Design optimization of a rolling piston compressor for refrigerators

In this paper, the performance of a rolling piston compressor has been optimized under preset operational conditions and design constraints by employing a multi-variable, direct search, constrained optimization technique. A mathematical model for the compressor was first formulated. The model accounts for geometrical configuration, thermodynamics effects, valve dynamics, flow and mechanical considerations. The accuracy of the model was verified by comparing its prediction with measured results. The model was then linked with an optimization algorithm to search for a combination of some six design dimensions and seven sets of design constraints, for an optimum compressor performance with minimum mechanical losses. The results of the study suggested that for a given compressor swept volume, a proper combination of the compressor design dimensions can lead to significant compressor performance. The theoretical study predicted that a 50% reduction in mechanical loss is possible and this brings about an improvement in the coefficient of performance of the compressor of more than 14%.