ENERGY PERFORMANCE OF ENVIRONMENTAL-FRIENDLY R435A AND R161 REFRIGERANTS IN SUB-COOLING REFRIGERATION SYSTEMS

The synthetic chlorofluorocarbon (CFC) and hydro-chlorofluorocarbon (HCFC) refrigerants are being phased out due to their high Ozone depletion Potentials (ODPs) and Global Warming Potentials (GWPs). In this study, the effects of sub-cooling on the energy performance of two eco-friendly refrigerants (R435A and R161) with zero ODP and negligible GWP are investigated theoretically and compared with those obtained using R413A. The results obtained showed that the thermodynamic properties of R435A matched those of R413A and it could be used as substitute for R413A. The two alternative refrigerants (R435A and R161) exhibited very high refrigerating effects and coefficient of performance (COP) with the average COPs of 9.17 and 7.68 % respectively higher than that of R413A. They also exhibited lower power per ton of refrigeration (PPTR), but R435A emerged as the most energy efficient refrigerant with the highest COP and lowest PPTR. Generally, incorporation of sub-cooling heat exchanger enhanced the system's performance.