Vapor quality and performance of an automotive air conditioning system

This paper reports the results of a study on the performance of an automotive air conditioning system with measuring the vapor quality. To quantitatively measure the vapor quality (two-phase flow) at outlet of the accumulator, a large diameter tube is inserted between the accumulator and the compressor to separate refrigerant vapor from the miscible mixture of liquid refrigerant and lubrication oil. The coefficient of performance, evaporator cooling capacity, compressor power consumption, total mass flow rate, vapor mass flow rate, liquid mass flow rate and oil in circulation, pressures and temperatures of refrigerant at every component (inlets and outlets) are measured and analyzed with the variation of the outside temperatures at the evaporator and condenser, the speed of the compressor, refrigerant charge and oil charge. The systematical experimental results obtained from this real-size test system depict the relations between the above parameters in an automotive air conditioning system, which constitute a useful source for automotive air conditioning systems design and analysis. The vapor quality (two-phase flow) measurements realized in this work provide an extremely important tool for diagnosing the system performances.