Abstract
High-performance automotive thermal management systems with environment-friendly refrigerants are essential for achieving carbon peaking and carbon neutrality goals.In this study,an R290 vapor-injection heat pump system for electric vehicles is developed and experimentally investigated.The effects of refrigerant charge mass,injection pressure,and in-cabin air tem-perature are analyzed in ambient temperatures from-30℃ to 0℃.The results show that the vapor-injection system can increase the coefficient of performance(COP)and heating capacity by 14.3％and 15.9％at 0℃/20℃(ambient/in-cabin temperature)compared with the basic system,and this increase becomes more significant at-20℃/20℃ with improvements of 32.5％and 38.1％,respectively.At a lower ambient temperature of-20℃,increasing refrigerant charge mass contributes to a more pronounced increase in heating capacity than at 0℃,which results from the more significant increase in injection mass flow.The optimal COP at various injection pressures are 2.07 and 1.63 at 0℃ and-20℃ ambient temperatures,corresponding to the relative injection pressures of 0.60 and 0.57,and the injection flow ratios of 0.23 and 0.29,respectively.At-30℃/0℃,a COP of 1.69 can be achieved.
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