Problem 3Refrigerant 22 in a refrigeration system enters one side of a counter-flow heat exchanger at 12bar, 28°C. The refrigerant exits at 22 bar, 20°C. A separate stream of R-22

enters the other sideof the heat exchanger as saturated vapor at 2 bar and exits as superheated vapor at 2 bar. The mass flow rates of the two streams are equal. Stray heat transfer from the heat exchanger to its surroundings and kinetic and potential energy effects are negligible. Determine the entropy production in the heat exchanger, in kl/K per kg of refrigerant flowing. What gives rise to the entropy production in this application?Show state point 1 and 2, then 3 and 4 on a T-s diagram, show the process from 1 to 2 and from 3 to 4.

Fig: 1

Fig: 2