Comparable Performance Evaluation of Hc and Hfc Refrigerants in an Optimized System

This paper presents an analytical evaluation of isobutane (R600a), propane (R290), R134a, R22, R410A, and R32 in a vapor compression system used for comfort cooling applications. The evaluation method was based on a system simulation model that was complimented with an evolutionary computation module for the optimization of refrigerant circuitries in the evaporator and condenser. The evaluation showed the coefficient of performance (COP) for the studied refrigerants to be within 13 %, with R32 and R290 having the highest system COPs. This evaluation produced a vastly different ranking of the compared fluids than that obtained from a theoretical cycle analysis based on thermodynamic properties alone. In the system simulations, the high pressure refrigerants overcame the thermodynamic disadvantage associated with their low critical temperature and had higher COPs than the low-pressure R134a and R600a, which were ranked the highest by the thermodynamic cycle analysis. The presented results include entropy generation information for complete systems and individual system components.