Theoretical analysis of the energy performance of three low global warming potential hydro-fluorocarbon refrigerants as R134a alternatives in refrigeration systems

In this study, the energy performances of low global warming potential R152a, R161 and R1234yf refrigerants were investigated theoretically as alternatives to R134a in vapour compression refrigeration system. The results obtained showed that the saturation vapour pressures for R152a and R1234yf are very close to the pressure of R134a, which indicates similar properties, while that of R161, between the temperatures range of −30℃ and 40℃, deviated significantly by being 49.2% higher than that of R134a. R152a emerged as the most energy efficient of the investigated refrigerants with average power per ton of refrigeration being 30.5% less than that of R134a. R152a and R161 exhibited higher volumetric refrigerating capacity and coefficient of performance than did R134a. The highest coefficient of performance was obtained using R152a in the system, with average value being 43.5% higher than that of R134a, while the average coefficient of performances for R161 and R1234yf are 4.8% higher and 7.1% lower, respectively. Generally, R152a performed better than other two alternatives, except that it is mildly flammable refrigerant. Major system redesign will be required before R161 can be employed as substitute for R134a. Also, R1234yf showed slightly low energy performance in terms of power per ton of refrigeration, volumetric refrigerating capacity and coefficient of performance.