Abstract: The mechanical noise produced by the discharge valve flapping the discharge stopper is one of the main noise sources of the refrigeration compressor. In order to reduce the noise of this part, the natural frequency simulation analysis and experimental research were carried out after the material of the compressor discharge stopper was changed. Through the analysis of natural frequency of PEEK material discharge stopper by ANSYS software, it can be seen that the natural frequency of PEEK material limit plate is lower than that of metal limit plate, which is not easy to excite response. At the same time, the frequency response area is avoided. It can be concluded that PEEK material discharge stopper has lower noise. It is found that PEEK material discharge stopper can not only improve the mechanical noise of the compressor, but also improve the efficiency of the compressor, and prolong the service life of the discharge valve.

Key words: Mechanical noise, Refrigeration compressor, PEEK material, PEEK discharge stopper, Discharge valve