved and can neither be
produced nor consumed. Exergy can be very easily converted in anergy troughirreversibility’s in the conversion processes.
Our attention will be given to the exergy of renewable sources of energy as the core of futureenergy system. With regard to energy carriers, exergy in the system can be also quantified
into several different type of exergy, such as: chemical, nuclear, physical, potential (g –gravitational constant, Z-height above the lowest level in environment), kinetic (v-velocity)and radiation exergy.
E = Ech + Enu + Eph+ v2/2 + gZ + Er

2

In real energy conversion processes we always have a loss of exergy. This mean that energy
can be balanced but the exergy in closed system cannot be. Exergy destruction or vanishing of
exergy because of irreversibility’s is natural phenomena which can be to some extent
controlled by design of our energy conversion equipment. Exergy efficiency is therefore aquality measure of our processes. Quotient between output exergy Eout and input exergy Ein isstandard definition of exergy efficiency.
ாȘex = ೚ೠ೟ா೔೙3

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Using standard data for exergy content in different energy carrier and embedded exergy inmaterials used in practice [10] we can calculated this efficiency. Beside the exergy efficiency
is important also to analyse the exergy destruction in processes during the time.
Exergy analysis can clearly indicate the locations of energy degradation in a process that may
lead to improved operation or technology. It can also quantify the heat quality in a rejected
streams. The main aim of exergy analysis is to identify the causes of irreversibilitie's and to
calculate the true magnitudes of exergy losses.
2.1 Exergy, sustainability and resource accounting
Resource “consumption and /or depletion” cannot be evaluated only according to mass andenergy balance, because they not disappear. Using the exergy as measure of resource
depletion we can evaluate quality of our processes taking into account the conservation ofmass and energy.
Exergy is close connected with sustainability. Sustainable development means les exergy
destruction or depletion. Circular economy promoted in the last years is policy to minimize
the resource destruction, to minimize the thermodynamics irreversibility’s with higher exergy
efficiency. To push the circular economy on the top of society development we need a serious
exergy analysis of present technologies and economic patterns.
Millennium goal “living well within the limits of the planet”, set out in EU can be reduced
to conclusions that any citizen have a minimum of sustainable commodities as: exergy or/and
adequate mixture anergy-exergy, food (secondary type of exergy), drinking water, home andjobs with salary able to cover cost for those commodity.
The exergy destruction during a process is proportional to the entropy created due toirreversibilities associated with the process. Exergy analysis [8] is a methodology that uses
the conservation of energy principle (embodied in the first law of thermodynamics) together
with non-conservation of entropy principle (embodied in the second law) for the analysis,design and improvement of energy and other systems.
The exergy method is useful for improving the efficiency of fossil and renewable energyresource use, for quantification of the destruction locations, types and magnitudes of wastes
and losses.
LCEA (Life Cycle Exergy Analysis) can be used as a method to quantify depletion of natural
resources and to assess the efficiency of natural resource used. It can be used for energy
system with fossil and renewable sources of energy, for different materials and in broader
sense for exergy of societies. In our case LCEA will be used to analyse sustainable energy
system, based on organic carbon circulation in future circular economy.
2.2. Life Cycle Exergy Analysis of Renewable Energy
The use of exergy in life cycle assessments (ELCA or LCEA) has been suggested by manydifferent researchers since the late 1990s. Based on work of Davidsson using LCEA for windenergy system analysis [7], where the renewable resources are separated from non-renewable,
we accept same methodology.
Natural resources are classified as natural flows and stocks. Stocks are then divided into
deposits (dead stocks) and funds (living stocks). Natural flows and funds are renewable while
deposits are non-renewable. All in- and outflows during the life cycle of production, use anddisposal or recycling, are then considered as exergy power over time. The direct exergy

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P. Novak: Exergy as measure of sustainability of energy system

input (e.g. solar, water, wind) of renewable sources can be disregarded since they
represent a natural flow and are therefore renewable. If not used natural exergy flows
will be wasted and lost. Non-sustainable use of exergy funds, like clearing of forests in a nonsustainable fashion and use of exergy deposits are regarded as non-renewable resources.
The simple presentation of LCEA is given in [7] and is shown on the Figures 1, 2 and 3.

Figure 1: Exergy flows from sun to society [6]The life cycle analysis of a system usually consists of three separate stages with different
exergy flows that are analogous to the three steps in the life cycle of a product in an LCA:
1- construction phase, 2 - operational phase and 3 - clean up phase.
During the construction phase, exergy is spent and none is created besides eventual
byproducts. The exergy used for construction combined with the exergy used for maintenanceand clean up make up the total indirect exergy. It is also very important at what moment intime the exergy is needed (storage problem at RES).
A fossil fuels power plant takes the exergy from the fuels used during the operational phase.
The exergy of output electricity will always be lower than the exergy of the fuels used. A
power plant using fossil fuels can therefore never be sustainable since it uses more exergy
than it generates. The exergy flow over the lifetime of a fossil fuel power plant is illustrated in
Figure 2.
Power plant using the renewable energy sources for production of electricity, on the other
hand, convert the natural flows exergy to a useable form of exergy. As an example, a PV
panel use solar exergy to convert it into electricity (same do the wind generators).
During the operational phase it will hopefully produce more exergy than the indirect exergy
needed during the life cycle. The exergy flow over the life cycle of a renewable energy isillustrated in Figure 3. The fact that the exergy utilized during the operational phase of the life
cycle comes from a renewable source does however not automatically mean that it issustainable. Some solar heat conversion technologies using high exergy demanded materials
can actually use more indirect exergy than it will ever generate during its life cycle (somesolar collector design). With LCEA method is possible to investigate this kind of issues.

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Figure 2. Exergy flow diagram for LCEA of a power plant using non-renewable fuels [6].

Figure 3: Exergy flow diagram for LCEA of a renewable energy power plant [6].
LCEA method enable us also to analyze the influence of intermittency of RES taking into
account the power factor CP and capacity factor CF by producing heat and electricity. In thiscontest we have to include storage systems, what influence the exergy needed in theconstruction phase.
The exergy (energy) conversion and use is usually presented either as exergy payback time
(EPBT) or exergy return of invested exergy (EROI). The way the energy is compared can be a
bit different between different assessments. In case of exergy produced from RES the EPBT
should be defined as:
EPBT =

௖௨௠௨௟௔௧௜௩௘ ௘௫௘௥௚௬ ௚௘௡௘௥௔௧௘ௗ

4௖௨௠௨௟௔௧௜௩௘ ௘௫௘௥௚௬ ௥௘௤௨௜௥௘ௗ

And forEROI =

௟௜௙௘ ௧௜௠௘ ௘௫௘௥௚௬ ௣௥௢ௗ௨௖௘ௗ
௖௨௠௨௟௔௧௜௩௘ ௘௫௘௥௚௬ ௥௘௤௨௜௥௘ௗ

=௟௜௙௘ ௧௜௠௘
ா௉஻்5

The use of EPBT and EROI defined in (4) are fairly good indicators that an exergy producing
process actually produces more exergy than it use during its life cycle, without regard ofsource of exergy required.
Cumulative exergy generated includes exergy generated during the operation time.
If the EPBT should be used also for the presumptions of the costs of exergy (in practice as
cost of energy), the MJ or kWh of exergy must be multiplied with agreed costs in time ofanalysis or agreed costs changes during the life cycle time.

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P. Novak: Exergy as measure of sustainability of energy system

Cumulative exergy required includes exergy of construction materials, maintenance, exergy
needed for destruction, minus exergy available because of recycling of some materials.
The value of EPBT for fossil fuels is always less than 1 (un-sustainable).Value of EPBT over1 means sustainable conversion of exergy (energy). Break-even point between sustainable
and un-sustainable energy device is EROI value of 1 (Figure 4.)

Figure 4. Exergy balance for any production scheme

3. THE EXERGY OF RENEWABLE ENERGY
Renewable energy forms considered in our study are: solar irradiation on the Earth surface,wind, water flows, waves, and planetary (geothermal, tidal) energy. Biomass is accumulated
solar energy and is taken as reserves. In literature are given different data about global
resources of RE on the Earth surface. From [11] we accept the following data (Table 1):

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Table 1: Renewable exergy (energy) resources on the Planet Earth with present conversion
technologies in electricity [11, 12, and 13]
Resource in TWex =TWh/8760 h/y

TWex
ideal

TWex
TWex
Technical possible Present delivery
as electricity
Solar irradiation
11500
580 ÷ 1640
0,00176Wind
1700
40 ÷ 170
0,02
Water flows
1,9
1,6 ÷1,9
0,32
Waves
2,7
0,5 ÷ 2,70,000002
Geothermal- shallow
45
0,07 ÷ 0,2
0,0065
Geothermal - deep
55
0,035 ÷ 2
0,0065Tidal
3,7
0,02 ÷ 0,8
0,00006
Biomass (dry)33,45,8 ÷11,7
0,039
Total
13.341,7 628,025÷1829,3
0,387322
Present needs of TPES (2013)
17,79
2,5877
Zamfirescu and Dincer [5] shows, that ideal conversion effectiveness of total normal solar
radiation is depended on time and also from the relation of scattering in the atmosphere
2EWDLQHGYDOXHRIȘex,S are between 0, 82 to 0, 95. From real solar irradiation data for Italy
Neri find out [6] the average exergy efficiency of Șex,S,IT = 0,839. Some other authors [4] findout that we have to include the entropy production at solar exergy conversion at device, if thetemperature mismatch between the incoming radiation temperature and the temperature of
the surface of the device (similar to entropy production in heat transfer). The entropy
production can approach zero if the receiver surface approaches the average thermodynamic
temperature of the incoming radiation. For South European region (latitude 37 to 47°) we
can use the relation for exergy loss from incoming solar energy to the surface level Șex
developed from [6; diagram Figure 5]:Șex, S = 0,820 + 1,76.10-5. (Etot – 4500)

6Where Etot = ED + Ed [MJ/m2/year] is sum of yearly direct (D) and diffuse (d) radiation thatreaches a horizontal surface on analyzed location. Equation (6) is valid for Etot = 4500 to 7000
MJ/m2/year.
Wind and water flow are the secondary and wave are the tertiary exergy form of solar
irradiation. Waves are the result of wind exergy transfer on the water surface because of shear
forces between air flow and water [12]. The available exergy is time and location depended
and calculation can be done only on the basis of measured data in given period of time,normal more than 2 typical meteorological years. Yearly data of wind velocity distribution
and for yearly water flow distribution at given height differences are input to calculate theavailable theoretical exergy potential on the given location.

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P. Novak: Exergy as measure of sustainability of energy system

4. SUSTAINABLE ENERGY SYSTEM
4.1 Concept
Different sustainable energy system has been proposed using only water, wind and solar withor without geothermal, with hydrogen or methanol as a basic energy carriers [11]. Sustainableenergy system (SES) as proposed in [13] consists of the three main renewable exergy (energy)
carriers, needed in any settlement: renewable electricity, gas (synthesized methane CH4; smethane), liquid (synthesized methanol CH3OH; s-methanol) and as fourth solid fuels frombiomass (less important in developed countries). The methane and methanol are the only
exergy carriers in nature with one carbon (in our case used from biomass) chemicallyconnected with four hydrogen’s. Necessary hydrogen and oxygen will be produced withelectrolysis of water or other processes, equalizing the sun daily and yearly irradiation
variations). They represent the chemical storage of solar exergy (like do the nature inbiomass) with efficiency close to the storage of atmospheric carbon in biomass.
To these three exergy carriers we can add transitional hybrid fuels: ethanol (C2H5OH)
dimethyl-ether (CH3OCH3), consisting of two carbons, six hydrogen and one oxygen atoms
and synthetic diesel, produced with catalytic de-polymerization process from biomass restsand organic waste. As fourth energy carrier - solid fuels in SES we propose to use, if
necessary, only the wood log.
In this way, natural circle of carbon dioxide and water is closed. Proposed SES has no GHG
emissions, because CO2 and water are recycled in natural photosynthesis process and vapor
cycle. We muss stress out that these exergy carriers can be used using the existing energy
conversion equipment’s and infrastructure in industry, buildings and transportation.
4.2. Characteristics of sustainable (renewable) energy system - SES
To fulfil the daily energy needs of different consumers, the new energy system has toresponse to the following six main requirements:
1. Source of exergy must be inexhaustible, available everywhere on the planet;
2. Zero emission of GHG by burning of the new fuels;
3. Available any place and any time (in all present forms of energy: solid, liquid,gaseous fuels and electricity);
4. Must be compatible with existing infrastructure with minor adaptation;
5. In transition period the present energy system and SES has to work in parallelwith no interference (coexistence of two system);
6. Should be competitive with fossil fuels system if all external — none
acknowledged environmental costs will be included in their exergy carriers’ price.
4.3. How the proposed SES comply with the six requirements?
1- Primary exergy sources
First primary exergy source in the system is solar energy (including direct irradiation and all
secondary forms of solar exergy: biomass, water, wind, waves), second is planetary energy(geothermal heat and tide). This exergy sources are inexhaustible, generally available for the
lifetime of mankind (see the data in T-2 in [13]). Solar irradiation on the planet is about

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174.103 TW. In 2013 TPES (Total Primary Energy Supply) on the planet was only 17,98 TW.
Converting only ‫׽‬0.01033% of solar irradiation we can cover all present exergy needs forworld population.
2- No emission of GHG
Burning product of synthesized (s- ) methane and methanol are water and CO2. Water isnormally circulated in the atmosphere. Carbon dioxide is released back into the atmosphereand is used for plants growth (200 Gt/y).
Intermittent solar radiation is chemically stored in two chemicals (methane and methanol)
which can be used as standard gaseous and liquid fuels. At the same time they can be used for
production of electricity during winter and night time. Part of biomass (in form of log,
exceptionally as pellets) can be used as solid fuels in transition period.
3- These four energy carriers can be used any time in any place
Renewable electricity, s-methane, s-methanol and wood can be used anytime and anywhere.
4- For proposed system we don’t need a new infrastructure
Solar electricity can be transported through existing grid on low and high voltage AC and DC
lines. New HVDC lines can be constructed and smart grid will be introduced. Synthetic gas
can be supplied via existing gas pipelines for natural gas (hybrid system).
Hydrogen can be also locally used in gas turbines for additional supply of electricity. Oxygenfor burning and/or syntheses processes can be available in the same place as hydrogenproduction. In this way high efficient combined gas-steam power plant cycle can be realizedwith efficiency of over 60%.
Distribution of liquid methanol is well developed and normal gas stations can be (with minor
adaptation) used for cars and trucks with adopted or new methanol engines. New engines forhybrid cars can be very efficient because of high possible pressure ratio of methanol. Using
the two stroke engine with turbocharger, its power/weight ratio can be doubled.
Heating systems based on s- gas don’t need any adaptation or new infrastructure. Boiler using
heating oil can be used further, modifying only the burner to use the methanol.
5- Coexistence with present energy system
All four energy carriers can coexist with the present energy system. Transition from thepresent system to a sustainable one is simple and can be implemented very smoothly. In
towns and buildings it doesn’t require a new local infrastructure. Bio-ethanol can also be usedin transition period in the system if the production and distribution will be competitive to smethanol.
6- Should be competitive
The answer on this requirement is difficult. All technologies for the conversion are almost
well developed (solar cells, wind generator, hydro PP, electrolysis, etc.). Methane andmethanol synthesis are old, known processes. New processes for direct conversion of CO2 andhydrogen to methanol are under development.
Solar electricity is more expensive, except large hydro and in some cases wind, thanelectricity from fossil or nuclear fuels. Situation can change if environmental impacts ofburning fossil fuels will be included in their price. Some storage system must be developedfor electricity (bateries), if storage in s-methane and s-methanol will not satisfy the
consumption patern.

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P. Novak: Exergy as measure of sustainability of energy system

It is well known that world pretax subsidies for fossil fuels are distorting energy market
and expand considerably.In year 2011fossil fuels subsidies go up to $523 billion/y (up 30%),
compared to all subsidies for renewable energy which amounted only $88 billion/y.
According to IMF report (January 2013), the world fossil fuel pre-taxsubsidies in 2013 havebeen $480 billion/y and post-tax subsidies $1.9 trillion/y. Including the $1.4 trillion/yenvironmental damages, total direct and indirect costs, not included in the price of fossil fuels
used are $2.78 trillion/y. Including this subsidies in the final price of fossil fuels,
competitiveness of RE will be out of question.
Investment in RE conversion technologies must be based on LCCEA, but taking in toaccount the fossil fuels subsidies wich will slowly disapear. Investment in SES should be
primary goal for abatement of GHG emissions. Energy independency and security of supply
is the second most important reason for such decision. Proposed SES is not totally new, but
enables smooth transition to a new sustainable “carbon recycling society”, which is not on
political agenda as “low carbon society”. SES is sustainable part of promoted “circular
economy”. Costs of all form of exergy will be in begining of transition period higher, but at
the end of transformation of present energy system to SES will be lower and stable forever with a minor or no impact on the planet climate [11].
5. EXERGY AS MEASURE OF SUSTAINABILITY OF SES
5.1. Exergy efficiency and sustainability indicator EROI for proposed SES
Some energy and exergy efficiency of present electrical devices, calculated according tosecond law of thermodynamic, are given in Table 2. Sustainability indicator of the conversion
device EROI, based on LCEA methodology are for RES defined as quotient of life time of
conversion device and expected EPBT (Eq.5). It can be defined also as quotient of life time
exergy produced and cumulative exergy required for construction, maintenance anddestruction in the life time, based on meteorological data. In transition period the exergy forconstruction will be mixture from non-sustainable exergy from fossil fuels and sustainable
exergy from renewable energy. In first approximation the construction exergy can becalculated as:
Ec = (1-a). Ect

7

Where:
Ec – construction exergy; a – percentage of country exergy produced from renewables
Ect – total needed construction exergy

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Table 2. Energy and exergy efficiency for selected electrical devices [8, 10]
DeviceGeneration
Coal fired power plant
Nuclear power plant
Hydro power plant
Wind turbine
PV system
Solar thermal
Co –, trigeneration system
Cogeneration
Trigeneration
Resistance space heater
Hot water heater
Heat pump**COP = 3,8Energy efficiency %Exergy efficiency %40 ÷ 6430
90
0,475 ÷ 0,576
6 ÷ 2510 ÷ 3038 ÷ 6228
90
0,475 ÷ 0,576
6 ÷ 258 ÷ 25

74
94
~ 100
90
380

31
28
6
10
19

Exergy for operation, if not from renewable exergy, can be calculated on the same principles.
Exergy for equipment destruction or de-commissioning is expecting to be from renewablesources at a life time over 30 years.
Exergy efficiency of biomass can be calculated as fund, or as exergy of used biomass.
In first case (fund) we have to include the efficiency of solar exergy conversion by plant. If
we use the biomass as exergy flow, we have to include exergy for harvesting. Using biomass
for final product e.g. electricity or sin-fuel we have used all conversion efficiencies. Thismethodology should be used when we compare floor area or land use for biomass growthwith conversion of solar radiation to final exergy with other conversion technologies. (PV on
the land compared with biomass for biofuel or electricity, e.g.). In this case the plant biomass
exergy content (high or low heating value of biomass) must be multiplied with this conversion
efficiency.
Șex ,b ȘS-p Șh. Șfc
8
Where:
Șex,b - total exergy efficiency for biomass: from solar to final exergy (e.g. electricity)
ȘS-p - efficiency solar irrad. to the plant; Șh - efficiency harvesting; Șfc - conversion efficiency
5.2.Calculations of sustainability indicator EROI for SES
5.2.1. Electricity production
Photo voltaic system
PV system consists of PV panel from glass und plastics, under construction in standard designfrom aluminium profiles, cables and converters. The mean harmonized EPBT varied from 1.0
to 4.1 years; from lowest to highest, the module types ranked in the following order: cadmium
telluride (CdTe), copper indium gallium diselenide (CIGS), amorphous silicon (a:Si), polycrystalline silicon (poly-Si), and mono-crystalline silicon (mono-Si). The mean harmonized
EROI varied from 8.7 to 34.2[16, 17, 22] and from [28] from 3 to 10, with mean 6,6.

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P. Novak: Exergy as measure of sustainability of energy system

Hydro
EPBT for hydro power plant differ from the size of installation, storage capacity and land use.
Hydropower clearly has the highest performance, with exergy ratios exceeding EROI = 170,
compared to energy ratios between 1.6 and 7 for power plant for fossil fuels. For projects
assessed in Quebec, the EROI = 205 for hydro with reservoir and 267 for run-of-river hydro(assuming a lifespan of 100 years). Destruction energy is from renewables so the last term inequation 9 goes to zero. EROI for hydropower plant is according the [20] ~170 to 267 andaccording to [27] 21 to 35 what can be for small hydro. Gupta [28] present the value of EROI
from 11, 2 to 267.
Wind
Large wind turbines also perform very well. According the analysis in [7, 22] EROI is about
19 to 34 for good on-shore sites, depending on wind generator design and meteorologicalsituation. However, this ratio is overestimated because the assessments do not consider thecapacity factor or need for backup capacity to compensate for fluctuations in wind turbine
output. On the other hand in [27] EROI for wind is evaluated from 27 to 70, in [28] the EROI
is given in the range of 18,1 to 24,6.
Geothermal
According to analysis in [19] the exergy efficiency of GPP with high temperature (165°C)
source without re- injection is 47,6 % and with re-injection is 51,5%. Expected life time isover 50 years. In [27,28] geothermal EROI is evaluated from 15 to 40 and for HDR 6÷32.
For for ground source heat pumps (GS HP) the EROI is 5÷7 [21, 22, 25 and 28 ].
5.2.2 Biomass for fuelBiomass performs well. EROI is of 27 when power is produced from forestry wastes [21].
But when trees are planted for the purpose of producing electricity, the EROI is much lower(about 3 to 5), because biomass plantations require high energy inputs. For all biomass
options, the distance between the source of biomass and the power plant must be short;otherwise the energy payback ratio drops to very low values.
Based on real data in case of bioethanol production in Brasilia the total efficiency from solar
irradiation to ethanol, presently achievable with the BAT, is only 0,032% [24]. In [28] thedata for ethanol from corn are EROI is 0, 8 to 2,1.
5.2.3 Hydrogen, oxygen
Hydrogen will be produced from if renewable electricity supply overrides the electricity
consumption. For hydrogen we need storage. The hydrogen can be economically stored if
ாௌைூ
ாோைூ

Where:--> 1- ĭ

(9)

ESOI is analogous to EROI, it is the ratio of exergy – electricity- stored over the
lifetime of a storage device to the amount of embodied electrical energy required
to build the device. ESOI is specially defined for the purpose of comparison ofdifferent storage.
ĭLVsurplus of exergy – electricity - needed to be stored.

In this condition one should store the electrical output from the renewable energy technology.
For production of hydrogen using the water electrolysis we need 54 – 67 kWh /kg of H2.

Energy and the Environment (2016) 467-482

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Efficiency is 0,73 to 0.56, depending on conversion technology [25,26]. EROI for hydrogenfrom fossil fuels is less than 1,5 [27]. Exergy for water splitting from renewable energy is freeflow and is not taken into account. EROI for hydrogen conversion with RES is not available.
ESOI for Pb batteries is 5, for Li-ion batteries 32 and for PHS (pumping hydro storage) 704.
Oxygen, as by-product of electrolysis can be used for production of methanol
5.2.4 Methane
Methane production from biomass is known process which can be realized with different
technologies. Present technology is known as “power to gas” using the renewable electricity
for conversion in hydrogen and hydrogen to methane with CO or CO2. Biomass can be asource of carbon. Total efficiency of exergy conversion from electricity to electricity is 30-38% and for CHP from 43 to 54 %, depend on used technologies [29], what is comparable to thepresent fossil fuel PP. EPBT and EROI are not published, but it is expected EROI to be over
1, 5 ÷ 5.
5.2.5 Methanol
The biomass is gasified and the resulting synthesis gas, a mixture of CO, H2 and CO2 isadapted to the quality requirements of MeOH synthesis. During synthesis the following
reactions occur:
CH3OH
CO + 2H2
CO2 + 3H2
CH3OH + H20
CO2 + H2
CO + H20
The formation of methanol is exothermic and is favoured by high pressures and low
temperatures. For reasons of process simplification, investment cost reduction and energy
consumption reduction, alternatives are under development, which could also be used formethanol from biomass.
Direct oxidation of Methane is the next possibilities: 2CH4 + O2
2CH3OH using oxigen
from the electrolysis [30]. EROI for methanol production using renewable exergy is not
published, but expected value to be 2-5.
Using the present devices in SES the sustainability is guaranteed that present technology
is not optimized. Exergy costs are higher as from fossil fuel, whose production and use
are always unsustainable and doesn’t include the externalities
6. Conclusions
Exergy approach to evaluate the quality of sustainable energy system using the EROI as
sustainability indicator gives us the possibility to make a distinction between fossil fuels
conversion technologies and technologies for conversion of renewable sources of energy.
Most important fact is, that EROI of RES are time in-depended, even more , with better
technologies will be grown within the time. On the other hand EROI of fossil fuels aredescending with the time, because of growing costs for fossil fuels mining from the Earth.
All proposed energy carriers in the new SES have the EROI more than 1. This mean that
proposed sustainable energy system is long term sustainable and from social point of viewacceptable for all countries on the planet Earth.

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P. Novak: Exergy as measure of sustainability of energy system

7. References[1] ECO Design Directive, 2009/125/EC; Renewable Energy Directive 2009/28/EC; Energy
Efficiency Directive 2012/27/EU; EPDB 2010/31/EU; Energy Union/*COM/2015/080final*/, Closing the loop – An EU action plan for the circular economy,/COM (2015) 614 final/,[2] http://eur-lex.europa.eu/resource.html?uri=cellar:1bd46c90-bdd4-11e4-bbe101aa75ed71a1.0001.03/DOC_1&format=PDF.
[3] http://eur-lex.europa.eu/resource.html?uri=cellar:8a8ef5e8-99a0-11e5-b3b701aa75ed71a1.0012.02/DOC_1&format=PDF.
[4] Kabelac, S.’Exergy of solar radiation’, Int. J. Energy Technology and Policy, 2005, Vol.
3, Nos. ½, pp. 115-122.
[5] Zamfirescu C., Dincer I.: How much exergy one can obtain from incident solar radiation
J. of Applied Physics 2009, 105, 02291.
[6] Neri M. et. all: Computing the exergy of solar radiation from real radiation data on the
Italian area, 12th Joint European Thermodynamics Conference, Brescia, July 1-5, 2013, pp.
452-457.
[7] Davidsson S.: Life Cycle Exergy Analysis of Wind Energy system, http://uu.divaportal.org/smash/get/diva2:435510/FULLTEXT01.
[8] Rosen A.M., Bulucea A. C.: Using Exergy to Understand and Improve the Efficiency ofElectrical Power System, J. Entropy 2009,11,820-835; doi:10.3390/e11040820.
[9] Rant. Z. Strojniški vestnik, Ljubljana, 1955, No. 1, pp. 1-3.
[10]The exergy calculator: http://www.exergoecology.com/[11] M.Z. Jacobson, M.A. Delucchi: Providing all global energy with wind, water, and solar
power, Part I, Part II: Technologies, energy resources, quantities and areas ofinfrastructure, and materials, Energy Policy 39(2011) 1159
[12] https://en.wikipedia.org/wiki/Biomass, 04.08. 2016;[13] https://en.wikipedia.org/wiki/Geothermal_energy, 04.08.2016[14] https://en.wikipedia.org/wiki/Wind_wave, 29.05.2016;[15] P. Novak, Sustainable Energy System with Zero Emissions of GHG for Cities andCountries, Energy and Buildings (2015), http://dx.doi.org/10.1016/j.enbuild.2014.10.085[16] Goe, M. & Gaustad, G. (2014). "Strengthening the case for recycling photovoltaic: Anenergy payback analysis". Applied Energy 120: 41–48.
[17] Yue, D., You, F. & Darling, S. B. (2014). "Domestic and overseas manufacturing
scenarios of silicon-based photovoltaic: Life cycle energy and environmental
comparative analysis". Solar Energy 105: 669–678[18] Krebs, F. C. (2009). "Fabrication and processing of polymer solar cells: a review ofprinting and coating techniques". Solar Energy Materials and Solar Cells 93 (4);[19] Bhandari, K. P., Collier, J. M., Ellingson, R. J. & Apul, D. S. (2015). "Energy payback
time (EPBT) and energy return on energy invested (EROI) of solar photovoltaic systems:
A systematic review and meta-analysis". Renewable and Sustainable Energy
Reviews 47:133–141.
[20] Varun1, I. K. Bhat, Ravi Prakash: Life Cycle Analysis of Run-of River Small Hydro
Power Plants in India, The Open Renewable Energy Journal, 2008, 1, 11-16[21] Self S.J, Reddy B.V.; Rosen M.A: Energy and exergy analyses of geothermal plants withand without re-injection. Research J. of Environmental Science 9 (2): 74-87, 2015;bab[22] Khagendra P. Bhandari , Jennifer M. Collier , Randy J. Ellingson , Defne S. Apul:Energy
payback time (EPBT) and energy return on energy invested (EROI) of solar photovoltaic
systems: A systematic review and meta-analysis, Renewable and Sustainable Energy

Energy and the Environment (2016) 467-482

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Reviews Volume 47, July 2015, Pages 133–141;[23] http://tc4.iec.ch/FactSheetPayback.pdf Comparing Energy Options, 6.8.2016[24] Novak P.: Full cycle from solar irradiation to the ethanol, sugar cane to ethanol, Brasilia,
EEA Seminaron Biomass, Copenhagen 2010; EEA Seminar: Transport, Mobility andEnvironment, Ljubljana, 02.10.2012[25] Kewen Li: Comparison of geothermal with solar and wind power generation systems,
PROCEEDINGS, Thirty-Eighth Workshop on Geothermal Reservoir Engineering
Stanford University, Stanford, California, February 11-13, 2013[26] Pandeyr S, Saini H: A techno-energetic review on hydrogen production using wind energy,International J. of Innovation and Scientific Research, Vol. 11 No. 2 Nov. 2014, pp. 312321[27] Kimball J.: Energy Return on Investment (EROI) for U.S. Oil and Gas Discovery andProduction, 17 OCTOBER 2011; http://8020vision.com/2011/10/17/energy-return-oninvestment-eroi-for-u-s-oil-and-gas-discovery-and-production/, 07.08.2016[28] Gupta A.K, Hall C. A.S.: A Review of the Past and Current State of EROI Data,
Sustainability 2011, 3, 1796-1809;[29] https://de.wikipedia.org/wiki/Power-to-Gas, 07.08.2016;[30] http://www.biofuelstp.eu/factsheets/methanol-fact-sheet.html, 07.08.2016

482

P. Novak: Exergy as measure of sustainability of energy system

EKSERGIJA KAO MJERA ODRŽIVOSTI ENERGETSKOG SUSTAVASažetak: Da li trebamo energiju ili eksergiju? Iznos eksergije u energetskim nosiocima je vrlo

UD]OLþLWLFLMHQD energije ukOMXþXMHVDPRYULMHGQRVWNROLþLQH, a ne i kvalitete energije. Eksergija
je mjera za kvalitetu energije, jer je eksergija samo dio energije koji je dostupan za rad. Za
UD]OLþLWHVYUKHWUHEDPR HQHUJLMXVUD]OLþLWLPL]QRVima eksergije]DJULMDQMHLKODÿHQMH
potrebna je energetska PMHãDYLQDL]PHÿXPDORJL]QRVDHNVHUJLMe i velikog dijela anergije.
Prijelaz na održivi energetski sustav bez ispuštanja staklHQLþNLKSOLQRYDQDWHPHOMX
obnovljivih izvora energije, otvara pitanje kako procijeniti eksergiju iz solarne energije.
Solarna energija u svim oblicima ]UDþHQMHWHNXüD voda, vjetar i biomasa) se sastoji od
gotovo 100% eksergije. Solarna energija je besplatna, dok sustavi za pretvorbu nisu. Za
maksimalnu iskoristivost SRVWRMHüH infrastrukture SRVWRML]DMHGQLþNLGRJRYRUGDtrebamoodrživi energetski sXVWDYVþHWLULJODYQHHQHUJHWVND nositelja: HOHNWULþQDstruja, plinovita,
WHNXüLQDLNUXWDJRULYD
Naša vizija je novi Sustainable Energy System (SES) baziran na temelju recikliranja ugljika iz
ELRPDVHSRPRüXVRODUQHLgeotermalne HQHUJLMH]DSURL]YRGQMXHOHNWULþQHHQHUJLMHLYRGLND
SES se WHPHOMLQDSRVWRMHüRMLQIUDVWUXNWXULLSR]QDWLPNHPLMVNLPSRVWXSFLma. S obzirom na
dostupnost obnovljivih izvora energije (OIE) QHRJUDQLþHQD je u odnosu na dosadašnja fosilna
goriva. Predloženi SES sustav sastoji se od tri glavne energetska nositeljaHOHNWULþQH
HQHUJLMHVLQWHWLþNLPHWDQ &+4 LVLQWHWLþNLPHWDQRO &+3OH).
.OMXþQHULMHþLenergija, eksergija, evaluacija, energetski sustavi, održivost.

Energy and the Environment (2016) 483-496

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QUASI-DIMENSIONAL NUMERICAL MODEL OF FUEL
EVAPORATION AND COMBUSTION IN DIESEL ENGINE
VedrDQ0U]OMDN7RPLVODY0UDNRYþLü, Igor Poljak
Faculty of Engineering, University of Rijeka, Vukovarska 58, 51000 Rijeka, Croatia,
vedran.mrzljak@riteh.hr, tomislav.mrakovcic@riteh.hr
Tel/Fax: +385-51-651-551
Abstract: This paper describes mathematical quasi-dimensional model of liquid fuelevaporation and combustion for direct injection diesel engines. Yoshizaki combustion modelis also presented and modified because the original combustion model was developed for thegasoline engine. Quasi-dimensional numerical models have been developed as a compromise
between zero-dimensional and CFD models for internal combustion engine simulations
because of the short processing time and highly accurate results. The crucial part ofdeveloped computer software is numerical model for simulation of fuel evaporation andcombustion, which are especially complex in direct injection diesel engine simulations. The
numerical model consists of many experimental coefficients that have a major influence on
chemical reaction dynamics during fuel evaporation and combustion in diesel engine
cylinder. Simulation results are validated with experimental measurements on direct injection
diesel engine. Such numerical simulation provides insight in many details of fuel evaporationand combustion process what is particularly important because these details cannot be
obtained by experimental measurements.
Keywords: fuel evaporation, combustion, diesel engine, quasi-dimensional numerical model

1. INTRODUCTION
Quasi-dimensional numerical models have been developed as a compromise between 0D and
CFD models for internal combustion engine simulations. 0D numerical models assume ahomogeneous gas mixture in the cylinder, so they cannot predict engine emissions [1], [2].
CFD models enable the most detailed simulations, but these simulations are time consuming
and often are lacking in reliable final results because the initial flow field is not known andturbulence intensity details are not completely defined.
Numerical model developed in this paper is based on the fact that during the fuel injection
spray packages (volumes) are created, which accompany each injected fuel spray, Figure 1.
Outside the fuel sprays is a large zone without fuel (zone without combustion), as proposed in
the papers [3] and [4]. Fuel spray packages are annular in shape, spatial creations and in thespray core they have a form of a truncated cone. Fuel injectors usually have a plurality ofnozzles, so separate volumes are created for each of the fuel sprays. Between spray packages,
exchanges of mass and energy are not allowed. This assumption is a basic parameter of any
quasi-dimensional numerical model. Only allowed mass exchange is the air entrainment fromthe zone without combustion into spray packages [5], when the necessary conditions in eachspray package are fulfilled.

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90U]OMDN70UDNRYþLü, I. Poljak: Quasi – Dimensional Numerical…

Figure 1 Fuel spray, divided into packages (volumes)
2. NUMERICAL MODEL OF FUEL EVAPORATION
The fuel evaporation occurs in the fuel spray packages. Developed quasi-dimensional
numerical model monitors the evaporation process in each individual spray package. The total
evaporation in one calculation step is the sum of fuel vapour in all spray packages.
Atomized fuel evaporation in diesel spray is a very complex process that is influenced by arange of physical and chemical factors. In order to calculate the amount of fuel vapour which
evaporates from all fuel droplets within a single spray package in one calculation step, thefollowing elements should be taken into account:a) It is necessary to know the distribution of the droplet size (droplet diameter) in every
spray package,b) It is necessary to know the relative velocity between the droplets and the surrounding
gas in every spray package,c) It must be considered physical phenomena typical for fluid movement and evaporationsuch as droplets distortion, non-stationary evaporation, droplet collision and similar
ones.
A theoretical calculation attempt of fuel spray vaporization is generally conducted in amanner to assume a certain fuel droplet size distribution and a zero relative velocity between
the droplets and ambient gas in the spray. When the evaporation of the individual droplets is
calculated, the evaporation of groups of droplets may also be calculated [6]. According to thisapproach, the problem of complete fuel spray evaporation is reduced to the problem of single
fuel droplet evaporation.
From the complexity of the evaporation process and a number of parameters that should betaken into consideration in the numerical simulation of this process, it is necessary to
introduce certain assumptions that enable a simpler numerical analysis. All assumptions musttake into account the real fuel and its properties.
The real fuel in internal combustion engine is a mixture of many different hydrocarbons, andtherefore such fuel does not have a single boiling point like one-component fuels whichusually approximates the real fuel in numerical calculations. Therefore, the real fuelevaporation is displayed with the evaporation (distillation) curve, which shows whatpercentage of the fuel evaporates at a certain liquid fuel temperature.

Energy and the Environment (2016) 483-496

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Huge temperature differences between fuel droplet and the environment in which it was
injected, as well as continuous change of the environment state, causes non-stationarity in theprocess of droplet evaporation in the diesel engine. Thus droplet does not achieve its
equilibrium temperature for a given environment state. Parallel execution of two processes,
the transfer of mass and energy (heat), further complicates the numerical simulations due tothe mutual influence of these two phenomena. In these situations, "Triple analogy" is typically
being used between the transfer of momentum, heat and mass [7].
Numerical models of fuel evaporation which take into account the gradient of temperaturefield and the circulation of the fluid within the droplet are already present. Despite of that thetheoretical approach is used more often and it is also numerically simpler. Such an approachassumes a homogeneous temperature field in the droplet, respectively infinitely large heat
conduction coefficient inside the droplet. In such numerical model, the evaporation process isbased on heat or mass transfer [8].
Finally, a problem of heat transfer from the environment to the every single droplet must be
considered. Previous research has shown that forced convection has the dominant influence.
The effect of radiation heat transfer is very small, except when the solid particles are added to
the fuel, to accelerate droplet evaporation. The influence of turbulence is negligible [6].
The first problem that appears in fuel evaporation simulation is to determine the temperature
at which the fuel vapour properties will be calculated. The relevant temperature is the averagetemperature between the fuel droplet temperature and the ambient temperature. According torecommendations from the literature [9] this temperature should be calculated according to
the equation:
Tbl

Ta  2  Td
.
3

(1)

The Reynolds number on the fuel droplet surface was calculated with the expression [10]:Re

U bl  v rel  Dd
.
P bl

(2)

Prandtl and Schmidt number were calculated according to the formulas:PrSc

cP,bl  P bl
k bl

P bl
U bl  DV

,

(3)

.

(4)

Nusselt and Sherwood number were calculated using Ranz-Marshall correlation [11]:Nu

2.0  0.6  3 Pr  Re ,

(5)

Sh

2.0  0.6  3 Sc  Re .

(6)

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90U]OMDN70UDNRYþLü, I. Poljak: Quasi – Dimensional Numerical…

The most important fact, which states what kind of fuel droplet evaporation will occur, is thecritical temperature of the observed fuel. If the temperature of the fuel droplet (liquid fuel) is
lower than the critical, evaporation is classical (standard). If the temperature of the fueldroplet is higher than critical, evaporation is rapid (limited only by diffusion).
At the classical (standard) evaporation fuel droplet mass change (the amount of fuel which
evaporates from the fuel droplet) is defined by the equation:
§
·
p cil
¸¸  Sh .
S  Dd  DV  U bl  ln¨¨

p
p
sat ¹
© cil

d md
dt

(7)

For high pressures in the cylinder during the fuel injection, the evaporation would be realized
too slowly if the equation (7) were used. In such conditions, the temperature of the droplet
could exceed the critical temperature before it completely evaporates. By exceeding thecritical temperature of the selected fuel, mass transfer in the gas phase of the fuel package islimited only by the diffusion coefficient, not also by temperature as before. Under these
conditions for calculation of fuel droplet mass change the following expression should be
used:
d md
dt

§p ·
0,018  S  Dd  ¨ cil ¸© 100 ¹

1,1

.

(8)

The total heat flux to the fuel droplet can be calculated by using the equation:d Qd,hfdt

S  Dd  k bl  Ta  Td z
 Nu ,
e 1

(9)

z

with a note that the dimensionless correction factor (z) reduces the transferred heat flux during
simultaneous increased mass transfer (evaporation) due to the connection of mass and heattransfer.

The mass of fuel droplets in the fuel spray package was calculated with the formula:mdS6

 Dd3  U d .

(10)Finally, the speed of droplet temperature change was defined by the expression:d Td
dt§ d Qd d m d
·
1
 ¨¨

 QLf ¸¸ .
dt
md  c P,d © d t¹

3. NUMERICAL MODEL OF FUEL COMBUSTION(11)

Energy and the Environment (2016) 483-496

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Fuel combustion was modelled by using the equations from literature [3]. Combustion is
calculated in each fuel spray package after the expiration of the package ignition delay andwhen the other necessary conditions have been met.
Before using Yoshizaki combustion model, excess air ratio for combustion of fuel vapoursmust be calculated. This excess air ratio is designated by ratio of available oxygen mass andavailable mass of fuel vapour in every fuel spray package, and it is calculated according to theequation:

Obl

mO 2
mfv  mO 2 ,st

.

(12)

Stoichiometric oxygen mass (oxygen mass per 1 kg of fuel required for complete fuelcombustion) shall be calculated by using the formula:

mO 2 ,stYO 2  Lst .

(13)

An auxiliary function RȜ in Yoshizaki combustion model is selected in accordance with thecalculated Ȝbl. Combustion model is characterized by the fact that, unlike other models, it
introduced the limits of mixture flammability and auxiliary function (RȜ) that determines how
much fuel vapour will burn out (will be transferred to the zone of combusted fuel) within eachof the observed volumes. The combustion process is assumed to be stoichiometric. The formof auxiliary function RȜ is shown in Figure 2.

Figure 2 Auxiliary combustion function RȜ [3]Auxiliary function depends on Ȝbl in the following way:
0  O bl  O minRȜ = 0,Omin  Obl  1RȜ =1  Obl  Omax

RȜ = 1,
RȜ = 0.

Omax  Obl  fO bl - O min,
1 - O min

(14)

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90U]OMDN70UDNRYþLü, I. Poljak: Quasi – Dimensional Numerical…

With additional function (14) the amount of fuel vapour which will burn out is completely
defined. The burned out fuel vapour will be transferred to the area of combustion products:
d mcf

RO  d mfv .

(15)

Yoshizaki et al. [3] have found that without the flammability limits, in the combustion
products zone temperature becomes too high, in every single observed volume, leading tohigh concentrations of nitrogen oxides. The linear dependence of the correction in the richmixture area reduces the combustion speed and also reduces the temperature of the
combustion products zone.
The amount of heat released by the combustion of fuel vapour was calculated according to theexpression:
d Qfv
d mcf
.
LHV 
(16)
dt
dt
The total heat released by fuel in the engine cylinder at some point is the sum of heat released
in all spray fuel packages (the sum of all observed control volumes). In the zone without
combustion, which is formed around the fuel sprays, combustion does not occur, so thiscontrol volume is not taken into account during calculation of the total heat released by
combustion in the engine cylinder.

This combustion numerical model is characterized with another interesting feature: it allows
the accumulation of fuel vapour in an observed control volume (fuel spray package). In thecase of too lean mixture, oxidant will "wait" until a sufficient amount of fuel vapour is
obtained, while in the case of rich mixture fuel vapour will "wait" until enough oxygen
entered into the fuel spray package from the zone without combustion. Flammable limits are
set on O min 0,22 and O max 1,60 according to data from the literature for the purehydrocarbon n-dodecane (C12H26).
The mass of unburned fuel vapours (mfv,nc) in any fuel spray package is the sum of the mass offuel vapour remaining in the observed volume after combustion and the total mass of the fuelvapour which is generated by evaporation from all fuel droplets during the integration step:
mfv,ncmfv,ac d mevap
dt

,

(17)

while the mass of fuel vapour after combustion is equal to the mass of fuel vapour at the startof combustion, reduced for the mass of fuel vapour which has burnt in one integration step:

mfv,acmfv  mcf .

(18)

The last undefined member of the equation (12) is the mass of oxygen available for
combustion process ( mO 2 ).
The oxygen in the fuel spray package can appear in two places (in two sub-volumes). The firstsub-volume consists of fresh air that entered into the spray package, and second sub-volume

Energy and the Environment (2016) 483-496

489

represents oxygen bonded in the stoichiometric combustion products. Oxygen in the second
sub-volume cannot be used for combustion in the next integration step. Oxygen relevant for
combustion is located in the mass of air, which exists inside the package, but has notparticipated in the combustion process yet. Free (fresh) air which enters into fuel spray
package (from the zone without combustion) must be added into the balance of relevant air inthe combustion process, in every integration step. The total mass of air in which all available
oxygen exists is marked with mair.
The mass of oxygen available for combustion in the fuel spray package is defined by theequation:mO 2

mair  YO 2 .

(19)

4. DIESEL ENGINE DATA AND MEASUREMENT RESULTS
Test engine was a high speed turbocharged direct injection diesel engine for the heavy vehicle
drive MAN D 0826 LOH15, Table 1, and the measurements were carried out in the
Laboratory for Internal Combustion Engines and Electromobility, at the Faculty of
Mechanical Engineering, University of Ljubljana, Slovenia.
Table 1 Engine specifications
Displacement
6.87 lNumber of cylinders
6
Peak power
160 kW
Cylinder bore
108 mmStroke125 mmCompression ratio
18
Crank radius
62.5 mm
Length of the connecting rod
187.2 mm
Length of nozzle bore
2.3 mmNozzle diameter
0.23 mm
Number of nozzle holes
7
Combustion chamber
Bowl in piston
Several measurement sets have been carried out. The measurement set shown in Table 2 hasbeen chosen for the numerical model simulation. The developed numerical model was
validated in four different operating points of presented internal combustion diesel engine.
Details of the numerical model validation and used validation parameters are presented in[12].
Table 2 The results of selected measurement set
Fuel
Soot
Air
Rotational
OperatingPowerconsumption consumption
emission
speed
point
kW
kg/h
BSU
kg/s
min-1
1
9.198
0.100764
1498
43.7760.25
218.0400.126717
1502
89.3190.55

NOxemissionppm
870.411202.46490

90U]OMDN70UDNRYþLü, I. Poljak: Quasi – Dimensional Numerical…

5. NUMERICAL MODEL RESULTS OF FUEL EVAPORATION ANDCOMBUSTION
The numerical model and simulation results follow a large number of different engine
parameters. Due to the limited space of this paper, only the numerical model results for fuelevaporation and combustion in the measured operating point 2 are presented in this chapter.
Changes in the total mass of the fuel different aggregate states in the engine cylinder wereshown in Figure 3. The liquid fuel mass in the cylinder increases during fuel injection, anddecreases during the evaporation and combustion. The fuel vapours mass increases at the
beginning of the process because of the intensive liquid fluid evaporation and decreases
during combustion. The mass of combusted fuel is constantly increasing since the beginningof air entry into the fuel spray packages. After the combusted fuel mass reaches its maximum,
its value is maintained until the opening of the exhaust valve.

Figure 3 Changes in the total mass of the fuel different aggregate states in the cylinder
Figure 4 shows the temperature change of two areas in the engine cylinder. The averagetemperature of all fuel spray packages is higher than the average cylinder temperature. This isa result of combustion and the most intense heat release in the packages. Low averagecylinder temperature is caused by low temperature in the zone without combustion. Thisphenomenon has been expected, because the zone without combustion is a large zone around
fuel spray packages.

Energy and the Environment (2016) 483-496

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Figure 4 Averaged temperatures in the engine cylinder
It should be noted that in the developed numerical model of fuel evaporation and combustion,
all of the displayed equations are related to the thermodynamic volume of the fuel spray
package (volume of gases and vapours). The thermodynamic volume of the package is thegeometric package volume reduced for the liquid fuel volume. The properties of the liquid
fuel, which is also present in each fuel spray package, are monitored by separate mathematicalmodels, independent of the displayed one. The energy conservation equation for the liquid
fuel was used to monitor the temperature of liquid fuel, which is a basic parameter for the fuelevaporation calculation.
The entire mass of fuel spray packages thermodynamic volume constantly grows during air
entry from the zone without combustion, Figure 5. At the moment when the mass of the zone
without combustion becomes very small, air stops entering the fuel spray packages. From thatmoment on, the entire mass of fuel spray packages thermodynamic volume remains
unchanged until the opening of the exhaust valve.

Figure 5 The entire mass of fuel spray packages thermodynamic volume (gas + fuel vapour)

492

90U]OMDN70UDNRYþLü, I. Poljak: Quasi – Dimensional Numerical…

Liquid fuel total volume change in the cylinder of the observed engine is presented in Figure
6. The total volume of liquid fuel in the cylinder firstly increases during the fuel injection. At
the beginning of fuel evaporation liquid fuel volume was reduced and the volume reduction
increases during intensive evaporation. When the entire evaporation of liquid fuel comes tothe end, the liquid fluid volume becomes equal to zero.
Figure 7 and Figure 8 show the changes of the number of moles for different elements in allfuel spray packages.
It should be noted that the change of number of moles was similar for both H2O and CO2 in
Figure 7 in all fuel spray packages. Number of moles of both components started to growduring combustion, reached their maximum values, and remained unchanged until leaving thecylinder through the engine exhaust.

Figure 6 Total volume change of liquid fuel in the engine cylinder
The movement of two-atomic oxygen O2 is essential for combustion because it represents
operating media, without which liquid fuel evaporation and fuel vapour combustion would
not be possible, Figure 7. It is characteristic for O2 that its number of moles in fuel packages
starts to grow during air entry from the zone without combustion. During combustion O2 is
consumed, and later in the packages it continues to increase until the maximum value,
because air from the zone without combustion continuously enters in the fuel spray packages
before, during and after combustion. At the moment when the zone without combustion
reaches its minimum mass, O2 stops entering the packages. O2 retains its maximum value inall packages until the exhaust.

Energy and the Environment (2016) 483-496

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Figure 7 Number of moles change of H2O, CO2 and O2 in all fuel spray packages
Trends of change in the number of moles for some very harmful substances in total diesel
engine emissions were presented in Figure 8. CO emissions should be emphasized, because
CO has a detrimental impact on human health and the environment. The most intensive CO
emissions in the fuel spray packages appear during intense combustion and significant heatrelease.

Figure 8 Number of moles change of fuel vapour, CO and OH in all fuel spray packages
6. CONCLUSIONSThe paper presents sub-models for fuel evaporation and combustion in a developed quasidimensional numerical model. These sub-models are especially complex in direct injection
diesel engine simulations because of many experimental coefficients that have a major
influence on chemical reaction dynamics during fuel evaporation and combustion.
Quasi-dimensional model results for the entire cylinder and summary results for all fuel spray
packages are presented. The model is also capable of calculating the operating parameters ineach fuel spray package, in order to predict the total emissions from the engine.

494

90U]OMDN70UDNRYþLü, I. Poljak: Quasi – Dimensional Numerical…

A numerical model was validated in several operating points. Due to the large number of data
which were calculated, the numerical model results for one selected operating point were
presented.
The presented results show the details of the processes of liquid fuel evaporation and its
combustion in the engine cylinder. Some of the displayed numerical model results would bevery difficult or impossible to obtain by experimental measurements. The biggest advantageof quasi-dimensional numerical models is a short time of calculation, as well as getting an
insight into the details of the cylinder process, what is a necessary prerequisite for the diesel
engine emissions calculation. Some results related to engine emissions are also presented andexplained.
The presented numerical model is very applicable for all the engineers and scientists who are
engaged in the development and simulation of internal combustion engines.
Quasi-dimensional numerical model can and will be upgraded by implementing precise
numerical sub-model for soot emission calculation.
NOMENCLATURE
Latin Symbols:
cP
specific heat at p FRQVW- NJÂ.
CA
Crank Angle, °Dd
Sauter mean diameter of the fuel droplet, mDVmean value of the fuel vapour diffusion coefficient, m2/s
k
WKHUPDOFRQGXFWLYLW\: PÂ.
LHV Lower Heating Value, J/kg
Lst
stoichiometric air amount, kg/kgmmass, kg
Nu
Nusselt numberppressure, Pa
Pr
Prandtl numberQheat amount, J
Qhf
heat flux, W
QLf
latent heat of liquid fuel evaporation, J/kg
Re
Reynolds numberRȜ
combustion auxiliary function
Sc
Schmidt number
Sh
Sherwood numberttime, sT
Temperature, K
vrel
relative velocity between the droplet and the surrounding gas, m/sYmass fractionzdimensionless correction factor
Greek symbols:
Ȝ
excess air ratio, G\QDPLFYLVFRVLW\NJ PÂVPUdensity, kg/m3
Subscripts:aambient

Energy and the Environment (2016) 483-496

ac
air
bl
cf
cil
d
evap
fv
nc
O2
sat
st

495

after combustion
air available for combustion
boundary layer of fuel droplet
combusted fuelengine cylinder
dropletevaporationfuel vapour
not combusted
diatomic oxygen
saturation
stoichiometric

REFERENCES
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]

Medica, V.: Simulation of turbocharged diesel engine driving electrical generator
under dynamic working conditions, Doctoral Thesis, University of Rijeka, Rijeka,
1988.
Engl, G.: The modeling and numerical simulation of gas flow networks, Numerische
Mathematik 72, 349-366, 1996.
Yoshizaki, T., Nishida, K., Hiroyasu, H.: Approach to Low NOx and Smoke Emission
Engines by Using Phenomenological Simulation, SAE Paper 930612, 1993.
Hiroyasu, T., Miki, M., Kamiura, J., Watanabe, S., Hiroyasu, H.: Multi-Objective
Optimization of Diesel Engine Emissions and Fuel Economy using Genetic Algorithms
and Phenomenological Model, SAE Technical Paper 2002-01-2778, 2002.
Hiroyasu, H., Arai, M.: Structures of Fuel Sprays in Diesel Engines, SAE Paper
900475, 1990.
Graves, C. C., Bahr, D. W.: Atomization and evaporation of liquid fuels. Chapter I:
Basic Considerations in the combustion of hydrocarbon fuels with air, ed. by H. C.
Barnett and R. R. Hibbard, NASA Report 1300, 1957.
Isachenko, V. P., Osipova, V. A., Sukomel, A. S.: Heat Transfer, MIR Publishers,
Moscow, 1977.
Morel, T., Wahiduzzaman, S.: Modeling of Diesel Combustion And Emissions, Paper
P1672, XXVI-th Congress FISITA, Prague, 1996.
Amsden, A. A., Ramshaw, J. D., O’Rourke, P. J., Dukowicz, J. K.: KIVA: A Computer
Program for two and three-dimensional fluid flows with chemical reactions and fuelsprays, LA-10245-MS, Los Alamos National Laboratory, Los Alamos, 1985.
Nishida, K., Hiroyasu, H.: Simplified Three-Dimensional Modeling of Mixture
Formation and Combustion in a DI Diesel Engine, SAE Technical Paper 890269,
1989.
Ranz, W. E., Marshall JR., W. R.: Evaporation from drops, Chem Eng Progs, Vol. 48,
No. 3, and No. 4, 1952.
Mrzljak, V.: Quasidimensional model for numerical simulations of marine two-stroke
diesel engine, Doctoral Thesis, University of Rijeka, Rijeka, 2015.

496

90U]OMDN70UDNRYþLü, I. Poljak: Quasi – Dimensional Numerical…

KVAZI-',0(1=,-6.,180(5,ý.,02'(/,63$5$9$1-$*25,9$
I IZGARANJA U DIZELSKOM MOTORUSažetak: Rad prikazuje matematLþNLNYD]L-GLPHQ]LMVNLPRGHOLVSDUDYDQMDLL]JDUDQMDWHNXüHJ
JRULYD]DGL]HOVNHPRWRUHVDGLUHNWQLPXEUL]JDYDQMHP<RVKL]DNLPRGHOL]JDUDQMDMHWDNRÿHU
prikazan i modificiran, jer je originalni model izgaranja razvijen za benzinske motore. KvazidimenzijskL QXPHULþNL PRGHOL UD]YLMHQL VX NDR NRPSURPLV L]PHÿX QXOWR-dimenzijskih i CFD
PRGHOD ]D VLPXODFLMH PRWRUD VD XQXWDUQMLP L]JDUDQMHP ]ERJ NUDWNRJ YUHPHQD L]UDþXQD
SURFHVD L YLVRNH WRþQRVWL GRELYHQLK VLPXODFLMVNLK UH]XOWDWD .UXFLMDOQL GLR UD]YLMHQRJUDþXQDOQRJVRIWYHUDMHQXPHULþNLPRGHOza simulaciju isparavanja i izgaranja goriva, što su
iznimno kompleksni procesi u simulacijama dizelskih motora sa direktnim ubrizgavanjem.
1XPHULþNL PRGHO VDGUåL EURMQH HNVSHULPHQWDOQR GRELYHQH NRHILFLMHQWH NRML LPDMX L]QLPDQ
utjecaj na dinamiku kemijskih reakcija tijekom isparavanja i izgaranja goriva u cilindru
dizelskog motora. Simulacijski rezultati validirani su na temelju eksperimentalnih mjerenja
QDGL]HOVNRPPRWRUXVDGLUHNWQLPXEUL]JDYDQMHPJRULYD2YDNYDQXPHULþNDVLPXODFLMDGDMH
uvid u mnoge detalje vezane za isparavanje goriva i proces izgaranja što je posebno važno jer
se takvi detalji ne mogu izmjeriti tijekom eksperimentalnih mjerenja.
.OMXþQHULMHþL isparavanje goriva, izgaranje, dizelski motor, kvazi-GLPHQ]LMVNLQXPHULþNLmodel

Energy and the Environment (2016) 497-508

497

7(502',1$0,ý.$$1$/,=$,=0-(1(723/,1(,
PRIJENOS TVARI U RASHLADNOM TORNJU
Ivan âRLü3DROR%OHFLFK%HUQDUG)UDQNRYLüTeKQLþNLIDNXOWHW6YHXþLOLãWDX5LMHFL9XNRYDUVNDRijeka
E-mail: ivansoic91@gmail.com, pblecich@riteh.hr, bernardf@riteh.hrSažetak: ovaj rad GRQRVL WHUPRGLQDPLþNX DQDOL]X L]PMHQH WRSOLQH L SULMHQRVD WYDUL X
rashladnom tornju s prisilnim strujanjem zraka. Rashladni toranj nalazi se u INA Rafinerijinafte Rijeka u Urinju, u sklopu rashladnog sustava od 8 tornjeva. U uvodnom dijelu þODQND
objašnjene su osnove ishlapljivanja i ukratko su opisani rashladni tornjevi s prisilnim
VWUXMDQMHP ]UDND 1XPHULþND DQDOL]D L]PMHQH WRSOLQH L SULMHQRVD WYDUL X UDVKODGQRP tornju
L]YUãHQD MH X UDþXQDOQRP SURJUDPX $16<6 )OXHQW D UDþXQDOQD GRPHQD XPUHåHQD MH X
programu Gambit. 2SLVDQ MH PDWHPDWLþNL PRGHO NRML VH VDVWRML RG UDþXQDOQH GRPHQH
MHGQDGåELRþXYDQMD i rubnih uvjeta. Domena je diskretizirana metodom kontrolnih volumena
GRN VX QHSR]QDWH YHOLþLQH QD JUDQLFDPD NRQWUROQLK YROXPHQD ULMHãHQH XSZLQG
diskretizacijskom shemom drugog reda. Za rješavanje polja tlakova i brzina strujanja
korišten je SIMPLE algoritam. 3ULND]DQL UH]XOWDWL REXKYDüDMX QXPHULþNLP SXWHP GRELYHQH
raspodjele brzina strujanja zraka, temperatura i sadržaja vlage zraka unutar rashladnog
tornja kao i prijenos tvari pri ishlapljivanju. 3RPRüX Woplinske bilance rashladnog tornja
L]UDþXQDWD je izlazna tempeUDWXUDYRGHLXVSRUHÿHQDVYULMHGQRVWLL]WHKQLþNH dokumentacije
UDVKODGQRJ WRUQMD 'RELYHQD MH L]OD]QD WHPSHUDWXUD YRGH RG  & ]D SURVMHþQL SURPMHU
kapljica vode od 2 mm odnosno 26,1 °C za promjer kapljica od 1,5 mm dok je vrijednost iz
WHKQLþNH GRNXPHQWDFLMH  & þLPH MH SRWYUÿHQD YDOMDQRVW SRVWDYOMHQRJ PDWHPDWLþNRJmodela za rashladni toranj.
.OMXþQHULMHþL UDVKODGQLWRUDQMSULVLOQRVWUXMDQMH]UDNDQXPHULþNRPRGHOLUDQMH
izmjena topline, prijenos tvari
1. UVOD
5DVKODGQL WRUQMHYL VX XUHÿDML NRML ]D KODÿHQMH YRGH NRULVWH SURFHV KODÿHQMD YRGH
ishlapljivanjem u zraku. Još se nazivaju i urHÿDML]DRSWRþQRKODÿHQMHYRGH.oriste se kada sežele ušteditLYHOLNHNROLþLQHUDVKODGHYRGHRGQRVQR kada na raspolaganju ne postoje dovoljneNROLþLQH VYMHåH YRGH LOL EL GRSUHPD L RGUåDYDQMH VXVWDYD VD VYMHåRm vodom bilo preskupo i
QHLVSODWLYR 5DVKODGQL WRUQMHYL NRULVWH VH ]D KODÿHQMH UDVKODGQH YRGH X WHUPRHOHNWUDQDPD X
procesima kemijske industrije, u sustavima klimatizacije i drugdje [1]. Rashladni tornjevi
mogu biti izvedeni s prirodnim strujanjem zraka ili s prisilnim strujanjem zraka [2-3], a takav
je i rashladni toranj kojeg se analizira u ovom radu. Kod rashladnih tornjeva s prisilnim
strujanjem zraka, prikazan na slici 1., strujanje zraka postiže se SRPRüXYHQWLODWRUD9HQWLODWRUmože biti postavljen u podnožju tako da VH ]UDN WODþL NUR] WRUDQM L WDNYD VH L]YHGED QD]LYDWODþQL toranj odnosno na vrhu tako da se zrak usisava kroz toranj i takva se izvedba naziv
usisni toranj. Rashladni tornjevi nazivajX VH L SR VPMHUX VWUXMDQMD L]PHÿX YRGH L ]UDND498,âRLü3%OHFLFK%)UDQNRYLü: 7HUPRGLQDPLþNDDQDOL]DL]PMHQHWRSOLQH«

protustrujni tornjevi kada voda i zrak struje u suprotnim smjerovima odnosno unakrsni
tornjevi kada se smjerovi struja vode i zraka križaju.
.DGD]UDNVWUXMLSUHNRþLVWHYRGHQHSRYUãLQHQDVWDMHLVKODSOMLYDQMe ili rošenje. Ishlapljivanje
vode u zrak razlikuje se od isparavanja po tlaku na površini vode. Kod ishlapljivanja površina
YRGHQDOD]LVHSRGYHüLPWODNRPQHJRNRGLVSDUDYDQMD>-5]. Taj se ukupni tlak puk sastoji iz
parcijalnog tlaka ps ]DVLüHQH YRGHQH pare i iz parcijalnog tlaka zraka (pf = puk – ps) koji se]EUDMDMX SUHPD 'DOWRQRYRP ]DNRQX .RG LVSDUDYDQMD WHNXüD YRGD L YRGHQD SDUD QDOD]H VH
SRG LVWLP WODNRP ]DVLüHQMD ps .ROLþLQD YRGH ‫ۦ‬w koja ishlapljuje s površine vode Ag
proporcionalna je razlici parcijalnih tlakova pare na površini vode pg i pare dalje od površine
vode pf odnosno razlici sadržaja vlage u zraku na površini vode xg i sadržaja vlage uslobodnoj struji xf, tj.
݉ሶ୵ = ܾ ቀ‫݌‬g െ ‫݌‬f ቁ ‫ܣ‬g = ߪ൫‫ݔ‬g െ ‫ݔ‬f ൯‫ܣ‬g(1)

Slika 1. Vanjski i unutrašnji izgled rashladnih tornjeva u INA Rafineriji nafte Rijeka [1]2. 0$7(0$7,ý.,02'(/
2.1 5DþXQDOQLSRVWXSDN=D SRWUHEH QXPHULþNRJ PRGHOLUDQMD RSLVDQ MH PDWHPDWLþNL PRGHO L GHILQLUDQD MH UDþXQDOQD
GRPHQD UDVKODGQRJ WRUQMD ]D NRMX YULMHGH MHGQDGåEH RþXYDQMD SRþHWQL L UXEQL XYMHWL
1XPHULþND DQDOL]D prijelaza topline i prijenosa tvari u rashladnom tornju provedena je
SRPRüXUDþXQDOQRJSURJUDPD$16<6)OXHQWGRNMHGRPHQDXPUHåHQD u programu Gambit.
Domena je diskretizirana metodom kontrolnih volumena, a nepoznate se YHOLþLQH QD
granicama kontrolnih volumena traže upwind diskretizacijskom shemom drugog reda [6-7].
Za rješavanje polja tlakova i brzina strujanja korišten je SIMPLE algoritam.
2.2 5DþXQDOQDGomena.DNR EL VH PRJOD SURYHVWL QXPHULþND DQDOL]D UDVKODGQRJ WRUQMD SRWUHEQR MH GHILQLUDWLSURUDþXQVNX GRPHQX 5DGL MHGQRVWDYQRVWL SURUDþXQD L XãWHGH QD UDþXQDOQLP resursima,
GRPHQX SUHGVWDYOMD QDMPDQML UHSUH]HQWDWLYQL GLR UDVKODGQRJ WRUQMD 8 RYRP VOXþDMX WR MH
dvodimenzijski presjek rashladnog tornja [1]. Domena REXKYDüD GYD SRGUXþMD SRGUXþMH
fluida odnosno zraka i SRUR]QR SRGUXþMH RGQRVQR ispuna rashladnog tornja. 5DþXQDOQD

Energy and the Environment (2016) 497-508

499

domena prikazana je na slici 2. 'RPHQDMHXPUHåHQDþHWYHURNXWQLPNRQWUROQLPYROXPHQLPD
SULþHPXMHXNXSQLEURMNRQWUROQLKYROXPHQDDSURVMHþQDYHOLþLQDVYakog kontrolnog
volumena je 4 cm2 [1].

Slika 2. 5DþXQDOQDGomena i detalj mreže
2.3 -HGQDGåEHRþXYDQMD-HGQDGåEHRþXYDQMDRSLVXMXstacionarno strujanje zraka i prijelaz topline u rashladnom tornju
i WHPHOMH VH QD ]DNRQLPD RþXYDQMD PDVH momenta NROLþLQH JLEDQMD L HQHUJLMH 1MLKRYLP
rješavanjem dobivaju se raspodjele brzina strujanja, tlak i temperatura zraka [7]. Za
promatrani problem PDWHPDWLþNL PRGHO RSLVDQ MH VXVWDYRP SDUFLMDOQLK GLIHUHQFLMDOQLKjednadžbi za dvodimenzijsko stacionarno turbulentno strujanje zraka. U poddomeni zraka,
prijelaz topline i turbulentno strujanje zraka opisani su jednadžbom RþXYDQMD PDVH -20 
MHGQDGåEDPD RþXYDQMD momenta NROLþLQH JLEDQMD -2.*  L MHGQDGåERP RþXYDQMD HQHUJLMH(JOE):JOM:

߲(ߩ‫߲ ) ୶ݓ‬൫ߩ‫ ୷ݓ‬൯
+
=0
߲‫ݔ‬
߲‫ݕ‬

(2)

500

,âRLü3%OHFLFK%)UDQNRYLü: 7HUPRGLQDPLþNDDQDOL]DL]PMHQHWRSOLQH«

JOKG – x:߲ߩ‫୷ݓ ୶ݓߩ߲ ୶ݓ ୶ݓ‬
+
߲‫ݔ‬
߲‫ݕ‬

JOKG –y:߲‫߲ ݌‬
߲‫୶ݓ‬
߲
߲‫୶ݓ‬
+
൬ߟ
൰ + ߲ ൬ߟ ߲‫ ݓ‬൰ + ܵெ౮߲ߩ‫ = ୷ݓ ୷ݓߩ߲ ୶ݓ ୷ݓ‬െ߲‫݌‬߲‫ݓ߲ ݔ߲߲ ݔ‬
߲‫ݕ‬
߲‫୷ݔ‬
߲‫୷ݕ‬
+
=െ
+
ቆߟ
ቇ+
ቆߟ
ቇ െ ߩ݃ + ܵெ౯߲‫ݔ߲ ݕ‬
߲‫ݕ‬
߲‫ݔ‬
߲‫ݕ‬
߲‫ݔ‬
߲‫ݕ‬

(3)
(4)

߲(ߩ‫)ܶ ୷ݓߩ(߲ )ܶ ୶ݓ‬߲ ߣ ߲߲ܶ ߣ ߲ܶ+=ቆቇ+ቆቇ + ܵ୯
(5)߲‫ݔ‬߲‫ܿ ݔ‬୮ ߲‫ݔ‬߲‫ܿ ݕ‬୮ ߲‫ݕ‬߲‫ݕ‬
Navier-Stokesove jednadžbe (3-4) vrijede za laminarno strujanje zraka u rashladnom tornju.
U VOXþDMu turbulentnog strujanja zraka, odabrani k-İ model turbulencije rastavlja svaku odovih dviju jednadžbi na dodatne dvije jednadžbe [6@SUYD]DWXUEXOHQWQXNLQHWLþNXHQHUJLMXki druga za GLVLSDFLMXNLQHWLþNHHQHUJLMHİ, tj.

JOE:

߲‫ݓ‬୨
߲
ߟ௧ ߲݇
߲‫ݓ‬୧ ߲‫ݓ‬୨
2
߲
߲‫ݓ‬୩
(ߩ‫ݓ‬୧ ݇) =ቈ൬ߟ + ൰቉ + ቈߟ୲ ቆ+ቇ െ ൬ߩ݇ + ߟ୲
൰ߜ ቉
െ ߩߝ
߲‫ݔ‬୨
3
߲‫ݔ‬୧
ߪ௞ ߲‫ݔ‬୨߲‫ݔ‬୨ ߲‫ݔ‬୧߲‫ݔ‬୩ ୧୨ ߲‫ݔ‬୧

(6)

߲‫ݓ‬୨
߲
ߟ୲ ߲ߝ
߲‫ݓ‬୧ ߲‫ݓ‬୨
2
ߝଶ
߲
ߝ
߲‫ݓ‬୩
(ߩ‫ݓ‬୧ ߝ) =ቈ൬ߟ + ൰቉ + ‫ܥ‬ଵக ቈߟ୲ ቆ+ቇ െ ൬ߩ݇ + ߟ୲൰ ߜ୧୨ ቉െ ‫ܥ‬ଶக ߩ
߲‫ݔ‬୨
3
߲‫ݔ‬୧
݇
ߪக ߲‫ݔ‬୨߲‫ݔ‬୨ ߲‫ݔ‬୧
߲‫ݔ‬୩
߲‫ݔ‬୧
݇

(7)

3UHWKRGQL PDWHPDWLþNL PRGHO SRWUHEQR MH GRSXQLWL MHGQDGåEDPD koje opisuju transport
NDSOMLFDYRGHL]PMHQXWRSOLQHLWYDULL]PHÿXNDSOMLFDYRGHL]UDNDEXGXüLGDVHYRGDSXWHPmlaznica raspršuje u struju zraka. Lagrangeov priVWXSSURPDWUDQMXGLVNUHWQLKþHVWLFDRSLVXMH
transport kapljica vode kroz struju zraka [6]. Putanja kapljice definira se jednadžbom
ravnoteža sila koja L]MHGQDþDYD VLOX XEU]DQMD þHVWLFH VD VLODPD RWSRUD JUDYLWDFLMH L
gradijentom tlaka u fluidu, tj.
݃୨ ൫ߩ୮ െ ߩ൯ ߩ݀‫ݓ‬୮,୨ 3 ‫ܥ‬ୈ ߩ
݀‫ݓ‬୨
ଶ
=
൫‫ݓ‬୨ െ ‫ݓ‬୮,୨ ൯ ++ ‫ݓ‬୮,୨
4 ݀୮ ߩ୮
ߩ୮
݀‫ݐ‬
݀‫ݔ‬୨
ߩ୮

(8)

U izrazu (8) varijable NRMH RSLVXMX GLVNUHWQX þHVWLFX VX EU]LQD wp JXVWRüD ȡp i promjer
kapljice vode dp, a one koje opisuju fazu fluida su brzina w L JXVWRüD ]UDND ȡ, dok je CD
koeficijent otpora fluida na kapljicu vode. Turbulentna dispHU]LMDþHVWLFDNUR]IOXLGRSLVXMHVHVWRKDVWLþNLP PRGHORP SUDüHQMD UHSUH]HQWDWLYQRJ EURMD þHVWLFD NRML X]LPD X RE]LU XWMHFDM
turbulentnih promjena brzine IOXLGD QD SXWDQMH þHVWLFD -HGQDGåED RþXYanja energije
GLVNUHWQLK þHVWLFD RSLVXMH L]PMHQX WRSOLQH L]PHÿX NDSOMLFD IOXLGD L RNROQRJ IOXLGD 2YDMHGQDGåED L]MHGQDþDYD L]PMHQX RVMHWQH WRSOLQH NDSOMLFH V WRSOLQVNLP WRNRP NRQYHNFLMH L
]UDþHQMDWRSOLQHQDSRYUãLQLNDSOMLFHWHVL]PMHQRPODWHQWQHWRSOLQe zbog ishlapljivanja.
݉୮ ܿ୮

݀ܶ୮
݀݉୮
= ߙ‫ܣ‬p ൫ܶλ െ ܶp ൯ + ߳p ‫ܣ‬p ߪ൫ܶ4R െ ܶ4p ൯ + ‫ݎ‬
݀‫ݐ‬
݀‫ݐ‬

(9)

3URPMHQD VDGUåDMD WRSOLQH NDSOMLFD YRGH SRMDYOMXMH VH NDR GRGDWQL þODQ L]YRUD LOL SRQRUD
topline Sq u jednadžbL RþXYDQMD HQHUJLMH ]D ]UDN ). Inertno KODÿHQMH NDSOMLFD (izmjena
topline bez ishlapljivanja) odvija se kada je temperatura kapljice Tp manja od temperatureishlapljivanja Tvap LXWRPMHVOXþDMXQHPDL]PMHQHODWHQWQHWRSOLQH r d mp/d t = 0). Izmjena
WYDUL L ODWHQWQH WRSOLQH XNOMXþXMH VH NDGD WHPSHUDWXUD þHVWLFD GRVHJQH WHPSHUDWXUX
ishlapljivanja Tvap. Temperatura ishlapljivanja za koju je ovdje usvojeno 0°C nema fizikalnog

Energy and the Environment (2016) 497-508

501]QDþHQMD YHü VH NRULVWL NDR SDUDPHWDU X QXPHULþNRP PRGHOLUDQMX UDGL SRNUHWDQMD SURFHVD
ishlapljivanja. U jednadžbi (9), ostale varijable su masa kapljice mp, toplinski kapacitet cp,
površina kapljice Ap, temperatura zraka T, koeficijent prijelaza topline konvekcijom Į, faktor
emisije kapljice İp, Stefan-Boltzmannova konstanta ı LWHPSHUDWXUD]UDþHQMDTR. Masa kapljicese ]ERJLVKODSOMLYDQMDVPDQMXMHLWRSUHPDVOMHGHüRMMHGQDGåEL݀݉୮= െ݇୫ ൫‫ܥ‬୥ െ ‫ܥ‬ஶ ൯‫ܣ‬୮ ݉୵
݀‫ݐ‬

(10)

U (10) molna masa vode je mw, a EU]LQD LVKODSOMLYDQMD UDþXQD VH NDR XPQRåDN NReficijenta
prijenosa tvari km i razlike molnih koncentracija vodene pare u zraku uz površinu kapljice Cg iu slobodnoj struji zraka Cf. Koeficijenti prijelaza topline D [W/mK] i prijenosa tvari km [m/s]UDþXQDMXVHL]PHÿXVREQRDQDORJQLKL]UD]D]D1XVVHOWRY Nu) i Sherwoodov (Sh) broj [6]ܰ‫= ݑ‬

݄ܵ =D ݀୮= 2 + 0,6ܴ݁d 1/2 ܲ‫ݎ‬1/3

(11)

݇୫ ݀୮
= 2 + 0,6ܴ݁ୢଵ/ଶ ܵܿଵ/ଷ
‫ܦ‬୫

(12)

ߣ

Koeficijent difuzije vodene pare u zraku je Dm, toplinska vodljivost zraka je Ȝ, a
EH]GLPHQ]LMVNH ]QDþDMNH VX Reynoldsov (Re), Prandtlov (Pr) i Schmidtov (Sc) broj. Molna
NRQFHQWUDFLMDMHUHFLSURþQDYULMHGQRVWPROQRJYROXPHQDLUDþXQDVHL]MHGQDGåEHVWDQMD1D
površini kapljice parcijalni tlak vodene pare jednak je WODNX]DVLüHQMD pg = ps) za temperaturu
kapljice Tp, a parcijalni tlak vodene pare u slobodnoj struji zraka UDþXQD se iz Daltonovog
zakona (pf =rip)‫ܥ‬௚ =‫݌‬ୱ,ࡾܶ୮‫ܥ‬ஶ =‫ݎ‬୧ ‫݌‬ࡾܶஶ

(13),VSXQDWRUQMDLOLãNURSLORVOXåL]DSRYHüDQMHGRGLUQHSRYUãLQHL]PHÿX]UDNDLYRGHDPRGHOLUDse kao porozna zona [1]. Strujanje zraka i prijelaz topline u poddomeni ispune opisuju izrazi(2-5 VGRGDWNRPSRQRUDNROLþLQHJLEDQMDSMx i SMy u jednadžbamDRþXYDQMDNROLþLQHJLEDQMD
(3-4  3RQRU NROLþLQH JLEDQMD VDVWRML VH RG YLVNR]QRJ L LQHUFLMDOQRJ RWSRUD VWUXMDQMX ]UDND X
SRGUXþMXLVSXQH [6]. 8KRPRJHQRMSRUR]QRM]RQLSRQRUNROLþLQHJLEDQMDUDþXQa se kao
ܵெ౟ = െ(‫ܥ‬ଵ ߟ‫ݓ‬୧ + ‫ܥ‬ଶ ߩ‫ݓ‬୧ଶ /2)(14)
Faktori viskoznog i inercijalnog otpora C2 mogu se odrediti iz Ergunove polu-empirijske
korelacije [8] za pad tlaka po jedinici duljine poroznog materijala (Si = –'p/L)‫ܥ‬ଵ =

150(1 െ ߪ)ଶ

I ݀ୣ୪
ଶ

ଶ ଷ
ߪ

,

‫ܥ‬ଶ =

3.5(1 െ ߪ)
I ݀ୣ୪ ߪ ଷ

(15)

Ispuna rashladnog sastoji od 1 440 elemenata L]UDÿHQLK od tvrdog PVC-a debljine 0,2 mm.
Dimenzije elemenata su 1,2×0,3×0,3 m. Površina i masa ispune po jedinici volumena iznosi
243 m2/m3 odnosno 36 kg/m3. Poroznost ispune rashladnog tornja iznosi ı = 0.97, a
NDUDNWHULVWLþQD dužina LVIHULþQRVWHOHPHQWDUQRJGLMHODXLVSXQLiznose del = 50 cm i I = 0,002.
Ubacivanjem ovih vrijednosti u (15) dobivaju se vrijednosti C1 = 148000 m-2 i C2 = 115 m-1.

502

,âRLü3%OHFLFK%)UDQNRYLü: 7HUPRGLQDPLþNDDQDOL]DL]PMHQHWRSOLQH«

Efektivna toplinska vodljivost ispune Ȝef NRULVWL VH X MHGQDGåEL RþXYDQMD SRGGRPHQH ispune(5) i dobiva se interpolacijom toplinskih vodljivosti zraka Ȝef i materijala ispune ȜsOୣ୤ = ߪOf + (1 െ ߪ)Oୱ

(16)

2.3 Rubni uvjeti
Na ulazu u rashladni toranj zadaje se maseni protok, temperatura i sastav zraka. Maseni
protok zraka iznosi 31,75 kg/s, a vektor brzine zraka je okomit na ulazni presjek. Ulazna
temperatura zraka je T = 302 K, relativna vlažnost 60% i temperatura vlažnog termometra od
Tf = 296 K. Sudionici u zraku definiraju se masenim udjelima: dušik mN2 = 0,755, kisik mO2 =0,23 i vodena para mH2O = 0,015 [1]. Fizikalna svojstva ]UDNDUDþXQDMXVHQDVHLQWHUSRODFLMRP
svojstva pojedinih sudionika. Na izlazu iz rashladnog tornja postavlja se rubni uvjet izlaznog
WODND NRML RPRJXüDYD EROMX NRQYHUJHQFLMX RG UXEQRJ XYMHWD L]REUDåHQRJ VWUXMDQMD Zidovi
rashladnog tornja su adijabatski jer su gubici topline prema okolini zanemarivi u odnosu naizmijenjenu toplinu unutar tornja. Topla voda masenog protoka ‫ۦ‬w = 26,16 kg/s i ulazne
temperature Tw = 311 K, jednoliko se dijeli na 12 mlaznica koje ju raspršuju na ispunu tornja
JGMHVHKODÿHQMHRGYLMDXSURWXVPMHUQRPVWUXMDQMXVD]UDNRP [1]. Mlaznice se modeliraju kao
injekcije, pri þHPX se zadaje položaj mlaznica kao na slici 2. Distribucija promjera kapljica
definirana je Rosin-5DPPOHUIXQNFLMRPSULþHPXMHUDVSRQSURPMHUDNDSOMLFD od 1 mm do 3mm, SURVMHþQLSURPMHU je 2 mm, a faktor rasapa distribucije 3,5. Nakon ispune, voda pada na
dno tornja, u bazen s vodom. Fizikalna svojstva vode su: JXVWRüDȡw = 998,2 kg/m3, toplinski
kapacitet cw = 4182 J/kgK, toplinska vodljivost Ȝw = 0,6 W/mK, latentna toplina r = 2420
kJ/kg. 0DWHULMDOLVSXQHMHWYUGL39&>@JXVWRüHȡs = 1300 kg/m3, toplinskog kapaciteta cs =900 J/kgK i toplinske vodljivosti Ȝs = 0,19 W/mK. 8SRGUXþMXLVSXQHtornja pretpostavlja se
konstantna temperatura materijala od 311 K i koeficijent prijelaza topline od 40 W/m2K
L]UDþXQDWQDWHPHOMXEU]LQHVWUXMDQMD]UDNDXLspunLRGPVSRPRüXL]UD]D ).
3. REZULTATI I ANALIZA
Rezultati su prikazani za pogon rashladnog tornja s maksimalnim protokom zraka od
31,75 kg/s. Protok vode iznosi 26,16 kg/s što rezultira omjerom protoka vode i zraka od
0,824. Temperatura i relativna vlažnost zraka na ulazu u rashladni toranj iznose 29 °C i 60%.
Temperatura vlažnog termometra zraka je 23 °C. Topla voda dovodi se pri temperaturi od
38°C.
Na slici 3 prikazane su raspodjele brzina strujanja i temperatura zraka unutar rashladnog
tornja GRELYHQH QXPHULþNLP SXWHP. Zrak u rashladni toranj ulazi brzinom od 5,5 m/s i
WHPSHUDWXURP RG  . 1DNRQ XOD]D EU]LQD VH ]UDND SRVWHSHQR VPDQMXMH ]ERJ SRYHüDQMD
slobodnog presjeka strujanja dok se masa zraka usmjerava prema vrhu rashladnog tornja.
=ERJWRJDVHXSRGUXþMXRNRSUYHPOD]QLFHVWYDUDUHFLUNXODFLMD]UDNDLEU]LQHVWUXMDQMD]UDND
su najmanje. 1DMYHüHEU]LQHVWUXMDQMD]UDNDMDYOMDMXVHQDVXSURWQRMVWUDQLL]QDGSRVOMHGQMLK
mlaznica gdje se masa zraka sudara sa zidom tornja, a slobodni se presjek strujanja smanjuje.

Energy and the Environment (2016) 497-508503b) T(K)a) w(m/s)

Slika 3. 1XPHULþNLPSXWHPGRELYHQD raspodjela:a) brzina strujanja i b) temperatura zraka u rashladnom tornju
8SRGUXþMXLVSRGLVSXQHWRUQMD]UDNVHKODGLGRWHPSHUDWXUHRG.]ERJL]PMHQHODWHQWQHWRSOLQH L]PHÿX NDSOMLFD YRGH L ]UDND 0HÿXWLP X SRGUXþMX LVSXQH ]UDN VH ]DJULMDYD
ponajprije zbog izmjene osjetne topline, sve do izlazne temperature od 309,4 K. Na slici 4
prikazane su putanje kapljica u bojama temperature. Kapljice vode se po izlazu iz mlaznicaSRþLQMX KODGLWL V SRþHWQH WHPSHUDWXUH RG  . SURFHVRP LVKODSOMLYDQMD NRML VH RGYLMD QD
SRYUãLQL NDSOMLFD YRGH 1DM]QDþDMQLMD SURPMHQD WHPSHUDWXUH NDSOMLFD GRJDÿD VH X LVSXQLWRUQMD3XWDQMHNDSOMLFDYRGH]DNUHüXXGHVQRSRGXWMHFDMHPNLQHWLþNHHQHUJLMHPDVH]UDND
T(K)

504

,âRLü3%OHFLFK%)UDQNRYLü: 7HUPRGLQDPLþNDDQDOL]DL]PMHQHWRSOLQH«

Slika 4. Putanje kapljica vode u rashladnom tornju
Slika 5 – a) prikazuje raspodjelu sadržaja vodene pare u zraku unutar rashladnog tornja.
Maseni udio pare u zraku na ulazu iznosi 0,015 kgv/kgz L SRYHüDYD VH ]ERJ LVKODSOMLYDQMDNDSOMLFD YRGH 'R QDMYHüHJ XGMHOD YRGHQH SDUH GROD]L X SRGUXþMX UHFLUNXODFLMH ]UDND ]ERJVPDQMHQRJ GRWRND VYMHåHJ ]UDND 3URVMHþQL XGLR YRGHQH SDUH na izlazu iz rashladnog tornja
iznosi 0,0282 kgv/kgz.
a) x(kg/kg)b) ‫ۦ‬p (kg/s)

Slika 5. 1XPHULþNLPSXWHPGRELYHQD raspodjela:a) masenih udjela vodene pare i b) izmjene tvari pri ishlapljivanju
Slika 5 – b) prikazuje izmjenu tvari kod LVKODSOMLYDQMD 2þHNLYDQR QDMYHüD L]PMHQD WYDULGRJDÿDVHQHSRVUHGQRLVSRGPOD]QLFDLGXåSXWDQMDNDSOMLFDYRGH.ROLþLQDLVKODSOMHQHYRGHpo jedinici zraka iznosi 0,0132 kg/(kgs)DXNXSQDNROLþLQDLVKODSOMHQHYRGHL]QRVLNJV
Stoga udio ishlapljeQH YRGH X XNXSQRP SURWRNX RSWRþQH YRGH L]QRVL  8 UDVKODGQLPWRUQMLPD JXELWDN RSWRþQH YRGH LVKODSOMLYDQMHm u zUDN L]QRVL L]PHÿX  L  >-4, 9].
7HPSHUDWXUX YRGH QD L]OD]X PRJXüH MH L]UDþXQDWL L] ELODQFH WRSOLQH UDVKladnog tornja. U

Energy and the Environment (2016) 497-508505VOXþDMXUDVKODGQRJtornja bez gubitaka topline prema okolini, sadržaj topline u masama zraka
i vode na ulazu jednak je sadržaju topline u masama zrake i vode na izlazu, tj.
݉ሶ୸,୳୪ ݄୸,୳୪ + ݉ሶ୵,୳୪ ݄୵,୳୪ = ݉ሶ୸,୧୸୪ ݄୸,୧୸୪ + ݉ሶ୵,୧୸୪ ݄୵,୧୸୪

(17)

Maseni protok zraka na izlazu jednak je onom na ulazu u rashladni toranj ( ‫ۦ‬z,ul = ‫ۦ‬z,izl) ali je
PDVHQL SURWRN YRGH QD L]OD]X XPDQMHQ ]D NROLþLQX LVKODSOMHQH YRGH ‫ۦ‬w,izl = ‫ۦ‬w,ul – ‫ۦ‬w,ish).
Temperatura vode na izlazu, tako da se (17) može zapisati kao‫୵ݐ‬,୧୸୪ =݉ሶ୵ ܿ୵ ‫୵ݐ‬,୳୪ െ ݉ሶ୸ (݄୸,୧୸୪ െ ݄୸,୳୪ )(݉ሶ୵ െ݉ሶ୵,୧ୱ୦ )ܿ୵

(18)Sadržaj topline X]UDNXSRYHüDYDVH]ERJL]PMHQH osjetne i latentne topline tako da vrijedi݉ሶ୸ ൫݄୸,୧୸୪ െ ݄୸,୳୪ ൯ = ܳሶ୭ୱ + ܳሶ୪ୟ୲ = ݉ሶ୸ ܿ୮ ൫‫୸ݐ‬,୧୸୪ െ ‫୸ݐ‬,୳୪ ൯ + ݉ሶ୸ ‫ݔ(ݎ‬୧୸୪ െ ‫୳ݔ‬୪ )(19)

Na ulazu u toranj zrak ima temperaturu od 302 K i sadržaj vodene pare od 0,015 kgv/kgz uz
relativnu vlažnost od 60%. Na izlazu zrak postiže temperaturu od 309,4 K, sadržaj vodene
pare od 0,0282 kgv/kgz, a relativna vlažnost iznosi 75%. ,]PLMHQMHQL WRSOLQVNL WRN L]PHÿXvode i zraka L]QRVL  N: RG þHJD  N: RWSDGD QD RVMHWQX WRSOLQX D 1014 kW na
latentnu toplinu.
UbacLYDQMHP SR]QDWLK YHOLþLQD X   VOLMHGL GD QXPHULþNLP SXWHP GRELYHQD WHPSHUDWXUD
vode na izlazu iz rashladnog tornja iznosi 27 °C. U rashladnom tornju, najniža temperatura na
NRMX VH PRåH RKODGLWL WRSOD YRGD RJUDQLþHQD MH WHPSHUDWXURP YODåQRJ WHUPRPHWUD ]D ]UDN
Stoga se XþLQNRYLWRVW UDVKODGQLK WRUQMHYD NRMD VH X SUDNVL NUHüH L]PHÿX  L  >@UDþXQDNDR

K=‫୵ݐ‬,୳୪ െ ‫୵ݐ‬,୧୸୪
100%‫୵ݐ‬,୳୪ െ ‫୸ݐ‬,୴୪(20)

Uz temperaWXUXYODåQRJWHUPRPHWUDRG&VOLMHGLXþLQNRYLWRVWUDVKODGQRJWRUQMDRG
7HKQLþND GRNXPHQWDFLMD UDVKODGQRJ VXVWDYD X ,1$ UDILQHULML 8ULQM >10] prenose vrijednost
izlazne temperature vode od 26 °C L XþLQNRYLWRVW UDVKODGQRJ WRUQMD RG . Odstupanje
L]PHÿX SUHGYLÿHQH L L]PMHUHQH YULMHGQRVWL L]OD]QH WHPSHUDWXUH YRGH PRåH ELWL SRVOMHGLFDXVYRMHQLKSUHWSRVWDYNLLRGDEUDQLKSDUDPHWDUDXQXPHULþNRPPRGHOLUDQMX]DNRMHQHSRVWRMH
GRYROMQR WRþQL VWYDUQL SRGDFL .RQNUHWQR QXPHULþNRP DQDOL]RP MH REXKYDüHQ
dvodimenzijsko strujanje i prijelaz topline u rashladnom tornju s pojednostavljenom
JHRPHWULMRP SRJRWRYR X SRGUXþMX LVSXQH ,VSXQD WRUQMD PRGHOLUD VH NDR SRUR]QR WLMHOR X
kojemu se zadaju konstantna temperatura površine i koeficijent prijelaza topline. Nadalje,
nekolicina parametara mlaznice poput kuta rasprskavanja, izlazne brzine i promjera kapljica
YRGHVQDåQRXWMHþXQDNRQDþQHUH]XOWDWH
3UHWKRGQDDQDOL]DMHSURYHGHQD]DUDVSRQSURPMHUDNDSOMLFDYRGHRGPPGRPPSULþHPXMH SURVMHþQL SURPMHU PP 6manjenje promjera kapljice vode UH]XOWLUD SRMDþDQMHP izmjene
ODWHQWQHWRSOLQH]ERJYHüHNRQWDNWQHSRYUãLQHL]PHÿXNDSOMLFDYRGHL]UDND3ULPMHULFHDNRVH
SURPMHUNDSOMLFHSUHSRORYLWDGDVHNRQWDNWQDSRYUãLQDXGYRVWUXþLDXNXSDQEURMNDSOMLFDNRML
izlazi L]POD]QLFDSRYHüDVH]DSXWD7DNRMH]DUDVSRQSURPMHUDNDSOMLFDRGPPGRPPX]SURVMHþQLSURPMHURGPPNROLþLQDLVKODSOMHQHYRGHLL]PMHQDODWHQWQHWRSOLQHSRYHüDQDza 14%: sa 0,42 kg/s na 0,48 kg/s odnosno sa 1014 kW na 1157 kW. S druge strane izmjena
osjetne topline se smanjuje: sa 241 kW na 196 kW zbog snažnijeg ishlapljivanja. Ukupna

506,âRLü3%OHFLFK%)UDQNRYLü: 7HUPRGLQDPLþNDDQDOL]DL]PMHQHWRSOLQH«

L]PMHQDWRSOLQHSRYHüDQDMHVDN:QDN:,]OD]QDWHPSHUDWXUDYRGHGRELYHQD]DVOXþDM PDQMLK NDSOMLFD YRGH L]QRVL  & ãWR MH YUOR EOL]X SRGDWNX RG  & L] WHKQLþNH
dokumentacije [10]. 0DQMHNDSOMLFHYRGHSRYHüDYDMXXþLQNRYLWRVWUDVKODGQRJWRUQMDQD
4. =$./-8ý$.
U ovom radu je izvršena analiza izmjene topline i tvari u rashladnom tornju. Dvodimenzijska
GRPHQD XPUHåHQD MH PHWRGRP NRQWUROQLK YROXPHQD L REXKYDüD SRGUXþMH ]UDND L SRGUXþMHLVSXQH 3RGUXþMH LVSXQH PRGHOLUDQR MH NDR SRUR]QR WLMHOR SRVWDYOMDQMHP RGJRYDUDMXüLKYHOLþLQD]DSRQRUNROLþLQHJLEDQMDRGQRVQRSULMHOD]WRSOLQHL]PHÿXPDWHULMDODLVSXQHL]UDND
Strujanje zraka unutar rashladnog tornja modelirano je standardnim k-ѓ modelom turbulencije.
.DSOMLFH YRGH NRMH VH SRPRüX  POD]QLFD UDVSUVNDYDMX SR LVSXQL WRUQMD PRGHOLUDMX VH
/DJUDQJHRYLPSULVWXSRP]DGLVNUHWQHþHVWLFH7XUEXOHQWQDGLVSHU]LMDNDSOMLFDYRGHRSLVXMHVHVWRKDVWLþNLPPRGHORPSUDüHQMDUHSUH]HQWDWLYQRJEURMDþHstica. Na svaku od reprezentativnih
kapljica vode postavlja se jednadžba ravnoteža sila kojom se definira putanja i jednadžba
RþXYDQMDHQHUJLMHNRMRPVHRSLVXMHL]PMHQDWRSOLQHLWYDUL
1XPHULþNDDQDOL]DUDVKODGQRJWRUQMDSURYHGHQDMH]DVOMHGHüHSRJRQVNH uvjete: protok zraka
od 31,75 kg/s i protok vode od 26,16 kg/s, ulazna temperatura i vlažnost zraka od 29 °C i
60%, ulazna temperatura vode od 38 & 7HKQLþND dokumentacija rafinerije daje vrijednost
izlazne temperature vode od 26 °C dok se ostali podaci poput temperature i vlažnosti zraka na
izlazu rashladnog tornja ne spominju, a mjerenja na lokaciji nisu bila izvediva zbog
nepristupaþQRVWL YUKX WRUQMD L VLJXUQRVQLK UD]ORJD. Stoga je osnovni parametar za provjeru
UH]XOWDWDQXPHULþNHDQDOL]HELOD temperatura vode na izlazu rashladnog tornja. Postavljanjem
ELODQFHWRSOLQHUDVKODGQRJWRUQMDQXPHULþNDDQDOL]DSUHGYLÿDL]OD]QHWHPSHUDWXUHYRGHRG°C za promjer kapljica od 2 mm odnosno 26,1 °C za promjer kapljica od 1,5 mm, što je vrlo
blizu vrijednosti od  & L] WHKQLþNH GRNXPHQWDFLMH 8þLQNRYLWRVW UDVKODGQRJ WRUQMD L]QRVL X VOXþDMX YHüLK NDSOMLFD YRGH RGQRVQR  X VOXþDMX PDQMLK NDSOMLFD YRGH Manje
NDSOMLFH YRGH UH]XOWLUDMX YHüRP NRQWDNWQRP SRYUãLQRP L]PHÿX NDSOMLFD L ]UDND þLPH VH
izmjena latentne topline pospješuje, a izlazna temperatura vode dodatno smanjuje. Na temelju
GRELYHQLKUH]XOWDWDQXPHULþNHDQDOL]HPRåHVH]DNOMXþLWLGDMHSRVWDYOMHQLPDWHPDWLþNLPRGHOX PRJXüQRVWL LVSUDYQR opisati izmjenu topline i tvari u rashladnom tornju. Smjernice za
GDOMQML UDG REXKYDüDMX QXPHULþNX DQDOL]X VWUXMDQMD ]UDND L]PMHQH WRSOLQH L WYDUL X
trodimenzijskom modelu rashladnog tornja te detaljniju DQDOL]X YDULMDEOL NRMH XWMHþX QD
XþLQNRYLWRVW UDVKODGQRJ WRUQMD SRSXW RPMHUD RSWRþQH YRGH L ]UDND XOD]QLK WHPSHUDWuri ivlažnosti zraka, svojstva ispune i mlaznica kao što su kut rasprskavanja, izlazne brzine ipromjera kapljica vode.
5. LITERATURA
[1]
[2]
[3]
[4]

,âRLü7HUPRGLQDPLþNDDQDOL]DL]PMHQHWRSOLQHL prijenos tvari u rashladnom tornju,
GLSORPVNLUDG7HKQLþNL IDNXOWHW6YHXþLOLãWDX5LMHFL5LMHND
D. Kröger: Air-cooled heat exchangers and cooling towers, Thermal-flow
performance evaluation and design, Vol. I, PennWell Corporation, Tulsa, 2004.
D. Kröger: Air-cooled heat exchangers and cooling towers, Thermal-flow
performance evaluation and design, Vol. II, PennWell Corporation, Tulsa, 2004.
F. %RãQMDNRYLü: Nauka o toplini, Svezak I, II i III, Graphis d.o.o, Zagreb, 2012.

Energy and the Environment (2016) 497-508

[5]
[6]
[7]
[8]
[9]
[10]

507

% )UDQNRYLü, . /HQLü: Termodinamika smjesa, materijali i bilješke s predavanja,
7HKQLþNLIDNXOWHW6YHXþLOLãWDX5LMHFL5LMHNDANSYS Fluent 16.2 – Documentation, PA, Pittsburgh, USA, 2015.
A. Trp, . /HQLü: 1XPHULþNR PRGHOLUDQMH X WHUPRGLQDPLFL, materijali i bilješke s
predavanja7HKQLþNLIDNXOWHW6YHXþLOLãWDX5LMHFL5LMHND
S. Ergun: Fluid flow through packed columns, Chemical Eng. Progress 48, 89-94,
1952.
E. Škrobonja: Termodinamska analiza uplivnLK YHOLþLQD NRG KODÿHQMD YRGH X
kaminima SRPRüX X]GXKD, doktorska disertacija, Fakultet strojarstva i brodogradnje
6YHXþLOLãWDX=DJUHEX=DJUHE
Grupa inženiring d.o.o: Ispitivanje rashladnog sustava u INA Rafineriji Urinj nakon
izmjene ispune tornjeva ET-005 do ET-008, Ljubljana, 1995.

508,âRLü3%OHFLFK%)UDQNRYLü: 7HUPRGLQDPLþNDDQDOL]DL]PMHQHWRSOLQH«

THERMODYNAMIC ANALYSIS OF HEAT AND MASS
TRANSFER IN A COOLING TOWER
Abstract: this paper gives the thermodynamic analysis of heat and mass transfer inside a
cooling tower with forced air draft. The cooling tower is situated in the INA Oil refinery in
Rijeka at Urinj, as part of a cooling system comprising 8 cooling towers. The introductory
part of this article discusses the basics of evaporation and briefly describes cooling towers
with forced draft. The numerical analysis of heat and mass transfer inside the cooling tower
was performed using the computer software ANSYS Fluent while the computational domain
was meshed in the software Gambit. The mathematical model which consists of theconservation equations, the computational domain and the boundary conditions is also
described. The domain is discretized using the finite volume method while the unknown
quantities between neighboring volumes are solved using the second order upwind scheme.
The coupling between pressure and velocity fields is performed by the SIMPLE algorithm.
The presented results include the numerically obtained distributions airflow velocity, airtemperatures and water contents inside the cooling tower as well as mass transfer rates by
evaporation. The outlet water temperature, as the most important parameter in the analysis,
is obtained from the cooling tower heat balance and compared against the value given by thecooling tower technical report.
The resulting outlet water temperature is 27 °C for a mean water droplet diameter of 2 mm
and 26.1 °C for a droplet diameter of 1.5 mm while the value given by the technical report is
26 °C, thus confirming the validity of the chosen mathematical model for the cooling tower.
Keywords: cooling tower, forced air draft, numerical modeling, heat transfer, mass transfer

Energy and the Environment (2016) 509-518

509

FEEDBACK INFORMATION ON THE DYNAMIC SIMULATIONS OF
OFFICES EQUIPPED WITH RADIANT HEATING AND COOLING
CEILING SYSTEM
S. Jordan1, J. Hafner1, F. Knez1, A. Legat1, M. Zbašnik-6HQHJDþQLN2,
Slovenian National Building and Civil Engineering Institute (ZAG), 'LPLþHYD
Ljubljana, Slovenia, +386 1 2804 454, +386 1 2804 484, sabina.jordan@zag.si
2
UL-Faculty of Architecture, University of Ljubljana, Zoisova cesta 12, 1000 Ljubljana,
Slovenia
1

Abstract: When creating a simulation model to assess various performances of buildings, there
is usually a lack of feedback information. Only in case of measurements and simulations on thesame and real building case, a direct comparison of the measured and simulated results ispossible. This way, more detailed data can be obtained for further use as well. It is widely known
that occupants’ activity and other events can influence indoor temperature conditions and thus
have an important impact on the operation of the heating/cooling system, on the energy balanceof building and the indoor thermal comfort. This is especially true for innovative technologies inbuildings and design concepts for which there is a lack of practical evidence. Frequency,
intensity and duration of such events, along with boundary conditions, are crucial. It is clearthat for computer modelling none of them can be predicted very precisely. But they are probably
also the main cause for the huge discrepancy between the expected and the real energy use inbuildings. In this paper, we present an analysis performed on the well-defined TRNSYS
simulation model of offices equipped with radiant ceiling panels for heating and cooling. The
model was based on and verified via measurements in real offices. The analysis, which includes
simulation and measurements results in a one-year period, was performed in order to define
what impact on the energy use specific inputs have.
Key words: offices, radiant ceiling panels, measurements, simulations, analysis, validation,energy impact.
1. INTRODUCTION

Dynamic simulation programs are commonly used for modelling and analyzing various building
systems, such as energy performance and thermal comfort of buildings. However, creating a
reliable simulation model equipped with adequate data can be crucial for the results. By
performing TRNSYS computer simulations of a typical office floor equipped with a radiantcooling system, it has been established that occupant behaviour can have an important influenceon the cooling needs and thermal comfort [1]. Similar conclusions have been made ininvestigations of a possible impact of occupant behaviour on building performance and thermal
comfort in conventionally heated buildings: compared to the design strategy used in the model,
the measured energy demand can be twice as high and thermal comfort much lower [2]. In caseof measurements on a real building and simulations on the model of the same real building, a
direct comparison of measured and simulated results proves possible and more detailed data forfurther use can be obtained.
The purpose of the present study was to analyze such a model. This was well-defined TRNSYS
model of offices equipped with radiant ceiling panels for heating and cooling. The model was a

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replica of real offices as much as possible. All simulation results were compared and validatedwith measurements results. The aim of the analysis was to define the impact of the specific input
data on the energy use for heating and cooling the offices.
2. MATERIALS AND METHODS
2.1 Modelling Basis
The model is based on a real case geometry of four interconnected offices in size of 108 m2(Figure 1a, 1b). These offices form part of the 5th floor of an office building in Ljubljana,
Slovenia (46°40 N, 14°31 E). This location is characterized by a mixed climate, with somecontinental and Mediterranean characteristics, i.e. warm summers and moderately cold winters.

a)b)
Figure 1. Office 2 (a) and Office 4 (b) of real premises, which were the basis for modelling.
The premises are equipped with radiant ceiling heating/cooling panels (Figure 2a, 2b) andmechanical ventilation [3] [4] [5]. The whole system is managed by the building’s management
system and respectively equipped with measuring devices: temperature sensors, calorimeters,
etc. (Figure 3a). Additional temperature sensors were installed for research purposes (Figure 3b).

a)b)
Figure 2. Radiant ceiling panels in the offices: the installation (a) and the final appearance (b).
In modelling, all necessary data, collected from the monitored real offices, were used: theorientation of the main façade (15° SW) with the dimensions, position and characteristics of theEnergy and the Environment (2016) 509-518

511

windows, dimensions and composition of structural elements, boundary conditions, air exchange
rate between indoors and outdoors, HVAC including radiant ceiling system and their regulation,user behavior and furnishing.

a)b)
Figure 3. Measuring equipment: calorimeters (a) and additional air temperature sensors (b).

2.2 Modelling for simulation execution
As in the real offices, the geometry of the TRNSYS model involved four main zones, and an
unconditioned attic above them as a surplus fifth model zone. It also comprised a roof above thewindows, which provided a shade for the office windows. An additional subdivision of modelzones into five equal horizontal layers was also made. The model was completed using a
TRNSYS Type 56 block [6] with an identical structure of building elements and indoor
furnishings as the real offices. A basic description of the building envelope elements that wereused in the model, including their calculated thermal transmittance and the total solar energy
transmittance of the glazing (g-value), is given in Table 1.
The windows in the model were used as to correspond to all the characteristics of the actual
façade, including its calculated share of 36 % glazing. The thermal capacitance of interior
furnishings and radiant ceiling panels was estimated and included in the model as well.
Furthermore, the air exchange rate between indoors and outdoors, which was measured on siteaccording to the standardized measuring procedure [7] at a pressure difference of 50 Pa, wasrecalculated to normal pressure and applied to the model.
The model was supplemented by the Layer Type Chilled Ceiling [6], which is one of the existingroutines defined in TRNSYS. It was used for the simulation of radiant ceiling system in theoffices. It consists of ceiling panels which cover the pipes and these contain water as energy
media. The panels were all set to operate in the same mode, i.e. in either heating or coolingmode. The regulation of the Layer Type Chilled Ceiling was implemented the same way as in thereal offices, that is by switching the water flow ON and OFF. All necessary data was prescribedwithin the Layer Type Chilled Ceiling, e.g. the radiant energy transfer coefficient 8.3 W/(m2K),
the nominal water flow 30 kg/(m2h).
Table 1: Main building elements of the model.

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Constructional elements

Description

U-valueW/(m2K)

External wall (façade)Concrete wall (20 cm) with 12 cm of thermal
insulation and artificial stone cladding

0.28

Ceiling to the unheated attic

Concrete slab (20 cm), plastered, with 20 cm ofthermal insulation on top

0.18Internal lightweight wall

Lightweight gypsum sandwich wall with 10 cm ofthermal insulation

0.34

Internal solid wall

Brick wall (12 cm) with plaster on both surface
sides

2.71

Internal wall to the corridor

Combination of brick wall (12 cm) and particle
board wall

1.31

Floor to indoor spaces

Concrete slab (20 cm) with 7 cm of screed and 2 cmof thermal insulation

1.00

Window frameHigh insulation aluminum window frame withspacer to avoid thermal bridge

1.60

Window glazing

Triple glazing with Argon gas filling and low-e
coatings (g-value 0.29)

0.70

The ceiling panels in the model were operated via virtual room temperature regulators, similar toroom temperature regulators in the offices. Settings in the model were adjusted to the actual
settings of the offices: the air temperatures were set to 22 °C in heating mode (with night-time
reductions by 1 K and weekend reductions by 2 K) and 24 °C in cooling mode (with adjustmentsof ±2 K). The mechanical ventilation system in the model was simulated at a level close to theceiling, in the same way, that the inlets and outlets of air in the real offices were arranged andwith the air inlet quantity (kg/h) and the temperature (°C) of 23-24 °C for both the heating andthe cooling mode. The air exchange between horizontal layers in specific zones of the model was
also taken into account.
External conditions as well as boundary conditions of the indoor environment were taken into
account for the simulations. The data for the external conditions, which were used in the model,
were provided by the Slovenian Environment Agency [8]. These data consisted of actual outdoor
air temperatures and solar irradiation for Ljubljana in 2013. Indoor boundary conditions of themodel were defined in quantity as they were measured in adjacent rooms, corridors, and officesof the real building. Solar gains through the windows of the model were recalculated
automatically by the software from the solar irradiation data in 2013 [8]. The calculation
involved the geometry of the model (counting also the roof geometry), automated venetianblinds, as well as the g-value of the glazing. Regulation of the solar gains by means of venetianblinds for further use in the model was estimated in correlation with the measurements. Their
shading coefficient varied between 0.40 and 0.80 when inhabited by occupants, with theminimum factor being typically applied in January and December. The shading coefficient ofEnergy and the Environment (2016) 509-518

513

internal roller blinds, estimated to amount to 0.30 and ultimately serving to reduce glare in thereal offices, was employed in the model as well.
The following three types of internal gains, which were assessed in real offices, were taken into
account: office users (four in office 2, and one of each in offices 1, 3, and 4), working devices,
and artificial lighting. Internal gains from users (estimation: light work) amounted to 75 W perperson, wherein only the sensible heat was taken into account [9]. The calculation was based on
the average daily values in working and non-working days. These were summarized into total
values, separately for the heating period and cooling periods. Internal gains for the heating
season amounted to 20.5 kWh/(m2period) in Office 1, 33.5 kWh/(m2period) in Office 2, 16.9
kWh/(m2period) in Office 3 and 18.8 kWh/(m2period) in Office 4. Internal gains for the coolingseason were 13.2 kWh/(m2period) in Office 1, 22.0 kWh/(m2period) in Office 2, 10.5
kWh/(m2period) in Office 3 and 11.5 kWh/(m2period) in Office 4.
3. ANALYSIS OF RESULTS
3.1 Validation of the model
The validation of the model was based on its comparison with the measurement results obtainedin the above mentioned real case office. The validation was taking place throughout the year
2013 (Figure 4) and consisted of regular assessments of measured and simulated indoor air
temperatures and energy utilization. Percentage values of root mean square error (RMSE) andmean bias error (MBE) for the simulated energy from the office panels and for the airtemperatures were calculated [4] according to the established protocols [10] [11].

Figure 4. Simulated and measured energy released to all offices via radiant ceiling panels andaveraged simulated and measured indoor air temperatures in Office 2 for the year 2013.

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The simulated yearly heating energy released by the ceiling panels was by 2.0 % higher than
measured energy utilization, whereas the simulated yearly cooling energy released by the ceiling
panels was by 0.2 % lower than measured energy. In total, the simulated energy utilization was
therefore only by 0.8 % higher than the measured energy released into the offices through theradiant ceiling panels. Moreover, the simulated indoor air temperatures in the offices matched
the measured temperatures very well. The average RMSE of the simulated temperature values
for all four pilot offices was ±0.45 K in the heating season and ±0.58 K in the cooling season.
3.2 Specific inputs and their impact
It is well known that occupants’ activities and other events can influence indoor temperature
conditions, and thus have an important impact on the operation of ceiling panels and energy
utilization. But what levels of frequency, intensity and duration of such events are crucial for thesystem (along with boundary conditions), and also – should they be included into the model?
While it is clear that none of these events can be predicted with utmost precision, some of themare probably among the main causes for the huge discrepancy between the predicted and the realenergy consumption in buildings.
Usually, when modelling different performances of buildings, there is a lack of feedback
information. The situation in our case was quite the opposite, as it was possible to directlycompare the results obtained from simulations with those from the measurements. A complex
but optimized model was created for the purposes of this research. It included all the importantelements and additional data, which were acquired through constant analysis of themeasurements. This model was later used for the analysis of the impact of specific inputs on theenergy utilization in the offices. The effect was observed on the seasonal as well as on the totalenergy output levels in the offices. The following four specific input data in the model weremonitored: intensive internal gains in one of the offices, use of internal roller blinds, additional
extraction of energy with exhausted air of the mechanical ventilation system due to unpredicted
temperature differences and the window opening by occupants (Table 1). The simulations were
performed for each single unit of input data so that the parameter under consideration was
excluded from the optimized model. Then the results were compared with the results from thesimulation on the optimized model (with all data/parameters included).
The first analyzed input data were the unusual and quite intensive internal gains in Office 4
which occurred in winter 2013. In March, an extra expert was working in this office for six days;
he was using supplementary computer and a 3D scanner. These additional internal gains were
included in the model. They were intensive but short-term and had noticeable impact on themeasured indoor air temperature curve. However, the simulations showed that, when excluded
from the model, they have a relatively moderate seasonal impact on the energy utilization, i.e.
2.3 % in the heating season. If they had been observed on an annual energy level, their impact
would have been small: according to these simulations, 1.0 % more energy is needed for heating
per year if these additional internal gains are excluded from the model.
Next, the impact of the use of internal shadings (roller blinds) was investigated. Occupants’
activities, such as their daily use of roller blinds for protection against glare, were estimated fromthe actual use. As such, they were included into the optimized model. For the purposes of thisanalysis, simulations on the model without the blinds confirmed that the use of internal roller

Energy and the Environment (2016) 509-518

515

blinds has positive influence in one season. But this positive effect is counterbalanced by thenegative one in another season. If the internal roller blinds were excluded from the model, theenergy utilization in the offices was lower by 2.6 % in the heating season and higher by 2.9 % in
the cooling season. The consequence was an impact of 0.5 %, which almost equals a zero energy
impact on the yearly simulation output of the whole model.
One of the features scrutinized in our analysis was the opening and closing of windows. The
simulation results showed that 2.0 % less energy was used on the model of offices due toelimination of window opening during the heating season. It should be noted that the offices
were mechanically ventilated and, in this respect, there was no need for opening the windows for
fresh air supply. A random and quite infrequent opening of the windows during the heating
season was essentially a result of the psychological needs of occupants. This also resulted in asmall impact of window opening on energy use in the offices during the heating period. In thecooling season, in contrast, the simulation results without window opening exposed a 7.3 %increase in energy utilization. This clearly showed that occupants opened the windows very
thoughtfully: mainly when the outdoor air temperatures were lower than indoor air temperatures.
Nevertheless, both effects resulted in a moderate 3.2 % yearly energy impact of higher energy
use in total.
Table 1. The simulation results for energy impact of input data in the model.
SPECIFIC INPUT DATA EXCLUDED FROM MODEL
Intensiveinternal
gains

Use ofinternal roller
blindsWindow
opening by
occupants

Extraction of
extra energy withexhausted air

Frequency

Once

Continuously

Many times

Continuously

Duration

6 days in
March

Whole year

Whole year

Whole year

Location

Office 4

All offices

All offices

All offices

Heating

1486

1414

1423

1438

Cooling

1806

1859

1938

1933

Total

3292

3273

3361

3371

Heating+2.3 %-2.6 %-2.0 %-1.0 %

Cooling-+2.9 %+7.3 %+7.0 %

Total+1.0 %+0.5 %+3.2 %+3.5 %

Energyutilization(kWh/a)Energyutilization(%)

A very similar situation also applies to the extraction of energy from exhausted air produced bymechanical ventilation due to unpredicted air temperature differences in the offices. These airtemperature differences were included into optimized model as the consequence of the analysis
of air temperature measurements. The energy impact of the extraction of this extra heat produced

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by the exhausted air flowing through the air outlets of mechanical ventilation system in thecooling season was quite significant. The simulations showed that if this specific input was
excluded from the model, 7.0 % more energy was used for cooling. This confirms that the airtemperatures in the upper air layers of the rooms, close to windows, can be considerably higher
than in other locations of an office. During the heating season, however, the above mentioned airtemperature differences were relatively small. Consequently, the energy impact was only 1.0 %,and counteracting. Nevertheless, the simulations on the model with no extraction of heat withexhausted air through the mechanical ventilation system’s air outlets due to unpredicted airtemperature differences resulted in a moderate 3.5 % higher energy use in total.
4. CONCLUSION
In this study, an analysis of detailed TRNSYS simulation model based on real case office data
was presented. Dynamic simulations on this model were performed for the year 2013, the same
year as the measurements. For this period, we evaluated the impact of occupants’ activities andseveral other identified events. The above mentioned TRNSYS model, which was optimized
according to in-depth analysis of the measured results, reflected the actual situation in the pilot
offices well. It can be concluded that the correlation between the measured and the simulated
results was indeed very good.
Through the analysis of the simulations on this optimized model, it has been established that
intensive but short term inputs actually have a very small impact on total energy use. It has also
been demonstrated that certain individual continuous impacts of specific inputs are practicallynegligible. Nevertheless, various seasonal or continuous activities can have a more significant
impact on energy utilization during a specific season of the year, which has consequences at theannual level as well. The simulations actually revealed that their influence in one season can beeither counteracted or/and dominated in another season. Furthermore, based on the analysis of
the simulations, it can be concluded that these activities can positively influence the energybalance on annual level, mainly because of the positive and dominant impact in the coolingseason.
In this study, the simulations have shown that intensive and short-term inputs, the so-called
unpredicted additional large internal gains, have a very small, 1.0 %, impact on the annual
energy level. At the same time, a continuous dynamics, such as the use of internal roller blinds,
has a small positive effect in one season, and a negative one in another. On the annual level,
however, its impact is insignificantly small, as it amounted to 0.5 % only. Two inputs in thisanalysis, namely the window opening and the extraction of extra heat with exhausted air of
mechanical ventilation system due to air temperature difference, did result in a positive and alsoquite a large impact during one season (7.0 % and more). Their total yearly energy impact was
thus 3.2 % and 3.5 % respectively.

Energy and the Environment (2016) 509-518

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REFERENCES[1] Saelens, D., Parys, W., Baetens, R.: Energy and comfort performance of thermally
activated building systems including occupant behaviour, Building and Environment,
vol. 46, 2011, pp. 835-848.
[2] Bonte, M., Thellier, F., Lartigue, B.: Impact of occupants actions on energy building
performance and thermal sensation, Energy and Buildings, vol. 76, 2014, pp. 219-227.
[3] Jordan, S., Hafner, J., Zbašnik-6HQHJDþQLNM., Legat, A., Knez, F.: Efficient energy use
and thermal comfort in the retrofitted pilot offices equipped with radiant ceiling panels,
24th Scientific Conference on Energy and the Environment, Opatija, Croatia, 2014.
[4] Jordan, S., Hafner, J., Kuhn, T. E., Legat, A., Zbašnik-6HQHJDþQLNM.: Evaluation of
Various retrofitting Concepts of Building Envelope for Offices Equipped with Large
Radiant Ceiling Panels by Dynamic Simulation, Sustainability, no. 7, 2015, pp. 1316913191.
[5] Jordan, S., Hafner, J., Kuhn, T. E., Legat, A., Zbašnik-6HQHJDþQLNM.: Unutarnja
okolina renoviranih ureda opremljenih stropnim LVLMDYDMXüLPSORþDPD,QGRRU
environment in retrofitted offices equipped with radiant ceiling panels, Gradjevinar, vol.
68, no. 2, 2016, pp. 125-134.
[6] Solar-Energy-Laboratory, TRNSYS 17, a transient simulation program, University of
Wisconsin - Madison, Madison, USA, 1994.
[7] SIST EN 13829 Thermal performance of buildings - Determination of air permeability ofbuildings - )DQSUHVVXUL]DWLRQPHWKRG7RSORWQH]QDþLOQRVWLVWDYE- Ugotavljanje tesnosti
obodnih konstrukcij - 0HWRGDWODþQHUD]OLNHz uporabo ventilatorja, Ljubljana: SIST,
2001.
[8] ARSO, ARHIV - opazovani in merjeni meteorološki podatki po Sloveniji, 2013. [Online].
Available: http://www.arso.gov.si. [Accessed 2014].
[9] SIST EN ISO 7730 Ergonomija toplotnega okolja - $QDOLWLþQo ugotavljanje in
LQWHUSUHWDFLMDWRSORWQHJDXJRGMD]L]UDþXQRP309LQ33'YUHGQRVWLWHUPHULOL]Dlokalno toplotno ugodje, Ljubljana: SIST, 2006.
[10] EVO, International Performance Measurement and Verification Protocol, Concepts andOptions for Determining Energy and Water Savings, Volume 1, [Online]. Available:
http://www.evo-world.org/index.php?lang=en. [Accessed 2014].
[11] FEMP, M&V Guidelines: Measurement and Verification for Federal Energy Projects,
Version 3.0, [Online]. Available: http://mnv.lbl.gov/keyMnVDocs/femp. [Accessed2014].

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3295$71(,1)250$&,-(',1$0,ý.(6,08/$&,-(7516<6
MODELA UREDSKOG PROSTORA OPREMLJENOG SUSTAVOM*5,-$1-$,+/$Ĉ(1-$3202û8675231,+3/2ý$Sažetak : Prilikom izrade simulacijskih PRGHOD ]D SURFMHQX UD]OLþLWih izvedbi zgrada, tu seRELþQR MDYOMD NDR SUREOHP QHGRVWDWDN SRYUDWQH LQIRUPDFLMH 6DPR X VOXþDMX PMHUHQMD L
simulacija na istoj promatranoj JUDÿHYLQi izravne usporedbe izmjerenih i simuliranih rezultata
su PRJXüH te se mogu dobiti i detaljniji podatci za daljnju uporabu. Poznato je da aktivnosti
ljudi u objektu i oVWDOLGRJDÿDMLPRJXXWMHFDWLQD unutarnje temperature, a time imati i ]QDþDMDQXWMHFDM QD UDG VXVWDYD JULMDQMD  KODÿHQMD QD HQHUJHWVNu bilancu zgrade i unutarnje toplinske
XGREQRVWL 8þHVWDORVW LQWHQ]LWHW L WUDMDQMH WDNYLK GRJDÿDMD ]DMHGQR V JUDQLþQLP XYMHWLPD RG
NOMXþQRJ VX ]QDþDMD 7R SRVHEQR YULMHGL ]D LQRYDWLYQe tehnologije u zgradama i konceptualna
rješenja ]DNRMHSRVWRMLQHGRVWDWDNSUDNWLþQLKLVNXVWDYDJasno je da sH]DUDþXQDOQRPRGHOLUDQMH
nijedan RGWLKGRJDÿDMDne PRåHSUHGYLGMHWLWRþQR1RRQLVXYMHURMDWQR zato i glavni razlog za
YHOLNL RGPDN L]PHÿX SUHGYLÿHQRJ L realnog korištenja energije u zgradama. U ovom radu je
prikazana pojednostavljena analiza osjetljivosti na dobro definiranom TRNSYS modelu ureda
RSUHPOMHQLK SORþama za stropno grijDQMH L KODÿHQMH 0RGHO MH SRWYUÿHQ SRPRüu mjerenja utakvim uredima. Analiza osjetljivosti, koja XNOMXþXMH MHGQu godinu simulacije i mjerenja
rezultata, provedena je kako bi se definirali ulazni parametri koji QHPDMX ]QDþDMDQ XWMHFDM QD
potrošnju energije, te stoga mogu biti suvišan dio modela. Osim toga, analiza je pokazala kako
VH]RQVNHDNWLYQRVWLXWMHþX na potrošnju energije.
.OMXþQHULMHþLGLQDPLþNDsimulacija, TRNSYS model, analiza osjetljivosti.

Energy and the Environment (2016) 519-528

519

IMPACT OF REAL WORKING MEDIA PROPERTIES ON THE
ENERGY CHARACTERISTICS OF A COMPRESSION HEAT PUMP
5REHUW%HGRLü9HOMNR)LOLSDQUniversity of Zagreb Faculty of Chemical Engineering and Technology, Savska cesta 16,
Zagreb, Croatia; Tel./Fax: +385 1 4597 109; e-mails: rbedoic@fkit.hr, vfilipan@fkit.hr
Abstract: The aim of the work is to examine the possibility of applying spreadsheet calculator
to a real thermodynamic process using the REFPROP base of thermodynamic properties forreal fluids. The heating process of a real soil-to-water heat pump has been analysed.
Thermodynamic process is shown in the respective comparative thermodynamic diagrams inorder to clearly present the different properties of refrigerants and their impact on the energy
characteristics of the heat pump. In the heating mode there is analysed how the changes in
evaporation temperature of refrigerant at constant condensation temperature (and pressure)influence the unit workloads, cooling capacity, heat of condensation, temperature after
compression, and the heating coefficient of a heat pump. Also, the energy characteristics of aheat pump using different refrigerants for the same temperature conditions are analysed.
There are included the following refrigerants: propane, isobutane, rejected R12 and its
environmentally friendly and widely accepted replacement R-134a, and for comparison
ammonia as the most commonly used refrigerant. Results of the analysis are displayed indiagrams and tables and accompanied by necessary comments.
Keywords: Heat pumps, thermodynamic process and diagrams, REFPROP, real refrigerants,
energy characteristics
1

INTRODUCTION

Heat pumps are devices which allow using of relatively low temperature sources (surrounding
air, sea water, soil, etc.) for space or domestic hot water heating purposes. Figure 1 show ascheme of a geothermal heat pump of the soil-to-water type which has been used for analysis.
Thermodynamic process in the heat pump that is optimized with superheating of dry saturated
steam before entering the compressor, and with undercooling of hot liquid before entering thethrottling valve is shown in Figure 2.
Depending on temperature regimes, heat pumps are able to work either in the heating or
cooling mode. Researches of soil as a heat source in heating mode or heat sink in coolingmode are presented in this article [1] [2]. Furthermore, in these articles there is describedborehole heat exchanger, U-tubes placed in soil, and other relevant system parts.
Next article presents the selection of real working media for heat pumps and use of computer
software in combination with REFPROP base in order to quantitatively described process [3].
According to Fig. 2 the coefficient of performance (COP) in heating mode can be given by
the expression (1):qc
h4  h2
COP
(1)
wtech
h1  h2520

5%HGRLü9)LOLSDQ Impact of real working media properties…

Figure 1 Schematic of a geothermal ground-source heat pump (soil-to-water type)Figure 2 Thermodynamic process in heat pump shown in a temperature (T) – entropy (s)diagramEnergy and the Environment (2016) 519-528

2

521

RESULTSThe calculation of ground-source heat pump is made by spreadsheet calculator withapplication of REFPROP thermodynamic base. The calculation model is applied to different
working media for the same given requirements in the heating mode. The analysis show how
the variation in evaporation temperature at constant condensation temperature (pressure)influence the unit workloads, cooling capacity, heat of condensation, temperature after
compression, and the heating coefficient (COP) of a heat pump.
2.1

Real thermodynamic process in the heat pump

For the real process using propane as working media the temperature of evaporation is set on
0 ºC and the temperature of condensation on 45 ºC. Dry saturated steam is superheated for 5°C, hot liquid is undercooled for 5 °C, and the isentropic efficiency of compressor is set on
75%. For constant mass flow rate of 0.050 kg/s, power of compression in heating mode (PH),heat flow rate of condensation ( Q c ) and heat flow rate of evaporation ( Q e ) are determined.
Thermodynamic state values are calculated by REFPROP programme and are given in Table
1.
Table 1 Thermodynamic state values of propane for the real thermodynamic process
Refrigerant state (process point)
dry saturated steam(1")
entrance to compressor(1)isentropic compression(2A)exit of real compressor(2)hot liquid(3')
entrance to throttling valve(4)exit of throttling valve(5)T[K]273.15278.15327.64336.03318.15313.15273.15p[kPa]
474.46474.46
1534.311534.311534.311534.31474.46v[m3/kg]
0.09661
0.099160.031430.033170.00218
0.002140.02894h[kJ/kg] s[kJ/kgK]
574.872.3724583.572.4040640.052.4040658.882.4607321.791.4046307.051.3579307.05
1.3919Using the data from Table 1 the energy characteristic values are determined as follows:-compressor unit work and power:
wtech =75.31 kJ/kg; P =3.77 kW
Q =13.83 kW-evaporator’s unit heat and heat power:q = 276.52 kJ/kg;eeQ c =17.60 kW-condenser’s unit heat and heat power:
qc =351.83 kJ/kg;
Heating coefficient of a heat pump in heating mode for given process is calculated as:
COP 4.67 .
Thermodynamic process is shown in T,s; p,v; h,s; p,T; T,h and p,h diagrams on following
Figures.

522

5%HGRLü9)LOLSDQ Impact of real working media properties…

Figure 3 Real thermodynamic process in T,s diagram

Figure 4 Real thermodynamic process in p,v diagram

Figure 5 Real thermodynamic process in a p,h diagram

Energy and the Environment (2016) 519-528

Figure 6 Real thermodynamic process in h,s diagram

Figure 7 Real thermodynamic process in p,T diagram

Figure 8 Real thermodynamic process in T,h diagram

523

524

2.2

5%HGRLü9)LOLSDQ Impact of real working media properties…

Impact of evaporating temperature change on the energy characteristics of the process

In order to determine the impact of the state value change of propane to the process in heatpump, temperature of condensation is set at constant value, 45°C and the evaporation
temperature is changed from -6°C to 6°C. Dry saturated steam is superheated for 5 °C, hot
liquid is undercooled for 5 °C, and the isentropic efficiency of compressor is set at 75%.
Results of are displayed in appropriate diagrams on the following Figures.

qe=f(੥e)276

qe= 1.102ࢡe + 256
R² = 1274
272
270
qe[kJ/kg] 268
266
264
262
260
-8

-6

-4

-2

0

2

4

6

8

੥e[°C]

Figure 9 Impact of evaporation temperature on unit heat of evaporation

IqcI=f(੥e)
344
342
340
IqcI[kJ/kg]

338
336
IqcI= -0.8389ࢡe + 337.19
R² = 0,9993

334
332
330
-8

-6

-4

-2

0

2

4

6

੥e[°C]

Figure 10 Impact of evaporation temperature on unit heat of condensation

8

Energy and the Environment (2016) 519-528

525

IwtechI=f(੥e)
100
IwtechI[kJ/kg] 50

wtech = -1.4443ࢡe + 53.994
R² = 0,9996

0
-8

-6

-4

-2

0

2

4

6

8

੥e[°C]

Figure 2 Impact of evaporation temperature on unit work of compression੥2=f(੥e)66
6564
੥2[°C] 63626160

੥2 = -0.1534੥e + 48.934
R² = 0,9983
-8

-6

-4

-2

0

2

4

6

8

੥e[°C]

Figure 3 Impact of evaporation temperature on temperature after the compression

COP=f(੥e)
654COP= 0.1511ࢡe + 5.81
R² = 0,9935

COP 3
2
1
0
-8

-6

-4

-2

0

2

4

6

8

੥e[°C]

Figure 4 Impact of evaporation temperature on the heating factor of heat pump526

5%HGRLü9)LOLSDQ Impact of real working media properties…

2.3

Impact of different working media properties on the process parameters of heat pump

In order to help in selection of the appropriate working media for a heat pump, in Table 2
there are given results of analysis of the same process with different refrigerants: propane,
isobutane, rejected R12 and its environmentally friendly and widely accepted replacement R134a, and for comparison ammonia as the most commonly used refrigerant. Temperature
regime is 0 °C/45 °C, dry saturated steam is superheated for 5°C, hot liquid undercooled for 5°C, and isentropic efficiency of compressor is 75 %.
Table 2 Comparison of thermodynamic state values and energy characteristics for different
refrigerants
WORKING MEDIA
PROPANEISOBUTANE
R-12
R-134aAMMONIApe[kPa]
474.46156.96308.15292.80429.38pc[kPa]
1534.31604.451082.08
1159.92
1782.66qe[kJ/kg]276.52266.17116.74146.691084.78qc[kJ/kg]351.83335.70147.44185.951368.86wtech[kJ/kg]
75.31
69.53
30.70
39.26
284.08

‫ׇ‬2
[°C]
62.88
53.96
66.18
63.44
138.74x[kg/kg]
0.286
0.272
0.257
0.284
0.151

COP
[-]
4.48
4.83
4.80
4.74
4.82

Furthermore, the saturation lines for propane, R-12, R-134a and ammonia for comparison aredisplayed in the same T,s diagram on Fig. 12.

400,00T[K]350,00propaneR-12
R-134aammonia

300,00250,00200,00
0,50

1,50

2,50

3,50

4,50

5,50

6,50

s[kJ/kgK]

Figure 5 Saturation lines for given refrigerants in T,s diagram
3

CONCLUSION

Analysis of thermodynamic process in heat pump using REFPROP data base shows that moredetail and precise calculation can be made, comparing to the classical reading out of the stateEnergy and the Environment (2016) 519-528

527

values from printed diagram. REFPROP contains data for a large number of fluids that areused in refrigerating and cryogenic processes, and also for their mixtures. By implementing
functions to spreadsheet calculator and to given calculation model, numerical data of statevalues can be displayed out, or changed in order to determine its impact on the process.
Furthermore, a soil as heat source for geothermal heat hump is a complex structure. Variationof temperature through soil depth and its thermal conductivity must be determined throughexperiment of drilling and sampling. Although soil looks like indefinite source of heat, in
heating mode through heat transfer it cools down significantly. That results in variation ofheat transfer coefficient and its further impact on the process. When temperature of soil equals
the temperature of fluid geothermal heat pump stops working.
4

LIST OF SYMBOLS

COP
h
P
p
Q
q
s
T
v
w
x

[-]
[kJ/kg]
[kW]
[kPa]
[kW]
[kJ/kg][kJ/kgK][K][m3/kg][kJ/kg][-]Greek symbols
‫ׇ‬
[°C]

coefficient of performance, heating coefficient
unit enthalpy
mechanical power
apsolute pressure
heat flow rate (heat power)
unit heat
unit entropy
thermodynamic temperature
specific (unit) volume
mechanical unit work
amount of steam in two-phase mixture at the exit of throttling valve
Celsius temperature

Subscripseevaporationccondenser
techtechnical
REFERENCES[1] X.Q.Zhai, X.W.Cheng, R.Z.Wang: Heating and cooling performance of a mini typeground source heat pump system, Applied Thermal Engineering, 2016 (in press)
http://dx.doi.org/10.1016/j.applthermaleng.2016.03.117[2] V.Soldo: Istraživanje i promocija plitkih geotermalnih potencijala u Republici Hrvatskoj,
GeoMapping, www.geothermalmapping.fsb.hr (pristup10.7.2016.)[3] Z. Sagia, C. Rakopoulos: Alternative refrigerants for the heat pump of a ground source
heat pump system, Applied Thermal Engineering, 100 (2016) 5, 768-774.

528

5%HGRLü9)LOLSDQ Impact of real working media properties…

UTJECAJ KARAKTERISTIKA REALNIH RADNIH TVARI NA(1(5*,-6.(=1$ý$-.(.2035(6,-6.(',=$/,&(723/,1(Sažetak: &LOMUDGDMHLVWUDåLWLPRJXüQRVWSULPMHQHWDEOLþQRJNDONXODWRUD]DSURUDþXQUHDOQRJWHUPRGLQDPLþNRJSURFHVDSRPRüX5()3523ED]HWHUPRGLQDPLþNLKVYRMVWDYDUHDOQLKIOXLGD
Analiziran je proces zagrijavanja u jednoj realnoj dizalici topline tipa tlo-voda.
TerPRGLQDPLþNLSURFHVSULND]DQMHXRGJRYDUDMXüLPXVSRUHGQLPWHUPRGLQDPLþNLKGLMDJUDPDNDNR EL VH ]RUQR SULND]DOD UD]OLþLWD VYRMVWYD UDGQLK WYDUL L QMLKRY XWMHFDM QD HQHUJLMVNH
]QDþDMNH GL]DOLFH WRSOLQH 8 UHåLPX JULMDQMD DQDOL]LUD VH NDNR SURPMHQH X WHPSHUDWuri
LVSDUDYDQMD UDVKODGQRJ VUHGVWYD SUL VWDOQRM WHPSHUDWXUL L WODNX  NRQGHQ]DFLMH XWMHþX QD
MHGLQLþQL UDG UDVKODGQL XþLQ, toplinu kondenzacije, temperaturu nakon kompresije, tekoeficijent grijanja dizalice topline 7DNRÿHU VH DQDOL]LUDMX energijske ]QDþajke dizalice
topline za UD]OLþLWe radne tvari uz iste temperaturne uvjete. 8NOMXþHQHVXVOMHGHüHUDVKODGQetvari: propan, izobutan, odbaþHQL 5 L QMHJRY HNRORãNL SULKYDWOMLY L ãLURNR SULKYDüHQ
zamjenski R-134a, a za usporedbu i DPRQLMDN NDR QDMþHãüH korišteno rashladno sredstvo.
Rezultati analize prikazanL VX X GLMDJUDPLPD L WDEOLFDPD WH SRSUDüHQL potrebnim
komentarima.
KOMXþQe ULMHþL: dizalice topline, termodinamiþNL procesi i dijagrami, REFPROP baza, realne
rashladne tvari, energijske ]QDþDMNH

Energy and the Environment (2016) 529-536

529

KORIŠTENJE INFRACRVENE TERMOGRAFIJE ZA
32%2/-â$1-((1(5*(76.(8ý,1.29,7267,235(0(U PROCESNOJ ENERGETSKOJ INDUSTRIJI$ULV7HUOHYLü3DROR%OHFLFK%HUQDUG)UDQNRYLü
7HKQLþNLIDNXOWHW6YHXþLOLãWDX5LMHFL9XNRYDUVND5LMHND
E-mail: aterlevic@riteh.hr, pblecich@riteh.hr, bernardf@riteh.hrSažetak: U ovom radu naglasak je stavljen na toplinske gubitke, koji se javljaju u procesnoj
energetskoj industriji zbog raznih nedostataka tijekom procesa i na infracrvenoj termografiji
kao metodi mjerenja, kojom se ti nedostaci mogu otkriti u cilju njihovog RWNODQMDQMD7DNRÿHU
posebno su opisane prednosti i nedostaci infracrvene termografije u procesnom energetskom
postrojenju s obzirom na okolinu, materijale i uvjete na koje se ondje nailazi. U radu su, uz
pojašnjenja, dani mnogobURMQL WHUPRJUDPL NDR SULPMHUL SRPRüX kojih se mogu objasniti
pojave važne za ovo ispitivanje, kao i ispitivanja razne procesne opreme izložene toplinskom
RSWHUHüHQMX.DNRMHLVSLWLYDQMHprovedeno u procesnom postrojenju Rafinerije nafte Rijeka, uradu su prikazani LSURUDþXQLWRSOLQVNLKJXELWDND2YLWRSOLQVNLJXELFLMDVQR prikazuju kakve
ekonomske gubitke trpe pogoni u procesnoj industriji, ukoliko je oprema zastarjela ineadekvatno održavana.
.OMXþQHULMHþL infracrvena termografija, energetsNDXþLQNRYLWRVWSURFHsna industrija, gubici
topline

1. UVOD
9HüLQD SURFHVD X SULURGL SD WDNR L X SRGUXþMX VWURMDUVWYD SRYH]DQD MH V L]PMHQRP topline.
Procesna industrija i rafinerijski procesi se WDNRÿHU ]DVQLYDMX QD WRP SULQFLSX SD MH
razumijevanje izmjene topline od velike važnosti za inženjere. 5DGLSRYHüDQMDXþLQNRYLWRVWL
energetskih procesa potrebno je smanjiti gubitke topline, bilo GDMHULMHþRWHUPRHOHNWUDQLLOLoprocesnoj opremi u rafinerijama. Cilj je da se pretvorbom dostupnije i manje kvalitetneenergije dobije YUMHGQLMD PHKDQLþND RGQRVQR elekWULþQD HQHUJLMD 3ULPMHULFH L] SULPDUQH
energije kao što je nafta ili visoko-oktanski benzin, posredstvom toplinske energije ukemijskim reakcijama, dobiva se energija više kvalitete. PraüHQMH WHPSHUDWXUD WLMHNRP RYLK
procesa potrebni su za NYDOLWHWQRYRÿHQMHSURFHVDL ]DSURFMHQXWRSOLQVNLKJXELWDND.ODVLþQR
mjerenje temperature zasniva se QD NRQWDNWX L]PHÿX PMHUQRJ XUHÿDMD L mjerenog predmeta,što kod termografskih VXVWDYD QLMH VOXþDM V RE]LURP GD MH ULMHþ R EHVNRQWDNWQRM PHWRGLPMHUHQMD7DNRÿHUWDNYo je mjerenje sigurnije, pogotovo XVOXþDMXNDGDMHmjereni objekt na
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530$7HUOHYLü3%OHFLFK%)UDQNRYLü: Korištenje infracrvene termografije…

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2. INFRACRVENA TERMOGRAFIJA
2.1. Prednosti i nedostaci
Infracrvena termografija kao mjerna metoda olakšava i ubrzava mjerenje površinske
temperature promatranog objekta u odnosu na druge metode. Kao rezultat termografskog
ispitivanja dobiva se termogram, koji se sastoji od velikog broja piksela, a svaki od tih piksela
je u biti jedno temperaturno mjerenje. 7HUPRJUDP VH VDVWRML RG QHNROLNR GHVHWDND WLVXüD
piksela þLPHVHSRVWLåHEU]LGYRGLmenzijski prikaz raspodjele temperature na površini objekta,što predstavlja osnovnu prednost LQIUDFUYHQH WHUPRJUDILMH X RGQRVX QD NODVLþQD NRQWDNWQD
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koji se može mjeriti je velik tako da se koristi za mjerenja vrlo visokih temperatura ali i za
temperature blizu apsolutnoj nuli. ýHVWR MH WHKQRORãNLP SURFHVLPD SRWUHEQR NRQWLQXLUDQRQDGJOHGDQMHVWDQMDRSUHPHãWRVHPRåHSRVWLüLLQIUDFUYHQRPtermografijom.
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tijela. Stoga je, osim poznavanja karakteristika površine promatranog tijela, potrebno znati i
stanje okoline s obzirom da objektiv LQIUDFUYHQHNDPHUHLVWRYUHPHQRELOMHåLLYODVWLWR]UDþHQMH
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faktora emisije površine tijela, udaljenostL L]PHÿX NDPHUH L WLMHOD UHIOHNWLUDQH WHPSHUDWXUH
okoline, temperature i vlažnosti atmosferskog zraka.
'YLMH RVQRYQH SRWHãNRüH LQIUDFUYHQH WHUPRJUDILMH NRMH XWMHþX QD NYDOLWHWX PMHUHQMD VXQHSR]QDYDQMHWRþQHYULMHGQRVWLIDNtora emisije površine WLMHODLUHIOHNVLMD]UDþHQMDVSRYUãLQHWLMHOD]ERJSULVXVWYDL]YRUD]UDþHQMDXRNROLQL8PMHVWRVDPRMHGQHYULMHGQRVWLIDNWRUDHPLVLMH
na cijeloj površini, stvarna tijela, zbog dugotrajnog utjecaja okoline, mogu imati nejednolike
faktore emisije na svojim površinama. S druge strane, refleksija se najviše pojavljuje kod
mjerenja tijela niskog faktora emisije poput glatkih metalnih površina.

Energy and the Environment (2016) 529-536

531

2.2. Nejednoliki faktor emisije na površini tijela
U procesnom energetskom postrojenju, infracrvenoj termografiji su najzanimljiviji oni
dijelovi u kojima se odvija pretvorba energije i izmjena topline poput procesnih SHüLUHaktora,
L]PMHQMLYDþDWRSOLQHLSDURYRGD1ejednolikosti u raspodjeli temperatura na površini oprememože ukazivati na potencijalne probleme. Kao primjer jednog takvog ispitivanja može senavesti ispitivanje oplate proceVQH SHüL NRMH VH SURYRGL V FLOMHP XWYUÿLYDQMD VWDQMD ozida iizolacije, gdje napukline ili RãWHüHQMD s unutarnje strane ozida mogu dovesti do RãWHüHQMD
oplate. Procesna energetska SRVWURMHQMDSDWDNRLSURFHVQDSHüNDRQMHQVDVWDYQLGLRUDGHX
kontinuitetu, bez gašenja, što otežava L RQHPRJXüDYD Xnutarnji pregled. Upravo u takvim
VOXþDMHYLPD LQIUDFUYHQD WHUPRJUDILMD QDOD]L VYRMX primjenu, jer se ispitivanje vrši s vanjske
stUDQH EH] SRWUHEH ]D SUHNLGDQMHP UDGD SURFHVQH SHüL 8 VOXþDMX YHüHJ RãWHüHQMD R]LGD V
unutarnje strane, na termogramu bi se primijetila YHüDnejednolikost temperatura. Na slici 1.
prikazan je GLRRSODWHSURFHVQHSHüLXvidljivom i infracrvenom spektru.

Slika 1. Detalj oplate SURFHVQHSHüLvidljivi spektar (lijevo) i termogram (desno)
StrelLFDPD VX QD]QDþHQL zanimljivi detalji oplate, gdje je vidljiv utjecaj promjene svojstva
površine na emiWLUDQR ]UDþHQMH D X VNODGX VD 6WHIDQ - Boltzmannovim zakonom. Površina
oplate je hrapavija, tamnija i V YHüLP faktorom emisije na mjestima prisutnih RãWHüHQja ikorozija. =ERJWRJDMHWRSOLQVNR]UDþHQMHVRYLKGLMHORYDRSODWHYHüHQHJRRNROQR, što se na
termogramima LVND]XMH NDR SRGUXþMD YLãLK WHPSHUDWXUD, iako je stvarna temperatura cijele
oplate jednolika. Stoga, PRåH VH ]DNOMXþLWL NDNR MH VWDQMH R]LGD L L]RODFLMH na promatranoj
površini oplate dobro iako termogrami sadrže prividne temperaturne nejednolikosti.

532$7HUOHYLü3%OHFLFK%)UDQNRYLü: Korištenje infracrvene termografije…

Nejednoliki faktori emisije na površinama procesne opreme su raširena pojava i gore
prikazani primjer je samo jedan u nizu. Na slici 2. prikazan je još MHGDQRþLWSrimjer gdje je na
RSODWLSURFHVQHSHüLþLWOMLYDR]QDNDLXLQIUDFUYHQRPVSHNWUXVDPR]DWRãWRMHFUQHERMHSDMH
faktor emisije R]QDNHYHüLRGIDNWRUDHPLVLMHRNROQHSRYUãLQH što se u termogramu iskazuje
NDRSRGUXþMHYLãHWHPSHUDWXUHLDNRWRXVWYDUQRVWLQLMHVOXþDM

Slika 2. Oznaka SURFHVQHSHüLYLGOMLYVSHNWDU OLMHYR LWHUPRJUDP GHVQR
Iz prethodnih slika i termograma postaje jasno da površine stvarnih tijela posjeduju cijele
raspone vrijednosti faktora emisije, što RWHåDYD WRþQX SURFMHQX temperature površine tijela.
'UXJLP ULMHþLPD QLMH MHGQRVWDYQR GRELWL WRþQH WHPSHUDWXUH VDPR NRULãWHQMHP iskustvenih
YULMHGQRVWL IDNWRUD HPLVLMH NRMH VH PRJX SURQDüL X YHüHP EURMX LQåHQMHUVNLK SULUXþQLND L
tablica. Ovaj problem je posebice izražen za metalne površine, gdje ovisno o stanju površine,faktor emisije može iznositi od 0.2 (glatka površina) do 0.8 (oksidirana površina). Faktor
HPLVLMHPRåHVHRGUHGLWLSRPRüXNDOLEUDFLMVNLKWUDNDSR]QDWRJIDNWRUDHPLVLMHNRMHVH]DOLMHSH
na površinu opreme. Infracrvenom kamerom izmjeri se temperatura kalibracijske trake
korištenjem poznatog faktora emisije, a nakon toga se za okolnu površinu traži faktor emisije
NRML RGJRYDUD SUHWKRGQR L]PMHUHQRM WHPSHUDWXUL 1D RYDM VH QDþLQ IDNWRU HPLVLMH PRåHodrediti za svD SRGUXþMD V UD]OLþLWLP VWDQMHP SRYUãLQH D WHUPRJUDIVNR PMHUHQMH YUãL VHX]LPDQMHPRGJRYDUDMXüLKYULMHGQRVWLIDNWRUDHPLVLMD]DSRMHGLQDSRGUXþMDQDSRYUãLQL
2.3. Refleksija s površine tijela
ProblHPUHIOHNVLMHMHQDMYHüDSRWHãNRüD koja se može javiti kod termografskog ispitivanja, jer
ga je ponekad teško otkriti i koje može utjecati na kvalitetu mjerenje. Refleksija s površine jenajviše prisutna kod metalnih površina koje su najzastupljenije u procesnoj energetskoj
industriji. 7RSOLQVNR ]UDþHQMH V SRYUãLQH promatranog tijela sastoji se od dviju komponenti:
YODVWLWR HPLWLUDQR ]UDþHQMH L UHIOHNWLUDQR ]UDþHQMD L] RNROLQH. Utjecaj refleksije je posebiceizražen kod površina s niskim faktorom emisije i visokim faktorom refleksije. Vlastito]UDþHQMHWLMHODodražaYDWHPSHUDWXUQRVWDQMHWLMHODGRNUHIOHNWLUDQR]UDþHQMHRYLVLRRNROLQL i

Energy and the Environment (2016) 529-536

533

nema veze s temperaturom promatrane površine. Za dobivanje vjerodostojnih termograma
potrebno je smanjiti utjecDMUHIOHNVLMHLSULGUåDYDWLVHQDSXWDNDXRYDNYLPVOXþDMHYLPD
Utjecaj refleksije prikazan je na jednom konkretnom primjeru na slici 3. Vidljiva je glatka i
YLVRNR UHIOHNWLUDMXüD SRYUãLQD NRMD X]URNXMH UHIOHNVLMX ]UDþHQMD VD VXVMHGQRJ FMHYRYRGD
Stvarni cjevovod R]QDþHQ MH SXQLP VWUHOLFDPD D ]UFDOQD refleksija na glatkoj površini
isprekidanim strelicama. Samim promatranjem termograma PRJOR EL VH ]DNOMXþLWL GD su
SULVXWQH GYLMH FLMHYL L WR SULEOLåQR MHGQDNLK WHPSHUDWXUD ãWR QDUDYQR QLMH VOXþDM 7DNRÿHUmože se primijetiti da je fiktivna cijev nešto hladnija od stvarne. TopliQVNR ]UDþHQMH NRMHQDSXãWDSRYUãLQXFMHYRYRGDGLMHORPVHDSVRUELUDLGLMHORPVHRGELMDQDYLVRNRUHIOHNWLUDMXüRMSRYUãLQH3UHPD.LUFKKRIIRYRP]DNRQX]UDþHQMD [2], faktor emisije jednak je po vrijednosti
faktorXDSVRUSFLMHDXVOXþDMXYLVRNRUHIOHNWLUDMXüHJDOXPLQLMVNRJOLPDoni iznose oko 0.2 [3].

Slika 3. Zrcalna refleksija u: vidljivom spektru (lijevo) i termogramu (desno)*RUHSULND]DQVOXþDMMHSULPMHUzrcalne refleksije, s obzirom da je površina glatka, a na slici 4.
SULND]DQ MH VOXþDM GLIX]ne refleksije s oksidirane površine. PrLND]DQ MH MHGDQ RG SULNOMXþDND
spremnika GHJD]DWRUDNRMLMHL]UDÿHQRGOLPDkoji je vremenom oksidirao, zbRJþHJDPXMH
površina hrapava i matirana.

Slika 4. Difuzna refleksija s oksidirane površine

534$7HUOHYLü3%OHFLFK%)UDQNRYLü: Korištenje infracrvene termografije…

Sada je refleksija manje izražena nego u SUHWKRGQRP VOXþDMX zato što je faktor emisijeoksidiranog OLPD YHüL RG IDNWRUD HPLVLMH JODWNRJ OLPD, D VDPD UHIOHNVLMD QLMH ]UFDOQD YHü
difuzna.
PRVWRMH QDþLQL QD NRML VH utjecaj refleksije može smanjiti ili otkloniti. Prije snimanja,
potrebno je promotriti kakva je površina objekta. Važno je da se prilikom snimanja ne stoji
LVSUHG REMHNWD MHU YLVRNR UHIOHNWLUDMXüH SRYUãLQH UHIOHNWLUDMX WRSOLQVNR ]UDþHQMH RVRED NRMH
vrše termografsko mjerenje. Poželjno je objekt snimiti iz više kutova i pomicati mjesto
promatranja MHUVHWLPHSRPLþHLHYentualna refleksija na površini. Refleksija iz okoline možeVHL]EMHüLNRULãWHQMHP]DVORQD LOLQRüQLPVQLPDQMLPDNDGDQHPDXWMHFDMDVXQþHYRJ]UDþHQMD
3. ANALIZA I REZULTATIU procesnoj energetskoj inGXVWULML SRVWRML þLWDY QL] RSUHPH QD NRMRM VH PRåH YUãLWL
WHUPRJUDIVNRPMHUHQMH.DRSULPMHURYGMHüH se navesti ispitivanje stanja cjevovoda s obzirom
da su oni brojni, njihova je duljina vrlo velika pa se ovakvom metodom mjerenja može brzoocijeniti stanje ove opreme.
Cjevovodi služe za transport sirovine, poluproizvoda, gotovog proizvoda, pare i slLþQR.
2ELþQRVHNRULVWHþHOLþQHYXþHQHEHãDYQHFLMHYLNRMHVX otpornije na tlak i više temperature.
Tri su vrste spajanja cjevovoda: zavarivanjem, prirubnicDPD L QDYRMHP 2SüHQLWR VX PMHVWD
VSRMHYD NULWLþna za propuštanje. Ako se kroz cjevovod transportira para ili zagrijana
kapljevina kojoj je potrebno održati željeni viskozitet, potrebno je primijeniti toplinsku
izolaciju. Kao toplinska izolacija u pravilu se koristi poliuretan ili staklena vuna, obloženiDOXPLQLMVNLP OLPRP NRML ãWLWL RG PHKDQLþNLK GHIRUPDFLMD L DWPRVIHUVNLK uvjeta. Toplinski
JXELFL SRYHüDYDMX VH kada je L]RODFLMD ]DVWDUMHOD PHKDQLþNL RãWHüHQD L V SULVXWQRP YODJRP
koja joj narušava toplinskD VYRMVWYD 2VLP YHüLK JXELWDND WRSOLQH X SDURYRGLPD VH VWYDUDNRQGHQ]DW ãWR PRåH X]URNRYDWL SRJRQVNH SUREOHPH SRJRWRYR DNR MH VXVWDY RGYRÿHQMD
kondenzata poddimenzioniran s obzirom na novonastalu situaciju [4]. Na slici 5. prikazan jesegment cjevovoda s vidljivim toplinskim gubicima.

Slika 5. Segment cjevovoda u: vidljivom spektru (lijevo) i termogramu (desno)

Energy and the Environment (2016) 529-536

535

6WUHOLFRPMHQD]QDþHQSUREOHPDWLþDQGLRFLMHYLJGMH preko zaštitnog lima na spoju cijevi curi
kondenzat, što ukazuje na propuštanje. Kako unutarnji cjevovod propušta paru, tako ona
kondenzira u izolaciji, a suha izolacija toplinske vodljivost od 0,035 W/mK postaje vlažna
izolacija toplinske vodljivosti od oko 0,5 W/mK2ãWHüHQLFMHYRYRGLX]URNXMXLVWRYUHPHQRL
velike gubitke topline i velike gubitke pare. =DSULPMHUJRGLãQMLKJXELWDNDWRSOLQHX]HWüHVH
cjevovod promjera  PP 12  VXKR]DVLüHQD SDUD WODNa 3,5 bara i SURVMHþQD
godišnja temperatura u Rijeci od  & 6DGD üH VH XVSRUHGLWL JXELFL WRSOLQH L QDVWDOLNRQGHQ]DW]DVOXþDMYODåne izolacije (0,5 W/mK) i za suhu izolaciju (0,035 W/mK). Debljinaizolacije iznosi 2/3 promjera cijevi. Pretpostavlja se ukupna duljina segmenta cjevovoda od
1 km. 7RSOLQVND YRGOMLYRVW þHOLND L]QRVL 53 W/mK. 8 VOXþDMX QHLVSUDYQH YODåQH L]RODFLMH
toplinski tok gubitaka topline iznosi.ROLþLQDQDVWDORJNRQGHQ]DWDXRYRPMHVOXþDMXU VOXþDMu ispravne, suhe izolacije toplinski tok gubitaka topline iznosi.ROLþLQDQDVWDORJNRQGHQ]DWDVDGDL]QRVL

Iz prikazanog primjera vidi se da korištenje ispravne izolacije smanjuje gubitke topline i do
osam puta u odnosu na neispravnu, vlažnu izolaciju.

Ovisno od cijene proizvedene toplinske energije može se procijeniti i ekonomska ušteda na
godišnjoj razini. Uz pretpostavku cijene od 0,4 kn/kWh slijedi da je godišnja ušteda
kn

536

4.

$7HUOHYLü3%OHFLFK%)UDQNRYLü: Korištenje infracrvene termografije…

=$./-8ý$.

U radu su objašnjene prednosti i nedostaci infracrvene termografije kao mjerne metode kod
ispitivanja metalnih površina u procesnoj energetskoj industriji 3RWHãNRüH YH]DQH ]DUHIOHNVLMX]UDþHQMDL]RNROLQH i nejednolikog faktora emisije na površinama mogu otežati i u
QHNLPVOXþDMHYLPD RQHPRJXüLWLWHUPRJUDIVNRVQLPDQMHRGQRVQRSURX]URþLWLQHYMHURGRVWRMQD
mjerenja. Infracrvenom termografijom izvršena je analiza gubitaka topline u procesnoj
energetskoj industriji. ,QIUDFUYHQD WHUPRJUDILMD RWNULOD MH YHüL EURM SRORåDMD V SULVXVWYRP
gubitaka topline poput osjetne topline dimnih plinova, prijelaza topline kroz stijenke toplinske
opreme i cjevovoda zbog lošeg stanja izolacije, zastarjele opreme i slabog održavanja.
8VSRUHÿHQL VX JXELFL WRSOLQH NUR] QHLVSUDYQX YODåQX L]RODFLMX L LVSUDYQX VXKX L]RODFLML ]DMHGDQSULPMHUFMHYRYRGDLSRND]DORVHMHPRJXüHSRVWLüL]QDþDMQHXãWHGHNRULãWHQMHPLVSUDYQH
izolacije. Smanjenje gubitaka topline u procesnoj energetskoj industrijL YRGL GR SRYHüDQMD
HQHUJHWVNHXþLQNRYLWRVWLSRMHGLQLKWHKQRORãNLKSURFHVDLSRVWURMHQMDXFLMHORVWLLITERATURA[1] M. Andrassy; I. Boras; S. Švaiü: Osnove termografije s primjenom, Kigen, Zagreb, 2008.
[2] F. Bošnjakoviü: Nauka o Toplini, svezak I, II, III, V. Izdanje, Graphis, Zagreb, 2012.
[3] P. Blecich; B. Frankoviü; K. Leniü: Primjena infracrvene kamere u termotehnici,
Engineering Review 29, 47-59, 2009.
[4] Z. Prelec: Energetski i procesni ureÿajiSUHGDYDQMD7HKQLþNLIDNXOWHW5LMHND

USING INFRARED THERMOGRAPHY TO IMPROVE
THE ENERGY EFFICIENCY OF EQUIPMENT
IN THE PROCESS ENERGY INDUSTRY
Abstract: this paper puts an emphasis on the heat losses occurring in the process energy
industry because of various defects during the process and on the infrared thermography as ameasurement method which is capable of detecting these defects with the aim of removing
them. Furthermore, the advantages and the disadvantages of infrared thermography for theprocess energy industry are particularly discussed, with regard to the environment, materials
and conditions encountered there. The paper, along with the explanations, offers a number ofthermal images explaining the phenomena relevant to this study and showing the performanceof process equipment under thermal load. Since the measurements were carried out at theprocess plant of the Rijeka refinery, the paper also gives the heat losses calculations. These
heat losses clearly reveal the economic drawbacks suffered by the process energy industry, inthe case of poorly maintained and outdated equipment.
Keywords: infrared thermography, energy efficiency, process industry, heat losses

Energy and the Environment (2016) 537-546

537

ENERGETSKA I EKSERGETSKA ANALIZA CIJEVNOG,=0-(1-,9$ý$723/,1(
0DWHR.LULQþLü*.ULVWLDQ/HQLü$QLFD7US
7HKQLþNLIDNXOWHW 6YHXþLOLãWDX5LMHFL, Vukovarska 58, Rijeka, Hrvatska*Telefon: +385 51 651 517, Faks: +385 51 675 801
Email: mateo.kirincic@riteh.hr, kristian.lenic@riteh.hr, anica.trp@riteh.hrSažetak: 8RYRPHUDGXSURYHGHQDMHDQDOL]DHQHUJHWVNHLHNVHUJHWVNHXþLQNRYLWRVWLFLMHYQRJ
L]PMHQMLYDþD WRSOLQH YRGD-YRGD PDOLK GLPHQ]LMD 3UHPD SRVWRMHüLP GLPHQ]LMDPD L]UDÿHQ MH
JHRPHWULMVNLPRGHOL]PMHQMLYDþDte je SURYHGHQDQXPHULþNDDQDOL]Dizmjene topline ]DþetiriVOXþDMDVUD]OLþLWLPXOD]QLPWHPSHUDWXUDPDWRSOHYRGHPotvrda fizikalne ispravnosti modela
dana MHXVSUHGERPELODQFLWRSOLQHL]UDþXQDWHL]QXPHULþNLKUH]XOWDWDLDQDOLWLþNLL]SRJRQVNLK
uvjeta. Prikazane su izlazne temperature tople i hladne vode, kao i energetske i eksergetskeXþLQNRYLWRVWL]DVYDNLRGþHWLULVOXþDMD,]UH]XOWDWDMHYLGOMLYRGDVHHQHUJHWVNDXþLQNRYLWRVWYUOR PDOR PLMHQMD D HNVHUJHWVND XþLQNRYLWRVW blago opada s porastom ulazne temperature
WRSOH YRGH 6OXþDM V QDMPDQMRP ulaznom temperaturom ocijenjen je najpovoljnijim senergetskog i eksergetskog aspekta.
.OMXþQH ULMHþL FLMHYQL L]PMHQMLYDþ WRSOLQH HQHUJHWVND DQDOL]D HNVHUJHWVND DQDOL]DQXPHULþNRPRGHOLUDQMHPHWRGDNRQWUROQLKYROXPHQD
1. UVOD
8L]PMHQMLYDþXWRSOLQHGYLMHVWUXMHIOXLGDL]PMHQMXMXWRSOLQXEH]PHÿXVREQRJPLMHãDQMDSUL
þHPXMHGQDVWUXMDSUHGDMHWRSOLQXLKODGLVHDGUXJDSULPDWXWRSOLQXL]DJULMDYDVH2SüHQLWR
XþLQNRYLWRVW L]PMHQMLYDþD RYLVL R QMHJRYRP WLSX JHRPHWULML L]PMHQMLYDþD WH SRJRQVNLP
uvjetima. 3UL UDþXQDQMX VWXSQMD GMHORYDQMD L]PMHQMLYDþD WRSOLQH SRQHNDG QLMH GRYROMQRDQDOL]LUDWL VDPR HQHUJHWVNX XþLQNRYLWRVW VWRJD MH SRWUHEQR SURYHVWL L HNVHUJHWVNX DQDOL]Xkako bi se odredio eksergetski stupanj djelovanja.
Mnoga istraživanja usmjerena su upravo QD RSWLPL]DFLMX UDGD L]PMHQMLYDþD WRSOLQH V
eksergetskog aspekta. Primjerice, Pandey i Nema [1] proveli su eksperimentalno istraživanje
RVPDQMHQMXHNVHUJHWVNLKJXELWDNDXL]PMHQMLYDþLPDWRSOLQHVNRUXJLUDQLPSORþDPD'RRKDQ
et al. [2] eskperimentalno su L QXPHULþNL RSWLPL]LUDOL SORþDVWL RUHEUHQL L]PMHQMLYDþ WRSOLQH
Dizaji et al. [3, @ L]YUãLOL VX HNVSHULPHQWDOQX RSWLPL]DFLMX SRJRQVNLK XYMHWD L]PMHQMLYDþD
topline sa spiralnim cijevima u s obzirom na eksergetsku iskoristivost. Martinaitis et al. [5]poboljšavali su eksergetsku iskoristivost elemenata sustava grijanja, ventilacije iklimatizacije. ýHVWR VH SURYRGH DQDOL]H i dijelova sustava obnovljivih izvora energije;
primjerice Naili et al. [6] izveli su eksperimentalno istraživanje i optimiranje horizontalnog]HPOMDQRJ L]PMHQMLYDþD WRSOLQH a Kalaiarasi et al. [7] eksperimentalnom eksergetskom
analizom poboljšali su solarni JULMDþ]UDND
2YDM üH UDG QXPHULþNRP DQDOL]RP ispitati utjecaj ulazne temperature tople vode u
NRPSDNWQRPFLMHYQRP L]PMHQMLYDþX WRSOLne voda-voda na njegovu energetsku i eksergetskuXþLQNRYLWRVW *HRPHWULMDL]PMHQMLYDþDWRSOLQHNRMLüHVHDQDOL]LUDWLSUHX]HWDMHL]LVWUDåLYDQMDJadhava i Kolija, [8] koji su istraživali prijelaz topline i pad tlaka, ali ne i energetsku i
HNVHUJHWVNX XþLQNRYLWRVW 3URYHVW üH VH þHWLUL VOXþDMD LVSLWLYDQMD V UD]OLþLWLP XOD]QLP

538

0.LULQþLü./HQLü$7US: (QHUJHWVNDLHNVHUJHWVNDDQDOL]DFLMHYQRJL]PMHQMLYDþDWRSOLQH

temperaturama tople vode, za stacionarno stanje izmjene topline te laminarno protusmjerno
struMDQMH 1DSRVOMHWNX üH VH XND]DWi na QDMXþLQNRYLWLMH UMHãHQMH V RE]LURP QD HQHUJHWVNX L
eksHUJHWVNXXþLQNRYLWRVW
2. 0$7(0$7,ý.,02'(/*HRPHWULMVNHNDUDNWHULVWLNHL]PMHQMLYDþDWRSOLQHVXVOMHGHüH:
 Promjer bubnja – 90 mm
 Promjeri cijevi – 16/20 mm, 30/34 mm
 Raspored i udaljenost cijevi u cijevnom snopu – trokutasti, 30 mm
 Broj cijevi – 7
 'XOMLQDL]PMHQMLYDþD– 600 mm
 5D]PDNL]PHÿXSUHJUDGD– 86 mm
 Broj pregrada – 6
 Materijal stijenke – þHOLN*HRPHWULMDL]PMHQMLYDþDL]UDÿHQDMHX'SURJUDPX]DPRGHOLUDQMHLSULND]DQDMHQDVOLFi 1,
zajedno s ucrtanim ulazima i izlazima oba fluida.

Slika 13ULND]GRPHQHVR]QDþHQLPXOD]LPDLL]OD]LPDIOXLGD
0DWHPDWLþNL model þLQH domena SRGUXþMHSURUDþXQD GLIHUHQFLMDOQHMHGQDGåEHRþXYDQMDWHSRþHWQi i rubni uvjeti.DNRMH]DGDQLSUREOHPVWDFLRQDUDQGHILQLUDWüHVHVDPRrubni uvjeti.
3.1. Domena%XGXüLGDMHL]PMHQMLYDþWRSOLQHVLPHWULþDQXRYRPVOXþDMXL]GYRMLWüHVHX]GXåQDSRORYLFD
L]PMHQMLYDþDNDRãWRMHSULND]DQRQDVOLFL2QDXNOMXþXMHWULSRGGRPHQHstruju tople vode(koja struji kroz cijevi), stijenku i struju hladne vode (koja struji oko cijevi). Za svaku od
SRGGRPHQDSULPLMHQLWüHVHRGJRYDUDMXüHMHGQDGåEHRþXYDQMD
2.2. 'LIHUHQFLMDOQHMHGQDGåEHRþXYDQMD
5.2.1. Poddomena 1 – topla voda (1) i hladna voda (2)-HGQDGåEDRþXYDQMDPDVH– jednadžba kontinuiteta߲‫ݓ‬௫ ߲‫ݓ‬௬ ߲‫ݓ‬௭
+
+
=0
߲‫ݔ‬
߲‫ݕ‬
߲‫ݖ‬

(1)

Energy and the Environment (2016) 537-546

539-HGQDGåEDRþXYDQMDNROLþLQHJLEDQMD
smjer osi x:
ߩଵ,ଶ ή ൬‫ݓ‬௫ ή

߲‫ݓ‬௫
߲‫ݓ‬௫
߲‫ݓ‬௫
+ ‫ݓ‬௬ ή+ ‫ݓ‬௭ ή
൰
߲‫ݔ‬
߲‫ݕ‬
߲‫ݖ‬
߲‫݌‬
߲ ଶ ‫ݓ‬௫ ߲ ଶ ‫ݓ‬௫ ߲ ଶ ‫ݓ‬௫=െ+ ߟଵ,ଶ ή ቆ ଶ +
+
ቇ
߲‫ݔ‬
߲‫ݔ‬
߲‫ ݕ‬ଶ߲‫ ݖ‬ଶ

(2)

߲‫ݓ‬௬
߲‫ݓ‬௬
߲‫ݓ‬௬
+ ‫ݓ‬௬ ή+ ‫ݓ‬௭ ή
ቇ
߲‫ݔ‬
߲‫ݕ‬
߲‫ݖ‬
߲ ଶ ‫ݓ‬௬ ߲ ଶ ‫ݓ‬௬ ߲ ଶ ‫ݓ‬௬߲‫݌‬=െ+ ߟଵ,ଶ ή ቆ ଶ +
+
ቇ
߲‫ݕ‬
߲‫ݔ‬
߲‫ ݕ‬ଶ߲‫ ݖ‬ଶ

(3)

߲‫ݓ‬௭
߲‫ݓ‬௭
߲‫ݓ‬௭
+ ‫ݓ‬௬ ή+ ‫ݓ‬௭ ή
൰
߲‫ݔ‬
߲‫ݕ‬
߲‫ݖ‬
ଶ
߲‫݌‬
߲ ‫ݓ‬௭ ߲ ଶ ‫ݓ‬௭ ߲ ଶ ‫ݓ‬௭=െ+ ߟଵ,ଶ ή ቆ ଶ +
+
ቇ
߲‫ݖ‬
߲‫ݔ‬
߲‫ ݕ‬ଶ߲‫ ݖ‬ଶ

(4)smjer osi y:ߩଵ,ଶ ή ቆ‫ݓ‬௫ ήsmjer osi z:ߩଵ,ଶ ή ൬‫ݓ‬௫ ή-HGQDGåEDRþXYDQMDHQHUJLMHߩଵ,ଶ ή ൬‫ݓ‬௫ ήߣଵ,ଶ ߲ ଶ ܶ ߲ ଶ ܶ ߲ ଶ ߲߲߲ܶܶܶܶ+ ‫ݓ‬௬ ή+ ‫ݓ‬௭ ή ൰ =
ήቆ
+
+
ቇ
߲‫ݔ‬
߲‫ݕ‬
߲‫ݖ‬
ܿଵ,ଶ ߲‫ ݔ‬ଶ ߲‫ ݕ‬ଶ ߲‫ ݖ‬ଶ

(5)

5.2.2. Poddomena 2 – stijenka-HGQDGåEDRþXYDQMDHQHUJLMHKako se radi o krutoj stijenci, ‫ݓ‬௫ = ‫ݓ‬௬ = ‫ݓ‬௭ = 0, pa slijedi:߲ଶܶ ߲ଶܶ ߲ଶܶ++=0߲‫ ݔ‬ଶ ߲‫ ݕ‬ଶ ߲‫ ݖ‬ଶ

3.3. Rubni uvjeti
3.3.1. Ulazni rubni uvjet (ulazne plohe tople i hladne vode)ܶ = ܶ୳୪ , ‫୳ݓ = ݓ‬୪
3.3.2. Izlazni rubni uvjet (izlazne plohe tople i hladne vode)
߲‫ݓ‬௡
߲ܶ
= 0,
=0
߲݊
߲݊

(6)

540

0.LULQþLü./HQLü$7US: (QHUJHWVNDLHNVHUJHWVNDDQDOL]DFLMHYQRJL]PMHQMLYDþDWRSOLQH

3.3.3. Rubni uvjet na krutoj stijenci‫ݓ‬௫ , ‫ݓ‬௬ , ‫ݓ‬௭ = 0
površina cijevi:ߣ୤ ή

plašt bubnja:߲߲ܶܶ= ߣୱ୲ ή
߲݊
߲݊
߲ܶ
=0
߲݊

3.3.4. Rubni uvjet simetrije‫ݓ‬௡ = 0߲߶=0߲݊

3. 180(5,ý.$35,35(0$,5-(â$9$1-(=D UMHãDYDQMH RYRJ SUREOHPD NRULãWHQD MH PHWRGD NRQWUROQLK YROXPHQD QXPHULþND PHWRGD
NRMD VH WHPHOML QD RSüRM MHGQDGåEL RþXYDQMD IL]LNDOQRJ VYRMVWYD RSLVDQD X knjizi Patankara[9]. %XGXüL GD MH UDVSRGMHOD EU]LQD ELOD QHSR]QDWD NRULšten je algoritam za polja brzina itlakova SIMPLE (eng. Semi-Implicit Method for Pressure-Linked Equations). NuPHULþNL
SURUDþXQL SURYHGHQL VX X SURJUDPVNRP SDNHWX Ansys (Ansys Geometry, Ansys Mesh, Ansys
Fluent). Stvorena je mreža s 2 075 550 kotrolnih volumena maksimalne veliþLQH VWUDQLFH 
mm3RVWDYOMHQLVXNULWHULMLNRQYHUJHQFLMH]DVYDNXRGMHGQDGåELRþXYDQMD -HGQDGåEDRþXYDQMDPDVH10-3,
 -HGQDGåEHRþXYDQMDNROLþLQHJLEDQMD10-5,
 -HGQDGåEDRþXYDQMDHQHUJLMH10-6.
Rješenje je konvergiralo za 31 sat nakon 1582 iteracije ]D VYDNL RG VOXþDMHYD Nakon toga
uslijedila je provjera fizikalne ispravnosti modela usporedbom bilanci toplinskih tokova
GRELYHQLKL]L]QXPHULþNLKUH]XOWDWDXPQRãNRPL]UDþXQDWHSRYUãLQHL]PMHQHWRSOLQHLJXVWRüH
toplinskog toka, WHDQDOLWLþNL, iz umnoãNDPDVHQRJSURWRNDVSHFLILþQRJWRSOLQVNRJNDSDFLWHWD
i razlike temperatura fluida. Usporedba toplinskih tokova dobivenih na oba QDþLQDSULND]DQD
je u tablici 1. Slika 2 SULND]XMH UDVSRGMHOX WHPSHUDWXUD X GRPHQL GRELYHQX QXPHULþNRP
DQDOL]RP]DVOXþDM
Tablica 18VSRUHGEDELODQFHWRSOLQVNLKWRNRYDGRELYHQLKQXPHULþNLPLDQDOLWLþNLPSXWHP
1XPHULþNLUH]XOWDWL$QDOLWLþNLUH]XOWDWL

1

ܳሶଵ
[W]
617,6

ܳሶଶ
[W]
614,9

ܳଵሶ
[W]
618,2

ܳሶଶ
[W]
598,4

2

886,1

882,3

882,9

860,4

3

1154,6

1149,7

1146,51120,841423,1

1417

1406,71380,26OXþDM

Energy and the Environment (2016) 537-546

541

Slika 25DVSRGMHODWHPSHUDWXUDXGRPHQL]DVOXþDMIz slike 2 je vidljivo smanjenje temperature tople vode pri prolasku kroz cijev te porast
temperature hladne vode koja VWUXML RNR FLMHYL 7DNRÿHU MH YLGOMLY L XWMHFDM SUHJUDGD NRMHSURGXåXMXVWUXMQLSXWKODGQHYRGHþLPHVHSRVSMHãXMHL]PMHQDWRSOLQH1DNRQSURYHdeQHþHWLULQXPHULþNHDQDOL]HLGRELYDQMDL]OD]QLKWHPSHUDWXUDREDIOXLGDPRJXüHMHSURYHVWLHQHUJHWVNX
i eksergetsku analizu.
4. REZULTATI ISTRAŽIVANJA
4.1. Toplinski stupanj djelovanja
Toplinski stupanj djelovanja protusmjernog L]PMHQMLYDþDWRSOLQH definira se kao omjer stvarno
L]PLMHQMHQRJWRSOLQVNRJWRNDLWRSOLQVNRJWRNDNRMLELVHL]PLMHQLRXL]PMHQMLYDþXEHVNRQDþQR
velike površine kada bi se hladniji fluid zagrijao do ulazne temperature toplijeg fluida [10].
Taj se odnos može pojednostaviti i izraziti omjerom razlike temperatura toplijeg fluida na
ulazu i izlazu i razlike ulaznih temperatura oba fluida:ߝ=‫ݐ‬ଵᇱ െ ‫ݐ‬ଵᇱᇱ‫ݐ‬ଵᇱ െ ‫ݐ‬ଶᇱ(12)

NXPHULþNRP DQDOL]RP GRELYHQH su temperature oba fluida na ulazu i izlazu, pa se mogu
L]UDþXQDWL WRSOLQVNL VWXSQMHYL GMHORYDQMD ]D VYDþHWLUL VOXþDMD 7RSOLQVNL VWXSQMHYL djelovanja
NRML SUHGVWDYOMDMX HQHUJHWVNX XþLQNRYLWRVW prikazani su u tablici 2 zajedno s izlaznim
temperaturama tople i hladne voGH*UDILþNLSULND]WRSOLQVNRJVWXSQMDGMHORYDQMDXRYLVQRVWLo ulaznoj temperaturi tople vode prikazan je na slici 3.
Tablica 23ULND]HQHUJHWVNHXþLQNRYLWRVWLLUHOHYDQWQLKSDUDPHWDUD]DVYHVOXþDMHYH

1

‫ݐ‬ଵᇱ
[°C]
50

‫ݐ‬ଵᇱᇱ
[°C]44,69‫ݐ‬ଶᇱᇱ
[°C]
31,07

0,2309

2

60

52,39

32,85

0,2306

3

70

60,08

34,62

0,2307

4

80

67,78

36,39

0,23066OXþDMߟ

542

0.LULQþLü./HQLü$7US: (QHUJHWVNDLHNVHUJHWVNDDQDOL]DFLMHYQRJL]PMHQMLYDþDWRSOLQH

Slika 3*UDILþNLSULND]WRSOLQVNLKVWXSQMHYDGMHORYDQMDL]PMHQMLYDþD]DVYDNLVOXþDM
Kao što je vidljivo iz slike 3SURPMHQDXOD]QHWHPSHUDWXUHWRSOHYRGHQLMH]QDþDMQRXWMHFDOD
QDWRSOLQVNLVWXSDQMGMHORYDQMDL]PMHQMLYDþDRGQRVQXHQHUJHWVNXXþLQNRYLWRVW2PMHUUD]OLND
ulazne i izlazne temperature tople vode i ulazne temperature tople vode i ulazne temperaturehladne vode ostao je približno jednak.
4.2. Eksergetski stupanj djelovanja
U ovome radu kao izvor eksergije uzimat üH VH VDPR WRSOD VWUXMD D SRYHüDQMH HNVHUJLMH
KODGQH VWUXMH SUHGVWDYOMDW üH GRELWDN HNVHUJLMH >11@ 3UHPD WRPH L]UD] ]D UDþXQDQMH
HNVHUJHWVNHXþLQNovitosti prikazat ELWüHߟୣ୶ =‫ܧ‬ଶᇱᇱ െ ‫ܧ‬ଶᇱ ‫ܩ‬ሶଶ [݄ଶᇱᇱ െ ݄ଶᇱ െ ܶ଴ (‫ݏ‬ଶᇱᇱ െ ‫ݏ‬ଶᇱ )]=‫ܧ‬ଵᇱ െ ‫ܧ‬ଵᇱᇱ ‫ܩ‬ሶଵ [݄ଵᇱᇱ െ ݄ଵᇱ െ ܶ଴ (‫ݏ‬ଵᇱ െ ‫ݏ‬ଶᇱᇱ )](13)

Stanje okoline 0 je pri temperaturi od 25 °C (298,15 K) i 101,325 kPa [12].
Vrijednosti entalpije i entropije vode pri stanju okoline i pri ulaznoj temperaturi hladne vode
MHGQDNHVX]DVYDNLVOXþDMSURUDþXQDEDãNDRLPDVHQLSURWRFLREDIOXLGD2QLUHGRPL]QRVH݄଴ = 104,92 J/kg‫ݏ‬଴ = 0,3672 J/kgK‫ݐ‬ଶᇱ = 27 °C
ᇱ݄ଶ = 113,282 J/kg‫ݏ‬ଶᇱ = 0,395 J/kgK‫ܩ‬ሶଵ = 0,0279 kg/s‫ܩ‬ሶଶ = 0,0352 kg/s
9ULMHGQRVWLHNVHUJHWVNLKLVNRULVWLYRVWL]DVYDNLRGþHWLULVOXþDMDSULND]DQHVXXWDEOLFL3, kao i
YULMHGQRVWLL]OD]QLKWHPSHUDWXUDHQWDOSLMDLHQWURSLMD]DREDIOXLGD*UDILþNLSULND]RYLVQRVWL
eksergetske iskoristivosti o ulaznoj temperaturi tople vode prikazan je na slici 4.

Energy and the Environment (2016) 537-546

543

Tablica 33ULND]HNVHUJHWVNHXþLQNRYLWRVWLLUHOHYDQWQLKSDUDPHWDUD]DVYHVOXþDMHYH
6OXþDM

‫ݐ‬ଵᇱ
[°C]

݄ଵᇱ
[J/kg]‫ݏ‬ଵᇱ
[J/kgK]݄ଵᇱᇱ[J/kg]‫ݏ‬ଵᇱᇱ
[J/kgK]݄ଶᇱᇱ[J/kg]‫ݏ‬ଶᇱᇱ
[J/kgK]

ߟୣ୶

1

50

209,420,704

185,880,630

130,30

0,451

0,176

2

60

251,25

0,831

219,41

0,735

137,73

0,476

0,167

3

70

293,12

0,955

251,580,832

145,13

0,5

0,158

4

80

335,06

1,076

283,82

0,928

152,53

0,524

0,153

Slika 4*UDILþNLSULND]HNVHUJHWVNLKVWXSQMHYDGMHORYDQMDL]PMHQMLYDþD]DVYDNLVOXþDM
Iz slike 4 vidljivo je GD VH SRYHüDQMHP XOD]QH WHPSHUDWXUHWRSOHYRGHVPDQMXMHHNVHUJHWVNDLVNRULVWLYRVW L]PMHQMLYDþD WRSOLQH ]D QHNROLNR SRVWRWDND =D SRYHüDQMH HNVHUJHWVNH
XþLQNRYLWRVWL ELOR EL QXåQR RVWYDULWL YHüH L]OD]QH WHPSHUDWXUH KODGQH YRGH NDNR EL VH
SRYHüDOD QMH]LQD HNVHUJLMD ãWR L]UDYQR SRYHüDYD HNVHUJHWVNX XþLQNRYLWRVW 3REROMãDQMH
HVNHUJHWVNH XþLQNRYLWRVWL QH PRåH VH RVWYDULWL SRYHüDQMHP LOL VPDQMHQMHP VDPR MHGQH
varijablHMHUVXRQHXPHÿXVREnoj vezi.
5. =$./-8ý$.
Cilj ovog rada bio je ispitati utjecaj promjene ulazne temperature tople vode na energetsku i
HNVHUJHWVNX XþLQNRYLWRVW FLMHYQRJ L]PMHQMLYDþD WRSOLQH PDOLK GLPHQ]LMD SULND]DQ X þODQNX
[1]. Za tu svrhu napravljen je geometrijski model L]PMHQMLYDþD SUHPD GLPHQ]LMDPDQDYHGHQLPXþODQNX Nakon izrade modela, bilo je potrebno provjeriti njegovu valjanost. To
MHXþLQMHQRXVSRUHÿLYDQMHPELODQFLWRSOLQVNLKWRNRYDQXPHULþNLPLDQDOLWLþNLPSXWHPNRMHVX]DVYDNLVOXþDMSRND]DOHYLVRNVWXSDQMSRGXGDUDQMDL]þHJDMH]DNOMXþHQRGDMHPRGHOYDOMDQ
1DNRQXVSMHãQHQXPHULþNHDQDOL]HVYLKþHWLULMXVOXþDMHYDVUD]OLþLWLPXOD]QLPWHPSHUDWXUDPDWRSOH YRGH ELOL VX SR]QDWL VYL SRGDFL SRWUHEQL ]D SURUDþXQ HQHUJHWVNH L HNVHUJHWVNH
XþLQNRYLWRVWLEnergetska analiza pokazala je vrlo malo promjenu toplinskog stupnja djelovanja
L]PMHQMLYDþDSRND]DYãLWDNRGDSRYHüDQMHXOD]QHWHPSHUDWXUHWRSOHYRGHQHXWMHþH]QDWQRQD

544

0.LULQþLü./HQLü$7US: (QHUJHWVNDLHNVHUJHWVNDDQDOL]DFLMHYQRJL]PMHQMLYDþDWRSOLQH

WRSOLQVNL VWXSDQM GMHORYDQMD L]PMHQMLYDþD WRSOLQH 1D SRYHüDQMH XþLQNRYLWRVWL L]UDYQR XWMHþHizlazna temperatura tople vode, koju je potrebno što više smanjiti. MRJXüL SULMHGOR]L
poboljšanja uvjeta izmjene topline su VPDQMHQMHXOD]QHEU]LQHWRSOHYRGHSRYHüDQMHSURWRND
hladne vode, poboljšanje geometrijskih karakteristika itd.
Eksergetski stupanj GMHORYDQMD SRND]DR MH EODJL SDG SRYHüDQMHP XOD]QH WHPSHUDWXUH WRSOH
YRGH =D SRYHüDQMH HNVHUJHWVNH XþLQNRYLWRVWL L]PMHQMLYDþD SRWUHEQR MH SRYHüDWL GRELWDN
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Energy and the Environment (2016) 537-546

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545

LITERATURA
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
[11]
[12]
[13]

Pandey, S.D., Nema, V.K.: An experimental investigation of exergy loss reduction incorrugated plate heat exchanger, Energy, 36 (2011), 2997-3001.
Doohan, R.S., Kush, P.K., Maheshwari, G: Exergy based optimization andexperimental evaluation of plate fin heat exchanger, Applied Thermal Engineering(2016).
Dizaji, H.S., Jafarmadar, S., Hashemian, M: The effect of flow, thermodynamic andgeometrical characteristics on exergy loss in shell and coiled tube heat exchangers,
Energy, 91 (2015), 678-684
Dizaji, H.S., Khalilarya, S., Jafarmadar, S. Hashemian, M., Khezri, M.: A
comprehensive second law analysis for tube-in-tube helically coiled heat exchangers,
Experimental Thermal and Fluid Science (2016).
Martinaitis, V., 6WUHFNLHQơ G., Biekša, D., Bielskus, J.: The exergy efficiency
assessment of heat recovery exchanger for air handling units, using a state property –coenthalpy, Applied Thermal Engineering (2016).
Naili, N., Hazami, M., Kooli, S., Farhat, A.: Energy and exergy analysis of horizontal
ground heat exchanger for hot climatic condition of northern Tunisia, Geothermics, 53(2015), 270-280.
Kalaiarasi, G., Velraj, R., Swami, M.W.: Experimental energy and exergy analysis ofa flat plate solar air heater with a new design of integrated sensible heat storage,
Energy, 111 (2016), 609-619.
Jadhav, A.D., Koli, T.A.: CFD Analysis of Shell and Tube Heat Exchanger to Study
the Effect of Baffle Cut on the Pressure Drop, International Journal of Research in
Aeronautical and Mechanical Engineering, 2 (2014), 7, 1-7.
Patankar, S.V.: Numerical Heat Transfer and Fluid Flow, Hemisphere Publishing
Corporation, Taylor & Francis Group, New York, 1980.
%RãQMDNRYLü, F.: Nauka o toplini I, 5., popravljeno izdanje, Graphis d.o.o., Zagreb,
2012.
Ahern, J.E.: The Exergy Method of Energy Systems Analysis, John Wiley & Sons,
New York, 1980.
Kanoglu, M., Çengel, Y.A., Dinçer, ø: Efficiency Evaluation of Energy Systems,
Springer, New York, 2012.
Bejan, A.: Entropy Generation through Heat and Fluid Flow, John Wiley & Sons,
New York, 1982.

546

0.LULQþLü./HQLü$7US: (QHUJHWVNDLHNVHUJHWVNDDQDOL]DFLMHYQRJL]PMHQMLYDþDWRSOLQH

ENERGY AND EXERGY ANALYSIS OF A SHELL AND TUBE HEATEXCHANGER
Abstract: In this paper, an analysis of energy and exergy efficiency of a small size shell andtube water-water heat exchanger has been presented. A geometric model was designed
according to pre-existing specifications and a numerical analysis of heat transfer for fourcases with different hot water inlet temperatures have been performed. Models have beenvalidated by comparing heat fluxes balance calculated from numerical data and analyticallyobtained results. Outlet temperatures of hot and cold water were presented, as well as energy
and exergy efficiencies for each of the four cases. The results show that energy efficiency hasvery little variation, however exergy efficiency exhibits a mild decrease as hot water inlet
temperature increases. The case with the lowest hot water inlet temperature has been deemed
the most favorable from both energy and exergy standpoint.
Keywords: shell and tube heat exchanger, energy analysis, exergy analysis, numerical model,
finite volume method

Energy and the Environment (2016) 547-558

547

RENEWABLE DISTRICT HEATING: CASE STUDY CROATIA
B. Doracic, T. Puksec, T. Novosel, N. Duic
Faculty of Mechanical Engineering and Naval Architecture, Department of Energy,
Power Engineering and Environment, University of Zagreb, ,YDQD/XþLüD
Zagreb, +385 1 6168242
email: borna.doracic@fsb.hr
Abstract: Highly efficient cogeneration and district heating systems (DH) have a significant
potential for primary energy savings which are still highly underutilized in most European
countries. They can provide significant benefits to the uptake of waste/renewable heat but
also help foster the integration of intermittent energy sources for electricity production (e.g.
wind and photovoltaics) through the use of heat storage and power-to-heat technologies. In
order to plan, design and implement DH in the most cost-effective way, spatial distribution of
the heating/cooling demands as well as waste/renewable heat sources need to be analysed,
mapped and compared to the existing systems.
In order to utilize some sources of waste/renewable heat, conditions in DH network have toreach certain parameters. Most DH in Eastern Europe still function in the category of socalled second generation, meaning that they utilize pressurised hot water with supply
temperatures well above 100 °C making them unsuitable for the exploitation of lowtemperature heat sources. A coherent refurbishment strategy of both the building stock and
DH is necessary for this to change. Elaborate strategies are necessary, both from thetechnical and sociological perspective.
The goal of this work is to demonstrate both sides of the strategies, technical andsociological, with Croatia as a case study example. In order to start heating/cooling demand
mapping, project development and implementation, elaborate schemes towards citizens andpublic authorities are necessary. Second goal of this work is to demonstrate heating/coolingdemand, as well renewable/waste heat source, mapping methodology and to utilize obtained
results for modelling the impact of DH on the penetration of renewable/waste heat utilizationin the overall energy system. The impact of urban refurbishment on the potential uptake of
low-temperature heat sources has also been presented. The mapping has been done using
ArcGIS tool while the energy planning has been done using EnergyPLAN.
Key words: Renewable district heating, Heat deman mapping, Public opinion, EnergyPLAN,
ArcGIS
1. INTRODUCTION
Europe has recognized that the security of energy supply and the reduction of CO2 emissions
are key issues that will define the development of its energy systems. For that reason,
utilization of highly efficient cogeneration with district heating (DH) systems should increasesignificantly since these systems can greatly increase energy efficiency and reduce the CO2
emissions of the energy sector.
Currently, only 13 % of European heat supply is covered by DH systems, which makes
potentials for increasing this share significant, especially in the urban areas which arecharacterised by high heat demand densities [1]. Further increase of said potentials is
expected with transfer to the 4th generation DH systems which incorporate low distribution
temperatures, use of renewable energy sources and waste heat, use of large scale heat pumps

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B. Doracic, T. Puksec, T. Novosel, N. Duic: Renewable district heating…

and thermal storage, integration of heat and electricity sectors, etc. [2]. Papers such as [3]have already shown that energy systems such as the Danish one could integrate upwards of
50% DH penetration and have highlighted its impact on the overall energy system if large
scale heat pumps and heat storage would be integrated into it.
The share of DH in the overall heat supply in Croatia is around 14 %, which is approximately
the same as the European average. However, majority of DH systems in Europe can beclassified as current 3rd generation systems, while most Croatian systems are older andbelonging to 2nd generation DH systems, which use pressurised hot water with supply
temperatures well above 100 °C as a heat carrier. This is mostly due to older building stockand the lack of adequate heating insulation, which usually results in heat demands of 150-250
kWh/m2 annually. Around 14 % of DH systems in Europe use renewable energy sources(RES) [4], while in Croatia, there is only one small geothermal DH plant and one small
biomass DH plant with the rest being fossil fuel powered DH plants. The biggest share of DH
production in Croatia is covered by natural gas, approximately 80-85 %, which is followed byfuel oil. Altogether 3 DH systems in Croatia are combined heat and power systems, but therest are comprised of heat only boilers. Although papers such as [5] showed that using
biomass fired cogeneration in a midsized town in Croatia results in much bigger primaryenergy savings than using a gas fired cogeneration, these facilities in Croatia are still
completely powered by fossil fuels. Nevertheless, some studies [6] show that using fossil
fuels is still economically more attractive than using biomass DH and therefore it is crucial tohave incentives from governments. It has to be pointed out that although there are no such
systems in Croatia, there are a growing number of small renewable DH systems in Europe,with Denmark being the leading country in this sector. For example, Marstal DH comprises ofa biomass cogeneration, heat pump and more than 30 000 m2 of solar collectors, combinedwith seasonal underground thermal storage [7]. More examples from Austria, Spain, Poland
and Germany are presented in Refs. [8] and [9].
The biggest issues facing the district heating sector in Croatia are the average age of thesystem, gas prices for households and, most crucially, the condition of the building stock inthe country. Average age of DH infrastructure in Croatia is rather high (e.g. for pipes in
Zagreb DH, around 30 years [10]), which makes specific heat losses of these systems
considerable. Heat losses are caused by the heat transfer between heat carrier and surrounding
ground (i.e. high distribution temperatures combined with low insulation protection, as
evaluated in [11]), but another important aspect are high water losses which occur due todamages on pipes. In order to reduce heat losses, different designs of pipes can be considered(e.g. twin pipes, double pipes and triple pipes [12]), as well as different insulation standards
for pipes in DH systems [13].
Due to mentioned reasons, the general public in Croatia has a negative opinion of DH
systems, which are perceived expensive and inefficient and should therefore be refurbishedalong with building stock to increase their cost-effectiveness over the individual heating. In
Ref. [14], authors presented different scenarios regarding future energy demand of Croatianhousehold sector and concluded that this sector has significant potentials for energy savingsand RES in the future as well as proposed measures to achieve them.
Concerning the heat market in Croatia, it is practically non-existent although the framework
for the market has been defined in Heat market act, which is the most important act regarding
DH in Croatia. Incentives as such are not existent for this sector but they can be received forelectricity production in the highly efficient cogeneration facilities, which also subsidizes
production of heat from these facilities. In order to implement renewable district heating
project in Croatia, a large number of administrative documents and permits have to beobtained, therefore making the process rather lengthy. Legal and market framework of
Croatian energy sector have been analysed in more detail in [15] and [16], with special focus
on district heating and cogeneration.

Energy and the Environment (2016) 547-558

549

In this paper, a step-by-step methodology for implementing renewable DH systems in Croatia
will be presented (with a focus on small renewable DH systems). In order to demonstrate apart of the methodology, detailed heat demand mapping methodology will be presented forthe city of Velika Gorica in Croatia, as well as the economic and environmental analysis ofexpanding the DH network in this city.
2. METHODOLOGY
In order to implement small renewable DH systems in Croatia, a methodology was developed
which consists of next steps:
1.
2.
3.
4.
5.

Building political and public support
Analysing the framework
Mapping the stakeholders
Gathering information
Analysing information

The methodology describes the planning phase of the implementation. In order to successfully
implement such systems, all of the presented steps should be followed.
2.1. Building political and public support
Building political and public support has been recognized as a vital step that determines how
the project will develop. Receiving support from influential local politician should be the firststep, followed by using his/her authority to gain the support and commitment of all involved
areas inside City Hall since this is the key to success.
Citizens should also be included in project activities in order to ensure sustained public
acceptance of renewable DH systems. Information events and workshops are great
opportunities to promote the project among the citizens and to gather their ideas, suggestions
and doubts, e.g. in the form of a survey. Their increased knowledge enables citizens of thetarget communities to get involved in the project activities. Checking the public opinion andwinning public support for the renewable DH system initiative may also contributesignificantly in convincing the municipality politicians to give their support.
2.2. Analysing the framework
Important aspect for the establishment and operation of DH systems are framework conditions whichhave to be analysed in detail, e.g. to ensure that the investments in hardware can be financed.

Analyses should include existing policies or strategies, defined on a city, regional andnational scale, which concern DH systems. This includes documents related to climatechange, energy, waste, planning etc. In this step, gaps in policies can be identified in order topropose improvements which will underpin the implementation plan. A brief analysis of
Croatian legislative framework for DH systems has already been made in the introduction.
Different policies that can help in market creation for renewable DH have been suggested in[4]: benchmarking and disclosure requirements of building energy performance; incentives
for energy efficient renovation and new construction; measures and standards that provide
incentives for the electricity produced in district energy systems (e.g. cogeneration) withclear, consistent rules for connecting to the grid; priority dispatch; licensing exemptions for

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B. Doracic, T. Puksec, T. Novosel, N. Duic: Renewable district heating…

small scale generators; and policies that open energy markets to decentralized generators andinternalize the public benefits of DH systems (net-metering, heat incentives).
This step should also include defining best practices in the country and analysing them inorder to learn from their specific experience and use them as a valid argument when building
political and public support.
2.3. Mapping the stakeholders
It is vital for the implementation of small renewable DH systems that all relevant stakeholders(i.e. organisations and individuals) are mapped as early as possible in the process and that
their roles are clearly defined. The most important stakeholders can be identified as:politicians; utilities, energy service companies and network operators; construction
companies; citizens; industries; component manufacturers; renewable energy industry; R&D
institutes and universities; project developers, designers; etc. Effective engagement andinvolvement of the stakeholders will be critical to succeed with the process as well as it will
be necessary to ensure good communication between them.
The challenge that appears in this step is in the number of stakeholders that are involved in
the planning process with an emphasis on exploiting waste heat potential from industrial sites
or including demand side measures in the concept. Increasing the number of stakeholders
implies a higher complexity in the planning task, more difficulties to access data and many
private economic interests to satisfy so that should be taken into account during the mappingof the stakeholders.
2.4. Gathering information
In order to evaluate the heating sector of the city/municipality, a large amount of data has tobe collected and organised. Important data for planning small renewable DH systems can bedivided into three sets, as described below:
1. Energy data of the city/municipality which includes heat consumption, energy sources
used for heating and domestic hot water preparation, waste heat production, etc.
2. Climate and geographical/geological data of the city/municipality which includes windspeeds, solar irradiation, ground temperatures, nearby water temperatures etc. whichmakes the basis for calculating the RES potentials of the community
3. Technical data of the city/municipality regarding heating, which includes current heatproduction and in-house distribution technologies, level of insulation of buildings,
household areas, etc.
Since large amount of data need to be gathered, all of the stakeholders in the project should be
included in this step in order to maximize the quality of gathered data. For example, energy
data of the municipality can be provided by utility companies if municipality has no direct
insight in this data. The official data available on a municipal level will vary depending on themunicipality in question, but it should be researched what kind of official energy, climate andtechnical data are available. For example, if a city/municipality has a Sustainable Energy
Action Plan (SEAP), it can serve as a good source of energy data, but the more precise data
can be gathered by surveying the citizens of the city/municipality. Since the focus of thispaper are small renewable DH systems in communities, i.e. small cities and municipalities,
gathering reliable energy data through surveys from citizens is relatively easy, but in large
cities this would require a large amount of time, manpower and funds.

Energy and the Environment (2016) 547-558

551

2.5. Analysing information
Analysing gathered information represents a crucial part of the methodology since themeasures and actions for implementation of small renewable DH systems are proposed basedon this step. This step demonstrates municipality's current heat sector situation and how
developed and sustainable it is. Analyses of the heat consumption of end-users enables theheat demand mapping. This gives a clear picture of current state of buildings as well as of theend-user behaviour. Also, this locates areas with highest potentials for DH systems as
mentioned before.
By analysing climate information on RES, potentials for their utilization can be determined.
For better analysis, evaluated RES potentials should be put on a map by the means of GIS
tools. This enables determining locations of potential plants in a much easier fashion. Data ofexcess heat production in the municipality should also be mapped for the same reason. Also,
the assessment of land (public or private) that is available for installation of DH systemshould be made.
Analyses of technical data of the municipality’s heating system, as well as the municipality’senergy data, enables determining current state of the heating system. This way, households
which already have a suitable heating system for connecting to a DH system are defined,
which significantly decreases the investment for the end users (i.e. households which would
only have to pay for connection to the grid and substations). Level of insulation of buildings,
as well as household areas, is both used as a valuable data for heat demand mapping.
After analysing all the data, models of current system have to be developed, as well as
different scenarios for the small renewable DH systems in order to determine what are thebest, most cost-effective measures that have to be implemented. Different tools for analysing
integration of RES into current energy systems have been presented in Ref. [17]. Feasibility
analysis of different scenarios (i.e. different measures and actions being implemented) has tobe done in this step of the methodology. The capital, operational and maintenance costs, alongwith likely revenues from heat, cooling and electricity sales, should be roughly estimated at
this stage. This will help to establish whether the proposed scheme is economically viable,
and affordable for customers.
3. CASE STUDY: CITY OF VELIKA GORICA
In order to present some parts of the developed methodology, an analysis of the heating sectorof the city of Velika Gorica in Croatia has been done. The city in question is located in central
part of Croatia, close to the capital. The analyses included heat demand mapping of the city as
well as the analyses of the impact that expansion of DH network (along with substituting
fossil fuels with renewable biomass) has on the overall system cost and CO2 emissions.
3.1. Heat demand mapping
Heat demand mapping, which is a part of the presented methodology for implementing small
renewable DH systems in Croatia, has been done using the ArcGIS tool. In order to ensure
replicability of this method, mostly public data was used.

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B. Doracic, T. Puksec, T. Novosel, N. Duic: Renewable district heating…

3.1.1. Methodology
Heat demand mapping methodology can be divided into 4 main parts:
1. Gathering data on rooftop areas and building locations from an online building census
Geoportal [18]. That way, the initial matrix of the existing buildings was created
2. Gathering data on the number of floors in every building. This step had to be
conducted manually since there is no such publically available data and therefore it
presented the most time consuming step. This data was added to the initial matrix bycolour coding it and was used for calculation of total gross area of each building.
3. Classifying buildings into 6 categories depending on their age and type, in order toassign them empirical values of specific heat demands. This step was done parallel tothe previous step since the data was collected the same way. Categories are: old house(215 kWh/m2), new house (110 kWh/m2), old apartment building (175 kWh/m2), newapartment building (85 kWh/m2), industrial facility (85 kWh/m2) and skyscraper (100kWh/m2).
4. Calculating total heat demand by multiplying total gross areas of buildings withspecific heat demand of different types of buildings. This final matrix is thentransferred into a GIS interface using the ArcGIS tool.
3.1.2. Results
The heat demand map of city of Velika Gorica is presented in Figure 1, on a scale of
100m x 100 m. By analysing both the data obtained from heat demand mapping and from the
SEAP [19] of the city of Velika Gorica, the given results show that the share of total heating
demand covered by DH is around 32% which would mean that annual heat demand ofconnected areas is 3 GWh. This data will be used in the next chapter for energy planning.

Figure 1. Heat demand mapping of the city of Velika Gorica
3.2. Energy planning
Energy planning has been done in order to calculate economic and environmental impact ofincreasing the share of DH in the overall heat demand of Velika Gorica, as well as the shareEnergy and the Environment (2016) 547-558

553

of RES in the heat production mix. For this purpose, energy system of Velika Gorica wasmodelled by EnergyPLAN [20], advanced energy system analyses tool. It represents adeterministic input-output computer modelling tool which provides analysis of an energy
system on an annual basis, with a time step of one hour. The required inputs include the total
demand and demand curves for electricity, installed capacities and efficiencies of different
types of energy producers and energy storage technologies, fuel mix, hourly distribution ofenergy production from intermittent sources like wind and solar, energy demands for thedifferent sectors and different regulation strategies. The outputs of the model include: energybalances, annual and hourly productions of energy and critical excess electricity production,
fuel consumptions, total cost of the system, CO2 emissions and more. The tool has alreadybeen used to make models of various energy systems and devise numerous energy
scenarios. For example, in Refs. [21] and [22], authors used this tool to simulate different
scenarios for the Macedonian energy system. Furthermore, in Refs. [23] and [24]EnergyPLAN has been used for modelling of Danish energy system and analysis of thepotential for the integration of RES, while in Ref. [25] both the EnergyPLAN and the H2RES[26] models were used to recreate the Croatian energy system and plan a 100% sustainableenergy scenario.
3.2.1. Methodology
The model of the energy system of Velika Gorica has been developed by utilising energy
consumption data from the city’s SEAP, hourly electricity distribution from Entso-E [27] for
Croatia and meteorological data (for calculating heat demand distribution) from Meteonorm[28]. Energy sources used for individual heat production in Velika Gorica comprise of oil,natural gas, biomass and electricity, while in DH system natural gas prevails (67%) and therest is covered by oil. All of the DH production facilities are heat only boilers. By using theabove mentioned data, a reference scenario was developed and calculated.
In order to make further analyses of the system, 4 additional scenarios have been developed,
which included expanding DH coverage of the city to include all the areas (100 x 100 m
blocks presented in the heat demand map) that have an average heat demand of at least 300,
250, 200 and 150 kWh/m2. Additionally, since the current DH system only uses fossil fuels,
biomass was introduced in the system to cover up to a 100% of heat production in Scenario 4.
The costs of expanding the DH system also had to be taken into account and they were
calculated with regards to the current estimated cost of the system in the city. This value wasthen increased for every scenario due to covering areas with lower heat densities. Table 1
shows assumptions that were used in the analyses.
Table 1. Assumptions ussed in different scenarios
Specific cost of new DH grid (EUR/kWh)
Share of biomass in DH production (%)
Share of oil in DH production (%)
Share of natural gas in DH production (%)
Minimum average heat demand of an area
covered by DH (kWh/m2)

Scenario
1
0,2
16,5
16,5
67
300

Scenario
2
0,25
33
0
67
250

Scenario
3
0,3
67
0
33
200

Scenario
4
0,35
100
0
0
150

554

B. Doracic, T. Puksec, T. Novosel, N. Duic: Renewable district heating…

3.2.2. Results
Percentage of city covered by DH for different scenarios is shown in Table 2. It can be seenthat for the lowest required heat density, this share increased from current 32 % to 68 %.
Table 2. Share of DH in the reference scenario and 4 addittional scenarios
Reference
Scenario 1
Scenario 2
Scenario 3
32%
37%
45%
55%

Scenario 4
68%

The results of presented scenarios have been compared to the results which would occur if theshares of oil, biomass and natural gas remained the same as in the reference scenario (i.e. 67%
natural gas, 33 % oil, 0% biomass) in order to measure the impact of increasing the share of
RES for DH production. The results can be seen in Figure 2 and Figure 3. It should be notedthat EnergyPLAN discounts the investment costs according to their assumed lifetime and thatthe costs include investments, fixed maintenance costs, variable and fuel costs. The results
show that only increasing the share of DH would already result in significant decrease of total
costs of the system, with the lowest costs being for the Scenario 3. If biomass is introduced in
the system, costs are decreased even further. Completely transferring to a biomass DH system(Scenario 4) results in a reduction of total costs of 15 % compared to a system without RES.
When it comes to environmental impact, increasing the share of district heating results inlower CO2 emissions due to the increased efficiency of such system. When biomass isintroduced in the system, major reductions can be achieved. For example, in Scenario 4,
emissions for the system without RES are 3,8% lower than in Reference, but for a biomass
DH system, CO2 emissions are 88% lower than in Reference.
Additionally, sensitivity analysis has also been conducted for Scenario 4 in order to quantify
the impact of the investment into the DH grid on the overall costs of the system. For thispurpose, the specific costs have been increased and decreased by 20% with a step of 5%. The
results can be seen in Figure 4. Changes in total system costs range from -3,1% to 3,1%,
which are relatively low values since the lifetime of the grid is relatively long.

Figure 2. Total costs of the system in the reference scenario and 4 addittional scenarios

Energy and the Environment (2016) 547-558

555

Figure 3. CO2 emissions of the system in the reference scenario and 4 addittional scenarios

Figure 4. Sensitivity analysis
4. CONCLUSION
In this paper, a step-by-step methodology for implementation of small renewable DH systems
has been presented. It consists of 5 general steps. The methodology will be used for futureplanning and implementation of such systems in Croatia. In order to demonstrate a part of themethodology, heat demand mapping was presented for the city of Velika Gorica. This data
was then used to measure the impact that expansion of DH network (along with substituting
fossil fuels with renewable biomass) has on the overall system cost and CO2 emissions. It was
shown that highest reduction of system costs was achieved for Scenario 4, which included
expanding DH network to cover 68% of heat demand (from current 32%) and replacing
natural gas and oil boilers with biomass boilers. The reductions in total system costs for this
scenario were 21,6% compared to Reference scenario, while CO2 emissions were reduced by
88%. Sensitivity analysis was also conducted for Scenario 4 related to the specific cost of the556

B. Doracic, T. Puksec, T. Novosel, N. Duic: Renewable district heating…

grid expansion, which showed that changing the DH installation costs by ±20% results inrelatively low changes in total system costs (±3,1%) mostly due to the relatively long lifetimeof the grid. For better analyses, more layers should be added in the heat demand mapping,including gas networks, DH networks (if existent) and potential waste heat sources, which
will be done in future work. That way, different heat production technologies (e.g. power toheat technologies, solar thermal, geothermal, etc.) and distribution grids will be analysed inorder to find the optimal solution.
ACKNOWLEDGEMENTS
Financial support from the European Union’s Horizon2020 project CoolHeating (grant
agreement 691679), Intelligent Energy Europe project STRATEGO (grant agreement
EE/13/650), and the 4DH project funded by the Innovation Fund Denmark are gratefully
acknowledged.
REFERENCES[1]

D. Connolly, H. Lund, B. V Mathiesen, S. Werner, B. Möller, U. Persson, T.
Boermans, D. Trier, 3$VWHUJDDUGDQG61LHOVHQ³+HDW5RDGPDS(XURSHௗ
Combining district heating with heat savings to decarbonise the EU energy system,”
Energy Policy, vol. 65, pp. 475–489, 2014.
[2]
H. Lund, S. Werner, R. Wiltshire, S. Svendsen, J. E. Thorsen, F. Hvelplund, and B. V.
Mathiesen, “4th Generation District Heating (4GDH),” Energy, vol. 68, pp. 1–11,
2014.
[3]
M. Münster, P. E. Morthorst, H. V. Larsen, L. Bregnbæk, J. Werling, H. H. Lindboe,and H. Ravn, “The role of district heating in the future Danish energy system,” Energy,
vol. 48, no. 1, pp. 47–55, 2012.
[4]
R. R. Schmidt, N. Fevrier, and P. Dumas, “Key to Innovation Integrated Solution Smart Thermal Grids,” 2013.
[5]'/RQþDUDQG,5LGMDQ³0HGLXPWHUPGHYHORSPHQWSURVSHFWVRIFRJHQHUDWLRQGLVWULFWheating systems in transition country – Croatian case,” Energy, vol. 48, no. 1, pp. 32–
39, 2012.
[6]
S. Akhtari, T. Sowlati, and K. Day, “Economic feasibility of utilizing forest biomass in
district energy systems – A review,” Renew. Sustain. Energy Rev., vol. 33, pp. 117–
127, 2014.
[7]
R. Wiltshire, Ed., Advanced District Heating and Cooling (DHC) Systems, 1st ed.
Elsevier Ltd, 2015.
[8]
D. Basciotti, R. R. Schmidt, E. Meissner, C. Doczekal, and A. Giovannini, “Lowtemperature district heating in AustriDௗ(QHUJHWLFHFRORJLFDQGHFRQRPLFFRPSDULVRQ
of four case studies,” pp. 1–10, 2016.
[9]
D. Bauer, R. Marx, and H. Drück, “Solar district heating systems for small districts
with medium scale seasonal thermal energy stores,” Energy Procedia, vol. 91, pp. 537–
545, 2016.
[10] D. Culig-Tokic, G. Krajacic, B. Doracic, B. Vad Mathiesen, R. Krklec, and J. Møller,“Comparative analysis of the district heating systems of two towns in Croatia andDenmark,” Energy, vol. 92, pp. 435–443, 2015.
[11] .dRPDNOÕ%<NVHODQGgdRPDNOÕ³(YDOXDWLRQRIHQHUJ\DQGH[HUJ\ORVVHVLQ
district heating network,” Appl. Therm. Eng., vol. 24, no. 7, pp. 1009–1017, 2004.
[12] A. Dalla Rosa, H. Li, and S. Svendsen, “Method for optimal design of pipes for low-Energy and the Environment (2016) 547-558

[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]
[22]
[23]
[24]
[25]

[26]
[27]
[28]

557

energy district heating, with focus on heat losses,” Energy, vol. 36, no. 5, pp. 2407–
2418, 2011.
R. Lund and S. Mohammadi, “Choice of insulation standard for pipe networks in 4th
generation district heating systems,” Appl. Therm. Eng., vol. 98, pp. 256–264, 2016.
T. Pukšec, B. Vad Mathiesen, and N. Duic, “Potentials for energy savings and longterm energy demand of Croatian households sector,” Appl. Energy, vol. 101, pp. 15–
25, 2013.
E. Banovac, T. Gelo, and J. Šimurina, “Analysis of economic characteristics of a tariff
system for thermal energy activities,” Energy Policy, vol. 35, no. 11, pp. 5591–5600,
2007.
'/RQþDU1'XLüDQGä%RJGDQ³$QDQDO\VLVRIWKHOHJDODQGPDUNHWIUDPHZRUN
for the cogeneration sector in Croatia,” Energy, vol. 34, no. 2, pp. 134–143, 2009.
D. Connolly, H. Lund, B. V Mathiesen, and M. Leahy, “A review of computer tools foranalysing the integration of renewable energy into various energy systems,” Appl.
Energy, vol. 87, no. 4, pp. 1059–1082, 2010.
“Geoportal - Državna geodetska uprava.” [Online]. Available: http://geoportal.dgu.hr/.
[Accessed: 10-May-2015].
-'RPDF9.ROHJD6'MXNLü,+RUYDW,/RQþDU+0DUDV,3UåXOM9âHJRQDQG
05XåLü³6XVWDLQDEOH(QHUJ\$FWLRQ3ODQRIWKH&LW\RI9HOLND*RUica.”“EnergyPLAN.” [Online]. Available: http://www.energyplan.eu/. [Accessed: 25-Apr2016].
%ûRVLü*.UDMDþLüDQG1'XLü³$UHQHZDEOHHQHUJ\V\VWHPLQWKH\HDU
2050: The case of Macedonia,” Energy, vol. 48, no. 1, pp. 80–87, 2012.
%ûRVLü10DUNRYVND*.UDMDþLü97DVHVNDDQG1'XLü³(QYLURQPHQWDODQG
economic aspects of higher RES penetration into Macedonian power system,” Appl.
Therm. Eng., vol. 43, pp. 158–162, 2012.
H. Lund and E. Munster, “Modelling of energy systems with a high percentage of CHP
and wind power,” Renew. Energy, vol. 28, no. 14, pp. 2193–2197, 2003.
H. Lund and B. Vad Mathiesen, “Energy system analysis of 100% renewable energy
systems—The case of Denmark in years 2030 and 2050,” Energy, vol. 34, no. 5, pp.
524–531, 2009.
*.UDMDþLü1'XLü==PLMDUHYLü%9DG0DWKLHVHQ$9XþLQLüDQG0*
Carvalho, “Planning for a 100% independent energy system based on smart energy
storage for integration of renewables and CO2 emissions reduction,” Appl. Therm.
Eng., vol. 31, no. 13, pp. 2073–2083, 2011.
“H2RES Model.” [Online]. Available: http://powerlab.fsb.hr/h2res/. . [Accessed: 01Aug-2016].
“European Network of Transmission System Operators for Electricity.” [Online].
Available: https://www.entsoe.eu/. [Accessed: 25-Apr-2016].
“Meteonorm.” [Online]. Available: http://www.meteonorm.com/. [Accessed: 25-Apr2016].

558

B. Doracic, T. Puksec, T. Novosel, N. Duic: Renewable district heating…

OBNOVLJIVI CENTRALIZIRANI TOPLINSKI SUSTAVI: ANALIZA+59$76.2*6/8ý$-$Sažetak: 9LVRNRXþLQNRYLWD NRJHQHUDFLMD L FHQWUDOL]LUDQL WRSOLQVNi sustavi (CTS) imaju]QDþDMDQ SRWHQFLMDO ]D XãWHGX SULPDUQH HQHUJLMH NRML MH MRã XYLMHN SRSULOLþQR QHLVNRULãWHQ X
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udjela otpadne i obnovljive topline u toplinskom sektoru te integraciju sa intermitentnim
REQRYOMLYLP L]YRULPD HQHUJLMH QSU YMHWDU L VXQFH  SRPRüX VSUHPQLND WRSOLQH L SUHWYRUEH
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WURãNRYQRRSWLPDODQQDþLQSRWUHEQRMHanalizirati i mapirati prostornu raspodjelu toplinskih
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sustavima.
.DNRELVHLVNRULVWLOLL]YRULRWSDGQHLREQRYOMLYHWRSOLQHPRUDMXVH]DGRYROMLWLRGUHÿHQLXYMHWLu mreži CTS-D9HüLQD&76-DXLVWRþQRM(XURSLVHPRåHVYUVWDWLXGUXJXJHQHUDFLMX&76-a,ãWR ]QDþL GD NRULVWH YUXüX YRGX SRG WODNRP NDR PHGLM ]D SULMHQRV WRSOLQH 7HPSHUDWXUH WLKsustava su znatno iznad 100 °C te su oni neprikladni za iskorištavanje niskotemperaturnih
izvora topline. Kako bi se to promijenilo, potrebna je koherentna strategija za obnovu CTS-a,
NDRL]JUDGDNRMHVXSULNOMXþHQHQD&763RWUHEQRMHQDSUDYLWLRSVHåQHVWUDWHJLMHQHVDPRVD
WHKQLþNHSHUVSHNWLYHQHJRLVDVRFLRORãNHSHUVSHNWLYH.
&LOM RYRJ UDGD MH SULND]DWL REMH VWUDQH VWUDWHJLMH WHKQLþNH L VRFLRORãNH VD +UYDWVNRP NDRSULPMHURP .DNR EL ]DSRþHOL PDSLUDQMH WRSOLQVNLK L UDVKODGQLK SRWUHED WH UD]YRM L
LPSOHPHQWDFLMXSURMHNDWDSRWUHEQRMHUD]YLWLRSVHåQHVKHPH]DJUDÿDQHLWLMHOD javne vlasti.
Drugi cilj ovoga rada je prikaz metodologije za mapiranje toplinskih i rashladnih potreba,
kao i izvora otpadne i obnovljive topline. Prikupljeni rezultati se mogu iskoristiti za
modeliranje utjecaja centraliziranih toplinskih i rashladnih sustava na penetraciju obnovljive
L RWSDGQH WRSOLQH X FMHORNXSQRP HQHUJHWVNRP VXVWDYX 8WMHFDM REQRYH ]JUDGD QD SRYHüDQRLVNRULãWDYDQMH QLVNRWHPSHUDWXUQLK L]YRUD WRSOLQH MH WDNRÿHU SULND]DQR X RYRPH UDGX
Mapiranje je provedeno korištenjem alata ArcGIS dok je planiranje energetskog sustava
provedeno korištenjem alata EnergyPLAN.
.OMXþQHULMHþLObnovljivi centralizirani toplinski sustavi, Mapiranje toplinskih
potreba, Otpadna toplina, EnergyPLAN, ArcGIS

Energy and the Environment (2016) 559-568

559

OPTIMIRANJE UGRAĈENE I OPERATIVNE ENERGIJE TEPRIPADAJUûIH EMISIJA CO2 U ENERGETSKI UýINKOVITIMZGRADAMA'U6F0LKD3UD]QLN*UDGEHQLLQãWLWXW=50.'LPLþHYDXOLFD/MXEOMDQD
Slovenija, miha.praznik@gi-zrmk.si, +386 51 357 025, +385 99 401 1335
Sažetak: U traženju optimalnog koncepta za novogradnju projektanti s investitorom najþešüe
traže tehnološka rješenja, u kojima dominira energetska uþinkovitost zgrade, cjelokupni troškovi
gradnje i korištenja zgrade te postignuti komfor za korisnike. Usmjerenja EU i zahtjevi
nacionalnog zakonodavstva nalažu dodatne prilagodbe koncepta za intenzivnije korištenjeobnovljivih izvora, korištenu primarnu energiju i posljediþne emisije CO2. Analize þlanka
prikazuju pristup za konfiguriranje održivih koncepta za novogradnje, koje imaju istovrjemeno ibolje ekonomske te korisniþke performanse.
.OMXþQHULMHþL pasivna kuüa, nisko energetska kuüa, energetski koncept, održivost, primarnaenergija, emisije CO2, ugraÿena energija, operativna energija
1. UVOD(QHUJHWVNL YLVRNR XþLQNRYLWH ]JUDGH X ]DGQMHP VX GHVHWOMHüX SRVWDOH GLR VYDNRGQHYQH
JUDÿHYLQVNHSUDNVH3ULFMHORYLWRRSWLPLUDQLPVWDPEHQLPSURMHNWLPDJRGLãQMDSRWURãQMDHQHUJLMH]DJULMDQMHSURVWRUDL]DKODÿHQMHþHVWRL]QRVLPDQMHRGN:K P2a) [1, 2]. U praksi dostignuta
HQHUJHWVNDXþLQNRYLWRVWXWRPMHVHJPHQWXWDNRYLVRNDGDSUHGVWDYOMDPDQMHRGJUDQLþQLK
vrijednosti zakonodavstva. U tom pogledu formiranje koncepta za novogradnje bitno se razlikuje
od postupaka za identifikaciju i pronalaženje UMHãHQMD]DHQHUJHWVNRVDQLUDQMHSRVWRMHüLK]JUDGDNRMLK HQHUJHWVND XþLQNRYLWRVW MH þHVWR X UD]UHGX  GR  kWh/(m2a) [3, 4]. Osviještenost
LQYHVWLWRUD MH X SULPMHUX GREUH JUDÿHYLQVNH SUDNVH L]X]HWQR QDSUHGovala i nalaže traženje
projektnih rješenja koja su racionalna u svakom pogledu. Životni ciklus energetski visokoXþLQNRYLWLK]JUDGDXSRWSXQRVWLMHXILQDQFLMVNRPVPLVOXRGUåLYWHMHXNRQNXUHQWVNRMSUHGQRVWL
SUHGQHRSWLPLUDQLPLHQHUJHWVNLPDQMHXþLQNRvitim projektima. Takav cjelovit pogled kroz više
faza životnog ciklusa, posebno još uzevši u obzir fazu gradnje, potrebno je u daljnjem razvoju
YLVRNRXþLQNRYLWLK]JUDGDXSRWULMHELWLL]DVHJPHQWHXSRWUHEHSULPDUQHHQHUJLMHWHHPLVLMH&22.
Osnovni nacionalne zahtjevi za zgrade trenutno su koncentrirani na fazu korištenja zgrada,
konkretno na operativnu potrošnju primarne energije i emisije CO2. Cjelovitijim, te usmjerenim
UDGRP SURMHNWDQDWD QD NRQFHSWX ]JUDGD PRJXüH MH WDNYR XVNR IRNXVLUDQMH ELWQR QDGRJUDditi te
RVLJXUDWL RGUåLYRVW ]D FLMHOL åLYRWQL FLNOXV ,]DEUDQL JUDÿHYLQVNL SURL]YRGL ]D JUDGQMX ]JUDGD WH
HQHUJHWVNLVLVWHPLQHXWMHþXVDPRQDSRWURãQMXHQHUJLMHLHPLVLMHXVDPRPUDGXYHüLXID]DPDXJUDGQMH SURL]YRGD )RNXV þODQND MH QRYR SRGUXþMH UD]PLšljanja u projektnom radu, koji se
RGQRVLQDHNRQRPLNXXJUDÿHQHHQHUJLMHLHPLVLMD&22VþLPHüHQRYRJUDGQMHELWLSURYMHUDYDQH
QH VDPR X ILQDQFLMVNRP YHü L ãLUH X HQHUJHWVNRP SRJOHGX L NUR] XWMHFDM QD RNROLã &LOMDQR
usmjerena projektna rješenja i strateJLMH PRJX NUR] UDG SURMHNWDQDWD SRVHEQR JUDÿHYLQVNLKLQåHQMHUDWHHQHUJHWLþDUDUH]XOWLUDWLXSURMHNWLPDVWDPEHQLK]JUDGDNRMHVXSURYMHUHQHLORJLþQHza njihov životni ciklus, za ekonomski, energetski i ekološki segment. To je izuzetno važno i za
nove cLOMQHJUXSHSULYDWQLKLMDYQLKLQYHVWLWRUDNRMLXSUDYRLRþHNXMXWDNYXVWUXþQXSRPRü

560

M. Praznik: 2SWLPLUDQMHXJUDÿHQHLRSHUDWLYQHHQHUJLMHWHSULSDGDMXüLK…

.RQFHSWHQHUJHWVNLYLVRNRXþLQNRYLWH]JUDGHSRGUD]XPLMHYDSUHOLPLQDUQRSURMHNWQRRSWLPLUDQMH
[5, 6] potrošnje energije u cijelom uporabnom vijeku, od energije potrebne za njezinu izgradnju,
upotrebu, održavanje i rušenje (operativna energija) do energije potrebne za proizvodnjuJUDÿHYQLKPDWHULMDODLXUHÿDMDXXSRUDEQRPYLMHNX]JUDGH XJUDÿHQDHQHUJLMD 8LVWUDåLYDQMLPD
se navodi, da je operativna energija još uvijek dominantan parametar, posebno u zgradama u
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investicijskih sredstava. Na osnovu takvih spoznaja u prošlosti ispostavio se i pitanje, koje se
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novogradnju prikazuju energetske, ekološke pa i ekonomske odnose u ulaganjima tokomživotnog tijeka.
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SULPDUQHHQHUJLMHLHPLVLMDVWDNOHQLþNLKSOLQRYDLXGLRRSHUDWLYQHHQHUJLMHLHPLVLMD1DGRGDQMHL
ekonomski parametDU NRML SUDWL ILQDQFLMVND XODJDQMD X ID]L LQYHVWLUDQMD WH EXGXüH WURãNRYHRGUåDYDQMD L XSRWUHEH ]JUDGH 9DULMDQWQD UMHãHQMD DQDOL]LUDMX YUHGQXMX L XVSRUHÿXMX VH X
UD]GREOMX NRULãWHQMD ]JUDGH RG  JRGLQD 8 WRP SHULRGX XNOMXþHQH VX GYLMH ID]H L]YRÿHQMD
rDGRYDQDWRSOLQVNRMRYRMQLFL QDJRGLQD VD]DPMHQRPLVWURãHQLKNRPSRQHQWLLL]YRÿHQMHPPDQMLK JUDÿHYLQVNLK UDGRYD 2VLP WRJD SUHGYLÿHQL VX L ]DKYDWL QD LQVWDODFLMDPD VXVWDYD ]Dgrijanje i ventilaciju, koji imaju periodiku od 15 godina, u kojima se mijHQMDMXNOMXþQLGLMHORYLLelementi sustava. Procjene troškova za gradnju i faze održavanja su zbog objektivnosti i
NRUHNWQRVWL XVSRUHÿLYDQMD YDULMDQWL GRELYHQH ]D WLSVNX PRQWDåQX NXüX VD VWUDQH QMHQRJ
SURL]YRÿDþD NRML QXGL VYH RSLVDQH NRQILJXUDFLMH 8 DQalizi su korištene i regionalne cijene
energenta te sa njime povezane ekološke karakteristike. Evaluacija je u energetskom dijelu
RPRJXüHQD X] SRPRü NRULãWHQMD QDSUHGQLK PHWRGD ]D HQHUJHWVNL XþLQNRYLWH NXüH $ SURFMHQD
ulaganja primarne emisije i sa tim poYH]DQD HNRORãND RSWHUHüHQMD SURL]OD]H L] NRULãWHQMD
LQWHUQHWVNLKED]DSURL]YRÿDþDPDWHULMDODLNRPSRQHQWL]D]JUDGH
2.1 Opis modela zgrade=DSRWUHEHSUH]HQWDFLMHDQDOL]LUDQMHPRGHORELWHOMVNHNXüHQDGYDNDWD*ODYQLSDUDPHWUL]JUDGH
su: ploština korisne površine zgrade Au = 137 m2, oplošje grijanog dijela zgrade A = 454 m2,
ploština površina prozorskih otvora Aw = 30 m2 i faktor oblika fo = 0,68 m-1. Utjecaj tehnološkihUMHãHQMD ]D UD]OLþLWH HQHUJHWVNH NRQFHSWH L]UDþXQDQ MH QD SRVHEQRP DUKLWHNWRQVNRm modelu(Slika 1), za montažnu zgradu sa drvenom konstrukcijom.

Energy and the Environment (2016) 559-568

561

Slika 1. Prezentacija arhitekturnog modela zgrade (lijevo), energetske interpretacije modela
VUHGLQD LSULPMHUJUDILþNRJSULND]DUH]XOWDWD GHVQR.DNR EL VH SRVWLJOL UD]OLþLWL WUaženi energetski razredi projektnog koncepta, modificirani suNOMXþQLSDUDPHWULSRSXWNRHILFLMHQWSURODVNDWRSOLQHLOL8-vrijednosti elemenata ovojnice zgrade
L JUDÿHYQH VWRODULMH QHSURSXVQRVWL WRSOLQVNH RYRMQLFH L XþLQNRYLWRVWL RþXYDQMD WRSOLQH NUR]
centralni ventilacijski sustav. Zbog prikaza utjecaja sustava za grijanje zgrade na konceptualnom
QLYRXPRGLILFLUDVHLNRULãWHQMHUD]OLþLWLKWLSLþQLKVXVWDYDNRMLKNRQILJXUDFLMHWLSLþQRVXVUHüHPRu projektima za zgrade skoro nulte energije (NZEB). Ostali klMXþQLSDUDPHWUL]DYDULMDQWHELOLVXMHGQDNL 3URVMHþQD L]PMHQD ]UDND SR VDWX MH Q   K-1. Zgrada je smještena u klimatskom
SRGUXþMX V WHPSHUDWXUQLPGHILFLWRP+'' .GDí /MXEOMDQD .XüDMHQDPLMHQMHQD]DþHWLUL RVREH 3URUDþXQ WRSOLQVNLK NDUDNteristika i prijenosa energije napravljen je primjenom
YDOLGLUDQH PHWRGH NRMD VH WHPHOML QD PHWRGRORJLML PHÿXQDURGQLK VWDQGDUGD UHOHYDQWQLK ]D WRSRGUXþMHJUDÿHYLQVNHIL]LNH
2.2 Opis varijanti energetskog koncepta=DPHÿXVREQXXVSRUHGEXGHILQLUDQLKMHSHWUD]OLþLWLKYDULMDQWLHQHUJHWVNRJNRQFHSWD 9GR9 
QD RVQRYX LVWRJ DUKLWHNWXUQRJ PRGHOD ]D RELWHOMVNX NXüX L PRQWDåQRJ WLSD JUDGQMH ]JUDGH VD
GUYHQRP NRQVWUXNFLMRP 0RGLILFLUDMX VH HOHPHQWL WRSOLQVNH RYRMQLFH L VXVWDY SUR]UDþLYDQMD
zgrade, koji utMHþX QD FLOMQH UD]UHGH HQHUJHWVNH XþLQNRYLWRVWL SRWUHEQD WRSOLQVND HQHUJLMD ]Dgrijanje zgrade QNH/Au) i sustav za grijanje zgrade.
Varijanta koncepta V1
1RYRJUDGQMD V NRQFHSWRP WHN LVSXQMDYD PLQLPDOQH ]DKWMHYH SR HQHUJHWVNRM XþLQNRYLWRVWL.ROLþLQDSRWUebne toplinske energije za grijanje zgrade iznosi QNH/Au = 50 kWh/(m2D 3URVMHþQL
koeficijent prolaska topline za toplinsku ovojnicu je Um = 0,25 W/(m2K). U njoj dominira
toplinska izolacija mineralnog izvora a vanjska stolarija je iz PVC. Nepropusnost toplinske
ovojnice je u razredu n50 = 1,0 h-13UR]UDþLYDQMHSURVWRULMDX]JUDGLMHSULURGQR=ERJSRYHüDQHNROLþLQHHQHUJLMH]DJULMDQMHSUHGYLÿHQMHUDGLMDWRUVNLVXVWDYVDNDPLQRPQDSHOHWH]DFHQWUDOQR
grijanje i dodanim solarnim panelima za grijanje tople sanitarne vode. Takav sustav je
HNRQRPVNRLHNRORãNRXþLQNRYLWWHNRPSHQ]LUDXWMHFDMHSRYHüDQHSRWURãQMHWRSOLQVNHHQHUJLMH
Varijanta koncepta V2
9DULMDQWDLPDQHNROLNRSRYHüDQXHQHUJHWVNXXþLQNRYLWRVW 4NH/Au = 40 kWh/(m2D LVNOMXþLYRzbog poboljšane toplinske izolacije (Um = 0,21 W/(m2K)). U ovojnici je još uvijek toplinska
izolacija mineralnog izvora a prozori i vrata su iz PVC. Nepropusnost toplinske ovojnice isto je
u razredu n50 = 1,0 h-1. Zbog kompenzacije investicije odabran je jednostavniji sustav za grijanje,
NRML MH ]ERJ WRJD GXJRURþQR HNRQRPVNR L HNRORãNR PDQMH XþLQNRYLW D WR MH SOLQVNL

562

M. Praznik: 2SWLPLUDQMHXJUDÿHQHLRSHUDWLYQHHQHUJLMHWHSULSDGDMXüLK…

kondenzacijski kotao sa solarnim panelima za grijanje sanitarne tople vode. Grijanje prostorija je
UDGLMDWRUVNRDSUR]UDþLYDQMHSULURGQR
Varijanta koncepta V3
1RYRJUDGQMD VD WLSLþQLP NRQFHSWRP ]D YUOR GREUX QLVNR HQHUJHWVNX NXüX 4NH/Au = 25
kWh/(m2a)), zbog dodatnog poboljšanja toplinske izolacije (Um = 0,20 W/(m2K)) i nepropusnosti
toplinske ovojnice (n50 = 0,8 h-). U ovojnici još uvijek prevladava mineralna izolacija a vanjska
VWRODULMD LPD GUYHQH RNYLUH %LWDQ XWMHFDM QD SRYHüDQX HQHUJHWVNX XþLQNRYLWRVW LPD L
ventilacijsku sustav sa povratom topline 85%. Dizalica topline koristi toplinu iz horizontalnog
L]PMHQMLYDþDX]HPOMLDJULMDQMHSURVWRULMDMHVD podnim sustavom.
Varijanta koncepta V4
1RYRJUDGQMD X VWDQGDUGX SDVLYQH NXüH 4NH/Au = 15 kWh/(m2a)) s poboljšanom toplinskom
izolacijom (Um = 0,16 W/(m2K)) i manje propusnom toplinskom ovojnicom (n50 = 0,6 h-).
Prozori i vrata imaju drvene profile. U vanjskom dijelu ovojnice još uvijek koristimo mineralnu
L]RODFLMXGRNMH]ERJ]DKWMHYD]DJUDGQMXSDVLYQHNXüHXNRQVWUXNFLMLSRGDNRULãWHQHNVWUXGLUDQLSROLVWLUHQ6XVWDYYHQWLODFLMHLPDXþLQNRYLWRVWSRYUDWDWRSOLQH$VXVWDYJULMDQMDSURVWRULMD
MH YHü LQWHJULUDQ X VXVWDY YHQWLODFLMH WH QH QDVWXSD YLãH RGYRMHQR ãWR XWMHþH QD VPDQMHQMH
investiranja.
Varijanta koncepta V5(QHUJHWVNL L HNRORãNL QDGRJUDÿHQD QRYRJUDGQMD X VWDQGDUGX SDVLYQH NXüH 4NH/Au = 10
kWh/(m2a)), sa nekoliko poboljšanom toplinskom izolacijom (Um = 0,14 W/(m2K)). Iste su
vrijednosti za nepropusnost ovojnice, isti je materijal za prozore te sustav ventilacije i grijanja.
Zbog poboljšanja ekoloških karakteristika u drvenoj konstrukciji je izolacija od celuloznih
pahuljica.
3. MEHANIZAM 6829,61267,,19(67,5$1-$(1(5*(76.(8ý,1.29,7267,
=*5$'(,â,5(*(.2/2â.2*237(5(û(1-$1DþLQ UD]PLãOMDQMD X SURFHVX REOLNRYDQMD SURMHNWQRJ HQHUJHWVNRJ NRQFHSWD SD L VDPRSULSDGDMXüHLQYHVWLFLMVNRRSWLPLUDQMHQDMODNãHSUH]HQWLUDPRNUR]VLPEROLþNLSULkaz mehanizmaPHÿXVREQRJXWMHFDQMDWULSRYH]DQDSDUDPHWUDLQYHVWLUDQMHX]JUDGX ; SRVOMHGLþQDHQHUJHWVND
XþLQNRYLWRVW ]JUDGH <  L SULSDGDMXüH HNRORãNR RSWHUHüHQMH =  7DM VLPEROLþNL SULND]
mehanizma su ovisnosti tri parametra apliciran je i objašnjen i na pet varijantnih rješenja (V1 do
V5), koja su predmet analize.
7LSLþQD HQHUJHWVNL XþLQNRYLWD ]JUDGD NRMD X VPLVOX RGUåLYRVWL MRã QLMH QDMEROMH SURMHNWQR
ULMHãHQD VOLND   LQYHVWLFLMVNL MH NRQFLSLUDQD VD SULSDGDMXüLP ILQDQFLMVNLP XODJDQMLPD X PMHUH
HQHUJHWVNHXþLQNRYLWRVWLQDWRSOLQVNRMRYRMQLFL]JUDGH;TO0 WHHQHUJHWVNLXþLQNRYLWLPVXVWDYRP
ventilacije XPP0 XNOMXþXMXüL HQHUJHWVNR XþLQNRYLWR UMHãHQMH ]D VXVWDY SURL]YRGQMH WRSOLQVNH
energije XGT0 3UYH GYLMH NRPSRQHQWH LQYHVWLFLMH XWMHþX SUHNR SROXJe VXY0 na potrebnu
toplinsku energiju za grijanje zgrade Y0 ORNDOQL XWMHFDM NRULãWHQMD ]JUDGH  'RN WUHüD
investicijska komponenta u odnosu na tehnološke utjecaje sa proizvodnjom toplinske energijeXWMHþH SUHNR 9XZ0 QD HNRORãNR RSWHUHüLYDQMH =0. Opisani dYRGLPHQ]LRQDOQL OLQHDUQL QDþLQ
razmišljanja o utjecajima projektnog koncepta korišten je kod generiranja tehnoloških
poboljšanja, koja su vidna u postepenom razvoju energetskog koncepta novogradnje od V2prema V3.

Energy and the Environment (2016) 559-568

563

ƉŽƚƌĞďŶĂƚŽƉůŝŶƐŬĂĞŶĞƌŐŝũĂ;zͿY0ekološko
ŽƉƚĞƌĞēĞŶũĞ (Z)

VXY0

Z0
VXZ0
XGT0

XTO0

XPP0

ŝŶǀĞƐƚŝƌĂŶũĞƵǌŐƌĂĚƵ (X)ƉƌŽǌƌĂēŝǀĂŶũĞ
toplŝŶƐŬĂ
ƉƌŽŝǌǀŽĚŶũĂ
ƚŽƉůŝŶĞ (XGT) ŽǀŽũŶŝĐĂ (XTO) ƉƌŽƐƚŽƌŝũĂ (XPP)

Slika 2. Utjecaji investiranja u mjere HQHUJHWVNHXþLQNRYLWRVWLLREQRYOMLYLKL]YRUDHQHUJLMHQD
potrebnu toplinsku energiju i ekološke utjecaje – primjer koncepta za manje održivu zgradu
7DNDY SULVWXS LQYHVWLFLMVNRJ LQWHUYHQLUDQMD X VYUKX SRYHüDQMD HQHUJHWVNH XþLQNRYLWRVWL L ãLUHodrživosti ]JUDGD MH QDUDYQR RJUDQLþHQ SD VH RG LQåHQMHUD ]ERJ HNRQRPVNLK SHUIRUPDQVL
SURMHNWDWUDåLLLQWHUGLVFLSOLQDUQRIXQNFLRQDOQRRSWLPLUDQMH ; DOLQDMþHãüHMRãXYLMHNXRNYLUXMHGQH GLPHQ]LMH SURMHNWQLK XWMHFDMD <  7LSLþQD MH VLWXDFLMD X UD]YRMX SURMHNWQRJ koncepta, u
NRMRM SREROMãDQMD QD WRSOLQVNRM RYRMQLFL LOL LQWHUYHQFLMH X DUKLWHNWXUL RPRJXüH ELWQL SUHVNRN X
NRQILJXULUDQMX LQVWDODFLMDWMSRMHGQRVWDYOMHQMXHQHUJHWVNRJVXVWDYD7DNDYMHVOXþDMLXUD]YRMX
koncepta od varijante V3 prema V4, u kojem se dobra nisko energetska novogradnja modificiraX XþLQNRYLWLMX SDVLYQX 'RGDWQR LQYHVWLUDQMH X JUDÿHYLQVNRP VHJPHQWX VH X WRP VOXþDMX
SUDNWLþNL NRPSHQ]LUD ]D XãWHGDPD QD LQYHVWLUDQMX X LQVWDODFLMH X NRMLPD QHVWDMH VDPRVWDOQL
sustav grijanja prostoriMDNRMLVHLQWHJULUDXYHüLQDþHSULVXWDQVXVWDYYHQWLODFLMH(QHUJHWVNLYLVRNRXþLQNRYLWD]JUDGDNRMDMHXLVWRYULMHPHEROMHRFLMHQMHQDLXVPLVOXRGUåLYRVWLVOLND   WLSLþQR WUDåL SRYHüDQD LQYHVWLFLMVND XODJDQMD QD WRSOLQVNRM RYRMQLFL GRN VX GRGDFi usegmentu instalacija bitno niži. Dodatno investiranje u mjere poboljšanja toplinske zaštite iXþLQNRYLWRVWLVXVWDYDYHQWLODFLMH]JUDGH 'XTO1+'XPP1 XWMHþHSUHNR9XY1 na dodatno smanjenje
SRWUHEQH NROLþLQHWRSOLQVNHHQHUJLMH 'Y1 WMQDSRYHüDQMHHQHUJHWVNHXþLQNRYLWRVWL]JUDGHQD
QDþLQNDNRMHWDGHILQLUDQDXQDMXåHPVPLVOX8LVWRYULMHPHVHGRGDWQDLQYHVWLFLMVNDXODJDQMDXWRSOLQVNXRYRMQLFXVDPRGLILNDFLMRPNRQVWUXNFLMHLPDWHULMDODVDNRMLPDXWMHþHPRQDVPDQMHQDHNRORãNDRSWHUHüHQMD 'XTO2), pojavljuju uz dodatno investiranje u održivi sustav za proizvodnju
toplinske energije ('XGT1), te putem utjecaja VXZ1 smanjuju utjecaj zgrade na širu okolinu ('Z1).
Takvu inter-GLPHQ]LRQDOQX QDGRJUDGQMX QDþLQD UD]PLãOMDQMD VXVUHüHPR NRG HQHUJHWVNRJ
koncepta V5.
YZ

Y0 - ' Y1

VXY1
VXZ1

Z0 - ' Z1
X

XGT0 + ' XGT1 +' XTO2

XTO0 + ' XTO1

XPP0 + ' XPP1

6OLND'RGDWQLXWMHFDMLLQYHVWLUDQMDXPMHUHSRYHüDQHHQHUJHWVNHXþLQNRYLWRVWLREQRYOMLYLK
izvora i održivosti gradnje – SULPMHUNRQFHSWD]DHQHUJHWVNLYLVRNRXþLQNRYLWXLRGUåLYX]JUDGX

564

M. Praznik: 2SWLPLUDQMHXJUDÿHQHLRSHUDWLYQHHQHUJLMHWHSULSDGDMXüLK…

Y

Y0 + ' Y2

Z

VXY2

VXZ2

XGT0 + ' XGT2

Z0 - ' Z2
XTO0 - ' XTO3

X
XPP=0

Slika 4. Modificirano investiranje sa ciljem manjih ekolRãNLKRSWHUHüHQMDXID]LNRULãWHQMD–SULPMHUNRQFHSWD]DHQHUJHWVNLPDQMHXþLQNRYLWX]JUDGXDHPLVLMVNRQHXWUDOQX(QHUJHWVNL QDMPDQMH XþLQNRYLWD ]JUDGD VD PLQLPDOQLP HNRORãNLP XWMHFDMHP X ID]L NRULãWHQMD
zgrade (slika 4), koncipirana je sa modificiraniPLQYHVWLUDQMHPXRGQRVXQDSUYLRSLVDQLVOXþDM(slika 2). Raspoloživa financijska sredstva reorganiziraju se sa ciljem intenzivnijeg investiranja u
VXVWDY JULMDQMD NRML LPD SUDNWLþNL  SRNULüH GRYHGHQH HQHUJLMH L] REQRYOMLYLK L]YRUD
Dodatno investiranje v takav energetski sustav ('XGT2 RPRJXüHQRMHVPDQMHQMHPLQYHVWLUDQMDX
sustave toplinske zaštite na ovojnici zgrade ('XTO3) te ukidanjem investiranja u sustav
HQHUJHWVNL XþLQNRYLWH YHQWLODFLMH XPP=0). Smanjeno investiranje u mjere energetskeXþLQNRYitosti preko poluge VXY2 XWMHþHQDSRYHüDQXSRWURãQMXWRSOLQVNHHQHUJLMHX]JUDGL 'Y2).
Dok proizvodnja toplinske energije sa obnovljivim izvorima preko VXZ2 XWMHþHQDELWQRVPDQMHQL
ekološki utjecaj ('Z2  7DNDY UHYHU]QL QDþLQ LQWHU-dimenzionalnog tehnološkog razmišljanjaNRULãWHQ MH NRG IRUPLUDQMD HQHUJHWVNRJ NRQFHSWD ]D YDULMDQWX 9 8 WRP VOXþDMX QD UDþXQ
VPDQMHQH HQHUJHWVNH XþLQNRYLWRVWL ]JUDGH XYRGLPR NRULãWHQMH L]YRUD WRSOLQVNH HQHUJLMH NRML MHskoro potpuno obnovljiv, a u isto vrijeme najkonkurentniji u smislu operativnog troška, u odnosu
QDRVWDOHWLSLþQHHQHUJHQWHYDULMDQWL9GR9
4. EVALUACIJA (1(5*(76.,+ (.2/2â.,+ (.21206.,+ , .25,61,ý.,+
INDIKATORA
4.1 Procjena rezultata za varijantne koncepte na nivou životnog tijeka zgradeZa varijantne koncepte V1 do V5 procijenjeno je korištenje primarne energije (slika 5-A), utjecaj
na emisije CO2 (slika 5-B) i nastali trošak (slika 5-C), za razdoblje od faze proizvodnjematerijala i ostalih komponenti za zgradu te do isteka 60 godina korištenja objekta. Varijante V2
GR9NRQILJXULUDQHVXVDFLOMHPSUDüHQMDXWMHFDMDOLQHDUQLKSREROMãDQMDXNRQFHSWLPD]D]JUDGH
VDSRYHüDQRPHQHUJHWVNRPXþLQNRYLWRãüX9DULMDQWD9SUHGVWDYOMDNRQFHSW]DSDVLYQX]JUDGX
sa minimiziranim potrebama za toplinskom energijomza grijanje, u kojoj su materijali za gradnju odabrani sa ciljem održivosti tj. poboljšanja
ekoloških performansi u fazi gradnje. Dok je varijanta V1 u odnosu na ostale odabrana
provokativno: to je koncept za zgradu sa pogoršanim energetskim performansama, u kojoj
XYRGLPR VXVWDY ]D SURL]YRGQMX WRSOLQVNH HQHUJLMH NRML QDMPDQMH HNRORãNR RSWHUHüXMH WM MHodrživ u fazi korištenja zgrade.

Energy and the Environment (2016) 559-568

565

5H]XOWDWL]DYDULMDQWQHNRQFHSWHLQMLKRYHXVSRUHGEHVXVOLMHGHüH- 6D SRVWHSHQLP SRYHüDYDQMHP HQHUJHWVNH XþLQNRYLWRVWL ]JUDGH SRYHüDYD VH L NROLþLQD
korištene primarne energije u fazi gradnje, npr. u opsegu do 25% (usporedba V4, V3 i V2 na
slici 5A). Korištenje primarne energije u fazi korištenja zgrade puno je intenzivnije i u
RGQRVX QD ID]X JUDGQMH SRYHüDQR MH ]D IDktor 2 do 3, što osigurava amortizaciju uložene
primarne energije i emisija. Kod emisija može biti razlika u dodatnim ulaganjima u gradnji iYLãHRGDOLMH]DKWMHYQRVWID]HNRULãWHQMDXVSRUHGLYãLVDID]RPJUDGQMHSXQRYHüDWM]Dfaktor 3,5 do 8 (slika 5B).
- Odabir izvora energije i tehnologije za proizvodnju toplinske energije ima izuzetan utjecaj na
performanse zgrade, a to je posljedica odnosa u fazi korištenja i gradnje (utjecaj na varijantu
9QD6OLFL$L% =DHQHUJHWVNLQDMPDQMHXþLQNRYLWH]JUade i zgrade koje koriste manjeodrživ sistem gradnje i materijala, cjelokupne ekološke performanse mogu se bitno poboljšati
YHü VD RGDELURP WHKQRORJLMH NRMD XNOMXþXMH LQWHQ]LYQR VXGMHORYDQMH REQRYOMLYLK L]YRUD
energije.
- Modifikacije tj. ciljne prilagodbe u izboru materijala imaju jaki utjecaj u fazi gradnje.
3ULOLNRPUD]YLMDQMDLGHMQLKNRQFHSWDXNRMLPDVHL]X]HWQRSRYHüDYDHQHUJHWVNDXþLQNRYLWRVW
ali i ulaganja u tehnološka rješenja, prilagodba materijala može performanse zahtjevnije
zgrade poboljšati QD UD]LQX LVSRG YULMHGQRVWL HNRORãNLK RSWHUHüHQMD HQHUJHWVNR PDQMH
XþLQNRYLWLK]JUDGD YLGOMLYRXXVSRUHGELYDULMDQWH9VDRVWDOLPDQDVOLFL$L% - %LWQDSREROMãDQMDHQHUJHWVNHXþLQNRYLWRVWL]JUDGDWUDåHUHODWLYQRQLVNDGRGDWQDLQYHVWLFLMVND
ulaganja. 5D]OLND L]PHÿX HQHUJHWVNR QDMPDQMH XþLQNRYLWH ]JUDGH JUDQLFD X ]DKWMHYLPD]DNRQRGDYVWYD LYUORGREUHQLVNRHQHUJHWVNH NXüH PRåH ELWL SRVWLJQXWD YHü ]D GRGDWDN RG
 YDULMDQWD 9 L 9 QD VOLFL &  =ERJ RSWLPL]DFLMH X NRQFHSWX SDVLYQH NXüH GRGDWQR
investiranje u odnosu na dobru nisko energetsku zgradu je zanemarivo (manje od 2% kod
YDULMDQWL9L9QDVOLFL& 3RYHüDQDUD]OLNDLQYHVWLUDQMXYLGOMLYDMHWHNXVOXþDMXFMHORYLWH
promjene materijala u energetskom konceptu održive gradnje (približno 9% u usporedbi V5 i
V4 na slici 5C).
- .RPELQDFLMH HQHUJHWVNH XþLQNRYLWRVWL ]JUDGH L]ERUD PDWHULMDOD SD L L]YRUD HQHUJLMH
GHWHUPLQLUD FMHORNXSQL HNRQRPVNL UH]XOWDW ]D SURMHNWQL HQHUJHWVNL NRQFHSW 8 VOXþDMXpostepenih poboljšanja (V2 do V4 na slici 5C) ekonomske performanse u životnom tijeku
XYLMHN VX EROMH X VOXþDMX HQHUJHWVNRJ NRQFHSWD ]D YLVRNR XþLQNRYLWH ]JUDGH 9LVRNR
XþLQNRYLWH ]JUDGH VX X HNRQRPVNRP SRJOHGX þDN SULKYDWOMLYLMH RG NRQFHSWD PDQMH
XþLQNRYLWH]JUDGHVDLQWHUYHQFLMRPQDVWUDQLSURL]YRGQMHWRSOLQVNH energije (usporedba V3 i
V4 u odnosu na V1 na slici 5C).

(A)

566

M. Praznik: 2SWLPLUDQMHXJUDÿHQHLRSHUDWLYQHHQHUJLMHWHSULSDGDMXüLK…

(B)

(C)
Slika 5. Procjena rezultata za pet varijantnih energetskih koncepta za novogradnju: ukupno
korištena primarna energija neobnovljivog izvora, ukupne emisije CO2 i ukupni trošak
4.2 5H]XOWDWLYUHGQRYDQMD]DNRQFHSWXDOQHYDULMDQWHX]SRPRüSRQGHULUDQLKSDUDPHWUD
Cjelovitija usporedba [7] pet ciljnih relevantnih parametra prikazana je za pet UD]OLþLWLKYDULMDQWQLKNRQFHSWD]DQRYRJUDGQMX VOLND 8VSRUHÿHQLVXUH]XOWDWL]DHQHUJHWVNHHNRORãNH
HNRQRPVNH L NRULVQLþNH SDUDPHWUH HQHUJHWVND XþLQNRYLWRVW 4NH/Au), korištenje primarneenergije neobnovljivog izvora (PECn.r.), emisijski utjecaj na globalno klimatsko zatopljenje(GWP100), ukupni troškovi (Cost) i postignuti komfor za korisnike zgrade (LE). Vrijednosti
parametrima u procentima dodijeljene su u odnosu na najlošiji rezultat, za pet koncepta (100%najlošiji je rezultat njihove usporedbe).
8 VOXþDMX SRQGHULUDQMDSDUDPHWUDNRMLLPDMXX XNXSQRPYUHGQRYDQMXMHGQDNLXWMHFDMUH]XOWDWLVXVOMHGHüLQDMEROMLUH]XOWDW]DYDULMDQWX9]D9]D9]D9LQDMORãLMLUH]XOWDW WM  ]D YDULMDQWX 9 .RG SRMDþDQRJ XWMHFDMD NRULsniku interesantnih parametraWURãNRYL L NRPIRU  UHGRVOLMHG UH]XOWDWD MH LVWL $ X VOXþDMX SRMDþDYDQMD XWMHFDMD HNRORãNLKparametra održivosti (primarna energija i emisije), redoslijed je isti uz zamjenu V3 i V1.

Energy and the Environment (2016) 559-568

567

Slika 6. 3RQGHULUDQLUH]XOWDWL]DHQHUJHWVNHHNRORãNHHNRQRPVNHLNRULVQLþNHSDUDPHWUH
za pet varijanti projektnih koncepta
5. =$./-8ý$.
EYDOXDFLMD UH]XOWDWD ]D DQDOL]LUDQH YDULMDQWQH HQHUJHWVNH NRQFHSWH QRYRJUDGQMH RPRJXüDYD
IRUPLUDQMHVOLMHGHüLK]DNOMXþDND- Dodatna ulaganja primarne energije i emisija CO2 u fazi gradnje su opravdana i višestruko se
SRYUDWH QD UDþXQ GXJRURþQRJ NRULãWHQMD ]Jrade. Sa jednostavnom evaluacijom idejnih
energetskih koncepta investitor i projektant mogu pratiti postizanje željenog cilja projekta.
- =JUDGX X XPMHUHQRP NRQWLQHQWDOQRP NOLPDWVNRP SRGUXþMX X VPLVOX RGUåLYRVWL GHWHUPLQLUD
faza korištenja, koja je energetski i ekološki puno intenzivnija od faze izgradnje. Sa tog
JOHGLãWD SULPDUQL ]DKWMHY X NRQFHSWLPD RVWDMH UMHãDYDQMH HQHUJHWVNH XþLQNRYLWRVWL SDVLYQD
versus nisko energetska zgrada), sekundarni se odnosi na osiguravanje kvalitetne tehnologije
i izvora energije za proizvodnju toplinske energije (obnovljivo versus fosilno), a tercijarni]DKWMHY X IRUPLUDQMXRGUåLYRJNRQFHSWDMHL]ERUJUDÿHYLQVNLKPDWHULMDODLNRPSRQHQWLNRML
imaju najmanji ekološki utjecaj (obnovljivo versus PLQHUDOQRLVLQWHWLþNR - Ekonomski UH]XOWDWLSRND]XMXGDMHPRJXüHGDLQYHVWLFLMVNRPLQWHUYHQFLMRPXRSVHJXGR
SRVWLüLWHKQRORãNDSREROMãDQMD]JUDGHVDNRMLPD]JUDGDVPDQMXMHHQHUJHWVNHSRWUHEHXNRULãWHQMX GR UD]UHGD SDVLYQH ]JUDGH 8QDWRþ QHNROLNR YHüLP WURãNRYLPD RGUåDYDQMD WDNYH
naprednije zgrade ušteda na troškovima korištenja nadmašuje dodatno investiranje i dodatniWURãDN ]D RGUåDYDQMH 8NXSQL WURãDN X åLYRWQRP WLMHNX ]JUDGH XYLMHN MH QLåL X VOXþDMX
SRYHüDQHHQHUJHWVNHXþLQNRYLWRVWL- Motiviranje investitora i njegove odluke ve]DQH QD HQHUJHWVNL NRQFHSW ]D ]JUDGX QDMþHãüHdeterminiraju ekonomski rezultati projekta i aspekti postignutog komfora. U odnosu na
SUH]HQWLUDQH UH]XOWDWH YLGOMLYR MH GD RED ]DKWMHYD LVSXQMDYDMX ]JUDGH VD SRYHüDQRPXþLQNRYLWRãüXLSRMDþDQLPHOHPHQWLPDRGUživosti.

568

M. Praznik: 2SWLPLUDQMHXJUDÿHQHLRSHUDWLYQHHQHUJLMHWHSULSDGDMXüLK…

LITERATURA[1] Zbašnik-6HQHJDþQLN 0DUWLQD DYWRU IRWRJUDI  3DVLYQD NXüD =DJUHE 681 $5+ GRR
2009. 130 str., ilustr. ISBN 978-953-98906-2-7.
[2] Praznik, Miha, Zbašnik-6HQHJDþQLN, Martina. Analiza kvalitativnih parametrov za energijskoXþLQNRYLWe hiše = Analysis of qualitative parameters for energy-efficient houses. AR, ISSN
1580-5573. [Tiskana izd.], 2011, [Št.] 2, str. 29-38, ilustr.
[3] Ostojiü, S., Veršiü, Z., Muraj, I.: Energgy analysis and refurbishment strategy for Zagreb
University buildings: Former Faculty of Technology in Zagreb by Alfred Albini", Energy and
Buildings, Vol. 115 (2016), March 2016., str. 47-54, Elsevier, ISSN 0378-7788.
[4] Veršiü, Z., Muraj, I., Biniþki, M.: Model višestambene zgrade zagrebaþkog donjogradskog
bloka. Analiza u svrhu poboljšanja energetske uþinkovitosti, „Prostor“, znanstveni þasopis za
arhitekturu i urbanizam 23(2015.) 2(50), Zagreb: 236-249, ISSN 1330-0652.
[5] Praznik, Miha, Butala, Vincenc, Zbašnik-6HQHJDþQLN, Martina. Simplified evaluation method
for energy efficiency in single-family houses using key quality parameters. Energy andbuildings, ISSN 0378-7788. [Print ed.], Dec. 2013, vol. 67, str. 489-499, ilustr., doi:
10.1016/j.enbuild.2013.08.045.
[6] Praznik, Miha, Zbašnik-6HQHJDþQLN 0DUWLQD 8JUDÿHQD SULPDUQD HQHUJija i optimizacija
HQHUJHWVNL XþLQNRYLWLK NXüD  7KH HPERGLHG SULPDU\ HQHUJ\ DQG RSWLPLVDWLRQ RI HQHUJ\efficient houses = Eingebaute Primärenergie und Optimierung energieeffizienter Häuser.
*UDÿHYLQDU ,661 -2465, Sep. 2015, vol. 67, [no.] 9, str. 853-864, ilustr.
http://www.casopis-gradjevinar.hr/assets/Uploads/JCE-67-2015-9-3-1193-EN.pdf.
[7] Praznik, Miha, Butala, Vincenc, Zbašnik-6HQHJDþQLN, Martina. A simple method forevaluating the sustainable design of energy efficient family houses. Strojniški vestnik, ISSN
0039-2480, Jun. 2014, vol. 60, no. 6, str. 425-436, ilustr., doi: 10.5545/sv-jme.2013.1561.

OPTIMIZATION OF EMBODIED AND OPERATIONAL ENERGY AND
CORRESPONDING CO2 EMISSIONS IN ENERGY-EFFICIENTBUILDINGS
Abstract: In the search for the optimum concept for the new building designers with clientsusually seek technological solutions. In them dominates the energy efficiency of the building, theentire cost of building process and use of the building and achieved comfort for users. The
directives of the EU and the requirements of national law requiring additional customization of
the concept. They're looking for more intensive use of renewable energy sources, used primaryenergy and the resulting CO2 emissions. Analysis of the article are showing the way to configuresustainable concept for the new buildings, which have simultaneously better economic and user
performance.
Key words: passive house, low energy house, energy concept, sustainability, primary energy,
CO2 emissions, embodied energy, operational energy

Energy and the Environment (2016) 569-580

569

UTJECAJ NAPREDNOG ENERGETSKOG MODELIRANJA NA
OPTIMIRANJE ENERGETSKIH KONCEPTA ZGRADA'U6F0LKD3UD]QLN*UDGEHQLLQãWLWXW=50.'LPLþHYDXOLFD/MXEOMDQD
Slovenija, miha.praznik@gi-zrmk.si, +386 51 357 025, +385 99 401 1335
'RF'U6F=RUDQ9HUãLü$UKLWHNWRQVNLIDNXOWHW6YHXþLOLãWHX=DJUHEX.DþLüHYD
10000 Zagreb, Hrvatska, zoran.versic@arhitekt.hr, +385 1 4639 122¶Sažetak: Projekte cjeloYLWHHQHUJHWVNHVDQDFLMH]JUDGDþHVWRSRLVWRYMHüXMHPRVSURMHNWLPD]D
QRYRJUDGQMH=DMHGQLþNLVXLPYLVRNL]DKWMHYLLQYHVWLUDQMDWUDåHQMHLQWHUGLVFLSOLQDUQR
SULODJRÿHQLKHQHUJHWVNLKNRQFHSDWDLRSWLPLUDQMHSURMHNWQLKUMHãHQMDNRMDüHXWMHFDWLQD
korištenMH]JUDGHXQDUHGQLPGHVHWOMHüLPD1DSUHGQRHQHUJHWVNRPRGHOLUDQMH]ERJFMHORYLWRJL
GHWDOMQRJXSR]QDYDQMDNDUDNWHULVWLND]JUDGHQHRPRJXüDYDVDPRGHILQLUDQMHRSWLPDOQRJRSVHJD
SRMHGLQDþQLKWHKQLþNLKPMHUDVRE]LURPQDWURãNRYHåLYRWQRJYLMHND]JUDGHLXWjecaja na
NRULVQLNH=ERJãLUHJSUHJOHGDRPRJXüDYDLVLQHUJLMVNRRSWLPLUDQMHWHVPDQMHQMHLQYHVWLFLMDXRGQRVXQDLQDþHLGHQWLILFLUDQHSURFMHQHSURMHNWDQWD
.OMXþQHULMHþL FMHORYLWDHQHUJHWVNDVDQDFLMDHQHUJHWVNLXþLQNRYLWH]JUDGHQDSUHGQRHQHUJHWVNRPRGHOLUDQMHRSWLPLUDQMHHQHUJHWVNRJNRQFHSWDGLQDPLþQRRGD]LYDQMH]JUDGHWURãNRYLåLYRWQRJ
vijeka zgrade
1. UVOD&MHORYLWD HQHUJHWVND VDQDFLMD ]JUDGD MH VSHFLILþQD V RE]LURP QD LQåHQMHUVNX L L]YHGEHQX
]DKWMHYQRVWSURMHNDWDVD]QDþDMQRSRYHüDQLPRSVHJRPLQYHVWLUDQMDWHVDUD]OLþLWLPHQHUJHWVNLP
ekonomskim i ostalim eksternim utjecajima [1, 2, 3]. Zbog navedenih svojstva i zahtjeva bitno
SUHOD]LGRVDGDãQMDLVNXVWYDL]QDQMDXNOMXþHQLKVXGLRQLNDXSURFHVHQHUJHWVNHVDQDFLMHNRMDVXELOD VWHþHQD X SURãOLP JRGLQDPD X L]YRÿHQMX PQRJREURMQLK SURMHNDWD GMHORPLþQH HQHUJHWVNH
sanacije javnih i stambenih zgrada. Projektirani investicijski zahvati za energetsku sanacijuXWMHþXQDYLãHSRGUXþMDSRWURãQMHHQHUJLMHQSUSRWURãQMDWRSOLQH]DJULMDQMHSURVWRULMD, energije]D KODÿHQMH L RGYODåLYDQMH ]UDND HOHNWULþQH HQHUJLMH ]D IXQNFLRQLUDQMH WHKQLþNLK VXVWDYD L
UDVYMHWH WH VX LVSUHSOHWHQL ]ERJ PHÿXVREQLK XWMHFDMD NRMD PRUDPR SUHSR]QDWL >4, 5]. Cjelovita
VDQDFLMD QH XWMHþH VDPR QD VPDQMHQMH SRWURãHQH HQHUJLMH Hmisija i troškova korištenja zgrade.
%LWDQ MH XWMHFDM QD SREROMãDQMH XYMHWD ]D NRULVQLNH ]JUDGH SRYHüDYD VH LVNRULVWLYRVW LOL þDN
NDSDFLWHWHWHVHQDWDNYHUD]OLþLWHQDþLQHXWMHþHLQDYULMHGQRVWVDPLKQHNUHWQLQD
-HGQDRGYHüLKVXVWDYQLKSRWHãNRüDXSURFHVXRGUHÿLYDQMDVDGUåDMDSURMHNWDFMHORYLWHHQHUJHWVNH
VDQDFLMHLãWRUHDOQLMHPYUHGQRYDQMXQMHJRYLKHQHUJHWVNLKHNRQRPVNLKHNRORãNLKNRULVQLþNLKL
ostalih utjecaja te kvantificiranju posljedica [6, 7, 8] je nesposobnost korektne upotrebe
SRVWRMHüLK MHdnostavnih inženjerskih metoda za cjelovito evaluaciju energetskih koncepta.
Pojednostavljeni inženjerski pristupi za energetsko vrednovanje mjera energetske sanacije, koji
VXLQDþHXLQåHQMHUVNRMSUDNVLPHWRGRORãNRGHILQLUDQLYHüGXåHYULMHPHXND]XMXQDnedostatke ine daju realne prognoze za cjelovite energetske i ekološke utjecaje. Takve u praksi generalnoNRULãWHQHPHWRGHVXXSURMHNWLPDFMHORYLWHHQHUJHWVNHVDQDFLMH]JUDGDSUDNWLþNLQHXSRWUHEOMLYH
tj. njihova upotreba može rezultirati nerealnim i varljivim vrijednostima, koje u daljnjem
YUHGQRYDQMXLQYHVWLFLMVNLKSURMHNWDYRGHXSRJUHãQHRFMHQHLQGLNDWRUDXþLQNRYLWRVWL570

03UD]QLN=9HUãLü: Utjecaj naprednog energetskog modeliranja…

8 SUDNVL VH SRWHãNRüH SRMDYOMXMX L X HNRQRPVNRP YUHGQRYDQMX SURMHNDWD FMHORYLWH HQHUJHWVNH
sanacije zgrada. U lancu investicijskih mMHUD HQHUJHWVNH VDQDFLMH RELþQR VH QDOD]H SULRULWHWQL]DKYDWLNRGNRMLKVXHQHUJHWVNLLHNRQRPVNLSRND]DWHOMLYHüQDRþLJOHGSR]LWLYQL8SURMHNWLPD
cjelovite energetske sanacije se tim investicijama pridruže i ostale, koje imaju niži energijski i
ekonomskL GRQRV WH þHVWR L XSLWDQ SRYUDW SRþHWQLK ILQDQFLMVNLK XODJDQMD D QMLKRYD L]YHGED MHnužna zbog osiguravanja uvjeta za korisnike zgrada, za optimalan rad sustava, itd. i s tim
predstavljaju kvalitetnu, a ne samo kvantitetnu dodanu vrijednost projekta. PosWRMHüL
metodološki pristupi za ekonomsko vrednovanje projekta energetske sanacije i definirane
JUDQLþQH YULMHGQRVWL ]D LQGLNDWRUH HNRQRPVNH XþLQNRYLWRVWL X SULPMHULPD FMHORYLWH HQHUJHWVNH
sanacije zgrada ne daju konkurentne rezultate. Kvalitetni investicijski projekti za cjelovitu
HQHUJHWVNX VDQDFLMX SUDNWLþNL QH PRJX ELWL SR]LWLYQR RFMHQMHQL XVSRUHGLYãL VH V SURMHNWLPD ]Dparcijalne sanacije.
&LOMþODQNDMHSULND]QRYRJPHWRGRORãNRJSULVWXSDLQDþLQDUDGDSULL]UDGLSURMHNDWDHQHUJHWVNH
sanacije, koji omogXüDYDIRUPLUDQMHRSWLPDOQRJSURMHNWQRJHQHUJHWVNRJNRQFHSWD]D]JUDGXWH
korektno vrednovanje cjelovite sanacije: u tehnološkom i funkcionalnom pogledu, u energetsko
HNRQRPVNLP SURFMHQDPD WH V QDJODãHQLP SUDüHQMHP L RVLJXUDYDQMHP ELWQLK NRULVQLþNLKparametara.
2. CJELOVITO ENERGETSKO SANIRANJE ZGRADA U NACIONALNOM I EU
KONTEKSTU
Energetsko visoko uþinkovite novogradnje su dnevna graÿevinska praksa u europskom prostoru
jer ih na neki naþin determiniraju zaoštreni zahtjevi za minimalnu energetsku uþinkovitost uz
poznato stanje tržišta tj. poveüane potražnje za nekretninama, koje su bolje od tih zahtjeva zbog
nadograÿenih korisniþkih prednosti i npr. troškovnih aspekta dugoroþnog korištenja. Zbog takvih
i ostalih svojstva te prednosti u usporedbi sa manje naprednim ili starijim zgradama takvi üe
objekti i u buduüe bolje zadržavati vrijednost nekretnine [9, 10]. Korištenje suvremenih
tehniþkih rješenja na novim zgradama i njihove performanse su se na neki naþin odrazili i u
obliku neposrednog poticaja na kvalitetnije i cjelovitije energetsko saniranje postojeüih
nekretnina. Potencijal ušteda je u sluþaju sanacije zgrada puno veüi veü zbog lošijeg polazišta,
npr. prosjeþna postojeüa zgrada koristi barem 3 puta više konaþne energije u odnosu na
novogradnju sa minimalnom razinom energetske uþinkovitosti. Zbog toga je segment energetske
sanacije zgrada prepoznat u EU kao podruþje sa najveüim potencijalom za energetske uštede. U
EU prostoru koristi se cca. 40% energije u zgradama (Direktiva 2012/27/EU), kod kojih je više
od cca. 40% fonda zgrada starijeg od 50 godina i s tim spremnim i za fazu cjelovite sanacije(Direktiva 2010/31/EU).
Poticanje cjelovite i troškovno uþinkovite energetske sanacije javnih zgrada uz pomoü javno
privatnih partnerstva je aktualna tema, koju prepoznaje i Europska komisija. Inovativna rješenja
potiþu se u programima npr. Horizon 2020, podruþje EeB PPP (engl. Supporting accelerated andcost-effective deep renovation of buildings through Public Private Partnership). Cjelovita
energetska sanacija zgrada po definiciji Europske komisije obuhvaüa projekte, u kojima je
postignuto smanjenje u potrošnji energije u visini najmanje 60% u odnosu na prethodno stanje
prije sanacije. Takve sanacije su uz klasiþni projektni pristup obiþno previše skupe i nedovoljno
troškovno uþinkovite. Kljuþna aktualna tema u prostoru EU je promocija cjelovitih optimiranih
pristupa, uz pomoü kojih se mogu postiüi rezultati iznad nivoa dosadašnjih nacionalnih i EU
projektnih praksi.
Direktiva o energetskoj uþinkovitosti (Direktiva 2012/27/EU) državama þlanicama EU nalaže
obaveznu pripremu dugoroþne strategije za poticanje investicija u sanaciju nacionalnog fonda

Energy and the Environment (2016) 569-580

571

zgrada i sanaciju odreÿenog udjela zgrada javnog sektora svake godine. Tako je na osnovu EU i
nacionalnog zakonodavstva u Sloveniji 2015. godine oblikovana Dugoroþna strategija za
poticanje investicija u energetsku sanaciju zgrada (DSEPS) s operativnim ciljevima do 2020 i do
2030. godine. Ciljevi ukljuþuju cca. 10% saniranih stambenih površina, 3% saniranih zgradaužeg javnog sektora godišnje i dodatan udio za širi javni sektor, poboljšanje omjera uloženih
javnih sredstava i potaknutih investicija u javnom sektoru (1:3), izvedba demonstracijskih
projekta energetske uþinkovitosti razliþitih tipova zgrada, itd. U poþetku 2016. godine objavljene
su upute za izvoÿenje projekta energetske sanacije zgrada užeg i šireg javnog sektora, a s timzapoþinju i aktivnosti za korištenje kohezijskih sredstava za programsko razdoblje 2014.-2020.
godine. U Hrvatskoj je trenutno na snazi Treüi nacionalni akcijski plan energetske uþinkovitosti(NAPEnU) iz 2014. godine u kojem su prikazane projekcije neposredne potrošnje energije do
2030. godine kao i Dugoroþna strategija za poticanje ulaganja u obnovu nacionalnog fonda
zgrada Republike Hrvatske (NN 74/2014) kojom su identificirane djelotvorne mjere za
dugoroþno poticanje troškovno uþinkovite integralne obnove fonda zgrada stambenog i
nestambenog fonda zgrada Republike Hrvatske do 2050. godine. Do 2020. godine predviÿa se
5% zgrada obnoviti na gotovo nula-energetsku razinu i visokih svojstava energetskeuþinkovitosti, a do 2030. to iznosi 30%. Dinamika obnove po godinama je okvirno
pretpostavljena i nije ravnomjerna kroz cijelo razdoblje. U razdoblju 2016. – 2017. godineoþekuje se porast obnovljenih zgrada na 1,5% godišnje, od 2018. – 2024. godine obnova üe seodvijati dinamikom od 3% godišnje, od 2025. – 2039. godine dinamikom 3,5% godišnje, a od
2040. – 2049. dinamika üe se smanjiti na 1,5% godišnje.
U nacionalnim strategijama definirana je i troškovno optimalna razina energetske sanacije
zgrada, koja se dalje prenosi u novelirane zahtjeve u propisima o energetskoj uþinkovitosti
zgrada, npr. slovenski Pravilnik PURES3 [slika 1]. Na takav naþin definirana razina minimalnog
efekta energetske sanacije još uvijek je udaljena od razine energetske pa i ekonomskeuþinkovitosti, koju inaþe traže. programi poticanja energetske sanacije zgrada, nacionalne
strategije za postizanje kategorije zgrada skoro nulte energije (nZEB), itd.
Cilj ukljuþivanja naprednog energetskog modeliranja u postupke projektiranja sanacije zgrada pa
i novogradnji je postizanje šire optimizacije i novih razina racionalnosti u projektnim
konceptima. To rezultira energetsko visoko uþinkovitim projektima, u kojima je zbog
racionalizacije cjelokupni ekonomski rezultat bitno poboljšan. To se odnosi na optimirano
investiranje te niže troškove korištenja zgrade. Razmišljanje o utjecaju inženjerske inventivnosti
i racionalizacije na razini koncepta za zgradu izostaje u nacionalnom tumaþenju (slika 1) u
kojem se pretpostavlja, da su energetsko visoko uþinkovite zgrade uvijek i bitno skuplje obzirom
na troškove investiranja pa zbog toga nemaju konkurentnog cjelokupnog ekonomskog rezultata.

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3. NAPREDNO ENERGETSKO MODELIRANJE I OPTIMIRANJE SANACIJSKIH
KONCEPTA
3.1 Znanstvena interdisciplinarnost u analizama na podruþju energetske uþinkovitosti
zgradaPostojeüi znanstveni izvori obraÿuju razliþita podruþja investiranja u energetsko uþinkovite
sanacije zgrada i ujedno prikazuju širinu i interdisciplinarnost. Tema naprednog energetskog
modeliranja i simulacija sanacijskih zahvata te formiranje optimalnih energetskih koncepta je pri
tome izuzetno bitni dio širine sagledavanja postavljenih zahtjeva. I ostale kljuþne kategorije sumeÿusobno povezane s ovom temom i znanost ih razvrstava npr. u:- Analize utjecaja razliþitih tehniþkih mjera na zgradama npr. izolacija toplinske ovojnice,energetski sustavi i instalacije, s naglašenim energetskim uštedama, smanjenim
emisijskim optereüenjima i ekonomskoj izvodljivosti. Sociološki aspekt, npr. korisniþki
komfor i kvaliteta stanovanja, funkcionalnost, itd. u tim analizama najþešüe nije uzet u
obzir.
- Analiza procesa odluþivanja se fokusira na motiviranje aktera, elemente pokretljivosti u
procesima i na prepreke te na utjecaj socioekonomskih faktora u odlukama.
- Analize utjecaja instrumenata i poticaja se koncentriraju na procjenama utjecalamehanizama regulacije, modela subvencioniranja i financijskog poticanja, energetskih
poreza, energetskog savjetovanja, itd.
- Analiza ekonomskih modela i simulacija na temi procjene investicijskih projekta u smisluživotnog tijeka, neto sadašnjih vrijednosti, troškova i prednosti te na temi analiza
investicijskog odluþivanja tj. ekonometriþkih metoda.
Prema navedenom može se zakljuþiti da se analizom energetsko uþinkovitih sanacija zgrada bavi
više disciplina, na parcijalnim podruþjima, s premalo naglašenom problematikom cjelovitosti u
smislu integralnosti i održivosti, koja postaje prepoznata i aktualna tek u zadnjih par godina.
Dodatni vanjski poticaj za istraživanja i korištenje naprednih metoda za energetsko modeliranje
u projektima za zgrade dolazi u više oblika. U istraživanjima i znanosti je identificiran fenomen,koji se odnosi na „raskorak u energetskoj uþinkovitosti“ (engl. energy efficiency gap).
Predstavlja diskrepanciju izmeÿu teoretsko prognoziranih potencijala ušteda za troškovno

Energy and the Environment (2016) 569-580

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uþinkovite mjere energetske uþinkovitosti na zgradama i praktiþkim rezultatima tj. posljedica
realiziranih investicija. Razlozi za takav raskorak se traže u više smjerova. Sociološka i ostalaistraživanja po jednoj strani ukazuju na smanjenje moguüih ušteda zbog promijene u ponašanju
korisnika zgrade (eng. rebound effect). Drugi razlog za raskorak izmeÿu prognoziranih i
postignutih performansi je korištenje neodgovarajuüih i premalo kompleksnih metoda za
preliminarne energetske i funkcionalne analize energetskih koncepta. Standardiziraneinženjerske metode jednostavno ne omoguüavaju analiza na pojedinaþnim segmentima i njihovihinterakcija, ne identificiraju lokalne specifiþnosti na nivou zgrade te su premalointerdisciplinarne. Zbog korištenja projektnih parametra, koji ne prate dinamike u korištenju i
odazivanju zgrade, su previše rigidni i previše udaljeni od realnog funkcioniranja zgrade, njenih
sustava, režima korištenja i korisniþkih intervencija.
3.2 Znanstvena istraživanja u naprednom modeliranju zgrada
Sektor zgrada je u EU najveüi pojedinaþni potrošaþ konaþne energije i racionalna upotrebaenergetskih izvora postaje izmeÿu ostalog i sociološka, tehnološka i nauþna tema. Za optimiranjeenergetskih koncepta i poveüanje energetske uþinkovitosti zgrada oblikovane su nove metodemodeliranja, koje omoguüuju realnije i toþnije prognoziranje energetskih karakteristika.
Znanstvena istraživanja na energetskom modeliranju zgrada usmjerena su u više podruþja i u
tom smislu razlikuju se dva kljuþna pristupa [11]. Fizikalni pristup fokusira se na rješavanje
jednadžbi, koje simuliraju toplinski odaziv zgrade i odazivanje sustava. Matematiþki pristup
koristi statistiþke modele prognoziranja, zahvaljujuüi strojnome uþenju.
Fizikalni pristup (engl. white box models) kategoriziramo u tri nivoa:- Najpotpunija i detaljna je metoda CFD (engl. Computal Fluid Dynamics). Volumen
zgrade u tom sluþaju modelira se trodimenzionalno. Zbog svojih karakteristika je previšeopsežna i u smislu potrošnje vremena za analize. U praksi se zbog toga koristi za
lokalizirano modeliranje i duboke parcijalne analize.
- Zonska metoda je prvostupanjsko pojednostavljenje CFD tehnike i s dvodimenzionalnimpristupom omoguüava brže izvoÿenje analiza. Za evaluacije i rad na energetskim
konceptima ova metoda još uvijek ne iskazuje oþekivanih karakteristika obzirom na
praktiþnost.
- Za simuliranje toplinskog odazivanja zgrada u praksi najviše se koristi napredna
programska oprema, þija je osnova najviše pojednostavljen fizikalni pristup tj.
jednodimenzionalni više zonski ili pristup þvorovima. Prednost treüe kategorije jeopisivanje odaziva zgrada s više zona u dužem vremenskom periodu, uz relativno malu
potrošnju vremena.
- Iz perspektive šireg korištenja svih suvremenih fizikalnih metoda za modeliranje odstrane inženjera i projektanata zahtjev je detaljno poznavanje graÿevinske fizike,energetskih sustava, matematiþkog programiranja i sliþno, što za širi krug struke
predstavlja problem. Zbog toga se u praksi projektanti oslone na usko profilirani krugstruþnjaka, koji se specijalizirao u tim novim metodama i postupcima.
Jedna od prilika za premoštenje tih zahtjeva se ukazala sa moguünošüu korištenja statistiþkih
metoda (engl. black box models), koji ne traže fizikalne informacije, npr. tehnike CDA (engl.
Conditional Demand Analysis), GA (engl. Genetic Algorithm), AAN (engl. Artifical Neural
Network) i SVM (engl. Support Vector Machine).
Matematiþki model za analiziranje upotrebljava metodu uþenja, na osnovi uzoraka podataka iz
mjerenja. Matematiþki model dakle nije primjenljiv u sluþaju u kojem ne raspolažemo smjerenjima u fazi korištenja zgrade, npr. ne možemo ga koristiti u sluþaju projektiranja i

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optimiranja novogradnji, a kod postojeüih zgrada bez prethodnog ciljnog praüenja tj.
monitoringa.
Ograniþenja i prednosti obiju pristupa, fizikalnog i matematiþkog, znanost pokušava balansirati
upotrebom hibridnih modela (engl. grey box models). Tu su moguüe tri strategije: upotreba
strojnog uþenja za procjenu fizikalnih parametra, upotreba statistika za izvedbu modela uþenja,
koji opisuje odaziv zgrade, te upotreba statistiþkih metoda na podruþju u kojem fizikalni modeli
nisu uþinkoviti ili su premalo precizni.
Opisani metodološki napredak osnova je i za optimizacijske metode energetske uþinkovitosti, na
osnovi rezultata simuliranja odaziva zgrada [12, 13]. Za optimizaciju energetske uþinkovitosti
zgrada koriste se najþešüe algoritmi, koje znanost klasificira u sedam skupina, u izvornoj
engleskoj terminologiji, npr. direct search family, integer programming family, gradient-based
family, stochastic population based family, trajectory search family, hybrid family i ostale.
3.3 Korištenje naprednih metoda za modeliranje i u projektnoj praksi
U praksi oblikovanja energetskih koncepata za energetske sanacije zgrada i za novogradnjenajþešüe se koristi linearni pristup u optimiranju mjera za poveüavanje energetske uþinkovitosti(slika 2). Za varijantna tehniþka rješenja parcijalno se prouþava utjecaj na energetskuuþinkovitost i ekološka optereüenja s obzirom na ekonomske indikatore npr. NPV (engl. net
present value), koju predstavlja investiranje s ukljuþenima diskontiranima operativnima
troškovima u životnom ciklu zgrade. Odabrani optimum u takvom sluþaju tipiþno je kombinacija
investicija, koje vode u energetsko uþinkovit koncept za zgradu uz uvjet minimalnih cjelokupnih
troškova.
ŽĚĂƚŶŽƉŽďŽůũƓĂŶũĞĞŬŽŶŽŵƐŬŽŐƌĞǌƵůƚĂƚĂǌďŽŐ ŬŽƌŝƓƚĞŶũĂŬŽŵƉůĞŬƐŶŝũĞŐŵŽĚĞůĂ;ŽƉƚŝŵŝƌĂŶũĞŝŶǀĞƐƚŝĐŝũĞ͕Ŷŝǎŝ ŽƉĞƌĂƚŝǀŶŝƚƌŽƓŬŽǀŝͿWĂƌĐŝjĂůŶĂ „ůŝŶĞĂƌna“ ŽƉƚŝŵŝǌĂĐŝũa
DƵůƚŝĚŝƐĐŝƉůŝŶĂƌŶĂ „ŶĂƉƌĞĚŶŝũa“ ŽƉƚŝŵŝǌĂĐŝũa
Naprednija optimizacija + napredni modelWŽďŽůũƓĂŶũĞƌĞǌƵůƚĂƚĂǌĂĞŶĞƌŐĞƚƐŬŽĞŬŽůŽƓŬĞƉĞƌĨŽƌŵĂŶƐĞŶĂƌĂēƵŶŬŽƌŝƓƚĞŶũĂŬŽŵƉůĞŬƐŶŝũĞŐŵŽĚĞůĂ;ƌĞĂůŶŽƐƚŝƉƌĞĐŝǌŶŽƐƚͿWŽƚƌĞďŶĂƉƌŝŵĂƌŶĂĞŶĞƌŐŝũĂŝĞŵŝƐŝũĞƵǎŝǀŽƚŶŽŵĐŝŬůƵǌŐƌĂĚĞ

Slika 2. Shematski prikaz utjecaja korištenja naprednih modela na energetske, ekološke i
ekonomske performanse projektnih optimizacija
Napredniji energetski koncepti cjelovito razraÿuju meÿusobne utjecaje razliþitih kombinacija
mjera energetske uþinkovitosti, energetskih sustava i ostalih sistema za kondicioniranje zgrade.
Takav multidisciplinarni pristup omoguüava dobivanje povezanih rješenja i naprednijeg
energetskog koncepta za zgradu sa rezultatom u poveüanoj energetskoj uþinkovitošüu tesmanjenim troškovima investiranja i korištenja zgrade (slika 2).
Napredno energetsko modeliranje koncepta u takvim procesima osigurava dodanu vrijednost u
dvije dimenzije. Zbog korištenja kompleksnijeg i preciznijeg numeriþkog modela energetski i

Energy and the Environment (2016) 569-580

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ekološki rezultati modeliranja i optimiranja su toþniji te se približavaju realnom odazivanju
zgrade, njezinih sustava, te režimu korištenja. Do poboljšanja ekonomskog rezultata dolazi zbog
lokaliziranih analiza, prepoznavanja razliþitih zonskih fenomena i sliþno, koji omoguüavaju
optimiranje tehniþkih rješenja, njihovo prilagoÿavanje i pojednostavljenje, sa rezultatom
dodatnog smanjenja u investiranju.
Proces i postupci naprednog energetskog modeliranja proizlaze iz korištenja suvremenih
numeriþkih metoda, sa kojima se dinamiþki simulira odazivanje zgrade, njenih sustava, režimi
korištenja i reguliranja, itd. Zgrada se prilagoÿeno modelira u 3D obliku u odnosu na neposrednu
tj. utjecajnu okolinu (slika 3).

Slika 3. Detaljna procjena mikrolokacije i utjecaja okoline na zgradu sa 3D modeliranjem
To dodatno podruþje praüenja i analiza omoguüava preliminarno vrednovanje posljediþnih
energetskih performansi i utjecaja na korisnike. Na taj naþin s naprednim energetskim
modeliranjem veü na samom poþetku procesa projektiranja utjeþemo i na moguüe prilagodbe
arhitektonskih rješenja, konfiguracije transparentnog dijela toplinske ovojnice te odabir
optimalnih tehnologija za ovojnicu obzirom na energetski rezultat i postignut korisniþki komfor(slika 3 i 4A).

(A)

(B)

Slika 4. Optimiranje ovojnice sa obzirom na udio i tehnologiju ostakljenja, prirodno osvjetljenje($ LNRULVQLþNLNRPIRULQGLYLGXDOQRSUDüHQMHHQHUJHWVNLKLWHKQLþNLKSDUDPHWUDSR
zonama (B) i cjelogodišnju bilancu

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Specifiþnost naprednog dinamiþkog simuliranja je numeriþki koncept modela za zgradu, koji sesastoji od pojedinaþnih zona tj. prostorija, kod kojih se konfiguriranje, odazivanje i korištenje
prati individualno (slika 4A i 4B). Kod standardnog modeliranja kalkulacije za zgradu su
pojednostavljenog tipa i reduciraju se na jednu ili samo nekoliko jako razliþitih zona, koje sevrednuju mjeseþno, a rezultati prikazuju nepraktiþne prosjeþne vrijednosti i s tim premalokorisne informacije, u kojima ne postoji moguünost praüenja dinamike i upoznavanja lokalnih
specifiþnosti. Napredno dinamiþno modeliranje zbog svojih karakteristika, koje se odnosi na
lokaliziranje, preciziranje i prilagoÿavanje izvedbenom stanju zgrade omoguüava puno više(slika 3).
Postupci dinamiþnih simulacija traže puno širi opseg ulaznih informacija, a uz to i definiranje
dinamike njihovih promjena. Svaka pojedinaþna zona konfigurira se odvojeno u arhitektonskom,tehniþkom, tehnološkom i korisniþkom pogledu (slika 5A). Rezultati se analiziraju odvojeno za
zone ili sumarno na razini više zona sliþnog tipa (slika 5B). Prepoznaju se lokalni fenomeni,zbog kojih se može prilagoÿeno modificirati energetski koncept te sa tim postižemo potpuno
novu razinu optimizacije projektnih rješenja.

(A)

(B)

Slika 5. Zonski pristup u modeliranju (A) za lokalizirano analiziranje i upoznavanje
VSHFLILþQRVWLNUR]GLQDPLNX % NRMHXWMHþXQDFMHORNXSQLHQHUJHWVNLNRQFHSWSa sliþnim naþelom individualnosti konfiguriraju se i programiraju zajedniþki i zonski sustavi za
zgradu (slika 6). Na osnovi prepoznatih rezultata za zone modificiraju se i tehnološke
karakteristike energetskih komponenti te se prati utjecaj promjena na razini zgrade, sa ciljem
identificiranja energetskog i ekonomskog optimuma, moguüih pojednostavljenja u sustavima,
osiguravanja funkcija, kapaciteta i sliþno.

Energy and the Environment (2016) 569-580

577

(A)

(B)

Slika 6. Energetski sustav (A), ventilacija i ostali sistemi (B) - modeliranje konfiguracije,
NDUDNWHULVWLNDNRPSRQHQWLWHUPLQDLUHJXODFLMHSUDüHQMDUH]XOWDWDLPRGLILFLranja
3.4 Ukljuþivanje naprednog modeliranja i optimiranja u procese projektiranja
Napredni postupci energetskog modeliranja mogu se ukljuþiti u procese projektiranja praktiþki
svih tipova zgrada (stambene, javne, poslovne) te se s istim ciljem i doprinosom koriste kod
parcijalnih ili cjelovitih energetskih sanacija postojeüih zgrada kao i kod novogradnji.
Tipiþno se ukljuþuju u projekte za srednje i veüe zgrade, a u sluþaju manjih zgrada, npr.
obiteljskih kuüa, upotrebljavaju se najþešüe za definiranje optimalnih tipskih projekta, za naselja
i sliþno. Razlog za to su poveüani troškovi rada ukljuþene struke, koji se kod veüih ili tipskih
projekta višestruko vrate investitoru veü u izvedbi, zbog samog optimiziranja potrebnih ulaganja.
U tom smislu moguüa su dva scenarija. Investitor za raspoloživa projektna financijska sredstva
dobiva uþinkovitiju zgradu sa optimalnim energetskim sadržajem, koja korisnicima omoguüava
bolje uvjete za rad ili stanovanje. U drugom sluþaju moguüe je zbog racionalizacije koncepta
postiüi projektno oþekivane energetske i korisniþke performanse uz smanjenu poþetnu
investiciju.
Zahtjev naprednog modeliranja je odreÿivanje konkretnih projektnih pretpostavki i ciljeva
projekta te izjašnjavanje vezano npr. na što preciznije predviÿanje režima korištenja zgrade,ukljuþivanje razliþitih tehnologija, itd. Pri tome to predstavlja dodatnu prednost jer su zbog
potrebe za intenzivnijim komuniciranjem i odreÿivanjem rubnih projektnih parametara investitor
ili korisnik, arhitekt te strojarski inženjer bolje povezani veü u fazi oblikovanja ideje za
energetski koncept te s tim kvalitetnije prate i razvoj investicije. Izvoÿenje procesa dinamiþkog
modeliranja i analiziranja varijanti je vremenski zahtjevno i zbog toga traži i optimiranje na
strani rada. Proces se u fazi modeliranja ubrzava u koliko arhitekt pripremi ciljno
pojednostavljeni 3D model zgrade, npr. na osnovi grafike, koja inaþe služi za prezentaciju
projekta. Osnovni arhitektonski model zgrade definiran je prije poþetka dinamiþkih simulacija i
kao takav dopušta jednostavne modifikacije s ciljem optimiranja arhitektonskih rješenja npr. u
toplinskoj ovojnici zgrade. Moguüa je i preliminarna analiza više potpuno razliþitih
arhitektonskih idejnih varijanti npr. za novogradnje u idejnoj fazi, ali je u tom sluþaju potrebno
odvojeno modelirati i analizirati svaki pojedinaþni idejni koncept.

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4. ZAKLJUýAK
Cjelovita energetska obnova zgrada u pogledu zahtjevnosti projekata, opsega investiranja,
razliþitih energetskih, ekonomskih i ostalih eksternih utjecaja bitno prelazi dosadašnja iskustva iznanja sudionika ukljuþenih u postupak razvoja projekta energetske sanacije, koja su dobivena u
proteklim godinama tijekom izvoÿenja brojnih projekata parcijalne energetske obnove javnih istambenih zgrada. Planirane investicijske mjere za pojedine objekte utjeþu na više podruþja
potrošnje energije, koje su isprepletene zbog meÿusobnih interakcija. Cjelovita energetska
obnova ne utjeþe samo na smanjenje potrošnje energije, emisije i troškova rada, veü utjeþe i na
poboljšanje uvjeta korištenja zgrada, poveüava iskorištenost objekata, a takoÿer može i poveüati
kapacitete te tako posljediþno utjecati na razliþite naþine na samu vrijednost nekretnina. Jedan odveüih sustavnih problema pri odreÿivanju sadržaja projekata cjelovite energetske obnove zgrada,
te procjene njihovih energetskih, ekonomskih, ekoloških, stambenih i ostalih utjecaja,
posljediþno i pri kvantificiranju uþinaka, nemoguünost je korektne upotrebe postojeüih
jednostavnih metoda za cjelovitu evaluaciju koncepata. Pojednostavljeni inženjerski pristupi zaenergetsku procjenu mjera energetske sanacije, koji su u graÿevinskoj praksi veü metodološki
definirani, veü duže vremena ukazuju na manjkavost i ne pružaju realnu prognozu za cjeloviteenergetske uþinke, te utjecaje na okoliš.
Jedna od kljuþnih zadaüa za istraživanja je prouþavanje i definiranje novog sistemskog pristupa,koji üe omoguüiti korektno kvantificiranje cjelovite energetske sanacije zgrada u energetskom iekonomskom smislu. Potrebno je odrediti modele za naprednu, te cjelovitu energetsku iekonomsku procjenu takvih investicijskih projekata. Tema þlanka je primjena naprednijihmodela, koja üe omoguüiti istovremeno i preliminarne evaluacije i posljediþno pravovremene
prilagodbe onih koncepata za energetsku sanaciju zgrada, koji su djelomiþni, te kao takvi neüeodgovarati kvalitativnim ciljevima nacionalnih strategija za cjelovitu energetsku obnovu. Prvu
fazu u razvoju novih modela potrebno je usmjeriti u podruþje javnih zgrada, za koje su planirani,odnosno za koje su u tijeku opsežni programi energetske sanacije. Zbog opsega planiranih
investiranja u energetsku sanaciju zgrada bitno je i optimiranje energetskih koncepta i
pojedinaþnih tehniþkih rješenja. Financiranje se usmjerava u investicijska rješenja koja
energetski poboljšavaju zgrade i predstavljaju produktivni dio investiranja. Optimiranje se neodnosi samo na ta rješenja. Novost je traženje sinergija na nivou koncepta za zgradu i
upoznavanja lokalnih specifiþnosti - kroz napredno energetsko modeliranje – kojim se
omoguüavaju posljediþne uštede u investiranju, npr. kod konfiguracije i pojednostavljenja
energetskih sustava. Cilj takvog pristupa su energetsko i ekonomski visoko uþinkovite zgrade.

LITERATURA[1] Praznik, Miha, Koviþ, Silvija. Cjelovita energijska obnova višestambenih i javnih zgrada.
Graÿevinar, ISSN 0350-2465, 2008, vol. 60, br. 6, str. 577-582. http://www.casopisgradjevinar.hr/assets/Uploads/JCE-60-2008-06-09.pdf.
[2] Ostojiü, S., Veršiü, Z., Muraj, I.: Energgy analysis and refurbishment strategy for Zagreb
University buildings: Former Faculty of Technology in Zagreb by Alfred Albini", Energy and
Buildings, Vol. 115 (2016), March 2016., str. 47-54, Elsevier, ISSN 0378-7788.
[3] Veršiü, Z., Muraj, I., Biniþki, M.: Model višestambene zgrade zagrebaþkog donjogradskog
bloka. Analiza u svrhu poboljšanja energetske uþinkovitosti, „Prostor“, znanstveni þasopis za
arhitekturu i urbanizam 23(2015.) 2(50), Zagreb: 236-249, ISSN 1330-0652.
[4] Praznik, Miha, Zbašnik-Senegaþnik, Martina. Ugraÿena primarna energija i optimizacija
energetski uþinkovitih kuüa = The embodied primary energy and optimisation of energy-efficientEnergy and the Environment (2016) 569-580

579

houses = Eingebaute Primärenergie und Optimierung energieeffizienter Häuser. Graÿevinar,
ISSN 0350-2465, Sep. 2015, vol. 67, [no.] 9, str. 853-864, ilustr. http://www.casopisgradjevinar.hr/assets/Uploads/JCE-67-2015-9-3-1193-EN.pdf.
[5] Praznik, Miha, Zbašnik-Senegaþnik, Martina. Trajnostna zasnova energijsko uþinkovitih
enodružinskih hiš. Ljubljana: Fakulteta za arhitekturo, 2016. 287 str., ilustr. ISBN 978-9616823-77-7.
[6] Praznik, Miha, Butala, Vincenc, Zbašnik-Senegaþnik, Martina. A simple method forevaluating the sustainable design of energy efficient family houses. Strojniški vestnik, ISSN
0039-2480, Jun. 2014, vol. 60, no. 6, str. 425-436, ilustr., doi: 10.5545/sv-jme.2013.1561.
[7] Praznik, Miha, Butala, Vincenc, Zbašnik-Senegaþnik, Martina. Simplified evaluation method
for energy efficiency in single-family houses using key quality parameters. Energy andbuildings, ISSN 0378-7788. [Print ed.], Dec. 2013, vol. 67, str. 489-499, ilustr., doi:
10.1016/j.enbuild.2013.08.045.
[8] Praznik, Miha, Zbašnik-Senegaþnik, Martina. Analiza kvalitativnih parametrov za energijskouþinkovite hiše = Analysis of qualitative parameters for energy-efficient houses. AR, ISSN
1580-5573. [Tiskana izd.], 2011, [Št.] 2, str. 29-38, ilustr.
[9] Filippini, M., Hunt, L. C., Zoriü, J. (2014). Impact of energy policy instruments on theestimated level of underlying energy efficiency in the EU residential sector. Energy policy 69,
73-81.
[10] Hrovatin, N., Dolšak, N., Zoriü, J. (2016). Factors impacting investments in energy
efficiency and clean technologies : empirical evidence from Slovenian manufacturing firms.
Journal of cleaner production, [in press] 2016, doi: 10.1016/j.jclepro.2016.04.039.
[11] Foucquier, A., Robert, S., Suard, F., Stephan, L., Jay, A. (2013). State of the art in building
modelling and energy performances prediction: A review. Renewable and Sustainable Energy
Reviews 23, 272–288.
[12] Nguyen, A.T., Reiter, S., Rigo, P. (2014). A review on simulation-based optimization
methods applied to building performance analysis, Applied Energy 113, 1043–1058.
[13] Kellerer, H., Pferschy, U., Pisinger, D. (2004). Knapsack problems. Berlin – Heidelberg:
Springer Verlag.

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03UD]QLN=9HUãLü: Utjecaj naprednog energetskog modeliranja…

IMPACT OF ADVANCED ENERGY MODELING IN THE
OPTIMIZATION OF BUILDING ENERGY CONCEPT
Abstract: Comprehensive energy rehabilitation projects for the buildings are often identified
with projects for new construction. Common to them is a high demand for investment, seeking
interdisciplinary customized energy concept and the optimization of design solutions, which willaffect the future use of the building in the following decades. Advanced energy modelling
enables a comprehensive and detailed knowledge of the characteristics of the building. It helps
to define the optimal range of individual technical measures, with respect to life cycle costs andimpacts on users. Because of the wider review of the project also enables the synergistic
optimization and reduction of investments, compared to the otherwise identified designer’s
estimates.
Key words: deep energy renovation, energy efficient buildings, advanced energy modelling,energy concept optimisation, building dynamic response, life cycle cost

Energy and the Environment (2016) 581-594

581

ANUAL HEAT STORAGE OPTIMISATION IN URBAN
REGENERATION PROJECTS FROM AN ENERGY PLANNINGPERSPECTIVE
03DYLþHYLü 71RYRVHO73XNãHF1'XLü
Faculty of Mechanical Engineering and Naval Architecture, Department of Energy,
Power Engineering and Environment
University of Zagreb, Zagreb, Croatiaemail: Matija.pavicevic@fsb.hr
Abstract: Growing presence of urban regeneration projects which reorganize and upgrade
existing urban and former industrial areas, city neighbourhoods or even whole districts, isstrongly related to the implementation of renewable energy sources. Interdependencies
between different energy carriers and the corresponding technologies lead to synergy effect,
which can have a significant impact on an energy system. Heat storage is in most cases a costeffective way to increase both the flexibility and the operational efficiency of low carbon
systems thus providing technical, economic and environmental benefits. The added flexibility
provides more possibilities for the utilization of renewable energy sources, whichconsequently reduces the share of fossil fuel consumption and thereby greenhouse gas
emissions. Additionally, power to heat technologies such as heat pumps or electric heaters,
can be used for integration of power and heating systems. This can increase the flexibility ofthe power sector, and moreover, the system’s capacity to utilize intermittent renewable energy
sources such as wind and solar. The goal of this work is to develop, demonstrate and validatea model capable of optimizing the heat storage capacity for small solar district heating
system, as well as its operation on an hourly level with a time frame of one year. Suchapproach allows the model to choose between short term and seasonal heat storage systems
which take into account both the hourly and the seasonal variations in the operation of thesystem. The model has been tested and validated as a case study on the small neighbourhood
Trnsko which is located in the southern part of Zagreb.
Key words: Urban regeneration, Solar district heating, Heat storage, Optimization, Energy
planning

1.

INTRODUCTION

Worldwide demand for energy and the cost of fossil fuel resources are continuously
increasing. In the same time widespread renewable energy sources such as solar and wind,and less spread such as biomass and biofuels are becoming more competitive. Their
penetration in the global final energy consumption sums up to 19,1% in the year 2013 [1].
The EU (European Union) has adopted the 2020 climate & energy package that sets three key
targets until the year 2020, which means that greenhouse gas emissions have to be cut by 20%
from 1990 levels, 20% of EU energy has to come from renewable energy sources and energy
efficiency has to be increased by 20% [2]. In the EU’s 2030 framework for climate and

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energy policies presented in January 2014 [3], continuing progress toward integration ofrenewable energy sources and low carbon economy is expected.
Pukšec and Mathiesen [4] have developed the NeD (National energy demand) model whichhas proven that an energy consumption reduction of nearly 40% in Croatia can be achieved by
the year 2050. According to Lund and Werner [5] district heating infrastructures have to play
an important role in the task of increasing energy efficiency and thus making these scarce
resources meet future demands. District heating comprises are a network of pipes connecting
the buildings in a neighbourhood, town centre or whole city, so that they can be served from
centralised plants or a number of distributed heat producing units. This approach allows
almost any available source of heat to be used. The inclusion of district heating in futuresustainable cities allows for the wide use of combined heat and power (CHP) together withthe utilisation of heat from waste-to-energy and various industrial surplus heat sources, aswell as the inclusion of geothermal and ST (solar thermal) heat [6]. The importance of heatstorage in a future sustainable energy system iQ &URDWLD ZDV DVVHVVHG E\ .UDMDþLü DQG 'XLü
[7]. Østergaard [8] has shown that integration of HP (heat pump) as a central heat production
unit in a DH system is possible when combined with a heat exchanger, or a combination of
DH based HPs and a small booster HP using DH water as low-temperature source for DHW(domestic hot water) production.
Dotzauer and Holmstrom [9] showed that optimizing heat and electricity production as well as
the size of TES is a complex optimization problem. Buoro and Pinamonti [10] explored the
optimal operation strategy in order to minimize the total annual cost based on a MILP (mixed
integer linear programing) model for a distributed energy supply system including CHP plant,a DH network system, a ST plant and conventional components such as boilers and chillers.
Christidis and Koch [11] optimized the design of heat storage devices together with theoperation of a power plant supplying a large district heating network by formulating a MILP
problem in GAMS (The General Algebraic Modeling System) and solving it with CPLEX(IBM ILOG CPLEX Optimization Studio) solver. Future district heating infrastructures
should, however, not be designed for the present energy system but for the more efficient
future system. One of the future challenges will be to integrate district heating with theelectricity sector as well as the transport sector [12].
The past studies have optimized the production of heat energy by assuming both perfect anduncertain information for the planning horizon. In all cases short term analysis with a time
horizon of one day or one week has been conducted. In this paper, the optimization of thecapacity of the thermal storage with three heat producing units, including a biomass HOB(heat-only boiler), ST (solar thermal) and HP for a longer time window has been
demonstrated. The problem has been formulated in MALAB [13] and solved using an open
source MINLP solver SCIP (Solving Constraint Integer Programs) [14].
2.

METHODOLOGY

2.1. Problem definition
Recently more and more investigation has been carried out on the feasibility of district
heating in terms of implementing a sustainable energy system which is based on renewableenergy and includes substantial reductions of space heating demand [15]. The study concludes
that the role of district heating is significant, but that district heating technologies must beEnergy and the Environment (2016) 581-594

583

further developed to decrease grid losses, exploit synergies, and thereby increase theefficiencies of low-temperature production units in the system. Renewable energy is an
essential factor in the climate change response in Europe as well as in many other regions[16]. The main challenges that have to be met for the transition to the 4th generation DH
system are energy conservation, switch to low-temperature space heating and DHW (domestic
hot water), peak shaving and intelligent control of the heating system and reduction of heatlosses ect. All of this could be achieved only if all of the challenges are tackled at the sametime, meaning that utilization of low carbon and renewable energy sources such as solar andbiomass makes only sense if buildings, where they are to be implemented, should be
retrofitted to meet new higher standards that allow utilization of low temperature heating and
DHW preparation. When such transition is carried out low cost systems such as TES andpower to heat technologies could be properly utilized.
2.2. Model description
The model optimizes the operation of all three heat production units as well as the size of
TES. Al the necessary variables describing these units are subjected to different constraints.
The main target of the system is to cover the given hourly heat demand from the small DH
network while at the same time produce maximal amount of electricity through PV (photovoltaic) panels to reduce the systems operating costs by selling it on the electricity market, or
to allow utilization of power to heat technologies such as HP (heat pumps). As a consequence,seasonal energy storage, besides storing energy in periods with lower demand, is used forpeak shaving in time periods with higher heating demand, which usually occur during the day,especially during the winter season. This way the on line time of the HOB is drasticallyreduced, lowering systems operation costs and CO2 emissions which consequently increases
total income of the system.

Figure 1 Scheme of the system

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The system presented in Figure 1 will cover all the heating energy demand from the network
as well as produce a significant amount of electricity which will be used for powering the HP
especially during the summer period no meter what the generation amount equals to. The sizeof TES will be optimized for storing the heat produced from the ST collectors and HP during
the summer period.
2.3. Biomass heat only boiler
Most of the heat production units work on the same principle, usually water is either heated or
evaporated through heat emitted from the fuel combustion. This model is developed as asimple linear relation between the heat production and the necessary fuel consumption needed
for the combustion process to take place. The efficiency is directly related to the heatproduction where at certain heat outputs the efficiency is higher than at others. This model is a
general description of such power units and can be used for describing multiple units with thesame amount of variables especially if all of them are driven by the same heat demand andtype of fuel.
2.4. Solar thermal collectors
Flat plate collectors consist of a dark flat-plate absorber, a transparent cover that reduces heatlosses, a heat-transport fluid to remove heat from the absorber and a heat insulating backing[17]. They usually use water or glycol as the heat transfer medium that transfers heat to the
TES. Although this technology isn’t new and can technically be combined with almost allother fuels for district heating, it is not always environmentally and economically feasible.
The price strongly depends on the amount of solar irradiation available at the installation siteand can range from 30 €/MWh in the Northern Europe down to 20€/MWh in Southern
Europe. Usual small scale systems have surface area of about 2m2 while large size systems
can reach up to 13 m2 [17]. In this paper large scale roof systems have been used.
2.5. Heat pump
According to [18], HP’s serve different purposes, e.g. industrial purposes, individual spaceheating, heat recovery and heat production for district heating. Today most heat pump systems
are driven by electricity and use various heat sources e.g. ambient air, water or ground, waste
heat from industrial process or geothermal energy. In an ideal case where the heating
temperature is 80°C and the cooling temperature is 10°C the theoretical COP or Carnot
efficiency is 5.0. In all practical appliances the COP will be lower because of losses in thesystem, typically around 50-65%. This rule-of-thumb is only valid with small temperature
differences on both sides (evaporator and condenser) and if the HP is used within the
optimum operating range of components and refrigerant. Typical heat output of today’s DH
HP’s is between 25 kJ/s to 3-5 MJ/s [18]. In this model air DH HP is chosen. The surrounding
air is used as the heat source for the HP so the COP factor is variable and outside temperaturedependent, as described in Heat Pumps in District Heating: Final Report [19]Energy and the Environment (2016) 581-594

585

2.6. Thermal energy storage
Pit thermal energy storage (PTES) is chosen for the seasonal heat energy storage. This ismostly due to low investment costs and high specific capacity that ranges between 60 and 80
kWh/m3 depending on the use of the storage. The sizes of the used PTES are typically verylarge and range between 5,000 m3 and 50,000 m3. This is essentially a hole in the ground
lined by a water-proof membrane, filled with water and covered by a floating and insulating
lid [17]. According to [20] typical seasonal efficiency of such storage is between 85 and 95%,
depending mostly on the temperature level in the storage and the surface to volume ratio.
Economy of scale applies for the PTES up to the size of 50,000 m3 or 3,000 MWh where afacility of 250 m3 or 15 MWh costs around 8,104 €/MWh and for a storage of 50,000 m3 or
3000 MWh the costs are around 1017 €/MWh. Nonlinear relation between total investment
costs into the existing PTES, from around EU, and thermal capacity are presented in Figure 2.
Investment costs of TES

Total investment costs [€]3 500 000
3 000 000
2 500 000

y = 37266x0,5547
R² = 0,9399

2 000 000
1 500 000
1 000 000
500 000
0
0

500

1000

1500

2000

2500

3000

3500

Total capacity [MWh]Figure 2 Price curve depending on the capacity of the TES [18]2.7. Photovoltaic panel
A photovoltaic panel turns solar energy into direct current electricity using semiconducting
materials (usually silicon). The cost of photovoltaic has declined steadily since the first solar
cells were manufactured [17] and the electricity cost from PV is starting to be competitive
with conventional electricity sources. These systems can be mounted on the building roofs oron the ground. Usually they have tilted axes so that most of the solar irradiation can be
harvested, increasing their overall efficiency. PV modules have relatively low overall
efficiency (<20%) compared to other conventional power production technologies. Most of
the losses (80 – 90%) occur directly in the PV panels, while other losses are mainly associatedto the DC/AC inverter, temperature, shade and dust. In this paper mid-range PV modules withoverall efficiency of 15% have been used.
2.8. Heat demand
Heating demand is calculated by using a degree hour method which is based on hourly
temperatures for a given location, the inside project temperature and assumed annual heatconsumption. This method was modified in order to accurately represent night time periods
when there is little or almost no heat demand. A modification was made through the
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03DYLþHYLü71RYRVHO73XNãHF1'XLü: Annual heat storage optimisation…

introduction of an additional reduced inside project temperature. This is valid only for thenight period, between 23 PM and 5 AM, and when the outside temperature is lower than -5°C.
This is common practice used in [20]. The calculated hourly heating demand for space heating
only, before and after the refurbishment, is shown in Figure 2.
Heat demand
4,0Current state

Heat demand [MWh]3,5After refurbishment

3,0
2,5
2,0
1,5
1,0
0,5
0,0
0.1.

31.1.

29.2.

31.3.

30.4.

31.5.

30.6.

31.7.

31.8.

30.9.

31.10.

30.11.

31.12.

Figure 3 Heating energy demand for the analysed neighbourhood.
2.9. Mathematical model
The mathematical model is developed for the case study of the small neighbourhood in thecity of Zagreb, but can also be applied for any other system involving the elements contained.
This model is very flexible and can easily be expanded with other heat production
technologies or elements such as minimal on and off times. However, in order to present themodel in the simplest possible way, the shape of the model related to the analysed case study
is retained.
2.9.1. Objective Function
The objective function represents the function that summarizes all costs from both the supply
and the demand side and therefore has to be minimized by finding the optimal set of variables
that represent all energy flows of the system. The cost function is given in the Eq.(1).
ே(1)݉݅݊‫ܥ‬௧௢௧ = ෍(‫ܧ‬௧ + ‫ܫ‬௧ )
௧ୀଵ

‫ܧ‬௧
‫ܫ‬௧

hourly values of all expenses in €,discounted values of all investment costs €.

2.9.2. Expenditure
There is only one expenditure item in the model described by Eq. (2) that represents cost of
biomass consumption for heat production in HOB. As the heating demand from the DH
network needs to be satisfied, it can be assumed that the combined output of all heatEnergy and the Environment (2016) 581-594

587

producing units needs to be high enough to cover the demand. The cost of gas consumption in
the HOB for every time interval ‫ܥ‬௚௔௦ equals:௧‫ܥ‬௕௜௢௠௔௦௦ ௧ =‫݌‬௕௜௢௠௔௦௦ ή ܳሶ௕௢௬

௧

(2)ߟ஻ை௒ ௧

price of gas in €/MWh,‫݌‬௕௜௢௠௔௦௦
ܳሶ௕௢௬ ௧ hourly value of heat delivered from the heat only boiler in MWh,ߟ஻ை௒ ௧ hourly value of boiler efficiency,
2.9.3. Investment costs
There are five items that represent investment costs. Discounted investment cost of biomass
HOB ‫ܫ‬ுை஻
(3)‫ܫ‬ுை஻ = ‫݌‬ுை஻ ή ܳሶ௕௢௬
௠௔௫‫݌‬ுை஻ - capacity dependent price of HOB discounted to hourly value in €/MWhܳሶ௕௢௬ ௠௔௫maximal heat output from the HOB in MWh,
Discounted investment cost of TES ‫்ܫ‬ாௌ equals:‫்ܫ‬ாௌ = ‫்݌‬ாௌ ή ்ܵாௌ ௠௔௫(4)‫்݌‬ாௌ - capacity dependent price of TES discounted to hourly value in €/MWh்ܵாௌ ௠௔௫
maximal capacity of TES in MWh,
Discounted investment costs of ST ‫ܫ‬ௌ் equals:‫ܫ‬ௌ் = ‫݌‬ௌ் ή ‫ܣ‬ௌ்

(5)‫݌‬ௌ் - price of ST discounted to hourly value in €/m2‫ܣ‬ௌ்
area of ST in m2,
Discounted investment costs of PV ‫ܫ‬௉௏ equals:‫ܫ‬௉௏ = ‫݌‬௉௏ ή ‫ܣ‬௉௏

(6)‫݌‬௉௏ - price of PV discounted to hourly value in €/m2‫ܣ‬௉௏ area of PV in m2,
Discounted investment costs of HP ‫ܫ‬ு௉ equals:‫ܫ‬ு௉ = ‫݌‬ு௉ ή ܳሶு௉ ௠௔௫(7)‫݌‬ு௉ - price of HP discounted to hourly value in €/m2ܳሶு௉ ௠௔௫
maximum heat output from the HP in MWh,

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2.9.4. Constraints
The heat demand in every hour ‫ ݐ‬throughout the whole heating season needs to be covered,either by heat production from the biomass HOB, ST system or HP; by heat stored in TES, or
by all four sources of heat at the same time:(8)ܳሶ௕௢௬ + ܳሶௌ் ௧ + ܳሶு௉ െ ܳሶ௜௡ൗ
= ܳሶ஽ாெ ௧௧௢௨௧ ௧ܳሶௌ் ௧
ܳሶ௜௡ൗhourly value of heat produced by ST system in MWh,charging/discharging energy from the TES in MWh.

௢௨௧ ௧

HOB has to operate in ranges between the minimum and maximum capacities. Since it cannot
deliver less heat then the minimal output, a binary variable ‫ݔ‬஻ை௒ ௧ is introduced that represents
on and off states:‫ݔ‬஻ை௒ ௧ ή ߛ௠௜௡ ή ܳሶ௕௢௬െ ܳሶ௕௢௬ ௧ ൑ 0+ ܳሶ௕௢௬ ൑ 0௠௔௫െ‫ݔ‬஻ை௒ ௧ ή ܳሶ௕௢௬ ௠௔௫(9)௧ߛ௠௜௡ ή ܳሶ௕௢௬ ௠௔௫ minimal heat output of the HOB in MWh,maximum heat output of the HOB in MWh.
ܳሶ௕௢௬
௠௔௫

Heat losses from the TES in every time step ‫ ݐ‬are in direct correlation with the amount of heatstored inside the TES in the time step ‫ ݐ‬െ 1:െߝ௦௧௔௥௧ ή ܵ௦௧௢௥ + ܳሶ௦௧௢௥ ௧ୀଵ െ ܳሶ௜௡ൗ
=0௢௨௧ ௧ୀଵ

ܳሶ௦௧௢௥ ௧ െ ܳሶ௦௧௢௥ ௧ିଵ + ܳሶ௟௢௦௦ ௧ െ ܳሶ௜௡ൗ

௢௨௧ ௧

=0

(10)

ܳሶ௟௢௦௦ ௧ୀଵ = 0
ή ߟ௦௧௢௥ = 0ܳሶ௟௢௦௦ െ ܳሶ௦௧௢௥
௧௧ିଵߝ௦௧௔௥௧ amount of heat available in the first interval in %,ܳሶ௦௧௢௥ ௧ amount of heat energy stored in the TES in every time interval,ܳሶ௟௢௦௦ heat energy losses from the TES due to heat exchange with the surrounding area,௧ߟ௦௧௢௥ thermal efficiency of the TES.
Sum of the all energy flows into and out of the TES are equal to the amount of energy in thelast interval:ே෍൫ܳሶ௟௢௦௦ ௧ + ܳሶ௦௧௢௥ ௧ ൯ = ܵ

(11)

௧ୀଵ

ܵ

amount of heat energy stored in the last time interval. When ܵ = 0 heat energy stored
inside the TES in the last time interval is equal to the amount of heat stored in the firsttime interval.

All thirteen optimization variables from the model are also subjected to the range between
minimum and maximum values.
ܵ௠௜௡ ൑ ܵ௦௧௢௥ ൑ ܵ௠௔௫(12)

Energy and the Environment (2016) 581-594

589

0 ൑ ܳሶ௦௧௢௥ ௧ ൑ ܵ௠௔௫ܳሶ௟௢௦௦ ൒ 0

(13)
(14)

െ(1 െ ߛ௠௜௡ )ܵ௠௔௫ ൑ ܳሶ௜௡/௢௨௧ ൑ (1 െ ߛ௠௜௡ )ܵ௠௔௫

(15)

௧

௧

ߛ௠௜௡ ή ܳሶ௕௢௬

௠௔௫൑ ܳሶ௕௢௬ ൑ ܳሶ௕௢௬௧0 ൑ ܳሶௌ் ௧ ൑ ‫ܣ‬ௌ் ή ‫ݍ‬ௌ் ௧
0 ൑ ܲ௉௏ ൑ ‫ܣ‬௉௏ ή ‫ݍ‬௉௏ ௧‫ݔ‬஼ு௉ ௧ = ‫ݔ‬஻ை௒ ௧ = {0,1}

௠௔௫

(16)
(17)
(18)
(19)

2.9.5. Optimization method
The solution of the problem is done by minimizing the objective function f, subject toinequality and equality constraints.
݂݉݅݊ = ‫ ݔ‬ή ‫ܥ‬
s.t.
(20)
‫ܣ‬ή‫ ݔ‬൑ܾ‫ܣ‬௘௤ ή ‫ܾ = ݔ‬௘௤
Vector C defines the costs associated with the vector x that presents the thirteen optimization
variables. Matrices A and Aeq together with vectors b and beq are assembled from theconstraints. From the mathematical point of view this is a mixed integer nonlinear programing
problem, since the model and constraint formulation have nonlinear correlations and twovariables are binary (either 0 or 1).
3.

CASE STUDY

The model is applied to the apartment block in the Trnsko neighbourhood located in thesouthwest part of the city of Zagreb. About 1.800 people live there in six five store highbuildings, built in the early 1960’s, when there were no policies and regulations that would
encourage construction of energy efficient buildings. All of these buildings have never been
refurbished and today still have almost no thermal insulation, so their average annual heatconsumption is according to [21] estimated to about 160 to 185 kWh/m2. This part of the city
has no available connection to the DH network and uses individual gas fired HOB for spaceheating and preparation of DHW. Most of these boilers are 25 or more years old and need tobe replaced in the near future. The main focus of today’s strict environmental standards is the
reduction of GHG emissions. This could be achieved if heating system in the analysedapartment block would be switched from gas to one of the renewable energy sources. One ofthe options is development of a small DH network with centralised biomass HOB. Since there
is a large unused public park area nearby and buildings roofs are free of shade anotherrenewable energy option is development of the solar DH system with seasonal TES. For these
purpose implementation of PTES (pit thermal energy storage) and covering of up to 60% of
the roof area with combination of ST collectors and PV modules as well as installation of DH
HP’s have been analysed. The input data from the analysed case study is presented in the
Table 1 Lis of data used in case studies

589

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03DYLþHYLü71RYRVHO73XNãHF1'XLü: Annual heat storage optimisation…

Case
SymbolHOB
TES
HP
Total roof area
Total heating area
ST roof area
PV roof area
4.

Unit
MW
MWh
MW
m2
m2
m2
m2

Case study “A”
Case study “B”
Scenario “1” Scenario “2” Scenario “3” Scenario “4”
1,45
1,45
0,01
1620
0,05
0,03
7.104
33.312
4.262
3.551
4.262
3.551
-710
710

RESULTS AND DISCUSSION

Both case studies have been analysed from the perspective of the future Trnsko
neighbourhood DH system. Its total costs consist of seven variables: fuel costs for powering
the biomass HOB and the investment costs into the TES, ST collectors, PV panels, HP andthermal insulation. Revenue comes from savings compared to the reference scenario where all
the heat is produced in the old gas boilers with average annual efficiency of about 85 - 90%.
Total of two cases have been carried out. In Case “A” potential savings from the investment
in to the new heating technology has been analysed. In Case “B” integration of new heating
technologies from the Case “A” and installation of new thermal insulation that lowers annual
heat consumption from 160 to 185 kWh/m2, down to about 45 kWh/m2 have been analysed.
Each case study has two scenarios. In Scenarios “1” and “3” installation of HOB in
combination with solar DH has been analysed. In Scenarios “2” and “4” solar DH is upgradedwith small HP which is powered with electricity produced from PV panels. There is also an
option to sell electricity from PV panels on the electricity market if conditions for doing so
are favourable for the system by additional reduction of total system costs.
Figure 4 presents the hourly load distribution and load duration curves for both case studies.
Activity of all heat production units, including biomass HOB, ST collectors and HP, as well
as TES is shown in the load duration diagrams. It is obvious that the integration of the ST in
combination with TES reduces the annual activity of the HOB by a significant amountcomparing it to the reference scenario where natural gas boilers have been used to cover thewhole heating demand. In first two scenarios most of the heating demand was covered bybiomass HOB. In second scenario where 50% of the roof was covered with ST collectors and
10% with PV panels, which were used for powering the HP, same biomass HOB could be
utilized for covering the demand. Since HP’s are highly efficient P2H (power to heat)technology, with heat output up to 4,5 times higher than the electricity needed for its
generation, excess electricity could be sold either on the electricity market or to the powercompany. In last two scenarios from Case “B” after installation of thermal insulation heat
demand is reduced significantly. It is clear that there is no need for biomass HOB, as wholeheat demand could be covered with heat from ST collectors, stored in the TES. Figure 5
presents an example of amount of the heat energy stored in the PTES. This diagram verifies
that the optimization process was successful as the amount of heat stored in the PTES isabove minimum of 15% of total capacity of the TES and below its maximum capacity thatwas optimised. Economical results from the analysis are presented in Table 2 from where it isclear that the whole project can not be profitable on its own. Such projects should apply for
grants from some kind of fund that focuses on energy efficiency, renewable energy sources
and reduction of GHG emissions. In this analysis minimum amount of grants needed for the
NPV (net present value) of project to equal zero after 20 years has been determined.

Energy and the Environment (2016) 581-594

591

Scenario “1”Scenario “2”Scenario “3”Scenario “4”

591

592

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Figure 4 Graphical presentation of hourly load distributions and load duration curves fromboth scenarios

Figure 5 Amount of heat energy stored in the seasonal TES
Table 2 Lis of data used in case studies
Case
SymbolAnnual savings/expenses
Grants
5.

Unit€

Case study “A”
Scenario “1” Scenario “2”-135.964-125.654
55.87%
51.63%

Case study “B”
Scenario “3” Scenario “4”-68.874-58.09428.30%
23.87%

CONCLUSIONSThis paper presents the optimization method for finding the optimal energy flows withminimal total operation costs in the system with three different heat production units(HOB,ST collectors and HP), that are connected to the TES whose storage capacity is
optimized. The method has been demonstrated using the hourly environmental variables forthe neighbourhood of Trnsko in the city of Zagreb, and fixed natural gas and biomass prices.
Investment costs for HP installation are fixed while the investment costs in TES are capacity
dependent and follow an exponential curve. Investment cost for biomass fired HOB are also
capacity dependent while investment costs for PV modules and ST collectors are fixed. The
presented method allows the use of optimization horizons smaller and larger than one hour.
This enables better and more time consuming, but more accurate or more robust, leastaccurate but less time consuming optimization of the operation of the system.
The results from the Case “A” are showing that the investment costs of solar DH withbiomass HOB could, due to the relatively low price of natural gas, and relatively high annual
boiler efficiency, not produce any savings in expected lifetime of the equipment. Investment
costs in these two technologies as well as construction of the DH network that connects these
five buildings to the central boiler and TES are to high. Total loses of 135.964 and 125.654 €have been identified. On the other hand GHG emissions in this case study are reduced by
1.108 and 1.198 tCO2 equivalent. In Case “B” results are again negative, and the fuel savingsaren’t enough to cover the investment costs although the heat demand has been reduced

Energy and the Environment (2016) 581-594

593

significantly. In this case study annual heating costs would be higher by 68.874 and 58.094 €.
GHG emissions would be reduced by 1.489 tCO2 equivalent. If such project would be
implemented almost no GHG emissions would be emitted.
It can be concluded that the use of TES in systems with ST collectors and HOB, as well as PV
panels and HP can potentially produce savings and increase the systems efficiency.
Additionally TES systems reduce the need for peak load boilers thus reducing the GHG
emissions while at the same time allowing the increased operation of the more profitable but
less carbon-intensive technologies such as HP, ST collectors or biomass boilers. Additionally
if refurbishment was subsidized by some kind of refurbishment or green technology
investment fund such projects could have great potential especially for meeting the EU 2050
targets for the reduced GHG emissions and energy efficiencies.
Acknowledgment:
Financial support from the European Union’s Intelligent Energy Europe project STRATEGO(grant agreement EE/13/650), Horizon2020 project CoolHeating (grant agreement 691679)
and the 4DH project funded by the Innovation Fund Denmark are gratefully acknowledged.
REFERENCES[1][2]

Renewables 2015 Global Status Report. 2015.
European Commission. memo on the renewable energy and climate change package.
Brussels European Council 8/9 March 2007 - Presidency Conclusions: n.d.
[3]European Commission. A policy ramework for climate and energy in the period from2020 to 2030. Brussels: n.d.
[4]3XNãHF70DWKLHVHQ%91RYRVHO7'XLü1$VVHVVLQJWKHimpact of energy saving
measures on the future energy demand and related GHG (greenhouse gas) emission
reduction of Croatia. Energy 2014;76:198–209. doi:10.1016/j.energy.2014.06.045.
[5]
Lund H, Werner S, Wiltshire R, Svendsen S, Thorsen JE, Hvelplund F, et al. 4thGeneration
District
Heating(4GDH).
Energy2014;68:1–11.
doi:10.1016/j.energy.2014.02.089.
[6]
Gebremedhin A. Optimal utilisation of heat demand in district heating system—A casestudy. Renew Sustain Energy Rev 2014;30:230–6. doi:10.1016/j.rser.2013.10.009.
[7].UDMDþLü*'XLü1=PLMDUHYLü=0DWKLHVHQ%99XþLQLü$$GD*UDoD&DUYDOKR0
Planning for a 100% independent energy system based on smart energy storage for
integration of renewables and CO2 emissions reduction. Appl Therm Eng
2011;31:2073–83. doi:10.1016/j.applthermaleng.2011.03.014.
[8]Østergaard PA, Andersen AN. Booster heat pumps and central heat pumps in district
heating. Appl Energy 2016. doi:10.1016/j.apenergy.2016.02.144.
[9]
Dotzauer E, Holmström K. Optimal Scheduling of Cogeneration Plants. 16.th Int.
Symp. Math. programing, Lausanne, Switzerland: 1997.
[10] Buoro D, Pinamonti P, Reini M. Optimization of a Distributed Cogeneration System
with
solar
districtheating.
Appl
Energy2014;124:298–308.
doi:10.1016/j.apenergy.2014.02.062.
[11] Christidis A, Koch C, Pottel L, Tsatsaronis G. The contribution of heat storage to the
profitable operation of combined heat and power plants in liberalized electricity
markets. Energy 2012;41:75–82. doi:10.1016/j.energy.2011.06.048.
[12] Jiang XS, Jing ZX, Li YZ, Wu QH, Tang WH. Modelling and operation optimization
593

594

[13]
[14]
[15]
[16]
[17]
[18]
[19]
[20]
[21]

03DYLþHYLü71RYRVHO73XNãHF1'XLü: Annual heat storage optimisation…

of an integrated energy based direct district water-heating system. Energy
2014;64:375–88. doi:10.1016/j.energy.2013.10.067.
The MathWorks Inc. MATLAB Optimization Toolbox Release 2015a n.d.
Achterberg T. SCIP: solving constraint integer programs. Math Program Comput
2009;1:1–41. doi:10.1007/s12532-008-0001-1.
Lund H, Möller B, Mathiesen BV, Dyrelund A. The role of district heating in future
renewableenergysystems.
Energy2010;35:1381–90.
doi:10.1016/j.energy.2009.11.023.
Lund H, Hvelplund F, Kass I, Dukalskis E, Blumberga D. District heating and market
economy in Latvia. Energy 1999;24:549–59. doi:10.1016/S0360-5442(99)00017-1.
The Danish Energy Agency, Energinet.dk. Technology data for energy plants. 2012.
doi:ISBN: 978-87-7844-940-5.
Danish Energy Agency. Technology data for energy plants. 2012. doi:ISBN: 978-877844-940-5.
DECC. Heat Pumps in District Heating: Final report 2016.
Lund R, Project SM, Planning SE. The Potential of Implementing Thermal Energy
Storage in an Energy System with a High Share of Wind Power 2013.
City of Zagreb. Sustainable Energy Action Plan for the City of Zagreb. 2013.

237,0,=$&,-$9(/,ý,1(723/,16.2G SPREMNIKA NA
GODIŠNJOJ RAZINI U PROJEKTIMA URBANE OBNOVE IZPERSPEKTIVE ENERGETSKOG PLANIRANJASažetak: 6YH YHüD SULVXWQRVW SURMHNDWD XUEDQH REQRYH NRML UHRUJDQL]LUDMX L XQDSUMHÿXMXSRVWRMHüDXUEDQDLELYãDLQGXVWULMVNDSRGUXþMDQDVHOMDLOLþDNFLMHOHJUDGVNHþHWYUWLXVNRVXSRYH]DQLVXSRUDERPREQRYOMLYLKL]YRUDHQHUJLMH0HÿXSRYH]DQRVWUD]OLþLWLKQRVLRFDHQHUJLMH
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VXVWDYH 7RSOLQVNL VX VSUHPQLFL X YHüLQL VOXþDMHYD ekonomski prihvatljivo rješenje za
SRYHüDQMH IOHNVLELOQRVWL L XþLQNRYLWRVWL QLVNR XJOMLþQLK VXVWDYD SUXåDMXüL WHKQRORãNH
HNRQRPVNH L HNRORãNH SUHGQRVWL 3RYHüDQD IOHNVLELOQRVW VXVWDYD SUXåD YHüX PRJXüQRVWXSRUDEHREQRYOMLYLKL]YRUDHQHUJLMHþLMDSULPMHQD smanjuje udio potrošnje fosilnih goriva, a
VDPLP WLPH L HPLVLMH VWDNOHQLþNLK SOLQRYD 7HKQRORJLMH ]D SUHWYRUEX HOHNWULþQH X WRSOLQVNXHQHUJLMX SRSXW GL]DOLFD WRSOLQH L HOHNWULþQLK JULMDþD RPRJXüDYDMX LQWHJUDFLMX WRSOLQVNLK L
HOHNWULþQLK VXVWDYD 7LPH VH SRYHüDYD IOHNVLELOQRVW HOHNWURHQHUJHWVNRJ VXVWDYD L QMHJRYkapacitet za iskorištavanje obnovljivih izvora energije poput sunca i vjetra. Cilj ovoga rada je
razvoj modela koji optimira kapacitet spremnika topline u sklopu malog centraliziranog
toplinskog sXVWDYD SRJRQMHQRJ VXQþHYRP HQHUJLMRP NDR L QMHJRY UDG QD VDWQRM UD]LQL X
YUHPHQX RG MHGQH JRGLQH 7DNDY SULVWXS RPRJXüXMH PRGHOX L]ERU L]PHÿX NUDWNRURþQRJ L
sezonskog spremnika topline koji uzima u obzir satne i sezonske varijacije u radu sustava.
Model jH LVSLWDQ L SRWYUÿHQ QD SULPMHUX PDOH JUDGVNH þHWYUWL 7UQVNR VPMHãWHQH X MXåQRPdijelu Zagreba.
.OMXþQH ULMHþL 8UEDQD REQRYD &HQWUDOL]LUDQL WRSOLQVNL VXVWDY SRJRQMHQ VXQþHYRP
energijom, Toplinski spremnik, Optimizacija, Energetsko planiranje

Energy and the Environment (2016) 595-604

595

ENERGETIC REHABILITATION OF A PROTECTED HISTORICALBUILDING IN RIJEKA – CROATIA'LHJR.R]ORYLü, mag.ing.arch.
Umag, HRkozlovicdiego@gmail.com
Abstract: Nowadays, the industrial process has changed a lot in comparison to the past
century and the production is maximally automated and robotized. This leads to different
needs in the configuration and planning of the industrial structures where the production ishosted. This work comes out from actual considerations about the global problem of thepreservation of post-industrial architectural heritage and the object will be the energetic
rehabilitation of a former industrial building, the so called industrial archeology with the aim
to give a technical solution for improving the thermal characteristics of a building in Rijeka.
The work analyzes and studies a template project based on a case study building which would
help in defining the key points that need to be studied in a rehabilitation project of a protectedbuilding. There are a lot of industrial buildings in Rijeka from the same period with similar
construction technology which could be similarly treated when preparing an energetic
rehabilitation project. So the objective of this thesis is to choose and study a building whose
strategies could be generalized to other industrial heritage buildings, to make a list of actions
and considerations that need to be done in each different project and point out the potentials
that the buildings have in common. The applied methodology is the division in steps of theprocedure. An important part of the work will be dedicated to the climate of the city. All thedata will be necessary for calculating the climographs which will be essential for the
rehabilitation project. It will be possible to distinguish the passive design strategies necessary
to achieve a high level of comfort in the building and to lower the necessity of energy
consumption.
Keywords: Rehabilitation, Energy, Climate, Industrial archeology, Retrofit

1. INTRODUCTION
Historically, the first production was agriculture and it’s so called „industry“ was connectedto the production of food only. All the production was handmade and handicraft was the only
production process. In the Middle Ages handicraft experienced its evolution, leading to the
manufacturing. The production was still handmade but it was an association of craftsmen
working in cooperation. The Industrial Revolution was the transition to new manufacturing
processes in the period from about 1760 to sometime between 1820 and 1840. This transition
included going from hand production methods to machines, new chemical manufacturing andiron production processes, improved efficiency of water power, the increasing use of steam
power, the development of machine tools and the rise of the factory system. The Second
Industrial Age was led by new inventions for the improvement of the production process ofsteel, by the use of electricity which started to replace steam energy and by the invention of
concrete. All this changes and inventions permitted the development of complex industrial
structures. One of the biggest changes was the start of mass production with the use of

596'.R]ORYLü: Energetic Rehabilitation of a Protected Historical Building…

conveyor belts which was firstly applied in the automobile industry by Henry Ford in the
beginning of the 20th century. The Third Industrial Revolution began with the introduction ofrobotics and automated systems which allows to reduce the necessity of high qualified
manpower and which allows to speed up the productions.
Currently, major industries are located in developing countries around the world, where prices
are lower and manpower is cheaper. This leads us to a Post-industrial era, beginning in thelast decades of the 20th century when a lot of industrial plants are being shut down.
Industrial archeology becomes the subject of conflict of interest of speculative capitalism andculture and two possibilities show up: reindustrialization and revaluation.
This work analyzes and studies a template project based on a case study building which
would help define the key points that need to be studied in a rehabilitation project of aprotected building. There are a lot of industrial buildings in Rijeka from the same period withsimilar construction technology which could be similarly treated when preparing an energetic
rehabilitation project. So the objective of this thesis is to choose and study a building whose
strategies could be generalized to other industrial heritage buildings, to make a list of actions
and considerations that need to be done in each different project and point out the potentials
that the buildings have in common.
The applied methodology is the division in steps of the procedure. The work begins with thehistorical analysis of the evolution of the entire industrial complex during the years, proving
its connection and relation with the expansion of the city. In the thesis only one building will
be analyzed, but the procedure can be generalized to the entire complex. An important part of
the work will be dedicated to the climate of the city, with the analysis of the minimum andmaximum temperatures, humidity, rainfall, wind, sun incidence. All this data will benecessary for calculating the climographs which will be essential for the rehabilitation project.
It will be possible to distinguish the passive design strategies necessary to achieve a high levelof comfort in the building and to lower the necessity of energy consumption.

2.

CLIMATE ANALYSIS

Rijeka has a humid subtropical climate (Köppen climate classification Cfa or Cwa) with warm
summers and relatively mild and rainy winters. Snow is rare (usually 3 days per year, almost
always occurring in patches). There are 22 days a year with a maximum of 30 °C or higher,
while on one day a year the temperature does not exceed 0 °C. Fog appears in about 4 days
per year, mainly in winter. The climate is also characterized by frequent rainfall. Cold winds(bura) are common in wintertime.

Energy and the Environment (2016) 595-604

597

Figure 1: climatological data of the city of Rijeka
source: http://worldweather.wmo.int/en/city.html?cityId=72
The climate data analysis from the above chart and other charts regarding annual solar

radiation, relative humidity, predominant winds provide the following conclusions for the cityof Rijeka: In the winter months the minimum temperature values registered on the site showthat attention is to be paid to heat loss and heating of the building. Similarly, in summer,
although the mean values appear to be mild, attention has to be paid to cooling andmaintaining the temperature values for the internal comfort. For these aspects it is essential to
avoid overheating in summer, using sun shading on the exposed windows, while in winter it
would be essential to benefit from free contributions, the internal loads and passive solar
radiation. The total annual irradiation suggests a high potential for passive and active solar
energy usage while the wind direction analysis indicates the presence of winds that can beused in the natural north-south building ventilation.
3.

CLIMOGRAPHSIn this chapter the focus was on the analysis of the climate data extracted in the previous
chapter and with the use of software Climate Consultant and CBA by professor Javier Neila(Faculty of Architecture at Technical University of Madrid) it was possible to determine thenecessary passive and active systems that are needed to maintain the requested comfort levelsin the interior of the building. This software associate the climate data with psychrometriccharts and specify the necessary strategies to be applied each month

598'.R]ORYLü: Energetic Rehabilitation of a Protected Historical Building…

Figure 2: Climate Consultant 6.0 software screenshot
By analyzing the diagram it is clear that only a part of the months of the year reach the
comfort zone. The psychrometric chart associated with the Givoni diagram allows to study thebest design strategies that need to be used along the year, depending on its humidity andtemperature. In the case of a building in Rijeka, the comfort zone is reached, without the useof any passive or active strategy in the 18,2% of the time meanwhile during the rest of thetime the following strategies are the ones with most influence: heating and humidification(33,2% of the year), internal heat gains (31,0%), passive solar direct gain with high thermal
mass (13,6%), sun shading of windows (9,7%), fan forced ventilation cooling (7,4%) andtwo-stage evaporative cooling (7,0%).
4.

BUILDING ANALYSISThe chosen building for this thesis was the so called T-building in the RLNDUG%HQþLüIRUPHU
industrial complex. So far, the carried out tests confirmed that the structure presents
deformation due to terrain sagging. The external structures of the buildings with I and II
category of protection indicate insufficient thermal insulation, the lack of waterproofing andwall plaster deterioration due to capillary rising water. The exterior walls are mainly built ofstone or in combination with bricks, and the load-bearing structure of the ceilings is made ofwooden beams.
According to the geotechnical characteristics of the site, the existing buildings are based onshallow strip foundations and footings, at a level 1,00-1,50m below the ground surface whichis still above the groundwater level. In the case of multiple floors, foundation structures are ata slightly lower elevation, closer to the level of groundwater, but the exact depth of thebottom of the foundation is generally unknown suggesting the possibility of foundations ontimber piles.
Unfortunately, the original archive documents of the T-building were not found. However, it
is known that the ground floor staircase was refurbished already in 1897. The building isconstructed with rough-hewn and quarry stone massive walls. The original wooden floor slab

Energy and the Environment (2016) 595-604599

was supported by two rows of cast iron pillars while the ground floor is supported by brickgroin vaults supported by stone pillars and the roofs are made of a wooden construction. The
building lies on a clay mixed with stone terrain. The facades of the building are decorated
with architectural elements in the spirit of historicism. In the mid-XX. century, when the
5LNDUG%HQþLüHQJLQHIDFWRU\UHSODFHGWKHWREDFFRIDFWRU\LWZDVIRXQGWKDWGXHWRKLJKRZQ
weight, machinery overload and because of poor foundations the structural walls and cast ironcolumns tilted, distorting parts of the building. The implementation project began in 1949 –the cast iron columns were corrected, the vaulting of the ground floor was reinforced andconnected with steel ties, and the original wooden ceilings of the ground floor and the firstfloor were removed and replaced with new prefabricated reinforced concrete structure while
the original wooden ceiling of the second floor has been reinforced with a reinforced concreteslab.
One of the most important analysis carried out about the building is the analysis of materials
and constructive elements composing the thermal envelope. All the wall types, glazing, roofs,
floors were analyzed in order to calculate their thermal performance and define theirimprovement possibility. The analysis permitted to quantify the thermal transmittance of thestate of art and conclude that the main intervention in the energy retrofit of a building of suchcharacteristics is the focus on its thermal envelope to control the thermal gains and losses
through the outer skin of the building.
5.

ANALYSIS CONCLUSION

After the analysis carried on in the first part of this thesis, all the conclusions and results
obtained will be used to propose an energetic rehabilitation project for the T-building,considering all the deterioration of the constructive elements and the potential of thegeometrical characteristics of the building for the maximal usage of passive systems.
From the climatological analysis of the city of Rijeka it is visible that the building is situatedin a rainy city with a monthly average of 128 mm and 10,75 rainy days. The relative humidity
during the year has a slight variation between 56-67% and the average temperatures vary
between 5-23 degrees Celsius. It is possible to conclude that the climate is mild and rainy
mostly during autumn and winter. Rain water could be accumulated and reused on site; theamount of solar radiation gives the possibility to be used for natural illumination, to produce
electricity with photovoltaic panels, heating; wind should be used for natural ventilation bycooling the interior during the night in hot months (June-September), but also for daily naturalventilation supported by mechanical systems with heat exchanger. The basic climate data isuseful to define the natural solutions for heating and cooling the building, limiting or avoiding
the necessity of active systems.
The analysis of the comfort climographs and isopleth graph state the required and mostefficient design strategies to reach the comfort zone for the different periods of the year:
heating and humidification; internal heat gains; passive solar direct gain by elements withhigh thermal mass; sun-shading to avoid overheating in summer; ventilation cooling; heat loss
should be avoided with a good thermal insulation of the walls. The regulations do not allow tointervene on the facade so the thermal insulation will have to be on the interior side of thewalls; facades with direct solar radiation should accumulate solar energy in the morning, butshould offset the entry of the thermal wave to the evening, avoiding the overheating in thepeak hours during summer. For each facade the thermal inertia required to slow down theentry of the heat wave is different. The aim is to accumulate thermal energy during the day
and to release it during the night, when the interior temperatures drop down; the northern

600'.R]ORYLü: Energetic Rehabilitation of a Protected Historical Building…

facade requires very good thermal isolation to avoid loss of energy; the windows on thesouthern facade should be adequately sun-protected to block the entry of excessive heat
during the peak hours in summer, but to guarantee the entry of the heat wave during winterand months with a lack of insolation. The above mentioned considerations and strategies
allow to study technical solutions for thermal isolation of the building envelope, the shading
system and the choice of materials depending on their thermal characteristics and the choiceof passive and active heating and cooling systems in order to obtain a building with low
energy consumptions.
The solar and shading analysis helps to understand the correlation of the building with its
environment and the results of the shadow range simulation show that the influence of the
shadows of the surrounding buildings is insignificant because the cast shadows affect the Tbuilding only for irrelevant periods of the day (early morning and late afternoon/evening).
Due to the geometrical structure of the building there are parts of the southern facade close to
the center that receive a different amount of solar radiation depending on the part of the day,limited by the cast shadow of the volumes in front of the facade. This windows in the central
part of the building will be in shadow during a few hours during the day.
From the irradiance analysis it is clearly evident that there will be a need of increasing thelevels of natural illumination reaching the interior of the building or an additional need ofartificial illumination to provide the required levels of illumination in the working spaces.
The internal distribution of the spaces and functions will be organized paying attention to thepassive systems applied to the building and to the needs and requirements of each function
regarding levels of illumination, area, vicinity to other areas, etc.
To sum up, the category of interventions to the existing building are the following:
improvement of the thermal envelope of the building, solar protection of the glazing,illumination improvement with passive systems, natural and forced ventilation systems, usageof solar energy, active and passive heating and cooling systems.

6.

RETROFIT PROJECT AND BIOCLIMATIC STRATEGIESIn order of importance, the intervention on the building envelope (walls, roofing, windows) isof primary interest. The adequate thermal insulation of the envelope is the first step in the
reduction of energy consumptions of the building, limiting the heat loss during the cold
months and lowering the heat entry during summer, especially by changing the glazing to one
with better thermal characteristics. So the first step is to study how to make a good thermalenvelope and after that all the other systems of passive energy production will be considered.
The priority of the project is to guarantee high thermal performance of the envelope and thenincorporate passive and active systems. Each part of the thermal envelope was studied
separately and an improvement solution for the thermal transmittance was given to each. Theintervention to the exterior walls consist of a new thermo insulating plaster applied to give tothe building its original look, providing at the same time a better thermal performance. A lime
and cement plaster with expanded polystyrene particles is used, with 20 mm total thickness
DQG WKHUPDO FRQGXFWLYLW\ Ȝ  :P. 7KLV Lntervention to the facade will preserve andrestore the initial historical look of the exterior of the building while the interior part of theenvelope is the one that can be altered and where the major intervention in terms of thermal
insulation is carried on. The first step is the removal of the existing lime plaster, withcomplete cleanup of the walls. A cement-based leveling compound is needed to obtain acompletely plain surface out of the rough surface of the limestone wall with variable thickness
up to 10 mm. One of the best solutions in terms of thermal insulation with the lowest

Energy and the Environment (2016) 595-604

601

conductivity and the lowest thickness of the used panels is based on vacuum panels withmaximum thickness 50 mm (reference Vaku-,VRWKHUP Ȝ  :P.  7KH SDQHOV DUHproduced with a compressed mineral powder (micro porous silicic acid) in an aluminium
vacuumed casing while the bonding of the panels to the wall assumes the usage ofpolyurethanic glues. There is no need to apply a vapor barrier over the panels. A 10 mm
gypsum plasterboard is bonded to the insulation panels and a plastering finish is applied tohomogenize the surface before the final color is applied.
The intervention to the windows needs to provide a better thermal transmittance, but also
provide illumination improvement of the interior with the usage of light shelves which at thesame act as sun protection elements during the peak hours of the summer days. The biggest
effectiveness of the shelves is when the solar altitude is lower, below the minimal angle ofprotection of the sun shadings, so that the incident radiation has a small angle and reflects
deeply to the interior of the building. A second illumination improvement is the usage of solar
tubes which have the possibility to illuminate the interior of the building by reflecting solar
light from the roof along reflecting tubes located in the building.
A highly energetically efficient building, with high levels of thermal insulation andminimization of thermal bridges all over the envelope can integrate the heating and coolingsystem with the ventilation system, meaning that the necessity of ventilating the indoor spaces
meets the requirements of heating and cooling the building respectively in winter andsummer, maintaining the required indoor air quality, but at the same time adjusting thetemperature and humidity levels. This integrated all-air system minimizes the necessity ofadditional installations which reduces the area occupied by the technical equipment for eachcooling or heating.
An important part of this work is also the usage of solar energy in terms of production ofelectricity and water heating. The characteristics of the building volume offer a large
possibility of solar energy usage for the production of electric energy and hot water. Due tothe large surface area of the roof with a favorable south orientation and 30 degree inclination
it would be possible to integrate the solar collectors and solar panels into the roofing,
lowering their impact in the overall aspect of the building.
During the winter period the most important aspect to carry about is to maximize thecontribution of solar gains through the windows. Even though the south façade is protected bysun shading elements, their geometry was studied to allow the entry of the solar rays during
the months when solar gain is appreciated. The interior thermal insulation layer allows themaintenance of heat while on the other hand nullifies the contribution of the thermal inertia ofthe limestone masonry. For that purpose the paving is made of materials capable of storing
thermal energy during the day and which releases it during the night, in order to maintain aconstant interior comfort.
In summer the main objective is to protect the building from overheating by preventing theentry of solar energy during the majority of the day. It is made by the sun shading elements on
the windows of the southern façade whose geometry protects the interior from the excessive
solar radiation, allowing lowering the consumptions needed for maintaining the interior
comfort. During the night it is possible to naturally ventilate the interior with night windbreezes, extracting the possible excessive heat accumulated during the day.
7.

CONCLUSION

The idea was to study a specific building that would permit to apply the used improvement
techniques to other buildings. In this sense the building was used as an example and so the602'.R]ORYLü: Energetic Rehabilitation of a Protected Historical Building…

interior spatial distribution and design were not carried on in this thesis because secondary in
the evolution of the project. After all the initial analysis about the building, from the historicalevolution of the surrounding area and the building itself which help to understand its methodsof operation and the usage of spaces, to the analysis of construction materials and techniques
used in the building it is possible to get an overall image of the building as a whole. By
accompanying these analyses to the study of the key points of technical regulations anddevelopment plans of the site and by the climatic analysis of the city it is possible toacknowledge the environment of the building which provides all the information needed todevelop a project. Up to here there are sufficient information about the building and its
surroundings and weather conditions of the city so the next step is the analysis of the results
given by the study of climographs and isopleth diagrams. These provide the exact thermal
behavior of the building and it is easy to recognize which are the main passive and active
bioclimatic strategies that need to be applied to the building during the different parts of theyear. This data is accompanied by the study of exterior and interior illumination of thebuilding and cast shadows from the surroundings. All the information achieved to this point
permits to have a list of strategies, limitations, priorities and regulations that canalize to theaction plan. The first focus was on the adequate treatment of the buildings envelope providing
excellent thermal transmittance results of all the constituting elements. Once the envelope isstudied, with its technical characteristics and law limitations, an improved solution isdeveloped in order to provide the building with a new thermo-insulating skin. The exterior
façade is reconstructed to reflect its original look while the interior of the bearing walls iscovered with a thin, highly performing skin which permits to obtain an insulated interior
space whose comfort is reached with the lowest possible energy consumption. The first goalof heat loss reduction is achieved and the next step is to improve the thermal behavior of thebuilding by studying adequate solar protections to avoid summer overheating through theglazing. Another important element that needs to be considered is the way the building will
maintain its interior comfort so heating, cooling and ventilation need to be studied. This also
relates to a basic study of the European standards and regulations, along with predimensioning the interior spaces in sense of an estimation of possible usage of the building
and number of users.
After having a highly performing building it is time to study the location possibilities that thebuilding offers in terms of usage of renewable energies. In this case, due to the favorable
orientation of the building it was easy to conclude that the Sun is the most important source ofenergy for the building for the production of electricity and hot water. In other contexts whereother sources would be easier to take advantage of, it would be possible to consider wind,geothermal or other sources of energy as a free resource.
In conclusion, it is possible to affirm that this thesis served to prove that it is possible to makerehabilitation interventions on protected buildings and achieve excellent results. The obtained
U-values for the elements of the building envelope are 7 to 13 times better than the starting
values and this results can be extended to buildings with the same conservation category thathave comparable characteristics.

Energy and the Environment (2016) 595-604

8.

603

BIBLIOGRAPHY AND SOFTWAREBENDALA ÁLVAREZ, F.: ¿Qué pasa aquí? Manual práctico para la investigación ydiagnóstico de las lesiones de la edificación, La Ley Actualidad, Madrid, 2012*/$92ý,û '.: 5LMHþND LQGXVWULMVND DUKLWHNWXUD ELYãH âHüHUDQH L 'XKDQMHUH, Zbornik 1.
0HÿXQDURGQH NRQIHUHQFLMH X SRYRGX  2EOMHWQLFH WYRUQLFH 7RUSHGD X 5LMHFL L RþXYDQMDULMHþNHLQGXVWULMVNHEDãWLQH5LMHND
LÓPEZ JIMENO, C.: Guía del Estándar Passivhaus. Fenercomcomunidad de Madrid,
Madrid, 2011
MAGAŠ, O.: .DNRQDVWDYLWLNRQWLQXLWHWSUYHãHüHUDQHX$XVWUR-ugarskoj monarhiji, Zbornik*UDÿHYLQVNRJIDNXOWHWD6YHXþLOLãWDX5LMHFLNQMLJD;5LMHNDMAGAŠ, O.: Industrijska arhitektura, Arhitektura historicizma u Rijeci, Rijeka, 2001.
MAJER, K., PUHMAJER P.:, 3DODþDâHüHUDQHX5LMHFL, Grad Rijeka, 2008.
0$7(-ý,û5.: .DNRþLWDWLJUDG, ICR, Rijeka, 1990.
MONJO Carrió, J.:. Tratado de rehabilitación (5 Tomos). Editorial Munilla-Lería, Madrid,
1999
NEILA GONZÁLEZ, J.: Arquitectura bioclimática en un entorno sostenible, Madrid, 2004.
Calumen II, Climate Consultant 6.0, Ecotect Analysis 2011, Excel based software, Radiance604'.R]ORYLü: Energetic Rehabilitation of a Protected Historical Building…

(1(5*(76.$2%129$=$â7,û(1(329,-(61(=*5$'(8
RIJECISažetak8GDQDãQMHYULMHPHMHXLQGXVWULMVNRPSURFHVXGRãORGRYHüLQVNHDXWRPDWL]DFLMHLURERWL]DFLMHãWRGRYRGLGRGUXNþLMLKSRWUHEDXVPLVOXNRQILJXUDFLMHLSODQLUDQMDLQGXVWULMVNLK
proizvodnih objekata. Ovaj rad nastaje od razmatranja globalnog probOHPDRþXYDQMDSRVWindustrijske arhitektonske baštine te je fokusiran na energetsku obnovu jedne takve zgrade u
5LMHFLW]YLQGXVWULMVNHDUKHRORJLMHVDFLOMHPGRELYDQMDWHKQLþNRJUMHãHQMDSREROMãDQMD
svojstava zgrade. Rad kroz analizu konkretnog objekta ima cilj postavljanja smjernica koje bi
se trebale provoditi u projektima energetske obnovH]DREMHNWHVOLþQLKNDUDNWHULVWLNDLPMHUD
zaštite. 85LMHFLVHQDOD]LYHOLNDNROLþLQDLQGXVWULMVNLK]JUDGDL]LVWRJSHULRGDVDVOLþQLP
NRQVWUXNFLMVNLPNDUDNWHULVWLNDPDXVOLþQRPVWDQMXRþXYDQMDWHELVWRJDELORPRJXüHDSOLFLUDWLQDXþHQRLQDRVWDWDNULMHþNHLQGXVWULMVNHDUKHRORJLMH.RULãWHQDPHWRGRORJLMDMH
SRGMHODSURFHGXUHXNRUDNH9DåQXXORJXLPDDQDOL]DNOLPHJUDGDSRPRüXNRMHMHPRJXüHL]YXüLSRWUHEQHSDVLYQHLDNWLYQHVLVWHPHNRMLVHWUHEDMXNRULVWLWLXHQHUJHWVNRMREQRYL zgrada,
kako bi se dostigao optimalan nivo komforta unutar zgrade i kako bi se smanjila potrošnja
energije.
.OMXþQHULMHþL: Obnova, Energija, Klima, Industrijska arheologija

Energy and the Environment (2016) 605-614

605

SIMULACIJA PROCESA U KOMORI IZGARANJA PLINSKETURBINE
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Energy and the Environment (2016) 605-614

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0.035 mm do 7mm.

Slika 1. Dimenzije komore izgaranja i SolidWorks model
Na ulazu, sa lijeve strane geometrije, korišteni su rubni uvjeti tipa “Velocity Inlet”, i to
odvojeno, središnji dio za gorivo, a okolni za zrak- Sa desne strane, na izlazu korišten je rubni
XYMHW³3UHVVXUH2LWOHW´6YHRVWDOHSORKHVXGHILQLUDQHNDRþYUVWDVWLMHQND. Trajanje simulacija
se je kretalo, zavisno o postavkama,u rasponu od 45 minuta do 2 sata. Pritom je korišteno
UDþXQDOR sa procesorom Intel i7sa radnim taktom 2666 MHz te sa 32GB RAM memorije.

6OLND3URUDþXQVNDPUHåDNRPRUHL]JDUDQMD
Izvedene su dvije serije simulacija. U prvoj seriji je analiziran utjecaj ulazne brzine na padtlaka. Ulazna brzina varirana je u rasponu od 20 do 50 m/s. Promatran je u prvom redu pad608

76HQþLü5/MXEHN6LPXODFLMDSURFHVDXNRPRULL]JDUDQMDSOLQVNHWXUELQH

tlaka, ali i raspodijela temperatura i obrazci brzina unutar komore. U drugoj seriji simulacija
MHXOD]QDEU]LQDGUåDQDILNVQRP PV DSRYHüDYDODVHMHXOD]QDEU]LQDJRULYDSDWDNRLNROLþLQDGRYHGHQRJJRULYDLVDPLPWLPHXNXSQLSUHWLþDN]UDNDNDRãWRMHSULND]DQRXWDEOLFL
1. Promatrana je raspodijela temperatura, kaR SRND]DWHOM PMHVWD JGMH GROD]L GR RVOREDÿDQMD
topline odnosno gdje se odvijaju reakcije izgaranja.
7DEOLFD6LPXOLUDQLVOXþDMHYL
6OXþDM Ul. brzina goriva (m/s).ROLþLQDJRULYD NJV 

3UHWLþDN]UDNDO

1

50,00108

11.9

2

10

0,00217

5.94

3

15

0,00326

3.95

4

20

0,0043

2.99

4. REZULTATI
2.1. Pad tlaka i turbulencije.RPRUDL]JDUDQMDPRåHLPDWLREOLNFLMHYLLOLNRQFHQWULþQLKSUVWHQRYD8VYDNRPVOXþDMXIOXLGYHOLNRP EU]LQRP VWUXML NUR] QMX RG XOD]D ND L]ODVNX SUL þHPX VH PDQLIHVWLUDMX JXELFL ]ERJ
viskR]QRVWLIOXLGDWH]ERJQDVWDQNDWXUEXOHQFLMD2GUHÿHQDUD]LQDWXUEROHQFLMDMHþDNSRåHOMQD
MHU SRVSMHãXMH PMHãDQMH JRULYD L ]UDND 0HÿXWLP QHL]EMHåDQ UH]XOWDW YLVNR]QRJ VWUXMDQMD MH
SDGWODNDNRMLSUHGVWDYOMDJXELWNHVXVWDYDLQHVPLMHSUHNRUDþLWLRGUHÿHQX granicu. Prva serija
VLPXODFLMDMHL]YHGHQDXVYUKXDQDOL]HSURWRþQRVWLNRPRUHL]JDUDQMD8WXVYUKXMHPLMHQMDQD
ulazna brzina zraka i goriva u rasponu od 20 do 50 m/s te je promatran pad tlaka. Na izlazu
komore je korišten Pressure Outlet rubni uvjet te je pretpostavljen tlak od 1215900 Pa. Za
promatrane ulazne brzine dobiven je tlak na ulazu od 1231600 Pa do 1314638 Pa. Pad tlaka
NUR]NRPRUXLVSDGDXUDVSRQXRGGR3DãWRþLQLGRNDRãWRMHYLGOMLYRQDVOLFL7RMHXVNODGXVDRþekivanjima, prema [10].

Slika 3. Pad tlaka zavisan o ulaznoj brzini

Energy and the Environment (2016) 605-614

609

Slika 4. Strujnice u komori izgaranja
2VLPRJUDQLþHQRJSDGDWODNDWXUEROHQWQRVWVWUXMDQMDMHMRãMHGDQYDåDQSUHGXYLMHWHILNDVQRJ
rada komore izgaranja. Kako bi se postigla dovoljna turbolentnost strujanja i time efikasnoPLMHãDQMH JRULYD L ]UDND X PRGHO NRPRUH UD]PDWUDQ X RYRP þODQNX QD XOD]QRP GLMHOX MHXJUDÿHQ NRQXV L YUWORåQLN HQJ VZLUOHU  NDNR EL VH GRELOR DGHNYDWQR VWUXMDQMH SULPDUQRJ
zraka. 1DVOLFLPRJXüHMHYLGMHWLREULVHORSDWLFDYUWORåQLNDLNRQXVD3ULND]DQHVXVWUXMQLFHIOXLGD 0RåH VH ]DNOMXþLWL NDNR SUHPD VLPXODFLML YUWORåQLN L NRQXV HILNDVQR REDYOMDMX VYRM
]DGDWDNMHULQGXFLUDMXYUWORåQRVWUXMDQMHXSRGUXþMXLVSUHGXOD]DJRULYDRGnosno primarnom
SRGUXþMXNRPRUHL]JDUDQMD3UHWLþDN]UDND
2VQRYQD]DGDüDNRPRUHL]JDUDQMDMHGDVHXQMRMRGYLMDL]JDUDQMHJRULYD1DVWRMLVHGDQMHQD
L]YHGEDEXGHNRPSDNWQDQDURþLWR]DRGUHÿHQHSULPMHQH6WRJDWUHEDXWYUGLWLNROLNRVHJRULYDmožHGRYHVWLXNRPRUXDGDSULWRPQHGRÿHGRQHSRWSXQRJL]JDUDQMDWHGDIURQWDSODPHQDVDHNVWUHPQR YLVRNLP WHPSHUDWXUDPD QH SURÿH VD GLPQLP SOLQRYLPD NUR] L]OD] SUHPDORSDWLFDPD WXUELQH 8 RYRP GLMHOX UDGD MH SURYHGHQD VHULMD VLPXODFLMD SUL þHPX se protok]UDND XOD]QD EU]LQD  GUåL NRQVWDQWQLP D SRVWHSHQR VH SRYHüDYD GRYHGHQD NROLþLQD JRULYD
2YDSURPMHQDUH]XOWLUDSURPMHQRPSUHWLþND]UDNDLWRXUDVSRQXRGGR
1DVOLFLSULND]DQMHSRSUHþQLSUHVMHNNRPRUHL]JDUDQMDVDSRGUXþMLPDWHPSerature, izraženeXVWUXSQMHYLPD.=DVYHVOXþDMHYHMHSRVWDYOMHQDXOD]QDEU]LQD]UDNDPV1DYUKXMH
SULND]DQVOXþDM]DXEUL]JDQXQDMPDQMXNROLþLQXJRULYDNRMDUH]XOWLUDSUHWLþNRP]UDNDRG
6WODþHQL ]UDN VH ]DJULMH QD RNR  . QD WRM UD]LQL VH QDOD]L VDY ]UDN L]PHÿX YDQMVNH L
XQXWDUQMH VWLMHQNH WH QD VDPRP XOD]X X NRPRUX 0RåHPR XRþLWL NDNR VH PLMHãDQMH ]UDND L
JRULYD EU]R RGYLMD QHSRVUHGQR QDNRQ XODVND JRULYD X NRPRUX X W]Y SULPDUQRP SRGUXþMX
2YGMHLPDPRSRGUXþMHYLVRNHWHPSHUDWXUHVDPDNVLPXPRPRNR.2YLYUXüLSURGXNWL
izgaranja se vrlo brzo izmiješaju sa hladnijim (400 K) sekundarnim zrakom koji ulazi kroz
RWYRUH ]D KODÿHQMH 7DNR WHPSHUDWXUD GLPQLK SOLQRYD NRML VH NUHüX SUHPD L]OD]X L] NRPRUH
brzo pada na 1200 K, pa na 900 K i prLMHL]OD]DYHüQD.,VWRWDNRPRåHPRYLGMHWLGD
VWLMHQNHQLVXQDURþLWRWHUPLþNLRSWHUHüHQHMHUMHXVORMXX]QMLKWHPSHUDWXUD]QDWQRQLåDQHJRXVUHGLQL 7R VH SRVWLåH SUDYLOQLP UDVSRUHGRP RWYRUD ]D KODÿHQMH NUR] NRMH XOD]L KODGQLML
sekundarni zrak.

610

76HQþLü5/MXEHN6LPXODFLMDSURFHVDXNRPRULL]JDUDQMDSOLQVNHWXUELQH

OGPDK LVSRG QD VOLFL  VOLMHGL VOXþDM VD SUHWLþNRP ]UDND RG  GDNOH XEUL]JDYD VH YLãH
JRULYD 3ULPMHüXMX VH VOLþQH SRMDYH L VOLþQD PDNVLPDOQD WHPSHUDWXUD RVLP ãWR MH MH]JUDplamena više odmaknuta od sapnice goriva, odnosno prema izlazu. Razlog tome je što je
SRWUHEQRYLãHYUHPHQDGDVHJRULYRL]PLMHãDVD]UDNRP6ORMX]VWLMHQNHMHLXRYRPVOXþDMX
GRYROMQR KODGDQ GD QH XJURåDYD PHKDQLþND VYRMVWYD VWLMHQNH 3ULPMHüXMH VH ]QDWQR YLãD
tempreratura na izlaznom presjeku dje imamo 1200 K.
8VOMHGHüHPVOXþDMXVDSUHWLþNRP]UDNDMH]JUDSODPHQDMHSRPDNQXWDMRãPDORSUHPD
izlazu, i postiže se nešto niža maksimalna temperatura. Objašnjenje ovoj pojavi nalazimo uþLQMHQLFL GD VH RYROXND NROLþLQD JRULYD QH VWLJQH HILNDVQR L]PLMHãDWL L ]DSDOLWL X NUDWNRP
vremenu koliko boravi u komori te se glavnina procesa izgaranja i razvijanje maksimalnih
WHPSHUDWXUDRGYLMDYDQNRPRUHL]JDUDQMD,VWRWDNRSULPMHüXMHPR]QDWQRYLãXWHHPSHUDWXUX1800 K, na samoj stijenci prije izlaznog presjeka.
2YH SRMDYH VX MRã RþLWLMH NRG VOXþDMD VD SUHWLþNRP ]UDND  -H]JUD SODPHQD VD
WHPSHUDWXURPRG.MHMRãEOLåHL]OD]XDOLWXRþLJOHGQRQHVWLJQHL]JRUMHWLVYRJRULYRMHU
QD L]OD]QRP SUHVMHNX X] VWLMHQNX LPDPR SRGUXþMH VD WHPSHUDWXURP GR  . ãWR MH
SRVOMHGLFD þLQMHQLFH GD VH ovdje nastavlja proces izgaranja. Ovo bi uzrokovalo prevelika
temperaturna naprezanja na lopaticama turbine.

Energy and the Environment (2016) 605-614

611

6OLND5DVSRGLMHODWHPSHUDWXUDX]DYLVQRVWLRSUHWLþNX]UDND
2.3. EmisijeâWRVHWLþHHPLVLMDãWHWQLKSOLQRYDDQDOL]LUDQLVXGXãLNRYLRNVLGL=DQMLKRYXWYRUEXQDMþHãüH
VH NRULVWL W]Y SURãLUHQL =HOGRYLüHY PRGHO 2VQRYQL SUHGXYMHW ]D QMLKRYX WYRUEX VX
WHPSHUDWXUHNRMHSUHPDãXMX.2VLPWRJD]QDþDMQDMHNRQFHQWUDFLMDNLVLNDLGXãLNDDOLXQDãHP VOXþDMX ]ERJ YHOLNRJ SUHWLþND ]UDND LPD ih u izobilju iz okolnog zraka. Nadalje, za
QMLKRYXWYRUEXMH]QDþDMQRYULMHPH]DGUåDYDQMDUHDNWDQDWDXSRGUXþMXYLVRNHWHPSHUDWXUH2G
VYLKSURYHGHQLKVLPXODFLMDGR]QDþDMQHWYRUEHGXãLNRYLKRNVLGDGRãORMHVDPRXVOXþDMXNRG
kojeg se pojavljuju najviše WHPSHUDWXUH QD L]OD]QRP SUHVMHNX RGQRVQR RQH VD SUHWLþNRP]UDND  1D VOLFL  PRåH VH YLGMHWL NDNR VH EDã X L]OD]QRP SRGUXþMX NRQFHQWUDFLMDGXãLNRYLK RNVLGD NUHüHGR  SSP 3UHWSRVWDYOMD VH GD VH X RVWDOLP VOXþDMHYLPD VD YLVRNLP
temperaturama ne pojaYOMXMX ]QDþDMQH NROLþLQH GXãLNRYLK RNVLGD MHU MH YULMHPH ]DGUåDYDQMDLVSXãQLKSOLQRYDXWRPSRGUXþMXSUHNUDWNR

612

76HQþLü5/MXEHN6LPXODFLMDSURFHVDXNRPRULL]JDUDQMDSOLQVNHWXUELQH

Slika 6. Koncentracija dušikovih oksida u uzdužnom presjeku komore izgaranja
5. =$./-8ý$.
U radu je provedena preliminarna analiza hipotetske NRPRUHL]JDUDQMDSRPRüX&)'VRIWYHUDU prvom dijelu je analiziran pad tlaka u zavisnosti o ulaznoj brzini fluida. Postignuti rezultati
VXVDVYLPXVNODGXVDUH]XOWDWLPDGRVWXSQLPXOLWHUDWXUL8JHRPHWULMLNRPRUHVXSUHGYLÿHQL
NRQXVLYUWORåQLN3RPRüX)Ouenta su uspješno reproducirani vrtlozi koji rezultiraju iz ovakve
geometrije.
1DGDOMH]DVOXþDMVDPDORPXOD]QRPEU]LQRPYDULUDQMHSUHWLþDN]UDND8VWDQRYOMHQRMHNDNRMHRYDJHRPHWULMDNRPRUHL]JDUDQMDSULWRMEU]LQLHILNDVQDGRSUHWLþND]UDNDRGRWSULlike 5, jerGRYRÿHQMHPYHüLKNROLþLQDJRULYDGROD]LGRSRMDYHYLVRNLKWHPSHUDWXUDXSRGUXþMXXNRMHPELUHDNFLMHL]JDUDQMDYHüWUHEDOHELWL]DYUãHQH7RXND]XMHQDþLQMHQLFXGDVHJRULYRQLMHVWLJOR
L]PLMHãDWL , L]JRUMHWL X SULPDUQRP SRGUXþMX 2YR PRåH Eiti iskorišteno kao kriterij zaRGUHÿLYDQMHPDNVLPDOQHVQDJHGRWLþQHNRPRUH
8 SRVOMHGQMHP GLMHOX MH DQDOL]LUDQD WYRUED GXãLNRYLK RNVLGD 8 YHüLQL VOXþDMHYD VX
NRQFHQWUDFLMHNRMHVHSRMDYOMXMXELOH]DQHPDULYHRVLPXVOXþDMHYLPDNRGNRMLKVHSRMDYOMXMXnajYLãHWHPSHUDWXUHXL]OD]QRPSUHVMHNXNRPRUH7RMHXVNODGXVRþHNLYDQMLPD
3RWYUGLOR VH MH NDNR MH UDþXQDUVND PHKDQLND IOXLGD &)'  HILNDVDQ DODW ]D SUHOLPLQDUQHSURUDþXQHVWUXMDQMDL]JDUDQMDLWYRUEHSROXWDQDWDNRGNRPRUDL]JDUDQMD2PRJXüXMHUHODWLYQR
EU]XDQDOL]X]DþLWDYXVHULMXXOD]QLKSDUDPHWDUDNDRãWRVXUD]OLþLWHXOD]QHEU]LQHLWODNRYLWH
UD]OLþLWH NROLþLQH GRYHGHQRJ JRULYD 7R MH ]QDþDMQR L]PHÿX RVWDORJ ãWR üH VH RG SOLQVNHWXUELQHXJODYQRPRþHNLYDWLGDUDGLXUD]OLþLWLPUHåLPLPD
Kao nastavak ovog istraživanja moglo bi se provesti simulacije u širem rasponu kao što je
YDULUDQMHSUHWLþND]UDND]DGUXJHXOD]QHEU]LQH]UDNDLOLSURYHVWLVYHVNXSDQDYLãHPWODNX
Nadalje, mogla bi se provesti optimizacija geometrije komore izgaranja kao što su raspored i
dimenzije otvora za domiješavanje sekundarnog zraka.
LITERATURA[1] Esmail M. A. Mokheimera *, Yousef N. Dabwana, Mohamed A. Habiba : Performance
Comparative Analysis of Three Different CSP Technologies Integrated with Gas Turbine
Cogeneration Systems in Saudi Arabia, Energy Procedia 75 (2015) 527 – 532[2] Antonio Marco Pantaleo, Sergio Camporeale, Bernardo Fortunato: Small scale biomass
CHP: Techno-economic performance of steam vs gas turbines with bottoming ORC, Energy
Procedia, Volume 82, December 2015, Pages 825-832[3] C. Priyant Marka,n, A. Selwyn : Design and analysis of annular combustion chamber of a
low bypass turbofan engine in a jet trainer aircraft , Propulsion and Power Research
2016;5(2):97–107

Energy and the Environment (2016) 605-614

613[4] K. V. Chaudhari, D. B. Kulshreshtha, S.A. Channiwala : Design and CFD Simulation ofAnnular Combustion Chamber with Kerosene as Fuel for 20 kW Gas Turbine Engine ,International Journal of Engineering Research and Applications (IJERA) , Vol. 2, Issue 6,
November- December 2012, pp.1641-1645[5] Digvijay B. Kulshreshtha, Salim A. Channiwala: Combustion Chambers of Small
Capacity Gas Turbine Engines , 23rdNational Conference onI. C. Engine and Combustion(NCICEC 2013), SVNIT, Surat, India ,13-16, December 2013
[6] Artur Tyliszczak, Andrzej Boguslawski, Dariusz Nowak: Numerical simulations ofcombustion process in a gas turbine with a single and multi-point fuel injection system ,Applied Energy 174 (2016) 153–165[7] H. K. Versteeg, W. Malalasekera: An introduction to computational fluid dynamics - The
finite volume method, Longman Scientific & Technical, England, 1995.
[8] ANSYS Fluent User's Guide[9] Singh, S. N., Seshadri, V.,Singh R.K., Mishra, T: Flow characteristics of an annular gas
turbine combustor model for reacting flows using CFD, Journal of Scientific & Industrial
Research, Vol. 65, November 2006, pp. 921-934[10] Philip Kiameh: Power Generation Handbook, Mc Grow Hill, 2002.

614

76HQþLü5/MXEHN6LPXODFLMDSURFHVDXNRPRULL]JDUDQMDSOLQVNHWXUELQH

GAS TURBINE COMBUSTION CHAMBER PROCESS SIMULATION
Abstract: The combustion chamber is one of the main parts of the gas turbine. It's task seam
simple: to mix fuel with air, to burn it and deliver the energy to the turbine. However there
are some conflicting design crieria which have to be fullfilled. The highly turbulent flow isdesirable becouse it enhences air and fuel mixing. O the other hand the pressure drop has tobe as low as possible. Considering the high flow velocity it is not simple. A compact
construction is desirable, but the walls have to be protected from the direct exposition to thehigh flame temperatures. In the late period the maximum temperature has to be reduced inorder to reduce the emission of nitrogen oxydes. It is wanted an as uniform as possible
temperature on the outlet face in order to decrease the termal loads on the turbine blades.
Theese requirements did not change but there are available new tools that allow an easier
fullfilment of the goals.
A numerical analisys of the combustion chamber is presented in the paper for which
different 3d computetional fluid dynamics softwares are used. In the first part it was analized
the air flow, the velocity field and the pressure drop. In the second part a combustion
simulation is performed with the air/fuel ratio analisys, the temperature fielsds and thepollutants formation. The geometry, the starting conditions and the results for comparrison
are found in literature.
Key words: combustion chamber, 3d numerical simulation, emissions

Energy and the Environment (2016) 615-616

615

2679$5(1-(,,6.867921$3$6,912-.8û,6$/$7,û1$
OTOKU KRKU

5DGRYDQ.DUDEDLü
Elektron d.o.o. iz Krk, Vršanska 26 f
www.elektron-krk.hr
direktor@elektron-krk.hr+38598327929
Sažetak: 2YLPUDGRPSUH]HQWLUDWLüH se faze izgradnje jednog višestambenog pasivnog
objekta te sva iskustva s kojima se jedan investitor može susresti prilikom izgradnje istog.
7DNRÿHUüHVHSULND]DWLRSLVVDPRJREMHNWDVYDLQVWDOLUDQDRSUHPDXREMHNWXWHHILNDVQR
korištenje objekta i opreme kako bi se postigli željeni efekti. 3RYXüLüHVHLDQDORJLMDVDVOLþQLPSXQRYHüLPYLãHVWDPEHQLPSDVLYQLPREMHNWRP(&2– SILVER HOUSE u Ljubljani,
QDþLMRMMHL]JUDGQMLWYUWND(/(.7521GRRVXGMHORYDODNDRpartner i savjetnik. Svrha ovog
rada je prezentacija ostvarenja jednog pasivnog višestambenog objekta s naglaskom naVWHþHQDLVNXVWYDWLMHNRPJUDGQMHVFLOMHPL]EMHJDYDQMDWLSLþQLKJUHãDNDSULOLNRPL]JUDGQMHMHGQRJRYDNYRJREMHNWDDOLLSUH]HQWDFLMDXJUDÿHQLKVXVWDYDLQMLKRYRJHILNDVQRJNRULãWHQMD
NDNRELVHRVLJXUDRQDMYHüL stupanj komfora i boravka u objektu uz minimalnu potrošnju
energije. Kroz rad se prezentiraju i naglašavaju prednosti takve gradnje kako u ugodi
ERUDYNDWDNRLXXãWHGDPDHQHUJLMHLYRGHNDRLGRSULQRVXRþXYDQMDRNROLãD Rad želidokazati da se takva gradnja i financijski isplati i da pruža vrhunsku kvalitetu boravka, aujedno pozitivna je prema okolišu i minimalno nas zadužuje prema generacijama koje dolaze.
.OMXþQHULMHþLvišestambeni pasivni objekt, efikasnost, uštede, komfor, kvaliteta, okoliš

616

5.DUDEDLü2VWYDUHQMHLLVNXVWYRQDSDVLYQRMNXüL6DODWLüLQDRWRNX.UNX&216758&7,21$1'(;3(5,(1&(2)3$66,9(+286(6$/$7,û
ON ISLAND KRK
Summary: All construction phases and investor's experiences of multiresidental passivebuilding construction are shown in this paper. Description of passive building, all installedsystems and efficient use of building and systems to achieve desired effects are also shown.
Building is also compared with similar, but much larger multiresidental passive building –ECO SILVER HOUSE in Ljubljana in whose construction company ELEKTRON d.o.o.
participated as a partner and consultant. Purpose of this work is presentation of constructionof passive multiresidental building focusing on gained experience during construction to
avoid typical mistakes during construction of this type of building and also presentation of
installed systems and their efficient use to achieve maximum comfort and staying in building
with minimum energy consumption. Through this paper all advantages of passive
construction are shown and highlighted such as comfort of living in this type of building,savings of energy and water or contribution to environmental protection. This paper want toprove that passive construction is financially viable, that gives maximum living comfort but
also that is environmental friendly and minimum threat to future generations.
Key words: multiresidental passive building, efficiency, savings, comfort, quality,
environment

Energy and the Environment (2016) 617-618

617

ROLE OF HYDROGEN IN ENERGY SYSTEMS WITH LARGE SHAREOF RENEWABLE ENERGY
Frano Barbir
Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture,
University of Split
R Boskovica 32, 21000 Split, Croatia
Tel. +385 91 4305953
e-mail: fbarbir@fesb.hr
Summary: It is possible to envision an energy system with a large share of renewable energy
sources, namely solar, wind hydro and some biomass. The installed power generating
capacity would be significantly larger than it is in the present energy system. This is due to atleast three major differences from the present energy system: 1) there would be much larger
need for electricity as electricity would also be used for transportation, thus completely
replacing diesel and gasoline; 2) there would be a need for storage of the large quantities ofenergy which is achieved mainly via power to gas technologies; 3) the solar and wind power
plants have much lower capacity factors which is determined by the available annual
insolation and wind power. Although both solar and wind are highly intermittent energy
sources their combination, particularly with hydropower plants would result in lower needs
for energy storage. Further reduction in needs for energy storage would be accomplished byintegrating the transportation sector, as well as with thermal energy storage.
Energy savings and rational use of energy in every sector are essential, particularly inbuilding sector by energy retrofitting the existing and building the new ones to higher energy
standards, also by applying efficient heat pumps, both electric and gas. The highest energy
savings are possible in transportation, as both electric and fuel cell vehicles are much more
efficient than the present, internal combustion engine vehicles.
Hydrogen would have a significant role in such an energy system, serving as a transportation
fuel, energy storage and a feedstock for methane generation. Methane is considered as anenergy carrier mainly in order to use the existing natural gas infrastructure. Eventually, in
more distant future hydrogen could also be used directly in all the applications where natural
gas is used today and methane in the envisioned renewable energy system. The presentation
will cover hydrogen as an energy carrier, its history, current status of technologies forhydrogen production, storage and use, and the role of hydrogen in future energy system witha large share of renewable energy sources. Particularly, hydrogen related activities atLaboratory for New Energy Technologies at University of Split will be addressed in greater
detail.
Key words: solar energy, wind energy, energy storage, transport sector, hydrogen.

618

F. Barbir: Role of Hydrogen in Energy Systems with Large Share of…

ULOGA VODIKA U ENERGETSKOM SUSTAVU S VELIKIM
UDJELOM OBNOVLJIVIH IZVORA ENERGIJESažetak: 0RJXüHMH]DPLVOLWLKUYDWVNLHQHUJHWVNLVXVWDYVYHOLNLPXGMHORPREQRYOMLYLKL]YRUDHQHUJLMHNDRãWRVXVXQþHYR]UDþHQMHHQHUJLMDYMHWUDLELRPDVD8WRPVOXþDMXELLQVWDOLUDQLNDSDFLWHW ELR ]QDþDMQR YHüL QHJR ãWR MH WR X VDGDãQMHP HQHUJHWVNRP VXVWDYX Nekoliko je
UD]ORJD]DWR SRWURãQMDHOHNWULþQHHQHUJLMHELELOD]QDWQRYHüDMHUELVHHOHNWULþQDHQHUJLMD
GLUHNWQRLOLLQGLUHNWQR NRULVWLODL]DWUDQVSRUWSRWSXQR]DPMHQMXMXüLGL]HOJRULYRLEHQ]LQ 
ELOR EL SRWUHEQR VNODGLãWLWL YHOLNH NROLþLQH HQHUJLMH ãWR MH PRJXüH V W]Y SRZHU-to-gas
HOHNWULþQD HQHUJLMD X SOLQ  WHKQRORJLMDPD   HQHUJLMD L] VXQþHYLK L YMHWUR HQHUJDQD LPD]QDWQR PDQML IDNWRU LVNRULãWHQMD NDSDFLWHWD RPMHU SURVMHþQH L QD]LYQH VQDJH  ãWR MH
XYMHWRYDQRUDVSRORåLYLPJRGLãQMLPVXQþHYLP]UDþHQMHPLHQHUJLMRPYMHWUD,DNRVXLVXQþHYR]UDþHQMH L HQHUJLMD YMHWUD UDVSRORåLYL V YHOLNLP DPSOLWXGDPD VQDJH QMLKRYD NRPELQDFLMD V
hidro-elektranama bi rezultirala manjim potrebama za skladištenjem viškova energije.
Viškovi energije bi se mogli NRULVWLWL NRULãWHQMHP X WUDQVSRUWX GDNOH LQWHJULUDMXüL VHNWRUWUDQVSRUWD VD VHNWRURP HOHNWULþH HQHUJLMH DOL L SUHWYRUERP X WHUPDOQX HQHUJLMX L QMHQLP
skladištenjem.
5DFLRQDOQR NRULãWHQMH HQHUJLMH L UH]XOWLUDMXüH HQHUJHWVNH XãWHGH ELOH EL QXåQH X VYLPsekWRULPD D QDURþLWR X ]JUDGDUVWYX L WR REQRYRP RGQRVQR SREROMãDQMHP HQHUJHWVNLKNDUDNWHULVWLNDSRVWRMHüLK]JUDGDNDRLSULPMHQRPVWURåLKVWDQGDUGDSULOLNRPL]JUDGQMHQRYLK]JUDGD D WDNRÿHU XJUDGQMRP GL]DOLFD WRSOLQH ELOR HOHNWULþQLK ELOR SOLQVNLK 1DMYHüH uštede
ELOH EL PRJXüH X WUDQVSRUWX MHU VX L HOHNWULþQL DXWRPRELOL V EDWHULMDPD L RQL V JRULYQLPþODQFLPD]QDWQRHILNDVQLMLRGVDGDãQMLKDXWRPRELODVPRWRULPDVXQXWUDãQMLPL]JDUDQMHP
8 WDNYRP HQHUJHWVNRP VXVWDYX YRGLN EL LPDR ]QDþDMQX XORJX NDR JRULYR ]D transport, kao
medij za pohranu energije i kao sirovina za proizvodnju metana. Sintetski proizvedeni metan
L] YRGLND L XJOMLþQRJ GRRNVLGD  EL VH NRULVWLR NDR JRULYR NRULVWHüL SRVWRMHüX LQIUDVWUXNWXUXSULURGQRJ SOLQD 8 GDOMQMRM EXGXüQRVWL YRGLN EL PRJDR potpuno zamijeniti prirodni plin,
RGQRVQR PHWDQ 3UH]HQWDFLMD üH REXKYDWLWL YRGLN NDR SUHQRVQLN HQHUJLMH QMHJRYX SRYLMHVW
sdašnje stanje tehnologija za njegovu proizvodnju, skladištenje i uporabu, te ulogu vodika u
HQHUJHWVNRPVXVWDYXEXGXüQRVWLVYHOLNLPXGMHORPREQRYOMLYLKL]YRUDHQHUJLMH3RVHEQRüHVH
prikazati aktivnosti Laboratorija za nove termo-energetske tehnologije na Fakultetu
HOHNWURWHKQLNHVWURMDUVWYDLEURGRJUDGQMH6YHXþLOLãWDX6SOLWX
.OMXþQHULMHþL HQHUJLMDVXQþHYRJ]UDþHQMDYMHWro-energija, skladištenje energije, sektortransporta, vodik.

Energy and the Environment (2016) 619-628

619

P59$3$6,91$.8û$635('*2729/-(1,0 FASADNIMSUSTAVOM 2'5(&,./,5$12**5$Ĉ(9,16.2*$*5(*$7$
/MXERPLU0LãþHYLü, 6YHXþLOLãWHX=DJUHEX$UKLWHNtonski fakultet
tel./fax: +385 1 4639394, www.arhitekt.hr www.kpk.hr miscevic@arhitekt.hr
Mark 0LãþHYLü, 6YHXþLOLãWHX=DJUHEX$UKLWHNWRQVNLIDNXOWHW
tel.: +385 1 4821501, www.arhitekt.hr mmiscevic@arhitekt.hrSažetak: U radu se predstavlja prva svjetska implementacija ECO-SANDWICH® ventiliranog
SUHGJRWRYOMHQRJ IDVDGQRJ SDQHOQRJ VXVWDYD NRML VH L]UDÿXMe od agregata dobivenog
UHFLNOLUDQMHPJUDÿHYLQVNLKPDWHULMDODLotpada. Toplinska izolacija sustava je od mineralne vune
koja je proizvedena uporabom inovativne i održive tehnologije kako bi se smanjilo korištenje
primarne energije u graditeljstvu i štetne utjecaje na klimatske promjene. ECO-SANDWICH®
zidni panel je razvijen kao rezultat suradnje hrvatskih znanstvenih institucija i industrije u kojoj
MH SURYHGHQR LVWUDåLYDQMH X VYUKX UD]YRMD QRYRJ NRPSHWLWLYQRJ SURL]YRGD XQDSUHÿHQMD
proizvodne opreme i održavanja kompetitivnosWL XNOMXþHQLK WYUWNL QD WUåLãWX (www.ecosandwich.hr). Sustav je patentiran proizvod industrijskog dizajna sa ]DãWLüHQLP imenom ivizualnim identitetom. 0HÿX QDMYDåQLMLP SRVWLJQXüLPD projekta je modularni sustav zidnih
panela, koji je održiv i priuštiv njegovim krajnjim korisnicima tijekom cijelog životnog ciklusa.
Ostvarenje Prve ECO-SANDWICH® NXüH je rezultat višegodišnjih istraživanja u razvoju
održivih materijala i sustava te metoda arhitektonskog projektiranja za novogradnje i energetske
obnove („faktor 10“) YLVRNH HQHUJHWVNH XþLQNRYLWRVWL GR HQHUJHWVNRJ VWDQGDUGD SDVLYQH NXüH
(„A+“) i višeg. 3ULND]DQ MH XUEDQLVWLþNR-arhitektonski i tehnološko-izvedbeni slijed ostvarenja
RELWHOMVNH NXüH V WUL VWDQD RGQRVQR PDOH YLãHVWDPEHQH ]JUDGH koja je projektirana kao tipskoUMHãHQMHNRMHüHVHL]YHVWLQDGYDQDHVWSDUFHODX=HOHQRPNYDUWXJUDGD.RSULYQLFH2SLVDQHVXL
ilustrirane teme energetskog koncepta razvoja grada, projekta i proizvoda ECO-SANDWICH®,
prostornog, energetskog i oblikovnog koncepta te izvedbe Prve ECO-SANDWICH® NXüH.
2EMDãQMHQL VX QRYL REOLN GLMDJUDPD VSHFLILþQH JRGLãQMH SRWURãQMH HQHUJLMH X ]JUDGDPD i nova
NODVLILNDFLMD SDVLYQLK NXüD SUHPD NRMRM üH X NRQDþQRM ID]L L]YHGEH LQWHJUDFLMRP DNWLYQLKWRSOLQVNLKLIRWRQDSRQVNLKVXQþDQLKVXVWDYDNXüDXGRYROMLWLNULWHULMLPD]DÄSDVLYQXNXüXSOXV³.OMXþQH ULMHþL: predgotovljeni ventilirani fasadni sustav, Prva ECO-SANDWICH® NXüD
SDVLYQDNXüDenergetska obnova “faktor 10”, suvremeni energetski standardi gradnje
1. UVOD
Prva ostvarena ECO-SANDWICH® NXüD MH RWYRUHQD  UXMQD 2016. godine u Koprivnici.
Izvedena je kao prva od dvanaest planiranih višeobiteljskih tipskih NXüD s tri stambene jedinice.
To je ujedno i novi stambeni tip unutar društvenog programa poticane stanogradnje (POS).

620

00LãþHYLü/M0LãþHYLü: 3UYDSDVLYQDNXüDVSUHGJRWRYOMHQLPIDVDGQLP…

(QHUJHWVNRJMHVWDQGDUGDSDVLYQHNXüH $ 6PMHãWHQDMHX=HOHQRPNYDUWXJUDGDKoprivnice/HQLãüH- Istok). KuüDMHMHGQRRGEURMQLKRVWYDUHQMDSURMHNWDÄ1RYROLFH.RSULYQLFH³ kojim seåHOLVWYRULWL]HOHQDHQHUJHWVNLXþLQNRYLWDLSURVSHULWHWQD.RSULYQLFDQRYHNXOWXUHåLYOMHQMD3UYLNRUDN X WRPH MH VWYDUDQMH QLVNRHQHUJHWVNRJD =HOHQRJ NYDUWD NRML üH VH VDVWRMDWL Rd sedamYLãHVWDPEHQLK ]JUDGD L GYDQDHVW VSRPHQXWLK YLãHRELWHOMVNLK NXüD 3UHPD SURJUDPX GUXãWYHQR
SRWLFDQH VWDQRJUDGQMH 326  GRVDG VX L]JUDÿHQH WUL ÄŠparne hiže“, višestambene zgradeenergetskog razreda A+ koje su smještene u istoj ulici nasuprot prve ECO-SANDWICH® NXüH.

Slika 1: 8UEDQLVWLþNL SODQ XUHÿHQMD =HOHQRJ NYDUWD X .Rprivnici (lijevo), izmijenjeni plan udijelu zapadne zone s dvanaest parcela za male višestambene zgrade (u sredini) i orto fotosnimak stanja u prostoru (Google, 2016.).

Slika 2: Situacija - parcela s vrtovima (lijevo) i montaža ECO-SANDWICH® panela.
2. ENERGETSKI KONCEPT RAZVOJA GRADA KOPRIVNICE
Energetski standard Prve ECO-SANDWICH® NXüHQDUD]LQLSDVLYQHNXüH, odnosno energetskog
razreda “A+” je zahtijevan projektnim zadatkom. U okviru projekta “Novo lice Koprivnice”
promovira se energetVNL YLVRNR XþLQNRYLW NRQFHSW UD]YRMD JUDGD X SRGUXþMLPD HnergetskeXþLQNRYLWRVWL X ]JUDGDUVWYX, uporabe obnovljivih izvora energije, uþLQNRYLWRg korištenja voda,održivog upravljanja otpadnim vodama, održivog prometa i smanjenja HPLVLMD VWDNOHQLþNLKplinova. Projekt je ujedno jedinstven poslovni koncept koji se provodi u svim sektorima

Energy and the Environment (2016) 619-628

621

GMHORYDQMD D X] *UDG VX XNOMXþHQH i sve gradske ustanove i SRGX]HüD Odluka o komunalnom
doprinosu Grada Koprivnice je bila prva i jedinstvena u Republici Hrvatskoj, a koja glasi:- LQYHVWLWRULNRMLJUDGHNXüHHQHUJHWVNRJUD]UHGD$RVWYDUXMXSRWLFDMHXYLVLQLMHGLQLþQH
YULMHGQRVWLD]DQLVNRHQHUJHWVNHJUDÿHYLQHRVWYDUXMXSRWLFDMXYLVLQLMHGLQLþQHYULMHGQRVWL]DVYH]RQHSODüDQMDNRPXQDOQRJGRSULQRVD
3RUXND Ä1D SRGUXþMX *UDGD .RSULYQLFH QH SODüD VH NRPXQDOQL GRSULQRV MHGLQL XYMHW MH GD
JUDGLWHNXüXHQHUJHWVNRJUD]UHGD$´.
Projekt „Novo lice Koprivnice“ dobio je glavnu nagradu Europskog energetskog tjedna“ManagEnergy Local Energy Action Award” - nagrada u kategoriji “Upravljanje energijom” iuvršten je PHÿXSHWILQDOLVWDXNDWHJRULML³6WDQRYDQMH´. Za nagradu Europskog klimatskog tjednabila su prijavljena ukupno 224 projekta, a najbolje je odabralo povjerenstvo neovisnihVWUXþQMDND. Nagrada je dodijeljena u lipnju 2013. godine u Bruxellesu.
3. PROJEKT I PROIZVOD ECO-SANDWICH®
Projekt ECO-SANDWICH® nastao je kao rezultat suradnje hrvatskih znanstvenih institucija*UDÿHYLQVNL L $UKLWHNWRQVNL IDNXOWHW 6YHXþLOLãWD X =DJUHEX  L LQGXVWULMH %HWRQ /XþNo, Knauf
Insulation i Eurco), a odobren je za financiranje u okviru programa Europske unije CIP-EIPEco-Innovation 2011. Projekt je prezentiran pod naslovom Prefabricated Façade Panels for
Newly Built and Refurbished Nearly Zero Energy Buildings (Predgotovljeni fasadni paneli za
energetski gotovo nultu novogradnju i obnovu), na prethodnom savjetovanju Energy and theEnvironment (Energija i okoliš) 2014. godine u Opatiji. Ciljevi projekta su poticanje reciklaže
JUDÿHYLQVNRJ RWSDGD SURPRYLUDQMH ]DPMHQH ãWHWQLK WRSOLQVNR-izolacijskih materijala te
SURPLFDQMH SULPMHQH SUHGJRWRYOMHQLK SDQHOD NRMLPD VH VPDQMXMH XJUDÿHQD HQHUJLMD X SURL]YRGNDR L HPLVLMH VWDNOHQLþNLK SOLQRYD L štetnih SUDWHüLK sastojaka iz proizvodnje. ECOSANDWICH® panel ima nisku toplinsku provodljivost zDKYDOMXMXüL EHWRQX s recikliranim
DJUHJDWRP NRMD MH  PDQMD X RGQRVX QD EHWRQ L]UDÿHQ V SULURGQLP DJUHJDWRP U presjeku
elementa je mineralnD YXQD L]UDÿHQD Ecose® tehnologijom s prirodnim smolama kao vezivom,
YLVRNHMHRWSRUQRVWLQDSRåDUYHüHJWRSOLQVNRJNDSDFLWHWDWHJDMHPRJXüHSRQRYRLVNRULVWLWLLX
cijelosti reciklirati.

622

00LãþHYLü/M0LãþHYLü: 3UYDSDVLYQDNXüDVSUHGJRWRYOMHQLPIDVDGQLP…

Slika 3: Uzorci reFLNOLUDQRJJUDÿHYLQVNRJRWSDGD- agregata od opeke za vanjsku stijenu (lijevo)
i za unutarnju betonsku stijenu od recikliranog betona (desno). Presjek ECO-SANDWICH®
panela (u sredini).
4. PRVA ECO-SANDWICH® .8û$Prva izvedba ECO-SANDWICH® sustava provedena je kao donacija investitoru, Agenciji za
društveno poticanu stanogradnju grada Koprivnice (APOS), koja je projekt podržavala od
VDPRJD SRþHWND 8MHGQR MH SURMHNW RVWYDUHQ ]DKYDOMXMXüL L SUYRM SULPMHQL RGUåLYH LQRYDWLYQH
zelene javne nabave kao modela financiranja u Hrvatskoj.
S obzirom da je cjeloviti fasadni sustav za prvu realizaciju financiran iz sredstava EU projekta,
prvo je ostvarenje ujedno i pilot-SURMHNWNRMLPVHLVWUDåXMXPRJXüQRVWLSULPMHQHVXVWDYD=ERJWRJD MH ]JUDGD NRPSOHNVQLMHJ UD]YHGHQRJ REOLND WH VH QD NXüL SRMDYOMXMX HOHPHQWL NDR ãWo su
konzolH XJDRQL SUR]RUL WHUDVH ORÿD L balkon. Time su se kroz projekt i izvedbu riješili
NDUDNWHULVWLþQL GHWDOML L VWYRULR VYRMHYUVQL NDWDORJ NYDOLWHWQLK UMHãHQMD ]D EXGXüH SULPMHQH 8
RYRMQLFL]JUDGHXJUDÿHQLVXVXVWDYL]DPMHUQRSURPDWUDQMHWRSOLQe i vlažnosti koji su relevantni]D XWYUÿLYDnje kvalitete unutarnjeg zraka, HQHUJHWVNH XþLQNRYLWRVWL L SRWURãQMH 3ULMH WHKQLþNRJpregleda i izdavanja uporabne dozvole izveden je i test zrakopropusnosti ovojnice (Blower-Doortest) i termovizijsko snimanje.
Prva ECO-SANDWICH® NXüDMHSUYDLPSOHPHQWDFLMD istoimenog predgotovljenog ventiliranog
IDVDGQRJVXVWDYDVEHWRQVNLPGLMHORYLPDRGUHFLNOLUDQRJJUDÿHYLQVNRJi otpada od rušenja.
Podatci o Prvoj ECO-SANDWICH® NXüL
autor i glavni projektant: prof. /MXERPLU0LãþHYLüGLSO ing. arh.
VXUDGQLFL7HD%HOLþHYGLSO ing. DUKL0DUN0LãþHYLüVWXGDUK
DUKLWHNWRQVNLXUHG=DYRG]DDUKLWHNWXUX$UKLWHNWRQVNRJIDNXOWHWD6YHXþLOLãWDX=DJUHEX
projekt konstrukcije: prof. dr. VF0ODGHQ0HãWURYLüGLSO ing. JUDÿGLSO ing. mat.
strojarski projekt: prof. mr. VF,YDQ&HWLQLüGLSO ing. stroj.
HOHNWURWHKQLþNLSURMHNW6WLSH0LKRWLüGLSO ing. el.
IRWRJUDILMH0DUN0LãþHYLü/MXERPLU0LãþHYLüwww.livecamcroatia.com
investitor: Agencija za društveno poticanu stanogradnju Grada Koprivnice (APOS)
površina parcele: 708,0 m², bruto površina: 393,9 m², projekt: 2014. - 2015., realizacija: 2016.
JODYQLL]YRÿDþL7HK-Gradnja d.o.o. i %HWRQ/XþNRGRR (&26$1':,&+®)

Energy and the Environment (2016) 619-628

623

Slika 4: Detalj ECO-SANDWICH® fasadnog panela. Slojevi s lijeva na desno: vanjska betonska
VWLMHQD GHEOMLQH  FP ]UDþQL - ventilirani sloj 4,0 cm, toplinska izolacija 20,0 cm i unutarnjibeton debljine 12,0 cm (lijevo), montaža panela na Prvoj ECO-SANDWICH® NXüi (u sredini) i
detalMXJUDÿHQRJSDQHOD GHVQR 
4.1. Prostorni koncept
3URMHNWLQMHJRYRRVWYDUHQMHLPDMXYLãHYDåQLK]QDþDMNLNRMHVXSUHSR]QDWHNDRELWQHUHIHUHQFH
.XüD 3U3N  VDGUåL WUL VWDQD VYDNL QD MHGQRM HWDåL WH ]DMHGQLþNL XOD]QL SURVWRU L VWXELãWH
ProjektiraQDMHQDQDþLQNRMLRPRJXüDYDPDNVLPDOQXXSRUDEXVXQþHYHHQHUJLMHQDSDVLYDQQDþLQ
6YL VX SULPDUQL VWDPEHQL SURVWRUL RULMHQWLUDQL RG LVWRND GR ]DSDGD YHüLQRP QD L]UD]LWL MXJ D
VHNXQGDUQL GXå VMHYHUQRJ SURþHOMD X] NRMH MH L VWXELãWH 2VXQþDQD SURþHOMD VX maksimalno
otvorena, a sjeverno je maksimalno zatvoreno. U zgradu se ulazi na sjeverQRP SURþHOMX kroz
YMHWUREUDQ8]LLVSRGSUYRJVWXELãQRJNUDNDMH]DMHGQLþNRVWDQDUVNRVSUHPLãWH U prizemlju senalazi 2,5 S, na katu 3,0 S, a u potkrovlju 2,0 S stan, ukOMXþXMXüLSURVWRUERUDYND Zapadni dio
stana s dnevnim boravkom, kuhinjom, izbom te WC-RPMHJRWRYRLGHQWLþDQXVYLPVWDQRYLPD
dok se X LVWRþQRP GLMHOX NXüH - stana, X NRMHPX MH VPMHãWHQ VSDYDüL GLR VD NXSDRQLFDPD igarderobom, mijenja u odnosX QD YHOLþLQu stanova. UUHÿHQMH RNROLãD SDUFHOH REXKYDüD]DMHGQLþNH vanjske prostore; staze, zelene površine, konzolnim volumenom 1. kata natkrivenu
površinu za odlaganje bicikala, pet parkirališnih PMHVWD XNOMXþXMXüL MHGQR ]D RVREH V
invaliditetom (iako prema PravilnLNX ]D RVLJXUDQMH SULVWXSDþQRVWL RVREDPD V LQYDOLGLWHWRP ismanjene pokretljivosti nije propisano) i tri vanjska stanarska spremišta. Svakom stanu pripada i
vrt NDRRGJRYDUDMXüLYODVQLþNLGLRSDUFHOH

Slika 5. Pogled s jugoistoka, sjeveroistoka i detalj pogleda s jugozapada.
4.2. Energetski koncept Prve ECO-SANDWICH® NXüH
=DKYDOMXMXüLWORFUWQRPREOLNXSDUFHOHLRULMHQWDFLMLNXüDMHNRQFLSLUDQDNDRSULMHPQLNVXQþHYRJ
]UDþHQMD SR SULQFLSLPD SDVLYQH VXQþDQH DUKLWHNWXUH =JUDGD MH SULNOMXþHQD QD sve mreže
NRPXQDOQHLQIUDVWUXNXUHXNOMXþXMXüL LQVWDODFLMXSOLQDDSUHGYLÿHQLVXLDNWLYQLVXQþDQLVXVWDYL]Dzagrijavanje potrošne sanitarne tople vode i prostora, kao i fotonaponski pretvornici za
SURL]YRGQMX HOHNWULþQe struje. .XüD MH projektirana i izvedena u u potpunosti u skladu s
definicijom “NODVLþQH SDVLYQH NXüH” koja u Hrvatskoj odgovara “A+” energetskom razredu
potrošnje za grijanje prostora do 15 kWh/m2a s obveznim ventilacijskim i rekuperacijskim
sustavom WRSOR]UDþQRJJULMDQMD. Prekinuti su toplinski mostovi i ostvarena je zrakonepropusnost
vanjske ovojnice zgrade. PULMHWHKQLþNRJSUHJOHGD]JUDGH test zrakopropusnosti ovojnice Blower-

624

00LãþHYLü/M0LãþHYLü: 3UYDSDVLYQDNXüDVSUHGJRWRYOMHQLPIDVDGQLP…

Door metodom i opremom L]YHRMHGUVF,YLFD.XãHYLüGLSOLQJIL] InVWLWXWJUDÿHYLQDUVWYD
Hrvatske, u skladXV7HKQLþNLPSURSLVRPRH ]DJUDÿHYLQHþLMDMHSRWURãQMDHQHUJLMH]DJULMDQMH
manja od 25 kWh/m2a, uz termovizijsko snimanje NRMHMHL]YHRGUVF%RMDQ0LORYDQRYLüGLSO
LQJ JUDÿ *UDÿHYLQVNL IDNXOWHW 6YHXþLOLãWD X =DJUHEX. Na temelju testa i termovizijskih slika
izvršene su manje korekcije na mjestima primLMHüHQRJ SURSXãWDQMD RYRMQLFH Eneregetska
potrošnja i kvaliteta unutarnje okoline (toplinska ugodnost i vlaga) se prate najsuvremenijim
sustavom mjernog promatranja.

Slika 6: Ventilacijski sustav u stanu na 1. katu, projektant PUVF,YDQ&HWLQLü (lijevo), prostor s
rekuperatorom (sredina) i istrujne ventilacijske rešetke u ovješenom stropu prostora blagovanja iboravka (desno).
Postav aktivnih toplinskih i fotonaponskih pretvornika na krov i njihovo integriranje u cjeloviti
LQVWDODFLMVNL VXVWDY MH SODQLUDQR X NRQDþQRM ID]L L]YHGEH NDGD üH NXüD SR QRYRM GHILQLFLML
3DVVLYH+RXVH,QVWLWXW SRVWDWL³SDVLYQDNXüDSOXV´

Slika 7: Položaj VXQþDQLK WRSOLQVNLK L IRWRQDSRQVNLK SUHWYRUQLND QD NURYX OLMHYR , prostorni
prikaz u pogledu s jugozapada (sredina) i detalj .
4.3. Oblikovni koncept Prve ECO-SANDWICH® NXüH
2EOLNRYDQMH NXüH SURL]OD]L L] VLQHUJLMH prostornih arhitektonsko-XUEDQLVWLþNLK energetskih,
ekoloških, tehnoloških i investicijskih preduvjeta i parametara.
Projekt je tipsko arhitektonsko rješenje QD NRMHP VH GDOMQMRP L]YHGERP QD SUHGYLÿHQLK
preostalih jedanaest parcela u Zelenom kvartu grada .RSULYQLFH QDPMHUDYD LVWUDåLWL UD]OLþLWH
WHKQRORãNHYDULMDQWHXSRUDERPUD]OLþLWLKPDWHULMDODVLGHMRPrazvoja predgotovljenih sustava.

Energy and the Environment (2016) 619-628

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Pojedini arhitektonski elementi koji se primjenjuju u praksi suvremenog arhitektonskog
oblikovanja poput ugaonog prozoUD QD SURþHOMX QD NRQ]ROQRP DUKLWHNWRQVNRP YROXPHQX NDRugaoni prozor na terasi, balkona - loggie, zahtijevaju originalne složene fizikalne i tehnološke
detalje koji su u ovom projektu provjereni i izvedbom.

Slika 8. Detalj ugaonog prozora na konzolnom volumenu, izlaz na loggiu, detalj boravka
5. DOSADAŠNJE REFERENCE SUSTAVA I PRVE ECO-SANDWICH® .8û(ECO-SANDWICH® IDVDGQLVXVWDYNDRLVWUDåLYDþNR- razvojni i industrijsko inovacijski projekt
MH SUYL SXWD SUH]HQWLUDQ X LQR]HPVWYX WLMHNRP  VYMHWVNH NRQIHUHQFLMH R SDVLYQRM NXüL X
Frankfurtu 2013. godine. ECO-SANDWICH® konzorcij je dobio nagradu Greenovation 2013.
Saveza za energetiku Zagreba kao “Najbolji hrvatski tim zelene ekonomije” i postao je nositelj
oznake “Green Mark” uz naziv “zelena revolucija u graditeljstvu”. Sustav je dobio Zlatnu
medalju za “INOVA najbolji ekološki izum” na 38. izložbi INOVA 2013. u Zagrebu. Projekt
ECO-SANDWICH® MH QD  PHÿXQDURGQRP VDMPX LQRYDFLMD ,1129$  RGUåDQRP X
Bruxellesu osvojio zlatnu medalju. 3UHGVWDYOMHQ MH L QD YRGHüRM HXURSVNRM L]ORåEL JUDGLWHOMVWYD
BAU u MinKHQX XVLMHþQMXJRGLQe, gdje je nominiran za BAU-trend AIT + Xia award i
pozicioniran u prvih deset inovacijskih proizvoda. 6YHXþLOLãWH X =DJUHEX MH WLPH SRVWDOR SUYRL]YDQ 1MHPDþNH NRMHP MH RPRJXüHQR L]ODJDQMH VYRMLK LGHMD LVWUDåLYDQMD L SURL]YRGD RG VWUDQH
organizatora sajma. Grad Koprivnica je ]DKYDOMXMXüL L SURMHNWX 3UYH ECO-SANDWICH® NXüH
GRELRL6YMHWVNXQDJUDGX]DHQHUJHWVNXXþLQNRYLWRVW World Global Award for energy efficiency)
u svibnju 2015. godine. 3URMHNW MH RGDEUDQ L L]ORåHQ QD  ]DJUHEDþNRP VDORQX DUKLWHNWXUH X
OLVWRSDGX  JRGLQH 7HPD 6DORQD VHOHNWRUD DUKLWHNWD +UYRMD 1MLULüD MH ELOD ³'RVOMHGQRVW´$XWRULJODYQLSURMHNWDQWMHQDSR]LY6WUXþQRJVDYMHWD81(&(SUezentirao projekt na sjednici uŽenevi 19. studenoga 2015. godine, kao primjer najbolje nacionalne inicijative i najbolje prakse
YLVRNHHQHUJHWVNHXþLQNRYLWRVWL
66895(0(1,(1(5*(76.,67$1'$5',*5$Ĉ(1-$Nova percepcija dijagrama (Dijagram 1.) potrošnje energije kojeg je autor prof. Ljubomir0LãþHYLüSULND]DRLSUHGORåLR]DGDOMQMXXSRUDEXQDNRQIHUHQFLMLRSDVLYQRMNXüLX$DFKHQX626

00LãþHYLü/M0LãþHYLü: 3UYDSDVLYQDNXüDVSUHGJRWRYOMHQLPIDVDGQLP…

2014. godine, s dodanim stupcima SDVLYQHNXüHSOXV i SDVLYQH NXüHSUHPLum, prije definiranja
njihove potrošnje primarne energije i udjela generirane energije iz obnovljivih izvora energije(OIE - 5(6 SUHPD,QVWLWXWX]DSDVLYQXNXüXL]'DUPVWDGWD 3DVVLYH+RXVH,QVWLWXW- PHI), kojeg
vodi prof. dr. sc. Wolfgang Feist, a koji su bili prvi puta prezentirani na 19. konferenciji o
SDVLYQRMNXüLX/HLS]LJXJRGLQH
6WXSDF ³)´ GLMDJUDPD SULND]XMH SDVLYQX NXüX V GRGDWNRP 2,( 5(6  X SRGUXþMLPD V YHOLNRPGR]UDþHQRP VXQþHYRP HQHUJLMRP SRSXW MXåQH UHJLMH +UYDWVNH NRMD MH SUHPD 5(+VA u 1. i 2.
]RQL ]D HQHUJHWVNL JRWRYR QXOWX JUDGQMX QHDUO\ =HUR (QHUJ\ %XLOGLQJ  JGMH MH PRJXü ODNLSULMHOD]L]QDGQXOWHHQHUJHWVNHUD]LQHSDSDVLYQDNXüDSRVWDMH³HQHUJHWVND´LOL³SDVLYQDNXüD
plus” kako ju definira ,QVWLWXW]DSDVLYQXNXüX 3+, 

Dijagram 1. 6SHFLILþQD JRGLãQMD HQHUJHWVND SRWURãQMD SUHPD VWDQGDUGLPD L YUVWDPD SRWURãQMH
Novi oblik dijagrama na kojem su vrijednosti potrošnje prikazane na negativnoj ordinati, adodane su plus eneregtske vrijednosti (autor: Ljubomir 0LãþHYLü 
6WXSFL GLMDJUDPD 'LMDJUDP   SULND]XMX JRGLãQMH XGMHOH VSHFLILþQH HQHUJHWVNH SRWURãQMH ]DSRMHGLQH YUVWH SRWURãQMH ]D VWDUH ]JUHGH VWXSDF $  ]D ]JUDGH SUHPD QMHPDþNLP SURSLVLPD L]
1980. i 1984. (stupci B, C i D), za niskoenergetsku ]JUDGX VWXSDF( ]DVWDQGDUGSDVLYQHNXüH
SUHPD L]YRUQRM GHILQLFLML ,QVWLWXWD ]D SDVLYQX NXüX - Passive House Institut (PHI), a kasnije(2014.) definirana kao “klasik”, za nultu energetsku za grijanje (stupac G), za nultu energetsku(stupac H), za pasivQX NXüX ³SOXV´ 3+, VWXSDF ,  RG NRMH VH SRþLQMX XNOMXþLYDWL L XGMHOL
generirani iz obnovljivih izvora energije (OIE - 5(6  ]D SDVLYQX NXüX ³SUHPLXP´ 3+, V MRã
YHüLP XGMHORP HQHUJLMH JHQHULUDQLP L] 2,( VWXSDF -  WH ]D VOLMHGHüL EXGXüL PRJXüL VWDQGDUGVWXSDF. NRMLMRãQLMHGHILQLUDQLPHQRPLNROLþLQRPSURL]YRGQMHHQHUJLMH SUHPDDXWRUX 
U svakom stupcu od A do G su prikazani udjeli pojedine namjenske vrste potrošnje (odozdo
SUHPDJRUH =DHOHNWULþQXVWUXMX]DNXüDQVNHXUHÿDMH RNHUERMD- najdonji dio stupca), zatim za
HOHNWULþQX VWUXMX ]D YHQWLODFLMX X VWXSFLPD & ( ) L * ]HOHQNDVWD ERMD  ]D JULMDQMH SRWURãQHEnergy and the Environment (2016) 619-628

627

VDQLWDUQH YRGH SODYD ERMD  L QDMYHüL XGLR HQHUJHWVNH SRWURãQMH X VWXSFLPD RG $ GR ) MH ]Dgrijanje prostora (crvena boja) koji nestaje XHQHUJHWVNLQXOWRMNXüL]DJULMDQMH VWXSDF* =ERJ XGMHOD 2,( NRML SUHPD SUYRWQRM GHILQLFLML SDVLYQH NXüH QLMH ELR XNOMXþHQ LVWL HQHUJHWVNL
standard postaje “+” energetski pa se od konferencije PHI u Leipzigu 2015. godine po prvi put
predstavlja kao paVLYQDNXüD³SOXV´QDNRQNRMHVOLMHGL³SUHPLXP´ prema definiciji Instituta za
SDVLYQXNXüXL]'DUPVWDGWD.
7. =$./-8ý$.
Prva implementacija ECO-SANDWICH® ventiliranog predgotovljenog fasadnog sustava koji seL]UDÿXMH RG DJUHJDWD GRELYHQRJ UHFLNOLUDQMHP JUDÿHYLQVNLK PDWHULMDOD L RWSDGD D ]D WRSOLQVNX
izolaciju se koristi mineralna vuna koja je proizvedena uporabom inovativne i održive
tehnologije, je ostvarena izvedbom Prve ECO-SANDWICH® NXüH 2VWYDUHQMH NXüH je rezultat
višegodišnjih istraživanja u razvoju održivih materijala i sustava te metoda arhitektonskog
SURMHNWLUDQMD]DQRYRJUDGQMHLHQHUJHWVNHREQRYH ÄIDNWRU³ YLVRNHHQHUJHWVNHXþLQNRYLWRVWLGRHQHUJHWVNRJVWDQGDUGDSDVLYQHNXüH Ä$³ LYLãHJ, kako bi se smanjilo korištenje primarneenergije u graditeljstvu i štetne utjecaje na klimatske promjene. Prema novoj klasifikaciji
energetskih standarda, Prva ECO-SANDWICH® NXüD MH SURMHNWLUDQD L L]YHGHQD X VNODGX V
SUYRWQRPGHILQLFLMRPSDVLYQHNXüHNRMDVH unatrag dvije godine naziva “SDVLYQDNXüDNODVLN”, a
XNRQDþQRMYDULMDQWLL]YHGEHLQWHJUDFLMRPDNWLYQLKVXVWDYD]DGRYROMLWüHNULWHULMH“SDVLYQHNXüH
plus”. 1D WHPHOMX GRVDGDãQMH QDMEROMH SUDNVH SRWYUÿHQH SULPMHULPD RVWYDUHQMD WULMX
višestambenih zgrada i Prve ECO-SANDWICH® NXüH X =HOHQRP NYDUWX JUDGD .RSULYQLFHPRåH VH ]DNOMXþLWL GD MH JUDGQMD VWDPEHQH DUKLWHNWXUH X VNODGX VD Vtandardom SDVLYQH NXüH
(energetski razred “A+”), uz visoke VWUXþQHLRUJDQL]DFLMVNHVSRVREQRVWLORNDOQHXSUDYHkakvu
SRWYUÿXMH uprava Koprivnice, priuštiva i u okviru džavnog programa poticane stanogradnje.
8. LITERATURA[1] 0LãþHYLüLj.: Passive houses in Croatia - projects and realizations, 11th International
Conference on Passive Houses 2007, Conf. Proceed., Bregenz, PHI, Darmstadt, pg 295-300[2] 0LãþHYLü/M([SHULHQFHLQDUFKLWHFWXUDOGHVLJQFRQVWUXFWLRQDQGXWLOL]DWLRQRISDVVLYH
houses and a start of PASS-NET IEE project in Croatia, 13th International Passive House
Conference 2009, Frankfurt, PHI, Darmstadt, 2009, 978-3-00-027511-1, pg 221-226[3] 0LãþHYLü/M$UFKLWHFWXUHDVD3RZHU3ODQW– from Passive House to Plus-energy
Architecture, Exhibition catalogue, ISBN 978-953-7316-09-9[4] 0LãþHYLü/M3DVVLYHKRXVHLQ6RXth-Central Europe, 14th International Passive House
Conference 2010, Dresden, PHI, Darmstadt, 2010, ISBN: 978-3-00-031174-1, pg 321-328[5] 0LãþHYLü/M)URPWKHXQLTXHLWHPWRSUHIDEULFDWHGZRRGHQ3DVVLYH+RXVHth Int. P. H.
Conf. 2011, Innsbruck, PHI, Darmstadt, ISBN: 978-3-00-034396-4, pg 165-170[6] 0LãþHYLü/M7KHILUVWWHQUHDOL]DWLRQs of Passive Houses in Croatia - experience in design,
construction and financing, 16th International Passive House Conference 2012, Hannover,Passivhaus Institut, Darmstadt, 2012, ISBN: 978-3-00-037720-4, pg 241-246[7] 0LãþHYLü/M%DQMDG3HþXU,0LORYDQRYLü%: Passive House and ECO-SANDWICH EU

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00LãþHYLü/M0LãþHYLü: 3UYDSDVLYQDNXüDVSUHGJRWRYOMHQLPIDVDGQLP…

Eco-innovation Project for Façade Panels, 17th International Passive House Conference
2013, Frankfurt, PHI, Darmstadt, 2013, ISBN: 978-3-00-041346-9, pg 517-518[8] 0LãþHYLü/M7KHILUVWWZHQW\SDVVLYHKRXVHVLQ&URDWLDth International Passive House
Conference 2014, Aachen, PHI, Darmstadt, 2014, ISBN: 978-3-00-045216-1, pg 503-508[9] 0LãþHYLü/M6RODUFLW\=DSUHãLüXUEDQSURMHFWJHQHUDWHGE\&URDWLDQ6RODU+RXVH &6+CERES), Eurosun 2012, ISES-Europe Solar Conference, Solar Energy for a Brighter
Future, 18-20 September 2012, Rijeka-Opatija, Book of abstracts, Rijeka, pg 99[10] 0LãþHYLü/M%DQMDG3HþXU,0LORYDQRYLü%Prefabricated Façade Panels for Newly
Built and Refurbished Nearly Zero Energy Buildings, Energy and the Environment 2014,
Opatija, 21.-24.10., ISBN 978-953-6886-18-0, 978-3-9814659-2-2, UDK 620.91:504>063[11] 0LãþHYLü, Lj.: PRVA ECO-6$1':,&+.8û$th Zagreb Saloon of Architecture and
Urbanism, Consistency / DosljednostVHOHNWRU+UYRMH1MLULü.DWDORJVWU-255, UHA,
Zagreb, 2015., ISBN 978-953-6646-29-6

THE FIRST PASSIVE HOUSE WITH PREFABRICATEDFAÇADE SYSTEM OF RECYCLED BUILDING AGREGATE

Abstract: The paper presents the world’s first implementation of ECO-SANDWICH® ventilated
prefabricated wall panel which utilises recycled construction and demolition waste (CDW) andmineral wool produced using innovative and sustainable technology for reduction of primaryenergy consumption in building stock and harmful impacts on climate changes. System wasdeveloped as a result of the cooperation of Croatian scientific institutions and industry, underwhich extensive research was performed in order to develop a new competitive product(www.eco-sandwich.hr). It is patented as the industrial design product with the brand name andits visual identity. Amongst major outputs and results of the project will be a scalable wall panel
system that is sustainable and affordable for its end users throughout the life-cycle. The
realization of The first ECO-SANDWICH® house is the result of a long research in developmentof sustainable materials and systems as methods of architectural design for the new and the highenergy efficient renewal („factor 10“) up to energy standard of passive house („A+“) andhigher. The paper presents urban-architectural and technological-construction realization
process of the small multifamily building with three flats that was designed as the type model
which will be performed on the next eleven sites in the Green Quartier of the town ofKoprivnica. The town energy development concept is described, as well as the project and thesystem, spatial, energy and design concepts and the construction. The new perception anddesign of the diagram of specific annual energy consumption in buildings (kWh/m2a) is
explained as the new clasification of passive houses, according to which in the last phase withintegration of active solar thermal and photo-voltaic systems, the house will comply the criteria
for the „passive house plus“.
Key words: prefabricated ventilated façade system, The first ECO-SANDWICH® house, passive
house, energy renewal “factor 10”, contemporary energy building standards

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UTJECAJ SNIŽENJA TEMPERATURE RASHLADNOG SPREMNIKA NA
1
KARAKTERISTIKE STIRLINGOVA MOTORA
Wilhelm Servis
Gutstrasse 51, 8400 Winterthur, Švicarska
w.servis@bluewin.chSažetak: O znanstvenom projektu „Novi koncept Stirlingova motora/ New Stirling Engine Concept(NSC)”, [1], su autor i njegovi suautori izvještavali u više navrata tokom njegovog razvoja uproteklom vremenskom periodu od oko 25 godina, [4 do 13], a predzadnji puta u s posterom u okviru
E&E2014 i ovaj puta isto tako s posterom u okviru E&E2016, Opatija 2016.
Iz objavljenih radova autora tokom tog perioda XNOMXþXMXüLLdoktorsku disertaciju, u kojoj su svi
relevantni dotadašnji radovi citirani, se može vidjeti, da RYDMSURMHNWRGVDPRJQMHJRYRJSRþHWND
XRþDYDekološke i energetske probleme Zemlje istaknute i od znanstvene ekipe „Club of Rome”, [1],,GDMHELRELWQRSRGUåDYDQRGQDãHJYUOR]QDþDMQRJ]QDQVWYHQLND, pokojnog profesora Ive Kolina i
od autorovog mentora prof. Dr.sc. Vlaimira Medice (RITEH-HR) i da nizom objavljenih radova
ispituje, traži i dokazuje PRJXüQRVWL UMHãHQMD tih problema, da bi u okviru disertacijskog rada
autora, [1], pa do danas dao definitivne, znanstveno fundirane analize tih problema i na kraju
NRQNUHWQHSULMHGORJHMHGQRJPRJXüHJDVSHNWDQMLKRYRJUMHãHQMD (to su NSC-koncept, NSC-proces,izotermalni NSC-motori, DSC-solarni konverter i od autora u najnovije vrijeme patentiranim
postupcima GEA i ISOTEX za karnotiziranje toplinskih/ dizelskih motora i nedavno jedan novi
koncept sistema trakcionih baterija, TRAKSER, koji omoguüDYDSHUPDQHQWXSUL]YRGQMXHOHNWULþQH
struje/ rada s primarnim baterijama tipa metal/ zrak). Na osnovi tih rezultata smatra autor danas;da bi se korištenjem NSC-NRQFHSWD]DLVWDPRJORSRVWLüL]QDWQXUHGXNFLMXXRþHQLKSUREOHPDDOLLGD
VH WX VXNREOMDYDPR V þLQMHQLFRP GD NDGD EL VH VYH WRSOLQVNH PRWRUH RYH =HPOMH XVDYUãLOR GD
funkcioniraju npr. po uputama NSC- ili nekog drugog pozitivnog koncepta, da bi još uvijek
energetska/ ekološka situacija Zemlje pokazana slikom 1 RVWDOD X ELWL QHSURPLMHQMHQD SD üH WD
situacija prije ili kasnije dovesti Zemlju do energetskog i ekološkog kolapsa" i da se rješenje trebatražiti u primjeni ekološki pogodnih poznatih i novih energetskih sistema (npr. VXQþHYe energije i s
QMRPSURL]YHGHQRJYRGLND SRPRüXQSUDXWRURYRJ'6&-konvertera), energije vjetra, energije vodei valova i u najnovije vrijeme i s najperspektivnijim energetskim sistemima s primarnim baterijama
tipa mHWDO ]UDN SRGUåDQLP V DXWRURYLP 75$.6(5RP ]ERJ þHJD WDNYL VLVWHPL SRVWLåX VWUDWHãNX
vrijednost neovisnosti od zemnog ulja ili plina.
.OMXþQHULMHþL NSC-koncept, Izotermalni NSC-proces, Izotermalni NSC-PRWRUL'LQDPLþNLVRODUQL
konverter DSC, GEA- ISOTEX-sistemi, koncept sistema TRAKSER.

1

Povodom 10. godišnjice autorove obrane doktorske disertacije (2006/ 2016) i 200. godišnjice Stirlingova motora(1816/ 2016)

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W. Servis: Utjecaj sniženja temperature rashladnog spremnika na…

1. UMJESTO UVODA

Namjera ove refleksije je, s ovdje pokazanim posterom pružiti sažeti pregled autorovog
znanstvenog rada za period od 10 godina od obrane autorove disertacije [1], posebno uperen na
konceptualnu novinu rezultata tih, sa izotermnom tematikom povezanih radova, koju su i Robert
6WLUOLQJVSUHGJRGLQDSDWHQWLUDQLPLDGKRFL]YDQUHGQRXVSMHãQRL]RWHUPQRIXQNFLRQLUDMXüLP
motorom,slika 2 LQHãWRNDVQLMH6DGL&DUQRW 5HIOHFWLRQV XVSMHãQRREUDÿLYDOLPoster Refleksije na Doktorsku Disertaciju "UTJECAJ SNIŽENJA TEMPERATURE RASHLADNOG SPREMNIKA NA
KARAKTERISTIKE STIRLINGOVA MOTORA", Kongres ENERGIJA I OKOLIŠ, Opatija 2016

Energy and the Environment (2016) 629-646

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Svojim disertacijskim radom [1]WHPDNRMHJMHYHüSUHGRNRJRGLQDWUDåLODUMHãHQMD]DYHüWDGDSULMHWHüHHNRORãNHHQHUJHWVNHSUREOHPH=HPOMHslika 1, je autor utvrdio da:«,]DNWXDOQHDQDOL]HVWDQMDLSHUVSHNWLYH =HPOMH QDþLQMHQH RG]QDQVWYHQHHNLSH&OXERI5RPH
L]PHÿX RVWDORJD SURL]OD]L GD VWDQRYQLãWYR =HPOMH L FMHORNXSQD VYMHWVND SRWURãQMD HQHUJLMH VWDOQR
rastu, da taj porast ima eksponencijalni karakter i da taj problem i njegove posljedice poprimaju
JOREDOQH UD]PMHUH D RþLWXMX VH a) X RSüHP LVFUSOMHQMX ]DOLKD SULURGQLK ERJDWVWDYD =HPOMHb) X HNRORãNLP SRWHãNRüDPD RGUDåHQLP ]DJDÿHQMHP L RãWHüHQMHP RNROLãD L ELRVIHUH L SRUDVWRP
srednje temperature atmosfere Zemlje i c) XVRFLRORãNLPSRWHãNRüDPD, odraženim padom životnog
VWDQGDUGDLRVLURPDãHQMHPXRþOMLYLKQHVDPRXQHUD]YLMHQLP]HPOMDPD NRMHDNWXDOQRNXOPLQLUDMXXUHJLRQDOQLPUDWQLPLL]EMHJOLþNLKNRQIOLNWLPD  Analiza svih mjera, s kojima bi se gore spomenuti
SUREOHPL ULMHãLOL SUHãOD EL XYHOLNH FLOMHYH L RNYLUH RYRJ UDGD DOL MH MDVQR GD WX VD VLJXUQRãüXmožemo ubrojiti i mjere za smanjenje potroška pogonskog goriva odnosno za povišenje korisnosti
toplinskih motora. U tom okviru je YUORYDåQRLSURQDODåHQMHRGJRYDUDMXüLKVXSVWLWXFLMDJRULYLPDX
današnjoj uporabi (zemni plin umjesto benzina ili dizelskog goriva), kao i traženje putova za
korištenje obnovljivih, alternativnih izvora energije u koje možemo ubrojiti: bio-plin, vodik, zrak i
QMHJRYHGHULYDWH XXNDSOMHQRPVWDQMXHNVHUJLMD DOLLVXQþDQXHQHUJLMXHQHUJLMXYMHWUDHQHUJLMX
vode i valova i druge mjere)…".
Slika 1 Porast stanovništva zemlje i posljedice [1, 11 i 14]

Slika 2 Stirlingov motor 1816 (BETA, E)
Iz slike se mogu razaznati sve
NDUDNWHULVWLþQHVDVWDYQLFHLXRþLWLQDþLQUDGDPRWRUD
Da bi se te motore moglo
razlikovati razvijene su
tipologije (npr. DEJ), od
kojih ovdje spominjemo
prezentiranu doktorskim
radom autora[1 s.19, 1 s.23, 2].

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U smislu gornje analize MH DXWRU SROD]HüL RG NODVLþQRJ Stirlingova motora i njegovog
izotermalnog procesa ([1], najboljeg PRJXüHJ!), usmjerio svoj rad prema daljnjem usavršavanju iWUDåHQMXPRJXüQRVWLSREROMãDQMDWRSOLQVNHNRULVQRVWLWRJSURFHVDGDELXRNYLUXGLsertacijskog rada,
korištenjem dva eksperimentalna Kolinova motora, (poster slika 3) slike 3a i 3b (koji su prvi,
uspješni i povijesno zapaženi KONSTRUKTIVNI NOVI KONCEPTI jednog Stirlingova motora) i
dva motora u autorovoj izvedbi, slike 3c i 5, po prvi puta eksperimentalno potvrdio Carnotovu
tvrdnju GDVXSRUDVWLXþLQNRYLWRVWLL]RWHUPQLKPRWRUDYHüLDNRVH]DLVWLWHPSHUDWXUQLSRMDVUDGDPRWRUDWHPSHUDWXUHGRYRÿHQMDWRSOLQHVQL]XMX[1 s.152 i 163].
Slika 3a
Eksperimentalni motor PROBA1 (Kolinova plosnata varijanta "WINTERTHUR 1988")
Mjerenja motora za: - IUC-Dubrovnik 1998 (TIM = 333K/ TOM = 303 -263K) i- 9th ISEC Pilanesburg 1999 (TIM = 283K/ TOM = 253 -213K)

Slika 3b
Eksperimentalni motor PROBA2 (Kolinova plosnata varijanta "ROMA 1988")
Mjerenja motora za: 10th ISEC Osnabrück 2001 (TIM = 293K/ TOM = 213 -163K)

Slika 3c
Eksperimentalni motor PROBA2B (Kolinova plosnata varijanta u izvedbi autora 2002.)
Mjerenja motora za: 11th ISEC Rome 2003 (TIM = 293K/ TOM = 233 -83K)

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Djelotvorni, sveukupni, bitni rezultati autorovog disertacijskog rada su bili:
1) definicija autorovog izotermalnog NOVOG KONCEPTA STIRLINGOVA MOTORA (engl.
NSC), [1 s.101], VNRMLPVHPRJXSRVWLüLQDMYLãLWHUPRGLQDPLþNHNRULVQRVWLPRWRUD, (poster slika 4)
vidi slike 4a, 4b, 4c, s uputama i rješenjima za izvedbe NSC-motora, i 2) niz patentnih prijava,
konstrukcija i izvedbi NSC-motora, od kojih je NSC-motor PROBA3D, tipa PROFIT0, slika 5, prvi
uspješno IXQNFLRQLUDMXüLRGXUDGXGHILQLUDQDWULPRJXüDWLSD16&-motora (PROFIT0, PROFIT1 i
PROFIT2), [1].
Slika 4aUsporedba izotermnog NSC-procesa sa Stirlingovim, Ottovim i Diesel/ Sabathé procesom

Slika 4b
3UHJOHGIDPLOLMHWRSOLQVNLKPRWRUD XNOMXÿXMXýL16&-motore)

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Na slici 4b vidimo shemu familije toplinskih motora iz koje vidimo, da su NSC-motori, izvedeni po
NSC-NRQFHSWX ORJLþQL QDVWDYDN UD]YRMD GR WDGD SR]QDWLK WRSOLQVNLK PRWRUD D QD slici 4c vidimo
usporedbe Izotermnog Novog Koncepta Stirlingova Motora (NK/ NSC) sa Diesel/ Sabathé
procesom kao i usporedbe 7HUPRGLQDPLþNH NRULVQRVWL L SURL]YHGHQRJ UDGD NUXåQLK SURFHVD za:.ODVLþQL 6WLUOLQJ .  'L]HOVNL '  6WLUOLQJ V NULRJHQLþNLP WHPSHUDWXUDPD ..  L 1RYL .RQFHSWStirlingova Motora (NK/ NSC). Iz te slike se vidi apsolutnu QDGPRüQRVW L]RWHUPDOQRJ 16&Slika 4c
Usporedbe:

Izotermnog Novog Koncepta Stirlingova Motora (NK/ NSC) sa Diesel/ Sabathé procesom i
7HUPRGLQDPLÿNHNRULVQRVWLLSURL]YHGHQRJUDGD kružnih procesa: .ODVLþQL6WLUOLQJ . 'L]HOVNL ' 
6WLUOLQJVNULRJHQLþNLPWHPSHUDWXUDPD .. L1RYL.RQFHSW6WLUOLQJRYD0RWRUD 1.16& , [1].

8VSRUHGEDWHUPRGLQDPLÿNHNRULVQRVWLLproizvedenog rada kružnih procesa:- .ODVLþQL6WLUOLQJ . - Dizelski (D),- Stirling VNULRJHQLþNLPWHPSHUDWXUDPD .. 
- Novi Koncept Stirlingova Motora (NK/ NSC)(ANALIZA EXSIMEL)

Slika 5Eksperimentalni motor PROBA3D (NSC, PROFIT0 u izvedbi autora 2003.), [1]Mjerenja motora za: Disertacijskii rad TFR/ Servis (TIM = 373K/ TOM = 132K)

Energy and the Environment (2016) 629-646

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procesa.
Daljnji autorovi radovi na tu temu su tokom 10 godina od obrane disertacije, 2006. godine dodanas slijedili i dobrim dijelom postigli tada postavljene prioritetne ciljeve (vidi poster E&E2016) ito:Cilj A) GRND] L L]YHGEX IXQNFLRQLUDMXüHJ 16&-motora tipa PROFIT1: to su bili Prototip-motor
PROSUNX slika 6 i Eksperimentalni motor KNSC slika 8, [27, 28, 29, 30, 31, 32, 33] i
Cilj B) rješenja za pogon NSC-motora tipa PROFIT1 sa visoko temperaturnom VXQþHYRP
toplinom, konvertirane s autorovim DSC-konverterom, slike 7, 11, 12, 13/ ili hibridno s vodikom[29] a neki rezultati tih radova (patentne prijave, konstrukcije i izvedbe njihovih prototipa ili
modela, su u poglavlju 2 uvršteni kao autorovi "NOVI KONCEPTI".
Slika 6
Prototip-motor PROSUNX (NSC-Sol/ Hyb) na probnom stolu (patentirano: CH 0275/12, [30])u izvedbi autora 2012 (privatno financirani projekt je bio prekinut- oko 90%)
(Projektirano: TIM = 1000 K/ TOM = 293 K)
Taj prvi prototip Solarni/ hibridni NSCmotor tipa PROFIT1 je projektiran u
modularnoj izvedbi sa po dva cilindra i
HOHNWULþNLPJHQHUDWRURPJHQHUDWRULPDL
kao takav je trebao proizvoditi
PEL=1kW/modulu pri n= 500 1/min.
Prototip motora je trebao biti pogonjen
VDHOHNWULþNLJULMDQLPVSLUDODPD NDVQLMH
DSC, vidi sliku 7 LOLYRGLN LKODÿHQV
radnim medijem (destiliranom vodom).

Slika 7
'LQDPLÿNLVRODUQLNRQYHUWHU DSC) (patentirano: CH 1579/11, [15 i 29]).
DXWRURY.RQFHSWNRULãWHQMDVXQþHYHHQHUJLMH
Projektirano: TIM = 293K/ TOM = 1400K

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Slika 8Eksperimentalni motor KNSC na probnom stolu
Ispitivanja i mjerenja tog motora su rezultirali s patentnim prijavama GEA- i ISOTEX-sistema za karnotiziranje procesa
toplinskih motora.

Na osnovi tih rezultata smatra autor danas; da bi se korištenjem NSC-koncepta zaista moglo
SRVWLüL]QDWQXUHGXNFLMXXRþHQLKSUREOHPD QHVDPRV16&-motorima i DSC-NRQYHUWHURPYHüLVD
od autora u najnovije vrijeme patentiranim postupcima GEA i ISOTEX za karnotiziranje
toplinskih/ QDURþLWRdizelskih motora, (poster E&E2016 slike 8.1. 8.2, i poglavlje 2 [31 i 32 , slike
14
i
15])
DOLLGDVHWXVXNREOMDYDPRVþLQMHQLFRP"da kada bi se sve toplinske motore ove Zemlje usavršilo da funkcioniraju npr. po uputama
NSC- ili nekog drugog pozitivnog koncepta, da bi još uvijek energetska/ ekološka situacija
Zemlje pokazana slikom 1 RVWDOD X ELWL QHSURPLMHQMHQD SD üH WD VLWXDFLMD SUije ili kasnije
dovesti Zemlju do energetskog i ekološkog kolapsa".
Zbog toga autor smatra, DYULMHPHüHSRND]DWLGDOLMHDXWRUXSUDYXda se Zemlja energetski i
HNRORãNL JOHGDQR GDQDV QDOD]L QD SRþHWNX MHGQH QRYH, SUDJPDWLþNH epohe, X NRMRM üH
SURL]YRGQMDUDGDSRVUHGVWYRPWRSOLQHGRELYHQHQHSRYUDWQLPL]JDUDQMHP SUDüHQDvrlo nepogodnom
kontaminacijom s proizvodima tog procesa) visokovrijednih primarnih energenata (ugljen, zemno
ulje i zemni plin) morati opadati, po potrebi do nekog smislenog minimuma i biti globalno
zamijenjena s proizvodnjom rada posredstvom postojanih/ povrativo uporabivih izvora energije, to
su: a.a.) VXQþHYD HQHUJLMD L V QMRP SURL]YHGHQL YRGLN SRPRüX QSU autorovog DSC-konvertera),b.b.) energija vjetra, c.c.) energija vode i valova i d.d.) u najnovije vrijeme razvijeni i vrlo
perspektivni energetski sistemi s primarnim baterijama tipa metal/ zrak (nepunjivim) podržani s
autorovim TRAKSERom, [34, slike 9, 16], vidi poglavlje 2.
Razlog te autorove procjene je tek u novije vrijeme ]DGRYROMDYDMXüL postignuti visoki potencijalenergetskih sistema s primarnim baterijama tipa metal/ zrak (vidi npr. WWW. Phinergy i primjenu
tih sistema za pogon npr. automobila), izražen s njihovom izvanredno visokom sposobnosti direktne
WUDQVIRUPDFLMHNHPLMVNHXHOHNWULþNXHQHUJLMX YLVRNDVSHFLILþQDHnergija od aktualno oko 64% od
dizelskog goriva, bez emisija, s vrlo jeftinim komponentama npr. u izvedbi s aluminijskim
DQRGDPD SRWSXQRM PRJXüQRVWL UHFLNOLUDQMD L što je najvažnije, u RSüRM UDVSRORåLYRVWL DOXPLQLMD  L
tek pred kratko vrijeme postignuta sposobnost usavršavanja tih sistema s autorovim TRAKSERom.

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2. Autorovi "NOVI KONCEPTI"NOVI KONCEPT 1 (slike 4a, 4b, 4c, 5, 10):
NSC, Disertacijski rad i rezultat „Novi koncept Stirlingova motora/ New Stirling Engine
Concept (NSC)“, [1, 17, Poster E&E2016 i ovaj rad],Patentirano: [18 do 25]
O NSC-konceptu, koji je bitni rezultat autorovog disertacijskog rada, je bilo više puta informirano[10 do 17] SDüHDXWRURYGMHnavesti samo bitne upute tog koncepta.
NSC-motore po NSC-NRQFHSWXNDUDNWHUL]LUDMXVOLMHGHüDVYRMVWYDLþLQMHQLFH:(1) Opis motora
Motori po NSC-NRQFHSWX VX RSLVDQL L ]DãWLüHQL  Va 17 patentnih prijava, [18 do 28, 30 do 33].
Te patentne prijave se direktno osnivaju na saznanjima dobivenim znanstvenim istraživanjem uokviru ovog disertacijskog rada i tokom 10 godina od odbrane rada do danas.
(2) 'RYRÿHQMHLRGYRÿHQMHWRSOLQHSURFHVXXPRWRUX'RYRÿHQMH L RGYRÿHQMH WRSOLQH RG SURFHVD X PRWRUX VH L]YRGL direktno. Time se izbjegavaju ili
umanjuju nekontrolirani tokovi toplina u motoru i na okolinu motora i (što se grijaQMDWLþH SRVWLåX
uvjeti kao u Ottovim ili dizelskim motorima.
(2a) 'LUHNWQRGRYRÿHQMHWRSOLQH JULMDQMH XSURFHVPRWRUDPRåHEiti izvedeno pri temperaturama
okoline ili niže pa do najviših postizivih temperatura, tako;-da se toplina proizvodi direktnim izgaranjem radnog medija u motoru ili-da se toplina dovodi izvana (ali ne prolazom topline kroz stjenke motora!) i predaje procesu motora
SRPRüXXJUDÿHQLKJULMDþD W]YWRSOHSORþHLOLVSLUDOH).
(2b) 'LUHNWQRRGYRÿHQMHWRSOLQH KODÿHQMH RGSURFHVPRWRUDPRåHEiti izvedeno pri temperaturama
RNROLQHSDGRQDMQLåLKSRVWL]LYLKNULRJHQLþNLKWHPSHUDWXUDWDNR
-da se toplina od procesa oduzima direktnim ubrizgavanjem ukapljenog radnog medija u motor itime tokom jednog dijela procesa približno postiže temperature isparavanja tog radnog medija ili-GDVHHQHUJLMDRGSURFHVDPRWRUDRGYRGLSRPRüXXJUDÿHQLKKODGQMDND W]YKODGQHSORþHLOLspirale,KODÿHQHnpr. ukapljenim plinovima itd.).
(3) Karnotiziranje procesa u motoru
Karnotiziranje Stirlingovih motora se izvodi tako da oni imaju regenerator i da se tokom procesa u
PRWRUXWRSOLQHL]PHÿXUDGQRJPHGLMDLUHJHQHUDWRUDL]PMHQMXMXSRPRJXüQRVWLL]RKRUQRDpri tome
se kompresija i ekspanzija radnog medija treba i]YRGLWLSRPRJXüQRVWLL]RWHUPQR'DELVHWRPRJORSRVWLüLSRWUHEQRMHLPDWLQDUDVSRODJDQMXWRSOLQVNLSRdobne regeneratore, pa se u tu svrhu, po NSCkonceptu može (DOLQHPRUD NRULVWLWLLMHGDQQRYLWLSUHJHQHUDWRUDW]Y³,JOLþDVWLUHJHQHUDWRU´ SLQ
regenerator, razvijen i isproban u okviru rada, ali još ne i znanstveno istražen). Najnovija ispitivanjas KNSC-motorom su rezultirala s dva nova postupka GEA- i ISOTEX-postupak (slike 8.1. i 8.2), vidi
poglavlje 2.
(4) +LEULGQLLVWLVNLYDþ
(4a) Istiskivanje radnog medija tokom procesa u motoru se po NSC-konceptu izvodi hibridnim
SRJRQRPLVWLVNLYDþD1DWDMQDþLQVHPRåHSRVWLüLRSWLPDOQRSULEOLåenje izohornoj izmjeni topline
L]PHÿXUHJHQHUDWRUDLUDGQRJ PHGLMDLRPRJXüDYDMHGQRVWDYQRXSUDYOMDQMHUDGDPRWRUD+LEULGQRSRNUHWDQMD LVWLVNLYDþD RPRJXüDYD IOHNVLELOQR YRÿHQMH SURFHVD motora i dobiva kroz primjenu
industrijske elektronike na važnosti (isto kao pokretanje ventila i izvRÿHQMHXEUL]JDYDQMDJRULYDNRG
današnjih motora s unutarnjim izgaranjem).
(4b) 2VLPNODVLþQRJKLEULGQRJLVWLVNLYDþDMH]DRYHPRWRUHSUHGYLÿHQMRãLW]Y³'LQDPLþNLKLEULGQLLVWLVNLYDþ´ V NRMLP VH UDGQL PHGLM SUL VWDOQRP YROXmenu stalno cirkulira u prostoru motora(uspješno isproban s motorom PROBA3A [1], PROSUNX i KNSC [30, 32, 33].

638

W. Servis: Utjecaj sniženja temperature rashladnog spremnika na…

7DMQDþLQLVWLVNLYDQMDUDGQRJPHGLMDMHSULPMHQMLYMHGLQRXNRPELQDFLMLVXEUL]JDYDQMHPXNDSOMHQRJ
radnog medija u motorima tipa PROFIT1 i PROFIT2.
(5) Prijenos rada na koljenasto vratilo motora
Prijenos rada od radnog stapa motora se po NSC-NRQFHSWX L]YRGL SRPRüX NODVLþQRJ VWDSQRJ
mehanizma sa ili bez križne glave i zamašnjakom (uvjet takve izvedbe kinematike motora je
KLEULGQLSRJRQLVWLVNLYDþD (6) 3UHGYLÿHQLWLSRYLPRWRUDSRNSC-konceptu(6a) Motori tipa PROFIT0: s direktnim grijanjem s nisko- i visoko-WHPSHUDWXUQLP]DJULMDþHP Qpr.
kDWDOLWLþNR ili ino izgaranje, solarno grijanje, temperatura geoloških izvora topline, toplina okoline
LWG LGLUHNWQLPKODÿHQMHPVKODGQMDNRPKODÿHQLPQHNLPXNDSOMHQLPSOLQRPLOLKODGQLPPHGLMHP
(eksergija) u zatvRUHQRPWHUPRGLQDPLþNRPVLVWHPX
(6b) Motori tipa PROFIT1: koji imaju istovjetno direktno grijanje kao i PROFIT0 (ali sa što višim
temperaturama) L GLUHNWQR KODÿHQMH V ubrizgavanjem ukapljenog radnog medija, u otvorenom
termodiQDPLþNRP VLVWHPX 9LãDN UDGQRJ medija se ispušta u okolinu ili se kondenzira (motori
PROBA3A, PROSUNX i KNSC).
(6c) Motori tipa PROFIT2: koji imaju direktno grijanje postignuto izgaranjem radnog medija s
NRQWUROLUDQLPGRYRÿHQMHPRNVLGDQWDXSURVWRUFLOLQGUDPRWRUDLGLUHNWQRKODÿHQMHVubrizgavanjem
ukapljenog radnog medija, u otvorenom termodiQDPLþNRPVLVWHPX9LãDNUDGQRJmedija se ispušta
u okolinu ili se kondenzira. Ti motori se do sada nisu ispitivali.
(7) 7LSLþQHWHPSHUDWXUH]DJULMDþDL hladnjaka po NSC-konceptu su pokazane na slici 10.
Slika 107LSLÿQHWHPSHUDWXUH]DJULMDÿDLKODGQMDND6WLUOLQJRYLKPRWRUDSR16&-konceptu, [1. s.102])(8) Prototip NSC-motora po NSC-konceptu tipa PROFIT0, je izrDÿHQ od autora pod radnim
nazivom PROBA3D (2003), slika 5.
(9) Prototip NSC-motora po NSC-konceptu tipa PROFIT1, je L]UDÿHQ (90%) u koprodukciji sautorom pod radnim nazivom PROSUNX (2012), slika 6.
(10) Eksperimentalni NSC-motora po NSC-konceptu tipa PROFIT1MHL]UDÿHQod autora pod
radnim nazivom KNSC (2015/ 2016), slika 8.

Energy and the Environment (2016) 629-646

639

NOVI KONCEPT 2 (slike 7, 11, 12, 13):
DSC, „'LQDPLþNLVRODUQLNRQYHUWHU“ [15, 16, Poster E&E2016 i ovaj rad]Patentirano: CH 1579/11, [29]
'LQDPLþNLVRODUQLNRQYHUWHUVHXNODSDX16&-koncept s tim, da RQRPRJXüDYDSRJRQ16&-motora(tipa PROFIT0 i PROFIT1) s vrlo visokim WHPSHUDWXUDPDLQDWDMQDþLQSRVWL]DQMHXWHKQLFLQDMYLãLK
WHUPRGLQDPLþNLKHNRQRPLþQRVWL.
O DSC-konverteru, koji je isto tako bitni rezultat autorovog disertacijskog rada, jer omoJXüava
ekološki podobni pogon NSC-motora s vrlo visokim temperaturama, je bilo više puta informirano[15 i u pripremi 16] SDüHDXWRURYGMHnavesti samo neka bitna svojstva tog sistema.
DSC-NRQYHUWHUNDUDNWHUL]LUDMXVOLMHGHüDVYRMVWYDLþLQMHQLFH
(1) DSC-konverter je uspješno isproban u mjerilu 1:10 (DSC300), slike 7 i 11,
Slika 11
)XQNFLRQLUDMXýLPRGHO'6&300-konvertera (1:10 ) u pogonu(2) DSC-sistem opskrbljuje SRWURãDþH WRSOLQH SXWHP WRSOLQVNL L]ROLUDQRJ FMHYRYRGD V po potrebi
visoko zagrijanim zrakom temperature (TSPOT), ovisno o koeficijentu koncentracije VXQþHYLK]UDND
C (npr. za C = 500 je TSPOT = 970 do 1700K)(3) DSC-VLVWHP RSVNUEOMXMH SRWURãDþH WRSOLQH SXWHP WRSOLQVNL L]ROLUDQRJ FMHYRYRGD V SR SRWUHEL
visoko zagrijanim zrakom s NROLþLQRP energije ovisnoj o promjeru, koeficijentu koncentracije,
NYDOLWHWLSDUDEROLþQRJRJOHGDOD i geografskoj širini QDNRMRMVHSDUDEROLþno ogledalo nalazi, slika 12.
Toplotna energija proizvedena s DSC ]DMHGQRSDUDEROLþQRRJOHGDOR je pokazana sa slikom 13.
(4) 7RSOLQXLVSRUXþHQXV'6&-konverterom se osim za individualni/ masovni pogon NSC- ili drugih
pogodnih toplinskih motora, slika 7, može upotrijebiti npr. za grijanje, kuhanje (patent u pripremi),
odsoljavanje morske vode, proizvodnju vodika (vodikova era) itd. [15, 16]

640

W. Servis: Utjecaj sniženja temperature rashladnog spremnika na…

Slika 122
6XQÿHYDNRQVWDQWDQDDWPRVIHUVNRMJUDQLFLje C = 1.366 kW/m a nakon prolaza kroz atmosferu, na površini
2
zemlje je C = od oko 0.05 do 0.35kW/m

45°

45°

Slika 13(QHUJLMDNRMXSDUDEROLÿQRRJOHGDORSUHGDMHQD'6&]DC = 0.35kW/m2, [15]Npr.
-3URPMHUSDUDEROLþQRJ
ogledala
dDSC= 22.9m (75ft),-PovršinaADSC = 412m2-Energija predana na
DSC
PDSC = 144kWNOVI KONCEPT 3 (slika 14):
GEA = Gasunterstützte Einspritzung des Arbeitsmediums/ „Carnotisieren der Kreisprozesse
der Wärmekraftmotoren durch isotherme Ausführung ihrer Kompression mit GEAVorrichtung“ [Poster E&E2016 i ovaj rad]Patentirano: CH 0091/16, [32]Energy and the Environment (2016) 629-646

641

GEA-sistem za karnotiziranje kompresije procesa toplinskih motora je razvijen i patentiran u okviru
testova s eksperimentalnim motorom KNSC, slika 8 (poster slika 8.1), sa ciljem razvoja jedne
varijante s NSC-NRQFHSWRPXWYUÿHQRJSRVWXSNDdirektnog GRYRÿHQMDradnog medija u motor (sada
SRPRüX NRPSULPLUDQRJ ]UDND L ]DWR MHGQRVWDYQLMH L MHIWLQLMH  kojom prilikom je bio i uspješno
isproban (pa je upotreba i tog sistema ovisna o iskustvima s hipotetskom upotrebom i korištenju
NSC-motora) slika 14.
Autor smatra da sistem GEA može biti upotrijebljen i za karnotiziranje faze kompresije dizelskog
procesa (utjecaj karnotiziranja QD LQDþH DGLDEDWVNL L]YHGHQX NRPSUHVLMX dizelskog procesa je pri
tome ovisan o SRWUHEQRMNRQDþQRMWHPSHUDWXULNRPSUHVLMHT2GEA konkretnog motora pa je prednost
postupka GEA da se zrak nakon nabijanja može pri upotrebi GEA-sistema manje hladiti = jeftiniji
hladnjak, dakle može se imati višu temperaturu na ulazu u motor a istu temperaturu na kraju
kompresije) i kao rezultat dulje izotermno komprimirati, od WRþNH  GR  ). Potencijal korištenja
GEA-sistema je osim karnotiziranja i u poznatom povoljnom utjecaju ubrizgane vode, na tvorbu
NOX tokom procesa izgaranja goriva u dizelskom motoru
Slika 14
GEA-sistem za karnotiziranje kompresije procesa toplinskih motora

NOVI KONCEPT 4 (slika 15):
ISOTEX = Isotherme Expansion/ „Carnotisieren der Kreisprozesse der Wärmekraftmotoren
durch isotherme Ausführung ihrer Expansion mit ISOTEX-Vorrichtung“ [Poster E&E2016 i
ovaj rad]Patentirano: CH 0224/16, [33]
ISOTEX-sistem za karnotiziranje ekspanzije procesa toplinskih motora je razvijen i patentiran uokviru testova s eksperimentalnim motorom KNSC, slika 8 (poster slika 8.2), kojom prilikom je
bio i uspješno isproban. Usporedbom slika 14 i 15 vidimo, da kombinacija GEA- i ISOTEXVLVWHPD RPRJXüDYD PDNVLPDOQR PRJXüH NDUQRWL]LUDQMH GL]HOVNRJ SURFHVD L XMHGQR GD MH XWMHFDM
GEA-sistema na karnotiziranje cijelog dizelskog procesa manji (slika 14) a da bi korištenje
ISOTEX-sistema (slika 15) kod dizelskih motora imalo vrlo pozitivno djelovanje.
Iz usporedbe vidimo i izvanrednu prednost potpuno izotermnog, NSC-procesa i ujedno neoborivuþLQMHQLFXGDVHGL]HOVNLSURFHV„ne može“ (vidi GEA, slika 14) potpuno karnotizirati.

642

W. Servis: Utjecaj sniženja temperature rashladnog spremnika na…

Slika 15
ISOTEX-sistem za karnotiziranje ekspanzije procesa toplinskih motora

NOVI KONCEPT 5 (slike 9 i 16):
TRAKSER = Traktion Servis/ „Konzept für eine Neuartige-Traktion-Batterie der nicht
wieder aufladbarer Art“ [Poster E&E2016, ovaj rad i u daljnjem razvoju od autora]
Patentirano: CH 0968/16, [34])TRAKSER, slika 16 stoji za koncept i izvedbu od autora patentiranog sistema, s kojom se za topogodne primarne baterije s visokom energetskom JXVWRüRP QSUWLSDPHWDO]UDNYLGL:::
Phinergy), RVSRVREOMDYDMXGDVOLþQRNDRNRGQSUWRSOLQVNLKPRWRUDSRVWLåXVSRVREQRVWVWDOQHSURL]YRGQMHHOHNWULþQHVWUXMH/ rada/ (kod toplinskih motora: uz nadopunu goriva u spremnik goriva akod TRAKSERA: uz nadopunu potrošenih dioda u spremniku dioda SULþHPXVHQSUNRGu novije
vrijeme razvijenih baterija tipa aluminij/ zrak (korištenje fenomena REDOX = Anoda Æoksidacija,
Katoda Æredukcija) aluminij posredstvom u zraku sadržanog kisika i na vodi osnovanog
elektrolita, elektrokemijski UD]JUDÿXMH(4Al+3O2+6H2OÆ4Al(OH)3) i pri tome potpuno
UHJHQHUDWLYQRLEH]LNDNYRJHNRORãNRJ]DJDÿHQMDRNROLãDJHQHULUDHOHNWULþQXVWUXMXQDSRQDod oko
1.2V. Tako dobiveni Aluminiumhidroksid se bez ekološkog ]DJDÿLYDQMDLEH]JXELWNDVXSVWDQFLMHPRåHSRWSXQRUHFLNOLUDWLX$OXPLQLMQSUNRULãWHQMHPYLVRNRWHPSHUDWXUQHVXQþHYHWRSOLQH
dobivene DSC-konverterom [29, NOVI KONCEPT 3] i onda ponovo upotrijebiti u TRAKSERu.

Energy and the Environment (2016) 629-646

643

Autor smatra da energetski sistemi s primarnim baterijama tipa metal/ zrak a posebno tipa aluminij/
zrak (nepunjivim) podržani s autorovim TRAKSERom, slike 9, 16 [34], imaju izvanrednu ekološku
i vrlo široku upotrebnu- i energetski-stratešku vrijednost izraženu postizanjem neovisnosti od
zemnog ulja ili plina.
Slika 975$.6(5PRJXýHSULPMHQH

Razlog te autorove procjene je:a) visoki potencijal energetskih sistema s primarnim baterijama tipa metal/ zrak (izražen s njihovoj
izvanredno visokoj sposobnosti direktne transformacije kemijsNH X HOHNWULþNX HQHUJLMX, odnosno
njihova YLVRNDVSHFLILþQDHQHUJLMDRGDNWXDOQRRNRRGGL]HOVNRJJRULYD),b) bez emisija,c) s vrlo jeftinim komponentama u izvedbi s aluminijskim anodama,d) u poWSXQRMPRJXüQRVWLUHFLNOLUDQMD aluminija,e) u RSüRMUDVSRORåLYRVWLDOXPLQLMD if) što je najvažnije!, zbog tek pred kratko vrijeme postignute sposobnosti usavršavanja tih sistema i
SRVWL]DQMX VSRVREQRVWL VWDOQH VDPR RG NROLþLQH PHWDOD DQRGH X VSUHPQLNX RYLVQH SURL]YRGQMH
HOHNWULþQHVWUXMHLXNUDMnjoj konsekvenci-rada, s autorovim TRAKSERom.

644

W. Servis: Utjecaj sniženja temperature rashladnog spremnika na…

Slika 16
Usporedba sistema Novog koncepta trakcijskih baterija (TRAKSER) sa sistemom toplinskih motora

SISTEM TRAKSEROTPADNATOPLINA

TRANSFORMACIJA
1HRJUDQLÿHQL
ENERGIJE
dovod pogonskee
energije (metalnaa (stalni elektrokemijski procesu primarnoj bateriji)
anoda) izvana

SISTEM TOPLINSKI
MOTOR

OTPADNATOPLINA

1HRJUDQLÿHQL
TRANSFORMACIJA
dovod pogonske
ENERGIJE
energije (goriva) (s(stalni WHUPRGLQDPLþNLSURFHV
izvanau toplinskom motoru)

TRAKCIJA VOZILA/PLOVILA

TRANSFORMACIJA ENERGIJE
HOHNWULþQa struja/ PHKDQLþNLUDG/
rotacija)

TRAKCIJA VOZILA/PLOVILA

TRANSFORMACIJA ENERGIJEWRSOLQDPHKDQLþNLUDGURWDFLMD

3. LITERATURA[1] SERVIS, W.: “Utjecaj sniženja temperature rashladnog spremnika na karakteristike
Stirlingova motora/ Influence of lowering the Cooler Temperature on the Stirling Engine
Performance”, PhD Thesis, Faculty of Engineering, University of Rijeka (226 pages)
UDC621.412: 621.43.016: 62.594: 519.62(043) - Rijeka 2006
[2] STIRLING, Robert: Patent No. 4081/ 1816
[3] KOLIN, Ivo: "Stirling motor", Zagreb University publications Ltd. - Zagreb 1991
[4] SERVIS, W.: “Investigation of the influence of the Stirling engine cold-side temperature
range from 303K down to 263Kon its performances”, Course Proceedings of “New andrenewable energies and Stirling engines”, Inter-University Centre (IUC) - Dubrovnik 27. - 29.
May 1998[5] KORBAR, A., SERVIS, W.: “The investigation of the low temperature influence of the
Stirling engine's performances”, Brodogradnja 47 pp. 50 - 54, 1999 - Zagreb[6] SERVIS, W.: “Effects of lowering the minimum cycle temperatures (down to approx. 213K)
on the Stirling engine performance”, Course Proceedings of “9th International Stirling engine
conference (ISEC)” - Pilanesburg 2. - 4. June 1999
[7] SERVIS, W., MEDICA, V.: “Influence of lowering the minimum cycle temperature (down tothapprox. 80K) on the Stirling engine performance”, Proceedings of the 10 International
Stirling engine conference and exhibition - Osnabrück 24. - 28. September 2001
[8] SERVIS, W., MEDICA, V.: “LGiSE (Liquid Gas injection Stirling Engine). A new Stirlingengine concept”, Proceedings of the 11th International Stirling engine conference andexhibition - Rome 19. - 21. November 2003

Energy and the Environment (2016) 629-646

[9]

645

MEDICA, V., SERVIS, W.: “Possibilities of exergy utilisation in the LPG (LNG) plants
using new Stirling engine concept LGiSE”, Proceedings of the 10th International Stirlingengine conference and exhibition - Rome 19. - 21. November 2003[10] MEDICA, V., SERVIS, W.: “MATE0$7,ý.,02'(/=$180(5,ý.(SIMULACIJESTIRLINGOVOG MOTORA PO NOVOM KONCEPTU”, TF Rijeka-2006 (arhivirano TFR,
neobjavljeno)[11] SERVIS, W., MEDICA, V., KORBAR, A.: "New Stirling Engine Concept (NSC-Engine) with
Application of Direct Heat Introduction", BRODOGRADNJA 59, No. 1 - Zagreb 2008[12] SERVIS, W., MEDICA, V.: "Preliminary tests on experimental isothermal NSC-engine
PROBA3AS for development of the New isothermal Solar engine NSC-PROSUN2000",
Energy and the Environment 2008 - Opatija 2008[13] SERVIS, W., MEDICA, V.: "Numerical Analysis of Stirling engine PROBA3AS", Energy andthe Environment 2008 - Opatija 2008[14] SERVIS, W., MEDICA, V.: "Actual and future perspectives of Isothermal NSC-engines",
STROJARSTVO Vol. 51 No. 3 September 2009 - Zagreb 2009[15] SERVIS, W.,: "Dynamic Solar Energy Converter (DSC)", BRODOGRADNJA UDC 536.7:
621.4 - Zagreb 2013[16] SERVIS, W.,: "Sea Water Desalination with help of Dynamic Solar Energy Converter (DSC)",STROJARSTVO - Zagreb/ u pripremi[17] SERVIS, W.: Poster i Informacije o projektu „Novi koncept Stirlingova motora/ New Stirling
Engine Concept (NSC)”, kongres E&E14 - Opatija 2014[18] SERVIS, W.: Patentgesuch CH 2382/01: “Heisskolben“[19] SERVIS, W.: Patentgesuch CH 0387/02: “ Kaltkolben“[20] SERVIS, W.: Patentgesuch CH 1432/02: „Solar“[21] SERVIS, W.: Patentgesuch CH 0728/02: „Kolbenvar“[22] SERVIS, W.: Patentgesuch PCT/CH 0727/02: „Injection“.
Patentanmeldung U.S. 10/499,110/02: „Injection“
Patentgesuch EPA 02765008.0-2311/14615233/02:„Injection“[23] SERVIS, W.: Patentgesuch CH 0710/03: „LDTSE“[24] SERVIS, W.: Patentgesuch CH 2710/03: „DHI/OTM“[25] SERVIS, W.: Patentgesuch PCT/CH 0614/04: „PROFIT“[26] SERVIS, W.: Patentgesuch EPA-04761954.9-2311/04: "PROFIT"[27] SERVIS, W.: Patentgesuch CH 0033/08: "NSC-Motor"[28] SERVIS, W.: Patentschrift CH 701579 B1/14: "NSC-Motor"[29] SERVIS, W.: Patentgesuch CH 1579/11: "Dynamischer Solar-Energie-Konverter fürIsothermen Wärmekraftmaschinen (DSC)"[30] SERVIS, W.: Patentgesuch CH 0275/12: "Solar/ Hybrid angetriebene Wärmekraftmaschinedes NSC-Motor-Typs PROFIT1"[31] SERVIS, W.: Patentgesuch CH 0443/12: "Anwendung der modular gestalteten Motoren fürHybrid-Fahrzeuge"[32] SERVIS, W.: Patentgesuch CH 0091/16: "Carnotisieren der Kreisprozesse derWärmekraftmotoren durch isotherme Ausführung ihrer Kompression mit GEA-Vorrichtung“(GEA = Gasunterstützte Einspritzung des Arbeitsmediums).
[33] SERVIS, W.: Patentgesuch CH 0224/16: „Carnotisieren der Kreisprozesse derWärmekraftmotoren durch isotherme Ausführung ihrer Expansion mit ISOTEXVorrichtung“ (ISOTEX = Isotherme Expansion)[34] SERVIS, W.: Patentgesuch CH 0968/16: "Konzept für eine Neuartige-Traktion-Batterie dernicht wieder aufladbarer Art, hier gekennzeichnet: TRAKTION SERVIS" (TRAKSER)

646

W. Servis: Utjecaj sniženja temperature rashladnog spremnika na…

INFLUENCE OF LOWERING THE COOLING TEMPERATURES ON
THE STIRLING ENGINE CHARACTERISTICS
Abstract: About a research project “New Stirling Engine Concept (NSC)”[1], the author and his
co-authors reported several times during its development in the past period of about 25 years [4 to13], penultimate times us a poster within the E & E2014 and this time also with the poster withintheE & E2016, Opatija 2016. From the published authors works during this period (including thedoctoral thesis, in which all relevant papers was quoted), one can see: that this project since its
beginning has observed the environmental and energy problems of the Earth, highlighted also by
the prominent scientific team "Club of Rome" [1], that this project was essentially supported by ourvery famous scientist, the late Professor Ivo Kolin and by the author's mentor prof. Ph.D. Vladimir
Medica (from RITEH-CRO) and that the author himself with a number of published works examinesand demonstrates potential solutions to these problems and to make finally in the context ofdissertation [1] up to date the definitive, scientifically funded analysis of these problems and one
possible aspect of their solutions (the NSC-concept, the NSC process, isothermal NSC-engines,
DSC-solar converter and recently the patented processes GEA and ISOTEX for carnotisation ofheat/ diesel engines and most recently the concept of traction battery system TRAKSER, whichenables the permanent production of electricity/ work with primary batteries types metal/ air).
Based on these results, is authors opinion today; that the use of the NSC concept really could
achieve a substantial reduction of the perceived problems, but that also we confront the fact:"That if all heat engines of this Earth perfected to function e.g. according to the instructions of
NSC- or an otherwise positive concept, that would still energy/ environmental situation of the
Earth, shown in Figure 1 remain essentially unchanged and therefore this situation will sooner orlater lead to the Earth energy and environmental collapse” and that a solution should be sought in
the application of environmentally friendly known and new energy systems e.g.: solar energy andwith it produced hydrogen (using e.g. author's DSC-converter), wind energy, water and waves
energy and in recent times, the most promising energy systems with primary battery type metal/ air
supported by the author's TRAKSER, which is why such systems will finally achieve the strategic
value of independence from natural oil or gas.
Keywords: NSC-concept, Isothermal NSC-process, isothermal NSC-engines, Dynamic solar
converter DSC, and GEA- ISOTEX-systems, concept system TRAKSER.

INDEX
Al-Neama, M. A., 187$OMLQRYLü$
Arici, M., 177
Awasthi, S., 81

Grabar, K., 457*UDGHþNL5
Gregov, G., 247, 409*XELü7

%DLü/
Balint, K., 111
Barbir, F., 147, 157, 277, 617
Baspinar, M., 415%DXWRYLü7%HGRLü5
Bekker, J., 267
Bilandžija, Z., 247
Blecich, P., 59, 425, 497, 529
Boban, L., 295%RãQMDNRYLü%
%UQþLü'

Haber, I. E., 221
Hafner, J., 509
Haydary, J., 89
Hudobivnik, B., 305

Can, A., 415

Kapros, Z., 257.DUDEDLü5.DUDVDOLKRYLü6HGODU'
Karner, K., 359
Katrašnik, T., 135
Kazalac-Miljan, D., 229.LULQþLü0
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Knez, F., 509.QHåHYLü$
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Košir, M., 305.R]ORYLü'
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Kumar, A., 81.XQLþ5

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Deur, J., 381
Dlouhy, T., 59'RUDþLü%
Došen, T., 239'UDJLþHYLü9
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El-Shimy, M., 209
Farkas, I., 169, 187, 221
Fekete, I., 169
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Golub, M., 457

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Janda, M., 59
Jelemesnky, L., 89
Jordan, S., 509-XNLü/

Leal-Arcas, R., 99
Legat, A., 509/HQLü.
Luttenberger, L., 315
Ljubek, R., 605

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Marciuš, M., 457
Markoš, J., 89
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Mrzljak, V., 369, 483

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Novak, P., 467
Novosel, T., 547, 581

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Pienaar, C., 197
Poljak, I., 369, 483
Praznik, M., 559, 569
Pukšec, T., 547, 581
Radica, G., 157
Radoš, D., 21

Tamas, L., 1117DYþDU*
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Trp, A., 537
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Međunarodni kongres
ENERGIJA I OKOLIŠ 2016
PRILAGODBA KLIMATSKIM PROMJENAMA I
ENERGETSKA SIGURNOST NA JUGOISTOKU EUROPE
ČISTA ENERGIJA ZA BOLJI SVIJET
XXV. znanstveni skup o energiji i zaštiti okolišaInternational Congress
ENERGY AND THE ENVIRONMENT 2016
CLIMATE CHANGE AND ENERGY SECURITY
IN SOUTH-EAST EUROPE
CLEAN ENERGY FOR A BETTER WORLDXXV Scientific Conference on Energy and the Environment

Organizatori / Organized by:

Sveučilište u Rijeci /University of Rijeka

Hrvatsko udruženje za sunčevu energiju, Rijeka /Croatian Solar Energy Association, Rijeka
Fakulteta za strojništvo,Univerza v Ljubljani, Slovenija /Faculty of Mechanical Engineering,
Universitiy of Ljubljana, Slovenija

Izdavanje ovog zbornika svojim doprinosom su pomogli
The publishing of this Book of Proceedings was helped by:
Ministarstvo znanosti, obrazovanja isporta Republike Hrvatske /Ministry of Science, Education andSports of the Republic of Croatia

HOPS - Hrvatski operator prijenosnog sustava, Viessmann,
Rockwool, Weishaupt, HEP - TE Plomin
Opatija - Croatia
October 2016Međunarodni kongres/International Congress

Vrhunskana djelovanje.
svim područjima
Održivost učinkovitostodređuje naše

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Naš strateški projekt održivosti koji se provodi u sjeciljevi za 2050. g. već danas mogu postići sa svakim
dištu tvrtke u Alledorfu (Eder) ne pokazuje samo da se
rješenjem.
već ciljeviživimos našimenergetski i Budućnost
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za 2050.
godinuDeutschlands nachhaltigste
Produktion 2009

hom i socijalnom odgovornošću. Godine 2009. primili
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kondenzacijski biomasu
kotlovi

Dizalice
toplineUređaji za grijanjena gorivne članke

ENERGIJA I OKOLIŠ
ENERGY AND
THE ENVIRONMENT2016

PRILAGODBA KLIMATSKIM PROMJENAMAI ENERGETSKA SIGURNOST NA JUGOISTOKU EUROPE
CLIMATE CHANGE AND ENERGY SECURITY
IN SOUTH-EAST EUROPE
ČISTA ENERGIJA ZA BOLJI SVIJET
CLEAN ENERGY FOR A BETTER WORLD

Deutschlands nachhaltigste
Marke 2011

strateškim
projektom
održivosti„EffizienzPlus“umogu postići
već danas,s na tržištu
dostupnom
tehnisjedištuuAllendorfu(Eder).
Više
informacijakom, već i dokazuje da se zaštita okoliša i učinkovitostmožetenašojuweb-stranici:
resursapronaći
mogu nadovestisklad s ekonomskim uspje-

ENERGIJA I OKOLIŠ 2016 / ENERGY AND THE ENVIRONMENT 2016

Na području učina od 1,5 kW do 120 MW

Solarni sistemi

OPATIJA, HRVATSKA /CROATIA
listopad /October 26-28, 2016