solution

The capacity of a propane vapor-compression refrigeration system is 10 tons. Saturated vapor at 40 lbf/in.2 enters the compressor, and superheated vapor leaves at 110F, 160 lbf/in.2 Heat transfer from the compressor to its surroundings occurs at a rate of 3.3 Btu per lb of refrigerant passing through the compressor. Liquid refrigerant enters the expansion valve at 80F, 160 lbf/in.2 The condenser is water-cooled, with water entering at 60F and leaving at 75F with a negligible change in pressure. Determine

(a) the compressor power input, in Btu/min.

(b) the mass flow rate of cooling water through the condenser, in lb/min.

(c) the coefficient of performance.