Research On Household Air Conditioner Charged With R1234yf As Substitute To R22

The widely used refrigerant in the household air conditioning system is R22. But it needs to be replaced because of the limitation of ODP and GWP. And the next generation of refrigerant as a substitute for R22 has not been decided until now. As a new candidate refrigerant, the ODP of R1234 yf is 0, and the GWP is 4. Therefore the paper gave the experimental and Simulation study about the performances of R1234 yf "drop- in" system for R22.First thermodynamic properties of R1234 yf were compared with R22. And the theoretical cycles of these two refrigerants under typical working condition of household air conditioning system were studied and their performances were compared. The effects of operation parameters to the performance of theoretical cycles were investigated, including evaporation temperature, condensation temperature, sub-cooling degree and superheat degree. The results show it needs to increase the filling quantity when using R1234 yf as a direct replacement for R22, and R1234 yf will have more advantages when replacing R22 in high temperature condition.The performances of R1234 yf “drop- in” system were experimentally investigated on a R22 window air conditioner base on the theoretical study. The experimental results showed that the optimal refrigerant filling quantity of R1234 yf is 830 g, the capillary size is 1.4mm * 1000 mm, and the COP of R1234 yf is 2% higher than that of R22 in the rated cooling condition T3, also its discharge temperature is lower than R22 by an average of 9.8 degrees centigrade.The simulation models of components and system of R1234 yf are developed. The simulation results show that the average error of cooling capacity calculation is 10%, and that of COP calculation is 18%, compared with the experimental data. By increasing the compressor exhaust volume can improve the capacity of the system, but it will reduce the coefficient of performance of the system.In summary, R1234 yf has more advantages when replacing R22 in high temperature conditions, but it needs to increase the filling quantity. And the cooling capacity can be improved by increasing the exhaust volume of compressor.