局域波法和高阶统计量在压缩机气阀状态监测中应用

为解决传统信号处理方法分析非平稳时变信号的不足,提出了一种适用于往复式压缩机气阀状态特征提取的新方法.首先使用局域波法将实测信号分解为多个基本模式分量,经过希尔伯特变换得到各分量的时频谱;然后计算归一化后幅值信号的高阶统计量,这些统计量很好地反映了气阀的劣化过程.通过对现场工作的聚乙烯二次压缩机组合阀振动信号的分析,验证了该方法在往复压缩机状态监测中的有效性和实用性.

Application of local wave method and higher-order statistics to valve-condition monitoring of reciprocating compressors

In order to avoid the deficiency in processing non-stationary and nonlinear signals by using traditional methods,a new method is presented for extracting condition features from reciprocating compressor valves.Firstly,tested signals are decomposed into number of intrinsic mode functions(IMFs) by using local wave method,and time-frequency spectrums of IMFs are acquired by means of Hilbert transformation.Then the higher-order statistics of normalized time-frequency amplitude are calculated.These statistics can reflect the degradation in the performance of the valves well.After used in condition monitoring for combined suction-discharge valves of the secondary ethylene compressor in site,it is testified that the method is effective and practical in reciprocating compressor condition monitoring.