For an outdoor air temperature of 20°f, 45,000 btu/hr is required to maintain the temperature in a house at 72°f. a heat pump using r-22 as the refrigerant is used to supply this heat. the r-22 leaves the evaporator at p = 45 psi, t - 12°f and the condenser operates at a pressure of 250 psi. assuming an isentropic compressor efficiency of 82%, determine: a) the refrigerant flow rate, b) the compressor power input, and c) the coefficient of performance

Refrigerant-134a enters the compressor of a refrigerator as superheated vapor at 0.14 mpa and -10°c at a rate of 0.05 ka/s and leaves at 0.8 mpa and 50°c. the refrigerant is cooied in the condenser to 0.72 mpa and 26'c. it is then throttled to 0.15 mpa. sketch the t-s diagram for the system and evaluate: 6) the rate of heat removai from the refrigerated space (kw), it) the power input to the compressor (kw), ii) the isentropic efficiency of the compressor (%), and iv) the cop of the refrigerator.