Heat transfer study of a hermetic refrigeration compressor

This paper presents an analytical study on heat transfer and temperature distribution for a hermetic reciprocating refrigeration compressor using the lumped thermal conductance approach. In this analysis, the intricate components of a hermetic compressor were divided into 46 geometrically simplified discrete elements and each was assumed to be at a uniform temperature. The lumped thermal conductance method was then applied to all the components of the compressor to form 46 simultaneous equations, which were then solved to get the components’ temperatures. The results obtained were in good agreement with measurement. The discrepancies in the prediction lie in the assumptions made in assigning various heat transfer correlations to model the convection heat transfer effects of the fluid and solid surface boundaries, and the simplification made in distributing the various components of the compressor into discrete parts. The results of this study have been applied to actual compressor design in industry and have resulted in improved compressor performance.