Experimental study of an auto-controlled automobile air conditioning system with an externally-controlled variable displacement compressor

In this paper, an experimental study of an auto-controlled mobile air conditioning (MAC) system with an externally-controlled variable displacement compressor (EVDC) is performed and analyzed. A new displacement control method of EVDC is developed concerning about evaporator characteristics and in-car temperature fluctuation, which indicate the quality of the MAC system. Based on occupant’s thermal comfort, the wind-tunnel test results show that the MAC system with an EVDC can maintain the deviation of in-car temperature no more than 2 °C compared with the occupants’ desired one. This MAC system gives the occupants a good thermal comfort sensation in the rapid changing environment. The comparison shows that the discharge pressure changes of EVDC vary faster than that of the fixed displacement compressor, which reflects the effect of the internal climate changes.