R1234yf

R1234yf refrigerant, tetrafluoropropene, as a single refrigerant, has excellent environmental parameters, GWP=4, ODP=0, lifetime climate performance (LCCP) is lower than R134a, and atmospheric decomposition substances are the same as R134a. Moreover, its system performance is better than R134a. If R1234yf is used to replace R134a refrigerant, car manufacturers can continue to use the original Mobile Air-Conditioning (MAC) system. Therefore, R1234yf is considered to be a potential new generation of automotive refrigerant alternatives and is currently accepted by automobile manufacturers in Western Europe.

The boiling heat transfer performance of R1234yf is slightly better than that of R134a, and the pressure drop during the condensation process is 5% to 10% lower than that of R134a, which is better than that of R134a system. In many simulations and experimental studies of R1234yf and R134a systems, the performance of R1234yf heat pump is slightly lower than that of R134a, but it can be made very close to or even surpass that of R134a by optimizing components, enhancing air supply, and improving working conditions. The low pressure saturation pressure of R1234yf is about 15% higher than that of R134a, which can adapt to higher compressor speeds. The heating performance at low temperatures is better than that of R134a. The lower compressor exhaust temperature makes the system work more stable, and the effect of strengthening air supply is also better than that of R134a.