Mechanical Impact Noise Analysis of Rotary Compressor

In the noise and vibration test of 8HP rotary compressor, the peak value of noise and vibration is especially high at frequency range between 600~1000Hz. The sound pressure level (SPL) exceeds the enterprise criterions and the sound quality is so tough that persons cannot bear such annoying noise. Two experiments, pressure pulsation above/ below compressor motor and mechanical impacts of compressor pump-rotor unit, are particularly carried out in order to identify the noise sources. The test results confirm that the axial up-down movement of pump-rotor unit is the primary reason, causing the abnormal noise and vibration. Several measures, including partially cutting the circumferential edge of the stator and increase the height differential between rotor and stator, have been taken in order to reduce pressure pulsation above/below motor and restrain the axial movement of shaft-rotor unit. With these measures, the noise problem of 8HP rotary compressor has been solved successfully. Finally the sound pressure level decreases about 4dB and the sound quality is comfortable and good to hear.

Development of Large-And-Small Volume-Switching Rotary Compressor for Residential Multi-Connected Air-Conditioner

Residential Multi-Connected Air-Conditioner(RMAC) are widely used in urban residential in China, but they have low energy efficiency problems in daily use. They are mainly due to the air-conditioning habits of Chinese residents in part space and part time , Which makes RMAC most of the time only 1-2 indoor units are turned on, and 60% of the operating time is at a low load rate of less than 30%. During low load operation, the compressor\u27s efficiency drops sharply, and there is also the problem of frequent start and stop when the minimum output is too large. In order to solve this problem, a large-and-small volume switching compressor suitable for RMAC is developed. The compressor can choose single-cylinder small-volume operation or twin-cylinder large-volume operation according to the change of system load. The new compressor technology for RMAC improves the energy efficiency by 124% under 10% load, and avoids the problem of frequent start-stops at low loads, making RMAC more energy efficient and more comfortable