Leakage characteristics and an updated volumetric efficiency prediction model of rolling piston type rotary compressor for small capacity air-conditioner and heat pump applications

Abstract

The rolling piston type rotary compressors consume huge amount of energy in buildings due to the large quantity of applications in household as well as commercial air-conditioners and heat pumps. Internal leakage losses significantly affects the energy utilization efficiency of a rolling piston type rotary compressor. This paper experimentally evaluate the internal refrigerant-oil mixture leakage characteristics of a rolling piston type rotary compressor. Effects of minimal clearance, pressure difference, length and geometry of the leakage channel on internal leakage losses are analyzed. The experimental results are compared with prediction results of different mathematical models. A preliminary optimization scheme for the mathematical model is proposed. The updated model can well predict the variation trend of the actual leakage process. Finally, volumetric efficiencies of a rolling piston type rotary compressor prototype under different rotated speeds are obtained based on the updated prediction model. The rolling piston type rotary compressor with high working efficiency will help to reduce the worldwide energy depletion and the present study provides significant reference for design, processing and assembling of the compressors.