This paper describes the thermodynamic optimization of a class of refrigerators without work input, which are driven by heat transfer from a solar collector. The model consists of a finite-size solar collector with heat loss to the ambient, and a refrigerator with three finite-size heat exchangers, namely, the evaporator between refrigeration load and refrigerant, the condenser between the refrigerant and the ambient, and the heat exchanger between the solar collector and the refrigerant. The total thermal conductance of the three heat exchangers is fixed. The solar collector heat loss to the ambient is proportional to the collector-ambient temperature difference. The first part of the paper reports the operating conditions for maximum refrigeration effect, specifically, the optimal collector temperature, and the optimal way of allocating the thermal conductance inventory to the three heat exchangers. For example, the optimal condenser conductance is equal to half of the total thermal conductance, and is independent of other operating parameters. The second part of the paper examines the changes in the optimal design when the price of the refrigeration load (pL) is different (higher) than the price of the heat input provided by the collector (pH). The optimal collector temperature and the optimal three-way allocation of the thermal conductance inventory are reported as functions of the price ratio pH/pL.

1.
Adebiyi
G.
, and
Russell
L. D.
,
1987
, “
A Second Law Analysis of Phase-Change Thermal Energy Storage Systems
,”
ASME HTD
, Vol.
80
, pp.
9
20
.
2.
Andresen, B., Salamon, P., and Berry, R. S., 1984, “Thermodynamics in Finite Time,” Phys. Today, Sept., pp. 62–70.
3.
Bejan
A.
,
Kearney
D. W.
, and
Kreith
F.
,
1981
, “
Second Law Analysis and Synthesis of Solar Collector Systems
,”
ASME JOURNAL OF SOLAR ENERGY ENGINEERING
, Vol.
103
, pp.
23
30
.
4.
Bejan, A., 1982, Entropy Generation through Heat and Fluid Flow, John Wiley and Sons, New York.
5.
Bejan, A., 1988, Advanced Engineering Thermodynamics, John Wiley and Sons, New York.
6.
Bejan
A.
,
1989
, “
Theory of Heat Transfer-Irreversible Refrigeration Plants
,”
Int. J. Heat Mass Transfer
, Vol.
32
, pp.
1631
1639
.
7.
Bejan, A., 1994,“Second Law Aspects of Solar Thermal Energy Conversion,” International Conference on Comparative Assessments of Solar Power Technologies (SOLCOM-1), Jerusalem, Feb. 14–18.
8.
Bejan, A., 1996, Entropy Generation Minimization, CRC Press, Boca Raton, FL.
9.
Bejan
A.
,
Vargas
J. V. C.
, and
Sokolov
M.
,
1995
, “
Optimal Allocation of a Heat-Exchanger Inventory in Heat Driven Refrigerators
,”
Int. J. Heat Mass Transfer
, Vol.
38
, pp.
2997
3004
.
10.
Belleci
C.
, and
Conti
M.
,
1994
, “
Phase Change Energy Storage: Entropy Production, Irreversibility and Second Law Efficiency
,”
Solar Energy
, Vol.
53
, pp.
163
170
.
11.
Charach
Ch.
,
1993
,“
Second Law Efficiency of an Energy Storage-Removal Cycle in a Phase-Change Material Shell-and-Tube Heat Exchanger
,”
ASME JOURNAL OF SOLAR ENERGY ENGINEERING
, Vol.
115
, pp.
240
243
.
12.
Chambadal, P., 1957, Les Centrales Nucleaires, Armand Colin, Paris, pp. 41–58.
13.
Curzon
F. L.
, and
Ahlborn
B.
,
1975
,“
Efficiency of a Carnot Engine at Maximum Power Output
,”
Am. J. Phys.
, Vol.
43
, pp.
22
24
.
14.
El-Wakil, M. M., 1962, Nuclear Power Engineering, McGraw-Hill, New York, pp. 162–165.
15.
El-Wakil, M. M., 1971, Nuclear Energy Conversion, International Textbook Company, Scranton, PA, pp. 31-35.
16.
Klein
S. A.
,
1992
, “
Design Considerations for Refrigeration Cycles
,”
Int. J. Refrig.
, Vol.
15
, pp.
181
185
.
17.
Krane
R. J.
,
1987
, “
A Second Law Analysis of the Optimum Design and Operation of Thermal Energy Storage Systems
,”
Int. J. Heat Mass Transfer
, Vol.
30
, pp.
43
57
.
1.
Novikov
I. I.
,
1958
, “
The Efficiency of Atomic Power Stations
,”
J. Nuclear Energy II
, Vol.
7
, pp.
125
128
;
2.
translated from
Atomnaya Energiya
,
1957
, Vol.
3
, No.
11
, p.
409
409
.
1.
Radcenco
V.
,
Vargas
J. V. C
,
Bejan
A.
, and
Lim
J. S.
,
1994
, “
Two Design Aspects of Defrosting Refrigerators
,”
Int. J. Refrig.
, Vol.
18
, pp.
76
86
.
2.
Sokolov
M.
, and
Hershgal
D.
,
1991
, “
Operational Envelope and Performance Curves for a Compression-Enhanced Ejector Refrigeration System
,”
ASHRAE Trans.
, Vol.
97
, No.
2
, pp.
394
402
.
3.
Sokolov
M.
, and
Hershgal
D.
,
1993
, “
Optimal Coupling and Feasibility of a Solar-Powered Year-Round Ejector Air Conditioner
,”
Solar Energy
, Vol.
50
, pp.
507
516
.
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