Evaluation of a low-GWP and nonflammable blend as a new alternative for R134a in the heat pump system

Abstract

R134a is a refrigerant widely used in heat pump systems, which has a high global warming potential (GWP) and cannot be used for a long time. In this study, a new mixed refrigerant, named RGT2 (GWP = 560), has been proposed as an alternative refrigerant to R134a in heat pump systems. RGT2 is a mixture composed of R134a/R1234yf/R161 (54%/43%/3% wt%) without toxicity. Firstly, the basic properties of RGT2 were tested, including flammability, miscibility, and saturated vapor pressure. The results showed that RGT2 is non-flammable and is well miscible with polyol ester (POE) oil and polyvinyl ether (PVE) oil. Moreover, the saturated vapor pressure curve of RGT2 is close to that of R134a in the range of -20∼80 °C. Secondly, the cycle performance of RGT2 and R134a were compared and analyzed by theoretical calculations and experiments. The cooling capacity of the heat pump system filled with RGT2 is close to R134a, and the coefficient of performance (COP) is 3.8% lower than that of R134a. Considering that RGT2 is more environmentally friendly and safer, and its thermophysical properties and cycle performance are close to R134a, it can be used as a substitute refrigerant for R134a in heat pump systems.