thermodynamics question 6.

A commercial freezer with R-134a must keep the refrigerator compartment at -28C. The heat is emitted from the condenser to a water system whose inlet temperature in the condenser is 18C and outlet temperature 26C. The water flow in this system is 0.3 kg/s. The refrigerant is supplied to the condenser at 1.5 MPa and 75C and leaves the condenser at 45C. At the entrance to the compressor, the refrigerant is at a pressure of 100 kPa and is superheated by 5C. During the compression, 500 W is supplied heat to the compressor.

a) Plot the actual cooling cycle in the attached P-h diagram.

b) Calculate the mass flow of R-134a in the circuit and the cooling effect.

c) Calculate the COP of the refrigerator.

d) Calculate the theoretical highest cooling effect that can be achieved with the same compressor power.