Research on the influence of check valve on noise performance of variable frequency scroll refrigeration compressor

Check valve is one of the core components of the scroll refrigeration compressor, which can directly affect its efficiency, life, and noise performance. Traditional check valve is the reed valve. This paper deeply studies the dynamic characteristics of reed valve and reveals the main reason of the valve noise under different rotation speeds. The large noise is mainly attributing to the large pressure pulsation as well as fast circulation velocity of fluid and the severe slapping of the reed plate on the valve seat, which is influenced by the high pressure ratio of the working condition and stiffness of the reed valve. In order to reduce the noise of the check valve, the circular valve is designed to replace reed valve in this paper. At each rotation speed, the circular valve shows a continuous exhaust process, which avoids the slapping of the valve plate on the valve seat. More importantly, the exhaust is smooth and the pressure pulsation as well as the flow rate of the fluid is reduced significantly leading to the low aerodynamic noise. Therefore, compared with the reed valve compressor, the sound pressure level of the circular valve compressor at 1800, 4200, and 6600 rpm is decreased by 3.0, 5.2, and 0.3 dB, respectively.