Compressor plays an important role in Automotive Air Conditioning (AC) System. It compresses the low pressure refrigerant and discharges the high pressure refrigerant vapour to condenser. Compressor performance mainly depends on two parameters, compressor oil and refrigerant gas charge quantity. Compressor oil is used to lubricate the movable parts in reciprocating compressors. Compressor oil is miscible in refrigerants in liquid state and amount of oil present in compressor increases the life of compressor. But, huge amount of oil may also reduce the thermal performance of system. Minimum gas quantity gives poor cooling performance and due to maximum quantity, increasing suction/discharge pressures, results in more compressor work and low cooling.
This paper discusses the experimental analysis of refrigerant quantity, oil quantity in different ratios to improving the cooling performance of a passenger vehicle. Experimentation was conducted on 7 seater passenger car (hatchback). For experimental study, testing was carried out inside Climatic Chamber under ambient conditions, road conditions. Grill level temperature were recorded over time to predict the passenger cabin cooling performance. Refrigerant side temperature, suction and discharge pressure were recorded at different charge quantity to understand the refrigerant side thermal performance. From the experimental study, Optimum refrigerant and oil quantity was determined.