A Study of Thermodynamic Cyclic Characteristics of HFC-134a Automotive Air-Conditioner System

HFC-134a 자동차용 공조시스템의 열역학적 사이클 특성에 관한 연구

Analytical study on the thermodynamical cyclic behabiour and characteristics of HFC-l34a refrigerant for automotive air conditionser system for the replacement of existing CFC-12 has been carried out in this paper through development of system performance simulation program, expecially in the view point of system design considerations. The results indicate that HFC-l34a system will give a greater refrigerating capacity than CFC-12 if appropriate engineering measures such as proper codensers, flow controllers, etc., taken for certain operating conditions. The results, however, also show that the operating power for compression process increases over entire temperature range as a result of decreasing volumetric efficiency due to larger specific volume and increased discharging pressure. The present study results indicate that proper selection of condensing and evaporating temperature plus refrigerant control is very important performance factor to have better COP in the HFC-134a system design.