Study on performance change in a linear compressor considering refrigerant leakage through the suction valve clearance

Leakage of refrigerant in a linear compressor is one of the main factors affecting compressor performance. The refrigerant leakage mainly occurs due to piston clearance or valve clearance. Valve clearance leakage has been studied [1, 2]. However, as in the present study, there is no research that accurately predicts the performance of a compressor using CFD while considering the valve clearance of a linear compressor. Therefore, in this study, the valve clearance leakage was experimentally measured according to the compression chamber pressure and a 3 - dimensional CFD cycle analysis was performed considering the valve clearance leakage. It was found that the actual clearance of the suction valve corresponds to about 2 ∼ 4 μm. According to the cycle analysis, when the valve clearance decreases from 5 μm to 3 μm, the cooling capacity increases by about 5 % and the EER increases by 6 %. Furthermore, considering leakage due to valve clearance, the simulated valve opening period and the valve vibration at closing were more in agreement with the experiment.