Refrigerant 134a at a rate of 0.8 lb/s enters a compressor operating at steady state as saturated vapor at 30 psia and exits at a pressure of 160 psia. There is no significant heat transfer with the surroundings, and kinetic and potential energy effects can be ignored.
(a) Determine the minimum theoretical power input required, in Btu/s, and the corresponding exit temperature, in °F.
(b) If the refrigerant exits at a temperature of 130°F, determine the actual power, in Btu/s, and the isentropic compressor efficiency.