Feasibility analysis on R1234yf/R152a replacing R134a as direct cooling refrigerant for electric vehicles.

R134a, commonly used in air conditioning (AC) for electric vehicles, may be gradually limited because its global warming potential (GWP) is 1430. This study combined the advantages of R1234yf and R152a. PR state equation and vdW mixing rule are used to construct the mixing model. The performance of R1234yf/R152a at different mass ratios was analyzed, a new mixture R1234yf/R152a (mass ratio 60.5/39.5) was selected. The cycling performance of mixture and R134a under three different evaporation temperatures was further studied. The results show that R1234yf/R152a belongs to a near-azeotropic mixture. In cycling performance, the R1234yf/R152a per-unit refrigerating capacity (RC) of refrigerant mass is about 12.45 % higher than that of R134a, the per-unit RC of swept volume is about 5.21 % lower than that of R134a. In this case, the GWP is 56.93, and the cost is moderate. The safety grade is A2L, which can replace R134a without changing the original system. [ABSTRACT FROM AUTHOR]