Page 21 - Low Temperature Energy Systems with Applications of Renewable Energy

10 Low-Temperature Energy Systems with Applications of Renewable Energy

Fig. 1.5 Carnot cycle in T-s coordinates.

T H
COP HP ¼ (1.2)
T H T L
In principle, a heat pump can be viewed as a refrigerator by focusing on the heat
removed from the low-temperature heat reservoir as the objective of the device.
Thus the system can be used to provide cooling, air conditioning, and ice-making un-
der the proper conditions. In such a case, the ideal coefficient of performance of refrig-
eration, COP R , is given by

T L
COP R ¼ (1.3)
T H T L

Fig. 1.6 Ideal heat pump cycle in T-s coordinates.