包络解调法在气阀弹簧失效故障诊断中的应用

考虑到往复式压缩机振动具有振源丰富、信息干扰大的特点,利用包络解调法分离出系统固有频率成分的振动信号。该包络信号每一峰值对应阀片的每一个冲击。对气阀半个周期内(包含气阀开启到关闭一次的过程)的时域信号进行包络解调处理,提取气阀开启、关闭、颤震等几处故障的时频特征信息来诊断弹簧失效故障,同时给出了弹簧失效系数的计算公式。以塔里木油田16SGT/MH 66注气压缩机为例进行了试验,故障诊断准确率大于85%,分析结果证明了该方法的正确性及有效性。

Application of envelope demodulation method to fault diagnosis of spring invalidation

According to the character of vibration in reciprocating compressor, the vibration signal was separated from intrinsic frequencies of the system by envelope demodulation method. Every peak value of the signal corresponded to every impact of valve patch. Time-domain signals of the air valve in half period including the process from unclosure to closure once were disposed by envelope demodulation method. And the fault of spring invalidation was diagnosed by extracting the fault time-frequency feature information. The information was included in the process of gas-valve unclosure, closure and vibration. The formula for calculating the coefficient of spring invalidation was then proposed. A test was held in 16SGT/MH-66 insufflation compressor of Tarim Oilfield. The nicety rate accedes 85%. The analysis result shows that this method is correct and effective.