R1234yf is one of the ideal alternative refrigerants for R134a. In order to study the refrigeration and heating performance of R1234yf system, a new energy vehicle heat pump air conditioning experimental bench was built, and the differences in refrigeration and heating performance between R1234yf system and R134a system were compared through experiments. The experimental results show that the cooling capacity and COP of R1234yf system are lower than that of R134a system. Under the heating condition, the heat production of R1234yf system is similar to that of R134a system, and the COP is lower than R134a system. The R1234yf system is more conducive to stable operation due to its lower exhaust temperature.
R134a has a global warming potential (GWP) of 1430, which is the highest GWP among current commonly used refrigerants. With the increase of people's environmental awareness, the use of high GWP refrigerants began to be gradually limited. The new refrigerant R1234yf, due to its GWP of only 4 and ODP of 0, has similar thermal physical properties to R134a and is expected to become one of the ideal alternative refrigerants for R134a.
In this experimental research, the R1234yf is directly replaced in the R134a new energy heat pump air conditioning system test bench, and the performance difference between R1234yf system and R134a system under different refrigeration and heat pump conditions is studied. The following conclusions are drawn.
1) Under refrigeration conditions, the cooling capacity and COP of the R1234yf system are lower than that of the R134a system, and the COP gap gradually increases with the increase of rotational speed. Compared with the heat transfer in the condenser and the cooling capacity in the evaporator, the higher mass flow rate of the R1234yf system compensates for its lower latent heat of vaporization.
2) Under heating conditions, the heat production of the R1234yf system is equivalent to that of the R134a system, and the COP is lower than that of the R134a system, and the mass flow rate and compressor power consumption are the direct reasons for the low COP. Under low temperature conditions, due to the increase of inspiratory specific volume and the decrease of mass flow, the heat production attenuation of both systems is relatively serious.
3) Under cooling and heating conditions, the exhaust temperature of R1234yf is lower than that of R134a system, which is conducive to the stable operation of the system.
Post time: Dec-18-2023