A combined power and cooling cycle is being investigated. The cycle is a combination of the Rankine cycle and an absorption refrigeration cycle. Evaluating the efficiency of this cycle is made difficult by the fact that there are two different simultaneous outputs, namely power and refrigeration. An efficiency expression has to appropriately weigh the cooling component in order to allow comparison of this cycle with other cycles. This paper develops several expressions for the first law, second law and exergy efficiency definitions for the combined cycle based on existing definitions in the literature. Some of the developed equations have been recommended for use over others, depending on the comparison being made. Finally, some of these definitions have been applied to the cycle and the performance of the cycle optimized for maximum efficiency. A Generalized Reduced Gradient (GRG) method was used to perform the optimization. The results of these optimizations are presented and discussed.

1.
Goswami, D. Y., 1995, “Solar Thermal Power—Status of Technologies and Opportunities for Research,” Proceedings of the 2nd ISHMT-ASME Heat and Mass Transfer Conference, Tata McGraw Hill, New Delhi, pp. 57–60.
2.
Goswami
,
D. Y.
, 1998, “Solar Thermal Power Technology: Present Status and Ideas for the Future,” Energy Sources, 20, pp. 137–145.
3.
Xu
,
F.
,
Goswami
,
D. Y.
, and
Bhagwat
,
S. S.
,
2000
, “
A Combined Power/Cooling Cycle
,”
Energy (Oxford)
,
25
, pp.
233
246
.
4.
Goswami
,
D. Y.
, and
Xu
,
F.
,
1999
, “
Analysis of a New Thermodynamic Cycle for Combined Power and Cooling Using Low and Mid Temperature Solar Collectors
,”
J. Sol. Energy Eng.
,
121
, pp.
91
97
.
5.
Tamm, G., Goswami, D. Y., Lu, S., and Hasan, A. A., 2003, “A Novel Combined Power and Cooling Cycle for Low Temperature Heat Sources—Part I: Theoretical Investigation,” J. Sol. Energy Eng., 125(2), pp. 218–222.
6.
Lu, S., and Goswami, D.Y., 2002, “Optimization of a Novel Combined Power/Refrigeration Thermodynamic Cycle,” J. Sol. Energy Eng., 125(2), pp. 212–217.
7.
Lu, S., and Goswami, D. Y., 2002, “Theoretical Analysis of Ammonia Based Combined Power/Refrigeration Cycle at Low Refrigeration Temperatures,” Solar Engineering 2002, ASME, NY, pp. 117–126.
8.
ASHRAE Handbook of Fundamentals, SI Edition, 1997, American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc., Atlanta.
9.
Szargut, J., Morris, D. R., and Steward, F. R., 1988, Exergy Analysis of Thermal, Chemical and Metallurgical Processes, Hemisphere, NY, p. 332.
10.
DiPippo, R., 1980, Geothermal Energy as a Source of Electricity: a Worldwide Survey of Design and Operation of Geothermal Power Plants, DOE Report, Washington, D.C., p. 370.
11.
Abrahamsson, K., Jernqvist, A., and Aly, G., 1994, “Thermodynamic Analysis of Absorption Heat Cycles,” Proceedings of the International Absorption Heat Pump Conference, New Orleans, LA, AES-Vol. 31, ASME, pp. 375–383.
12.
Lorenz, V. H., 1894, “Die Ausnu¨tzung der Brennstoffe in den Ku¨hlmaschinen,” Zeitschrift fu¨r die gesammte Ka¨lte-Industrie, 1, pp. 10–15.
13.
Rosen, M. A., and Le, M., 1995, “Efficiency Measures for Processes Integrating Combined Heat and Power and District Cooling,” Thermodynamics and the Design, Analysis, and Improvement of Energy Systems, AES-Vol. 35, pp. 423–434.
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