A solar-powered refrigeration system receives heat from a solar collector at TH, rejects heat to the atmosphere at T0 and extracts heat from a cold space at TC. The three heat transfer rates are Q⋅H, Q⋅0 and Q⋅C, respectively.
(a) Do an energy and entropy analysis of the system to derive an expression for the maximum possible COP, defined as the ratio Q⋅C/Q⋅H.
(b) Determine the COP for TH = 400°C, T0 = 30°C, and TC = -20 °C.