Study On The Vibration And Noise Control Techniques In Large Power Machines

With the development of industry and society, aggravation of environmental pollution, the control and treatment of various sources of industrial noise and vibration pollution hazards has become a urgent social problem and important scientific research objective to solve.Power machinery as the main research target, this paper mainly studies vibration and noise sources, transmission mechanism, principles of performances, and soon,in-depth studies vibration and noise control technologies, formulates optimization programs, and forecasts the implementations of the program results. Two grades vibration and noise control concept is put award, that is, passive and active control of combining control. The energy radiation is reduced from fault sources and propagating processes. The concrete research contents are as follows:(1) Base on fault diagnosis, summarized the large-scale power generator breakdown diagnosis detailed process. It discusses how to analyze signals widely with time analysis, frequency analysis, demodulation analysis, exiguous analysis, axes tracking analysis and azimuth analysis. Then withdraws the machine unique breakdown indication and the breakdown sensitive parameter and so on. Solves unit's vibration problem from the root, and proposes the government measure.(2) The noise eradiated from large power machine have large channel characteristic. Compounding sound-absorbing structure for large channel is put forward in this paper. The sound-absorbing channel can be increased, absorbing efficient canbe obtained by using this structure. The compounding large channel sound-absorbing structure and normal sound-absorbing structure finite element model is built using SYSNOISE. The variation of sound field is much different after compounding large channel sound-absorbing structure is place into the field of point sound source. The effect of noise reducetion with compounding large channel sound-absorbing structure is much better than with normal sound-absorbing structure. The reverberation canbe faded by using compounding large channel sound-absorbing structure.(3) Noise control on refrigerator of screw compressor. Signal of vibration eradiated from Refrigerator of screw compressor had been collected, and transform the signal into spectrum. The fault of unit is determined and eliminated, then make vibration reduction measure. Signal of noise had been colledted, and determined sound absorption material and structure by signal feature. Reverberation had disappeared and sound pressure level had declined in the room by treatment.