자동차용 대체냉매 Drop-In 성능 평가를 위한 실험적 연구

The aim of this study is to investigate the performance of drop-in A/C system for alternative refrigerants. Due to environmental regulation as a global issue, R-134a, present mobile A/C refrigerant, need to be substituted before long. Among possible alternative refrigerants, R-1234yf and R-152a have been highly regarded in Mobile Air Conditioning System(MACS) because of similar operating pressure characteristic and technologies to apply have been studied. Cost effective way to change the refrigerant for MACS concerned cool-down performance for drop-in test, which substitute only a refrigerant without any change of components. In this study, before drop-in test on the road, thermodynamic properties for R-1234yf and R-152a were analyzed and theoretical performance prediction from property’s characteristic was found. In P-h diagram, evaporating heat of R-1234yf in main operating region is about 82% while that of R-152a is about 155% compared to present R-134a. From this, cool-down performance in a drop-in test had different results, which R-1234yf had higher level of temperature and R-152a had lower level of temperature than R-134a in initial fast cooling-side of cabin room. After a drop-in test, R-1234yf need additional technical developments to cope with 10% performance difference and R-152a need to find other system to solve the flammability concern in spite of good cool-down performance in a drop-in test. Further studies will be required to change a refrigerant for MACS.