자동차용 대체냉매 적용 기술 개발 동향 연구

The aim of this study is to investigate mobile air conditioning system using alternative refrigerants. Due to environmental regulation as a global issue to use working fluids under GWP 150, R-134a, present mobile A/C refrigerant and GWP(Global Warning Potential) 1,430, need to be substituted. Among possible alternative refrigerants, R-1234yf has been highly regarded in air conditioning system because of similar operating pressure characteristic and technologies to apply have been studied. In this study, R-1234yf and R-744 were introduced on the performance, such as cooling capacity and coefficient of performance(COP), compared to R-134a. While R-134a has been generally used for passenger’s thermal comfort, R-404a has been applied to freezing system, such as refrigeration truck to keep certain temperature below –18℃, thanks to its physical characteristics. However, because R-404a has GWP 3,920, R-404a is required to be changed to deal with environmental regulation. XP44 by Dupont and N40 by Honeywell have been regarded as alternative refrigerants for R-404a. Because they have zeotropic characteristics, some technical approaches will be developed with respect to control logic and heat exchangers to substitute. Further studies of improved alternative refrigerant A/C system will be required to change the refrigerant for vehicles.