Consider a counter-flow heat exchanger in a refrigeration system. Saturated liquid-vapor mixture of R-22 enters the heat exchanger at -12?C with a quality of 20% (State 1) and exits as saturated vapor without any pressure drop (State 2). Air enters the heat exchanger at 27oC and 1.1 bar (State 3) with a volumetric flow rate of 1.2 m3/s and rejects 23 kW of heat which is completely absorbed by the refrigerant. Air exits the heat exchanger without any pressure drop (State 4).
(a) Calculate temperature of air at the exit of the heat exchanger.
(b) What is the mass flow rate (kg/s) of R-22?