Technical Briefs

Performance Analysis of 15 kW Closed Cycle Ocean Thermal Energy Conversion System With Different Working Fluids

[+] Author and Article Information
Jianying Gong

e-mail: gongjianying@mail.xjtu.edu.cn

Tieyu Gao

e-mail: sunmoon@mail.xjtu.edu.cn

Guojun Li

e-mail: liguojun@mail.xjtu.edu.cn
School of Energy and Power Engineering,
Xi'an Jiaotong University,
Xi'an 710049, China

1Corresponding author.

Contributed by the Solar Energy Division of ASME for publication in the Journal of Solar Energy Engineering. Manuscript received November 25, 2011; final manuscript received September 20, 2012; published online October 24, 2012. Assoc. Editor: Robert Palumbo.

J. Sol. Energy Eng 135(2), 024501 (Oct 24, 2012) (5 pages) Paper No: SOL-11-1255; doi: 10.1115/1.4007770 History: Received November 25, 2011; Revised September 20, 2012

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.

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Bisio, A., and Boots, S., eds., 1995, Encyclopedia of Energy Technology and the Environment, John Wiley, Sons, Inc.
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. [CrossRef]
Uehara, H., Miyara, A., Ikegami, Y., and NakaokaT., 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. [CrossRef]
Straatman, P., WilfriedG., and SarkV., 2008, “A New Hybrid Ocean Thermal Conversion—Offshore Solar Pond (OTEC-OSP) Design: A Cost Optimization Approach,” Sol. Energy, 82(6), pp. 520–527. [CrossRef]
Yamada, N., Hoshi, A., and IkegamiY., 2009, “Performance Simulation of Solar-Boosted Ocean Thermal Energy Conversion Plant,” Renewable Energy, 34(7), pp. 1752–1758. [CrossRef]
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.
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.
Vega, L. A., 2002, “Ocean Thermal Energy Conversion Primer,” Marine Technol. Soc. J., 4(6), pp. 25–35. [CrossRef]


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Fig. 1

Schematic diagram of the CC-OTEC

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Fig. 2

Cycle efficiency—turbine inlet pressures for different working fluids

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Fig. 6

Net work per mass working fluid—turbine inlet pressures for different working fluids

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Fig. 7

Warm sea water pump work—inlet turbine pressures for different working fluids

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Fig. 3

Cycle net output work—turbine inlet pressures for different working fluids

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Fig. 4

Working fluid pump work—inlet turbine pressures different working fluids

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Fig. 5

Working fluids mass flow rate—the inlet turbine for different working fluids

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Fig. 8

Cold sea water pump work—inlet turbine pressures for different working fluids

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Fig. 9

Overall heat exchanger area per net output work—inlet turbine pressure for different working fluids




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