Heat Transfer Characteristics of a Centrifugal Compressor Under Complex Heat Transfer Conditions

Deposit formation within turbocharger centrifugal compressor housing is a main issue that leads to significant compressor efficiency degradation. Housing temperature decrease by compressor cooling is an effective method to reduce this coking effect. The study of temperature distribution and heat transfer characteristics in compressor is of guiding significance for compressor cooling design. In current study, the temperature distribution in the centrifugal compressor under complex heat transfer conditions was investigated with both flow-thermal coupling numerical and experimental methods. The heat transfer characteristics of the cold and hot ends of the compressor and the surface temperature distribution of the diffuser under diverse working conditions were also carried out. Results show that the compressed air is the main heat source in the compressor, which leads to the high temperature level at the contacting surface of the housing. The highest temperature of the diffuser surface appears at the hub side of the inlet area and significant temperature gradient can be observed near the diffuser wall. The heat transfer coefficient on the diffuser wall decreases significantly along the radial direction, which indicates that the development of the boundary layer hinders the heat transfer between the fluid and the solid. Therefore, technical approach by using compressor housing cooling measures can effectively decrease the diffuser wall temperature and mitigate coking effect.