Performance Research And Optimization Of Compression-Ejector Heat Pump Automobile Air Conditioning System

As the problem of climate warming becomes more and more severe,and the environmental protection requirements of countries all over the world are becoming more and more stringent.It is urgent to find a suitable automobile heat pump air-conditioning system and suitable refrigerant.Through the thermodynamic analysis of five kinds of automobile air conditioning systems:Conventional Single Vapor Compression heat pump System（CSVCS）,Conventional Double evaporator Vapor Compression heat pump System（CDVCS）,Single Evaporator compression Ejection heat pump System（SEES）,Double Evaporator compression Ejection heat pump System（DEES）,Flash Tank Vapor Injection（FTVI）.The compression ejection heat pump system shows good performance.Compared with the CDVCS,the DEES has the highest COP improvement rate of 21.4%.Among them,when R744 is used as the refrigerant,as the evaporation temperature of the low temperature evaporator increases from-25°C to-10°C,the evaporation temperature of the high temperature evaporator increases from-5°C to 10°C,and the condensation temperature and the outlet temperature of the gas cooler increase from 40°C.When the temperature increases to 60℃,the COP increase rate ranges from 4.7%to 18.9%,1.5%to 21.4%,and 3.5%to17.7%.Designed 5 different electric vehicle air-conditioning systems:CSVCS,CDVCS,SEES,DEES,FTVI,and carried out the whole life cycle performance evaluation of vehicle air-conditioning on 5 different refrigerants（R134a,R32,R152a,R290,R744）.TEWI（Total Equivalent Warming Impact）is the equivalent CO₂ emitted into the atmosphere due to system refrigerant leakage（direct emissions）and energy consumption（indirect emissions）.The results show that the use of compression ejection system in automobile air conditioners can significantly reduce equivalent CO₂ emissions.Using high and low pressure refrigerants,the equivalent CO₂ emissions of the DEES system relative to the CDVCS system are reduced by approximately 5%～7%and 11%,respectively;the SEES system is reduced by approximately 11%～16%and 17%relative to the CSVCS system;the SEES system is relative to FTVI System-equivalent CO₂emissions are reduced by approximately 8%to 15%.Compared with the traditional R134a cycle,CO₂ compression ejection heat pump automotive air conditioners have lower emissions.In these eight major cities,the latitude is from north to south,SEES using CO₂ refrigerant reduces CO₂ emissions by 23%,17%,14%,9%,7.2%,7%,6%,2%,respectively,compared with CSVCS using R134a.Figure 40;Table 11;Reference 68...