Research On Mechanism And Application Of Noise Reduction Of Rotary Piston Compressor

With the improving level of people's life, noise of air-condition, which is one of symbols of high quality life, is attached more importance. As main noise source of air-condition, low noise design of refrigeration compressor has become one of research keystones of many research organizations and enterprises. Integrating practical application of noise reduction of rotary piston compressor, the dissertation designs and develops the system of signal collection and analysis to test vibration and noise and analyze structure dynamics. Furthermore, the dissertation researches the theory of noise resource, noise reduction and modern signal analysis and solves some problem of theory and practice. The main achievements are as follows: Based on the research of principles and methods of data collection and processing, the dissertation put forward using VXD to accomplish break response of hardware and utilizing control principle of DMA to realize data transfer of high speed. So the dissertation conquers the defect of bad real-time characteristic of Windows because of multitask function and message mapping and accomplish real-time of collection and analysis. And the dissertation develops the system of signal collection and analysis to test vibration and noise and analyze structure dynamics. The dissertation researches theory of modern signal analysis such as time-frequency analysis and wavelet analysis and use STFT distribution and wavelet analysis to process noise signal of rotary compressor.Starting with experiments, the dissertation researches theory of noise resource identification and uses the methods of spectrum and cepstrum analysis to identify the noise resource. And it uses the new method of hierarchy identification of complex noise resource to firm noise resource of compressor accurately and extend the methods of noise resource identification of rotary piston compressor. We used the method of experiment to change the cavity volume of muffler to improve extinction character and resonance vibration of gas column and to reduce noise of compressor. And the method has characteristics of simple and high speed and reduce defects of common metheods.Using four-load method to analyze mufflers, the dissertation designs newtwo-expansion chamber muffler and analyzes the acoustic characteristics of it. Then model of optimization design is made up and optimum solution is got. Based damping principles of connecting surface and coulomb friction, the dissertation brings forth new idea of the two-layer shell structure for compressor shell and analyze principle of noise reduction by expriment. In the end, the dissertation put forward next work and prospect of this research.