Unsteady characteristic and flow mechanism of a scroll compressor in small-scale compressed air energy storage system

Abstract

Tangential leakage loss reduction has significant impact on improving the performance of scroll compressors. In this study, the flow field of a scroll compressor working with air was numerically investigated. The characteristics of the tangential leakage flow in different radial clearances were studied, which was obtained by analyzing the field quantities distributions. Moreover, the influence of radial clearance on the time-averaged performance of the scroll compressor and the aerodynamic force on it in each direction are analyzed. The results showed that the gas flowed into the low-pressure chamber through the radial clearance, and the downstream gas in compression chamber was compressed and collides with the leakage flow, having aggravated the uneven distribution of the flow field in the compression chamber. The gas velocity was faster in the region with large pressure difference, and the peak velocity appeared near the radial clearance. Moreover, as the radial clearance continues to increase in a certain range, its influence on the working characteristic curve of scroll compressor has two sides. The research can provide theoretical basis for the structural design of scroll compressors.