Question

Consider a commercial refrigerator which operates on the refrigeration cycle. R-
134a is used as the working
uid and the refrigerated space is kept at -25oC by rejecting its
waste heat to cooling water that enters the condenser at room temperature, that is 20oC, at a
rate of 0.1 kg/s and leaves at 40oC. The refrigerant enters the condenser at 1.2 MPa and 70oC
and leaves at 40oC. The inlet state of the compressor is saturated vapor at 100 kPa and the
compressor is estimated to release a net heat of 450 W to the surroundings. Determine
(a) the quality of the refrigerant at the evaporator inlet,
(b) the rate of heat removal from the refrigerated space,
(c) the coecient of performance of the refrigerator and
(d) the theoretical maximum coecient of performance of the refrigerator.

Answer 1