Task: A Carnot-cycle refrigerator rejects heat at the pressure of 1000 kPa during which the working fluid R-134a changes from saturated vapor to saturated liquid. The heat is added to the cycle at the pressure of 320 kPa. Show the cycle in a T-s diagram and determine the coefficient of performance of the cycle using a) the first law of thermodynamics b) the Carnot cycle COP equation and c) the T-s diagram.