Closed cycle ocean thermal energy conversion (CC-OTEC) is a way to generate electricity by the sea water temperature difference from the upper surface to the different depth. This paper presents the performance of a 15 kW micropower CC-OTEC system under different working fluids. The results show that both butane and isobutane are not proper working fluids for the CC-OTEC system because the inlet stable operating turbine pressure is in a very narrow range. R125, R143a, and R32, especially R125, are suggested to be the transitional working fluids for CC-OTEC system for their better comprehensive system performance. Moreover, it is recommended that propane should be a candidate for the working fluid because of its excellent comprehensive properties and environmental friendliness. However, propane has inflammable and explosive characteristics. As for the natural working fluid ammonia, almost all performance properties are not satisfactory except the higher net output per unit sea water mass flow rate. But ammonia has relative broader range of the stable operating turbine inlet pressure, which has benefits for the practical plant operation.

References

References
1.
Bisio
,
A.
, and
Boots
,
S.
, eds.,
1995
,
Encyclopedia of Energy Technology and the Environment
,
John Wiley, Sons, Inc.
2.
Yeh
,
R. H.
,
Su
,
T. Z.
, and
Yang
,
M. S.
,
2005
, “
Maximum Output of an OTEC Power Plant
,”
Ocean Eng.
,
32
(
5
), pp.
685
700
.10.1016/j.oceaneng.2004.08.011
3.
Uehara
,
H.
,
Miyara
,
A.
,
Ikegami
,
Y.
, and
Nakaoka
T.
,
1996
, “
Performance Analysis of an OTEC Plant and a Desalination Plant Using an Integrated Hybrid Cycle
,”
J. Sol. Energy Eng.
,
118
(
2
), pp.
115
122
.10.1115/1.2847976
4.
Straatman
,
P.
,
Wilfried
G.
, and
Sark
V.
,
2008
, “
A New Hybrid Ocean Thermal Conversion—Offshore Solar Pond (OTEC-OSP) Design: A Cost Optimization Approach
,”
Sol. Energy
,
82
(
6
), pp.
520
527
.10.1016/j.solener.2007.12.002
5.
Yamada
,
N.
,
Hoshi
,
A.
, and
Ikegami
Y.
,
2009
, “
Performance Simulation of Solar-Boosted Ocean Thermal Energy Conversion Plant
,”
Renewable Energy
,
34
(
7
), pp.
1752
1758
.10.1016/j.renene.2008.12.028
6.
Tchanche
,
B. F.
,
Papadakis
,
G.
,
Lambrinos
,
G.
, and
Frangoudakis
,
A.
,
2008
, “
Criteria for Working Fluids Selection in Low-Temperature Solar Organic Rankine Cycles
,”
Proceedings of Eurosun Conference
,
Lisbon, Portugal
, Oct. 7–10.
7.
Ikegami
,
Y.
,
Yasunaga
,
T.
, and
Haruo Uehara
,
H.
,
2005
, “
Effect of Regenerator Heat Transfer Performance on the Cycle Thermal Efficiency of OTEC Using Ammonia—Water as Working Fluid
,”
Proceedings of the Fifteenth International Offshore and Polar Engineering Conference, Seoul, Korea, June 19–24.
8.
Vega
,
L. A.
,
2002
, “
Ocean Thermal Energy Conversion Primer
,”
Marine Technol. Soc. J.
,
4
(
6
), pp.
25
35
.10.4031/002533202787908626
You do not currently have access to this content.