Prediction of Leakage Flow of Radial Clearance in a Rolling Piston Rotary Compressor

The functional formula of the flow coefficients for the radial clearance in a rolling piston rotary compressor was developed by the experiments and Computational Fluid Dynamics (CFD) to improve the accuracy of a compressor simulation program. The experiments and CFD simulation were conducted to obtain the flow coefficients at the radial clearance under the assumptions of incompressible flow and steady state. The experiments were carried out with the variation of pressure ratio and low upstream pressure using the nitrogen as a working fluid. The CFD simulation was adopted to calculate the flow coefficients at the radial clearance with change of the radial clearance and high upstream pressure. The results of CFD calculation were compared with the experimental results for verifying the reliability of CFD simulation. The functional formula obtained from the results of the CFD calculation was applied to compressor performance simulation for calculating the leakage flow through the radial clearance. The results of compressor simulation with the functional formula showed tolerable errors with the experimental data of the compressor calorimeter in terms of EER (Energy Efficiency Ratio). Thus, the function of the flow coefficients may be acceptable for prediction of leakage through the radial clearance under the various conditions.