Assessment of a rotary compressor performance operating at transcritical carbon dioxide cycles

The unique features of the CO2 transcritical cycle of high mean effective pressure, high pressure differential and low pressure ratio have significant impact on the design of the compressor. This paper assesses the performance of a rolling piston compressor when operating at a transcritical CO2 cycle. The compressor performance in terms of refrigerant flow rate, leakage mass flow, friction loss, compressor torque and valve performance are discussed and shown. Among others, the results suggested that for a given compressor capacity, it is better to have a compressor with a shorter cylinder operating at a higher compressor speed than vice versa.