摘要
Abstract
Valve abrasion failure is one of the main fault of valve,the valve cannot be accurately,smoothly opened and closed, and the circulating gas’s temperature and pressure would be changed,because of abrasion,the efficiency of compressor would be affected and caused energy loss,so it is necessary to extract fault characteristics and diagnose fault of valve abrasion failure.First-ly,it gets that the feature band is 2000 ~4000Hz by comparison of AR spectra,then,decomposed the signal by the method of EMD and secured IMF,IMF would be chosen in the criterion with wavelet packet frequency band energy,it means selecting some IMF which have larger energy proportion within the range of 2000 ~4000Hz to reconstruct.Finally,the reconstructed signal was denoised again by wavelet packet energy soft threshold,afterwards,and the denoised signal was decomposed into two layers,then the wavelet packet coefficients which band is 2000 ~4000Hz have be reconstructed,namely obtained the final denoised signal within the feature frequency bands.On the basis of above,fault comprehensive value of time domain parameters is established to distinguish whether valve is failure or not finally.The study shows:first,when failure occurs,the impact of the valve plate against valve guard and valve seat would increase,meanwhile,during the suction and exhaust period,the valve plate would be disturbed by airflow.Second,fault comprehensive value is beneficial to visually determine the degree of wear,the larger the value means the more serious wear.关键词
往复式压缩机/气阀磨损/故障特征/降噪Key words
reciprocating compressor/valve abrasion/failure feature/denoising分类
机械制造
