An ammonia vapour-compression refrigerator operates between an evaporator pressure of 2.077 bar anda condenser pressure of 12.37 bar. The following cycles are to be compared ; in each case there is noundercooling in the condenser, and isentropic compression may be assumed :
(i) The vapour has a dryness fraction of 0.9 at entry to the compressor.
(ii) The vapour is dry saturated at entry to the compressor.
(iii) The vapour has 5 K of superheat at entry to the compressor.In each case calculate the C.O.P.(ref.) and the refrigerating effect per kg.What would be the C.O.P.(ref.) of a reversed Carnot cycle operating between the same saturation temperatures?