압축기 회전수 변화에 따른 R134a/R1234yf 혼합냉매를 적용한 자동차 공조 시스템의 성능 특성에 대한 해석적 연구

Analytical Study on the Performance Characteristics of Automobile Air-Conditioning System Using the Mixed Refrigerant R134a/R1234yf for Varying Compressor Rotation Speeds

This study presents the performance analysis for an automobile air-conditioning system using the mixed refrigerant R134a/R1234yf with varying compressor rotation speeds. Accordingly, the compressor, condenser, expansion device, and evaporator of the automobile air-conditioning system were designed using the EES program, and the cooling capacity and COP of the automobile air-conditioning system using the mixed refrigerant were comparatively analyzed for simulated data. The cooling capacity using the mixed R134a/R1234yf(30%) system at a compressor rotation speed of 2500 rpm was about 6.13% lower than that using the R134a system alone. Moreover, the COP using the mixed R134a/R1234yf(30%) system at a compressor rotation speed of 2500 rpm was about 7.45% lower than that using the R134a system alone. The use of the R134a /R1234yf mixed refrigerant can thus reduce global warming potential; further, as there is no significant difference in performance compared with the system using only R134a, the applicability of the mixed R134a/R1234yf refrigerant is confirmed.