EÜAŞ Ambarlı Doğalgaz Kombine Çevrim Santralinin enerji ve ekserji analizi
EÜAŞ Ambarlı Natural Gas Combined Cycle Power Plant energy and exergy analysis
Yazar: SERDAR ÇİLOĞLU
Danışman: DR. ÖĞR. ÜYESİ MURAT ÇAKAN
İstanbul Teknik Üniversitesi / Enerji Enstitüsü / Enerji Bilim ve Teknoloji Ana Bilim Dalı / Enerji Bilim ve Teknoloji Bilim Dalı
Derece: Yüksek Lisans, 2019
Konu: Enerji = Energy

Özet:
Bu çalışmada İstanbul'da bulunan Elektrik Üretim Anonim Şirketi Ambarlı Doğalgaz Kombine Çevrim Santralinin termodinamik çevrimi incelenmiş, enerji ve ekserji analizi hesaplamaları Cycle-Tempo 5.0 bilgisayar yazılımı ile oluşturulan EÜAŞ Ambarlı Doğalgaz Kombine Çevrim Santrali termodinamik analiz modeli ile yapılmıştır. Enerji ihtiyacının giderek arttığı günümüzde enerji üretimi kaynaklı çevre kirliliği giderek artan bir sorun olarak karşımıza çıkmaktadır. Yenilenebilir enerji kaynaklarının kullanıldığı santrallerde enerji arzının çevresel etkenlere doğrudan bağlı olması ve fosil yakıtlı santrallerde enerji arzının devamlılığının sağlanabilmesi sebebiyle fosil yakıtlı santraller toplam enerji talebinin karşılanmasındaki önemlerini korumaktadır. Bu nedenle yeni inşa edilen fosil yakıtlı enerji santrallerinin tasarımlarında yüksek verim elde edilmesi ve üretilen birim enerji başına çevre kirliliğine sebep olan emisyon değerlerinin azaltılması amaçlanmaktadır. Yeni kurulacak santrallerin tasarımında uygulanacak bilgisayar yazılımı destekli enerji ve ekserji analizi çalışmaları sayesinde yatırım ve işletme masraflarını en aza indirerek santral tasarımları geliştirilebilmektedir. Ayrıca, yeni santrallerin kurulması planlanan bölgelerdeki atmosferik hava şartlarının yıllık değişimi kullanılarak yapılan parametrik enerji ve ekserji analizi çalışmaları ile uygun santral kurulum yeri tespit edilebilmektedir. Diğer taraftan mevcut santrallerin verimini arttırmaya yönelik iyileştirme çalışmalarında ihtiyaç duyulan enerji ve ekserji analizi çalışmaları bilgisayar yazılmaları ile yapılarak, yapılacak iyileştirmelerin etkisi henüz fiziki olarak yatırım gerçekleştirilmeden yani yatırım masrafı yapılmaksızın öngörülebilmektedir. Bu tez çalışmasında mevcut bir santralin bilgisayar yazılımı ile kurulan termodinamik modeli sayesinde enerji ve ekserji analizi hesaplamaları yapılmış ve bu analiz sonuçlarının santralden ölçülen değerlerle uyumlu olduğu gözlemlenmiştir. Bu çalışmada yapılan analizlerde kullanılan veriler EÜAŞ Ambarlı Doğalgaz Kombine Çevrim Santrali kumanda odasındaki merkezi veri izleme ve kayıt sisteminden elde edilmiş, bu sistemlerle ölçülemeyen değerler ise santralin dizaynına esas teşkil eden dokümanlardan alınmıştır. Delft Teknoloji Üniversitesi'nde (Delft University of Technology) geliştirilen Cycle-Tempo 5.0 bilgisayar yazılımı ile oluşturulan EÜAŞ Ambarlı Doğalgaz Kombine Çevrim Santrali termodinamik modeli kullanılarak enerji ve ekserji analizi hesaplamaları yapılmıştır. Gerçekleştirilen bu enerji ve ekserjiye dayalı termodinamik analiz sonucunda santrali oluşturan ekipmanlarda oluşan tersinmezlikler ayrı ayrı hesaplanarak karşılaştırmalı olarak irdelenmiştir. Bu sayede, santrali oluşturan ekipmanlar için enerjiye ve ekserjiye dayalı verim iyileştirmelerine müsait olanlar belirlenmiştir.

Abstract:
Ambarlı Combined Cycle Power Plant which is located in Istanbul is examined in this study for the purpose of an energy and exergy analysis. Calculations are done with the thermodynamic models created with Cycle-Tempo 5.0 software. With rapidly increasing population and its eventual energy demand that has reached 14 Gtoe, pollution caused by energy production at fossil fuel power plants is becoming a major environmental problem. 
Although there is a growing interest in harvesting renewable energy sources, taking into consideration that energy supply by power plants using renewable energy resources are directly dependent on environmental conditions and energy supply by fossil fuel power plants is relatively more sustainable, as for time being thermal power plants are believed to be keeping their leader position in total energy supply. 
Therefore, it is one of the main goals of the thermodynamic studies to increase the efficiency of new thermal power plant designs in order to reduce the pollution caused by unit energy produced. 
Computer aided energy and exergy analysis are used for increasing the efficiency and reducing the investment and running costs of thermal power plants. Also with the help of such energy and exergy analysis it has become possible to make feasibility studies for selecting geographical locations and thus climatic conditions for new power thermal plants according to yearly change of environmental conditions without investment costs of construction. On the other hand, for the existing thermal power plants, the investigation of opportunities for potential improvements without any investment cost can be foreseen with the help of computer based energy and exergy analysis software which are widely in use today.
This study deals with setting the thermodynamic model of an already existing power plant; EÜAŞ Ambarlı Natural Gas Combined Cycle Thermal Power Plant that has been empowering the base load of Istanbul and its periphery since 1988.  Ambarlı Natural Gas CCPP has three blocks of combined cycles; each of them having an installed power capacity of 450 MW. Each combined cycle block consists of two identical gas turbine groups which has installed power capacity of 138.8 MW each and one steam turbine group which has installed power capacity of 172.2 MW.  Total installed power capacity of EÜAŞ Ambarlı Natural Gas CCPP is 1350 MW and its thermal efficiency is around 52%.   
The dynamic data used in the analysis was taken directly from the central data monitoring and recording system of Ambarlı Natural Gas Combined Cycle Power Plant.  The data, which neither can be taken from the central data monitoring and recording room of Ambarlı Natural Gas Combined Cycle Power Plant nor from the design documents of the power plant, have been retrieved with the help thermodynamic equations such as mass and energy conservations of the closed system.
The thesis makes use of Cycle-Tempo 5.0 software which was developed by TU Delft to run energy and exergy calculations based on CCPP's dynamical data and on relevant thermodynamical equations. 
Section 1.2 focuses on thermodynamical analysis conducted for various thermal and nuclear power plants by using Cycle-Tempo 5.0 software.  This section also explains different strategies followed in modelling thermal power plants and their energy-exergy outcomes.   
The following Chapter describes the working scheme of Ambarlı CCPP and introduces the different equipments of the entire system including gas turbine groups, steam power group, heat recovery steam generator, feed water system, deaerotor, condenser, water demineralisation system, main condensate pump and the stack unit.        
In Chapter 3, the Cycle-Tempo 5.0 software, which was developed at TU Delft was described in detail.  Concepts such as how to run the software, how to form its modelling scenarios, how to enter the data and how the analysis is run were considered separately and in detail.   Besides, in order to get acquinted with the usage of the program, initially a simple gas turbine cycle model was formed and run by using the Cycle-Tempo 5.0 software.    
The sub-systems of the entire Ambarlı Natural Gas CCPP were modelled in Chapter 4.  In order to prove the credibility of the software and cross checking the accuracy of the model, the sub-systems need to be handled one by one before they were consolidated.  These sub-systems were separately run so that the probable errors could be detected immediately if any errenous result occured.   
The fundamental concepts and descriptions on energy and exergy analysis were explained in Chapter 5. The energy and exergy analysis equations derived by assessing the energy balance diagram of Ambarlı Natural Gas CCPP were described in detail.
Chapter 6 is reserved for feeding the Ambarlı Natural Gas CCPP model with the data obtained either from the instantaneously recorded parametric values that were measured by pressure, temperature and mass flow rate sensors, the design data and the results obtained through mass and energy conservation equations.  The measurements reflects the fact that the performance of Ambarlı Natural Gas CCPP was affected by both the outdoor and sea water temperature variations. But moreover, the performance of the plant varied with respect to the manual and automatic fine tuning of power plant equipment that aimed to set the operation at a steady regime. Therefore the Cycle-Tempo 5.0 software analysis was assessed only for the fix outdoor temperature of 30°C not for the entire year.  Finally, a good agreement was found between the power generated by the plant and the power predicted by the Cycle-Tempo 5.0 software for the specific outdoor temperature of 30°C.  Under these conditions, the success of the software prediction was thus proved.  
In the last chapter, the results pertaining to equipment irreversibilites for each system component were assessed through energy and exergy analysis of Cycle-Tempo 5.0 software.  Based on this analysis, exergy transfer, rather than energy loss of various components, were compared to each other in order to specify system improvement possibilities.  The results show that the highest irreversibilites occurred, with decending order, in the combustion chamber, gas turbine, low pressure steam turbine, compressor, condenser and high pressure steam turbine.
The thesis proposes improvement strategies for all of the above mentioned equipments in order to decrease the ratio of irreversibilities to the energy transferred to the system which would naturally increase the efficiency of the Ambarlı Natural Gas CCPP.