61ＯＴＥＣ
Vol. 25（2020），61 ～ 68

%$' "#HCBD75IX!JL (N4C1[@Z4C1®§ Ó*1Üwu Á*2Üm_ ÖI*1Ü° I*1
                 §N Ë*1ÜÄ§ dQ*1Üo W*3ÜL ~P*3
Ocean Thermal Energy Conversion Plant Using Integrated Hybrid Cycle― KumejimaÜOkinotorishima ―Masateru ISHIDA*1, Yoshihiro SHIMAOKA*2, Junichi OHARA*1, Kazuhiro HATA*1, Tatsuhiko
TANAKA*1, Tetsuya NISHIDA*1, Takeshi YASUNAGA*3and Yasuyuki IKEGAMI*3*1

National Fisheries University
2-7-1 Nagata-Honmachi, Shimonoseki-shi, Yamaguchi, 759-6595, Japan*2
National Institute of Technology, Toba College
1-1 Ikegami-cho, Toba-shi, Mie, 517-8501, Japan*3
Institute of Ocean Energy, Saga University
1 Honjo-machi, Saga-shi, Saga, 840-8502, Japan

Abstract
An Integrated Hybrid Ocean Thermal Energy Conversion (I-H OTEC) system is one of the OTEC systems. This system
is composed of electric generating plant and desalination plant. The submarine topography of east side of Kumejima region issuitable for arranging pipelines to take in deep ocean water. Therefore, Kumejima region is one of the place that is expected toconstruct an OTEC plant, and already OTEC experimental plant is under running. Okinotorishima region is also considered
suitable for OTEC plant, because of its steep bottom topography and high sea surface temperature. In the present study, theanalyses are conducted on the performance of Hybrid OTEC system adopting ammonia as a working fluid, that is using theresults of oceanographic investigation carried out by the fisheries training ship. A procedure is developed to maximize a net
power of power system consisting of heat exchanger under the condition of designate power system. The maximum net poweris given by minimizing the heat exchangers which consume most of a power system. The minimum value of objective function
decreases with the increase of the temperature difference between hot seawater and cold sea water.
Key words : Ocean Thermal Energy ConversionÜI-H OTECÜRenewable EnergyÜKumejima regionÜOkinotorishima region

 Q   S}xªÕÚSMOTECÛÜÃtt}x%( .>D/H+Õ.>D/Hl(45:B'ÜÃttZ}x 15SL) Ü·«'³ * (ÚL_ 2007ÛÝOTEC Ü^®¡+U¦ ¹b¿Y¤b¿.>D/H+\¦ªÕ'Ü#Ü^®¡+U¦45:B" COß[Ï $s &ÜopAH5FH=hªÕ45:B'(¾&)(ÚL_ 2004Û
Ý-G:1EH<?-@C9=30DÜOTEC 45:B!ÜªÕ  ÜªÕÒU¦+¦Ü+( (¢ (ÚL_Ü2007ÛÝ_±aR 2020 { 11  20 
*1 ¥mnÚ759-6595 MÑy§¨ 2 J¬ 7-1Û*2 Ù½eÀØ´rÐnÚ517-8501 KÎ­Ù½yL¨ Þ © Þ cÛ
*3 TÈmn.>D/H¯²6G8HÚ840-8502 TÈy|¨ 1 ©gÛE-mail of corresponding author: m_ishida@fish-u.ac.jp

62石田 雅照，嶋岡 芳弘，大原 順一，秦 一浩，田中 辰彦，西田 哲也，安永 健，池上 康之»­Ôv(OµvÜvXÅ¼) 8 j;,H7DªÕ%'Õ] V¸)Üz 26 {ºªÕ[]¶ 18,500 kW (Ú»Õ] pdfÜ` 2020 { 11  14 )ÝÔvªÕªÕ¦¡+ÊÌ($ÊÌ25<'Ü&Ü;,H7DªÕ+ÍÉ($£kÇÂ m( f×(Ý$ÔvÜ^®¡+U¦ÜÆq(+\¦( OTEC 45:B ¬)(Ý#ÜOµviIÍÜhgj o Üt+E'Ã ¤Å¼
|\j$ÜOTEC G<Å¼RX{|]5¶gÜ_¾,HD=Ìp)'ÜÜ100 kW ¦_×G< 7N(Ý&ÜOµvXt+\¦#ªÊ($Üt¸H\¦£k Á«x'ÜÑÈ(¥ ¯ b¿(ÚL)Ü2016ÛÝIÜÙ%BBÄ¶ 1,700 .¼(ÔS{B¡v'Ü&v( Üv49a¢'k\¦½Àº ´*)(ÝÙv)«·iXLI eA;)ÜÄ ( OTEC 45:BÅ¼b¿5¶gN{Ëi!¾&)(Ú§)Ü2014ÛÝiÙvJPÜo 'Ü 4,000ß7,000m D Ú%Î¥ =7dÜ` 2020 { 11  14 ÛÝ#Ü{Ò+ÅÃt} Ø$ÚNV)Ü2001Û
OTEC G<Ëg¾&)(Ý                                      ¯²ÜOµviÙviÜ¥mnª¬À®![Ø!+¦ÜÀ+´Ý))À&);H8+jÜ-G:1EH<?-@C9=3-0D+¦
OTEC 45:BÚSMI-H OTEC 45:BÛp¿»+´Ü))i´*)À©+jÜ^¥l?X¢pÜI-H OTEC 45:B¿2+´Ý©W
I(ÝV=0E.V=:A& V=0E

Q 1 ÜOµvi (Àg+ÝÀOµv6iÜ2017 { 1 Ü2018 { 6 %2019 { 12 ´ÜÀg St.1ÜSt.2ÜSt.3  3 _yÝ#ÜQ 2 Ùvi (Ài+ÝÀÜÙvB6iÜ2015 { 11 Ü2019 { 10 ´ÜÀg St.1ÜSt.2ÜSt.3  3 _yÝ





Fig. 1 Kumejima region.

Fig. 2 Okinotorishima region.

インテグレートハイブリッドサイクルを用いた海洋温度差発電システムの研究― 久米島海域，沖ノ鳥島海域 ―63

& V=:AÀÜ¥mnª¬À®!ª¬À[Ø!+¦Ý®!"(Ü9Ñ 87.59 ÞÜg 13.6 ÞÜRÒº<Gw 2,703 tonÜ°Æ] 14.0 knot (Ý#Ü[Ø!"(Ü9Ñ 62.6 ÞÜg 10.4ÞÜR
Òº<Gw 1,020 tonÜ°Æ] 12.5 knot (ÝÀÜ®![Ø!uÂ)Õ-b}¼ÚCTDÜConductivity Temperature Depth SMCTDÛ+¦´Ý®!Ü2017 { 1 Ü2018 { 6 Ü2019 { 12 OµviÜ2019 { 10 Ùv
iÜ3 *¬[Ø!ÚU 4 *¬ÜSM[Ø!ÛÜ2015 { 11 ÙviÀ+´ÝGÀgÜCTD +Nq8Üsp}# 1.0 m ÜÜY;Ü]Ð§Ï+pÝ%$' "!

Q 3 Ü-G:1EH<?-@C9= OTEC 45:B¹+Ý45:BÜÅf OTEC v²+<Ü³1?0%'8HG+OÉªÕ(  Ü³ªM $+´k+94`T³ª(Ü+·Ç(  (¢ (Ý1?0m£G%³ªM Ì&)(ÝÜµ¼%< )Ü³ª³(Ý³8HG+ÅÉÜ8HGªÕ+OÉªÕ(Ý8HG+[³Ü:«MtZ%ZC)Y0(ÝIÜ³ªM $+´Ü G%T)94³ª`8'ÜD%'N[)ÜÜ5EH94³ª+(Ýª¤³ÜÇ¦:«Mb )Ü:«M $+´ZC%'ZC)Ü:«(ÝÚNuÜ2008Û             

            



Fig. 3 Arrangement of I-H OTEC system.
f h b id OTEC 

64

石田 雅照，嶋岡 芳弘，大原 順一，秦 一浩，田中 辰彦，西田 哲也，安永 健，池上 康之

Table 1 Calcuration
condition.
Power generation end output

PMWorking fluid
Warm seawater inlet temperatureT WSI
Kumejima
Okinotorishima

Cold seawater inlet temperature

T CSI


Kumejima
OkinotorishimaPlate length
Plate width
Plate thickness
Warm seawater side spacing
Cold seawater side spacing
Working fluid side spacing
Thermal conductivity
Pump efficiency
Turbine efficiency
Generator efficiency

 Working fluid pump efficiency
XLδ Y WS Y CS Y WF
λη PL
ηTηGη WF

Jan.2017
Jun.2018
Dec.2019
Nov.2015
Oct.2019
Jan.2017
Jun.2018
Dec.2019
Nov.2015
Oct.2019



1,000(kW)NH3
St.1 St.2 St.3
23.8 24.1 24.0
26.2 25.7 25.8
23.5 23.5 23.4
28.4 28.4 28.5
28.7 28.3 28.4
5.3 5.4 5.3
5.3 5.4 5.4
4.9 5.1 5.0
4.8 4.5 4.5
4.7 4.8 4.7
2.0
1.0
1.0
5.0

()
()
()
()
()
()
()
()
()
()
()
(m)
(m)
(mm)
(mm)

5.0(mm)

5.0(mm)17.2 (W/(mK))
80.0()85.0()96.0()75.0()

TM:A¼£ÜªÕ¡[]  + 1,000 kW +pÜ1?0G+U¦(ÝÃ 1 Ü¼£~,+Ý
Ã%'Ü8F}))ÀgÃt}(ÝZ8F}Ü 850 Þ ((Ý#ÜGÕÜ³8HGÜªÕÜ1?0G>Üz]45:BU¦)(I±«>(Ý¢Ü-G:1EH<?-@C9= OTEC 45:Bp¿+$(, Ãtt ~,Î¹(Ý $M ÅÉ3wÃtt}%l*($Ü $Mº- Óm
Ñ3Ü $Mm  l*(ÜÃtÏÜtÏ%1?0G?]l^(ÝlÜÅ¼~,ÅpÜ-G:1EH<?-@C9= OTEC 45:B ~, l^XH;-G+´ÒÜi }~,+(n¹ 'Ü ÀÎ¹(ÚI)Ü2007ÛÝ& ;3U*W8
-G:1EH<?-@C9= OTEC 45:B¿2Ü45:BKªÕ[] 1 kW a(Ü $MÝº- Ó m2 +ÜiÚ1Û¿2Ñw γ +¦ÚL_Ü2007Ûγ Ý  Û                             

Ú1ÛÜ  $Mº- ÓÜ KªÕ[](Ý¿2ÑwÜKªÕ[]m a
( $Mº- Óm Ã)Ü¿2Ñw c  45:B+ch^ (Ý*Ü¿2Ñw γ {c( 45:B{ËÅ¼(Ý ¿2Ñw γo@Ï+¦{c¿2Ñw γ  +£[Ý{c(+Ü{インテグレートハイブリッドサイクルを用いた海洋温度差発電システムの研究― 久米島海域，沖ノ鳥島海域 ―65U¦)( $MÜZZ (Ý)&N &{Ë+Ìr(Ü >ÜÅÉÜT]t\Ü­OpÜ­ÖpÜ·Ç25<ÜÅ¼ÓÜG:G5ZÓ*ºH«½+´n¹ ( ÜÜEH<i $M+U¦Ý#Ü¿2ÑwÜ{¨«ªÕ_2£[+´n¹ ( ÜÅ¼X~,Ü1?0Ü- Ó}
´~,+Åp(%'£[( n¹(Ý& >/IX+-KªÕ[]ÜiÚ2Û%'£[ÝÝ  Ú ( Ù  Ù  Ù  )                            Ú2ÛÜ  ªÕ¡[]Ü G?]Ü ZG?]Ü 1?0GÜ G?](Ý& P)FYKº- Ó AT ÜiÚ3Û%'£[Ý Ý  Ù  Ù                                  Ú3ÛÜ ³ªM- ÓÜ :«M- ÓÜ Ç¦:«M- Ó(ÝO<R2
& ?D,6

ÜOTEC  (}x+$(Ò¢Î¹ÜÃtt}x {/¶ 15 SLn¹(ÚL_Ü2007Û
ÝQ 4 ÜOµvi ( St.Þ 2017 { 1 Ü2018 { 6 % 2019 { 12 l^+
ÝQ%'Ü 600 m RÄ#ÜIp"H¶ 8 # /M( ÜkÜ}M ' ( 'Ü 900 ÞRÄ ¶ 5 (Ý#Üt} 2017 { 1 Ü2018{ 6 % 2019 { 12 Ü¶ 5  ÜÃtÜ6   Ø (Ý$ÜÃ 1 %'Ü2017 { 1  2019 { 12 Ãtt}x¶ 18.6 'Ü2018 { 6 ¶ 20.9 (ÝQ 5ÜQ 6 ÜOµvi ( St.2  St.3  2017 { 1 Ü2018 { 6 % 2019 { 12 l^+Ý St.2  St.3 l^ ' St.Þ&'Ü 900 ÞRÄt} 2017 { 1 Ü2018 { 6 % 2019 { 12 Ü¶ 5  ÜÃt}Ü6   Ø(Ý$ÜÃ 1 %'ÜSt.2  2017 { 1  2019 { 12 Ãtt}x¶ 18.7 Ü2018 { 6 ¶ 20.3 (Ý#ÜSt.3  2017 { 1  2019 { 12 Ãtt}x¶ 18.7 Ü2018 { 6 ¶ 20.4 (ÝQ 7 ÜÙvi ( 2015 { 11 % 2019 { 10 ÜSt.Þl^+ÝQ%'Ü 100 ÞRÄ#Ü}M 'o( Ü)SW 600 ÞRÄ#ÜIp"H¶ 7 # /M( ÜkÜ}M ' ( 'Ü 800 ÞRÄ ¶ 5 'Ü)SW M '¹ (Ý#Ã 1 %'Ü2015 { 11 % 2019 { 10 Ãt 850 Þt}x¶ 23.5ß24.0 (ÝQ 8ÜQ 9 ÜÙvi ( 2015 { 11 % 2019 { 10 ÜSt.2  St.3 l^+ÝQ%'ÜSt.2  St.3 l^ ' St.Þ&'Ü 800 ÞRÄ¶5 (Ý66

石田 雅照，嶋岡 芳弘，大原 順一，秦 一浩，
田中 辰彦，西田 哲也，安永 健，池上 康之

00

5Temperature ()1015202530

005Temperature ()1015202530

Depth (m)200200

400

400

600
Station

1Jan. 2017

800

Jun. 2018
Dec. 2019

1000
1200

00

5Temperature ()1015203000

200

200400400



00




Depth (m)Temperature ()1015202530Station1

Nov. 2015
Oct. 2019

1000

Kumejima region

Okinotorishima region

1200

5Temperature ()10152025Fig. 7 Vertical profile of seawater temperature
Okinotorishima region (St.1).

0030

400

600
Station2

Nov. 2015

800

1200
Fig. 8 Vertical profile of seawater temperature
Okinotorishima region (St.2).

Temperature ()1015202530

Station3Nov. 2015
Oct. 20191000
Okinotorishima region

5600

Oct. 2019

1000

5Dec. 2019

400




Jun. 2018200

Kumejima region

800

200

800

Dec. 2019600

Fig. 6 Vertical profile of seawater temperature
Kumejima region (St.3).



3Jan. 2017

800

1200





Station

1000





600

Depth (m)

Depth (m)Depth (m)Jun. 2018

Fig. 5 Vertical profile of seawater temperature
Kumejima region (St.2).



800

1000

252

Jan. 2017

1200



StationFig. 4 Vertical profile of seawater temperature
Kumejima region (St.1).



600

Kumejima region

Depth (m)Okinotorishima region

1200
Fig. 9 Vertical profile of seawater temperature
Okinotorishima region (St.3).

67

インテグレートハイブリッドサイクルを用いた海洋温度差発電システムの研究― 久米島海域，沖ノ鳥島海域 ―& ;3U*W8

Q 10 Ü{c¿2Ñwmin Z8F}x (  Ú  ) Ñ3+ÝQ%'Ü{c¿2ÑwÜOµviXHÜ2018 { 6  19.6ß22.2 m2/kWÜ2019 { 12  37.6ß40.3 m2/kW (Ý#ÜÙviÜ2019 { 10  10.4ß11.4 m2/kW (ÝIÜÃ 1 %'ÜZ8F}xÜOµvi 2018 { 6 18.4ß18.6 (Ý#ÜÙviÜ2019 { 10  23.5ß24.0  (Ý#ÜQ%'Ü{c¿2Ñw γ ÜZ8F}x (  Ú )

m20.3ß20.9 Ü2019 { 12 ( c (ÝÜ9:C¬(ÜOµvi 2018 { 6  2019 { 12 +"XHÜ2018 { 6  Ü{c¿2Ñw c ( * (Ý) 2018 { 6  ÜÃt}8F}x m&I

2.2ß2.7  Ø ÜZ

($(Ý#ÜÃ 1 %'ÜZ8F} 2018 { 6 Ü2019 { 12 Ü&}(ÜZ8F}x0Y+(Ãt}(ÝIÜÙviXHÜ{c¿2ÑwOµv)©%'c (Ý)ÜÙviOµvi"ÜÃt} Ø$(Ý& >/IX+- Q  ÜKªÕ[] Z8F}x   Ú   Ñ3+ÝQ%'ÜKªÕ[]ÜOµviXHÜ {   ß Ü {     ß   (Ý#ÜÙviÜ {   ß    (Ý)&© &ÜZ8F}x m  KªÕ[] m(Ý)ÜZ8F}x m
(ÜGÜZGÜ1?0GÜ GGG?] c (ÚNuÜ Û$¾&)(Ý& P)FYK

Kumejima12(Jun. 2018)

3Kumejima(Dec. 2019)

Okinotorishima (Oct. 2019)




10515



20TCSITTWSIWSI TCSI (K)Fig. 10 Objective function.

25

Net Power P N (kW)

Station2

Objective Function γ m in (m /kW)

 Q  Üº- Ó Z8F}x  Ú  Ñ3+ÝQ%'Ü?-@C9= OTEC 4
5:Bn¹º- ÓÜOµviXHÜ { ß    Ü {   ß  (Ý#ÜÙviÜ {    ß  (Ý)&© &ÜZ8F}x m  Üº- Óc (ÝStation12310310210215(Jun. 2018)(Dec. 2019)

Okinotorishima (Oct. 2019)20
TCSITTWSIWSI T
CSI (K)
Fig. 11 Net power.

25

68

2Total Heat Transfer Area A T (m )

石田 雅照，嶋岡 芳弘，大原 順一，秦 一浩，田中 辰彦，西田 哲也，安永 健，池上 康之

105
StationKumejima1

23(Jun. 2018)(Dec. 2019)

Okinotorishima (Oct. 2019)

104

103
15

20TTWSI
TTCSIWSICSI (K)

25

Fig. 12 Total heat transfer area.

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