A Heat Transfer Model Combining Differential and Integral Formulations for Thermal Analysis of Reciprocating Compressors
Abstract
Heat transfer in hermetic compressors is a complex phenomenon strongly affected by fluid flow inside and outside the compression chamber and by the efficiency of both the electrical motor and the crankshaft mechanism. This paper presents a heat transfer model for thermal analysis of reciprocating compressors formed by combining a lumped formulation for convective heat transfer in some selected regions and a three-dimensional differential formulation for heat conduction in the solid components. Convective heat transfer coefficients were evaluated from correlations available in the literature so as to avoid calibration based on experimental data. The model was applied to a reciprocating compressor operating in a fully periodic condition and predictions for temperature distribution, heat transfer and volumetric efficiency were seen to be in reasonable agreement with measurements.