A refrigeration process operates using the vaporcompression cycle, using a proprietary refrigerant that the inventor claims is better than R-134a. At low pressures, the refrigerant can be assumed to act as an ideal gas with constant C_V = 14R and reportedly has a molecular weight of 400 g/mol. The steady-state refrigeration cycle reportedly works as follows:

∎ A boiler produces saturated vapor at P = 0.02 MPa and T = 5°C, which has H = 50 kJ/mol.

∎ The vapor is compressed to P = 0.06 MPa and T = 50°C.

∎ The vapor is then condensed to saturated liquid at P = 0.06 MPa, which has H = 20 kJ/mol.

∎ The liquid undergoes an isenthalpic expansion to P = 0.02 MPa, and enters the boiler

A. What is the efficiency of the compressor?

B. If we wished to scale the process described above so that it provides 3000 kJ/min of cooling, what is the required flow rate of refrigerant in kg/min?

C. What is the coefficient of performance of the refrigeration cycle? 

D. Design a refrigeration cycle using R-134a as the refrigerant, in which the rate of cooling is 3000 kJ/min. In designing this process, you should make all specifications and design decisions in such a way as to allow a meaningful comparison between R-134a and the proprietary refrigerant.

E. Based on the outcomes of questions A through D, comment on the inventor’s claim that the proprietary refrigerant is better than R-134a.