Influence of Wear on Leakage through Reed-Type Valves of Small Reciprocating Compressors

Leakage can significantly decrease the efficiency of small reciprocating compressors adopted in household refrigeration systems. Leakage occurs in the piston-cylinder clearance and through gaps in valves formed by geometric irregularities associated with the manufacturing process. This paper presents a procedure developed to analyze experimentally gas leakage in reed-type valves taking into account the wear effect. Accordingly, leakage is measured in the valves of a small-capacity reciprocating compressor before and after the valves being subjected to wear, with the roughness of the reed and seat being measured in both conditions. Measurements of leakages in the suction and discharge valves were carried out independently in an experimental setup based on the constant volume method. Finally, a simulation model for valve leakage and an optimization algorithm were used to estimate the edge gap between the reed and seat. The edge gap was found in the range between 0.13 and 0.94 µm before wear and between 0.11 and 0.47 µm after wear. It was also found that the reed and seat roughness were reduced by approximately half after wear