阀门内漏声发射检测传感器布局的试验研究

Experimental Research on Layout of Acoustic Emission Detection Sensor for Valves Internal Leakage

为研究传感器布局对阀门内漏声发射检测效果的影响,搭建了阀门内漏声发射检测试验平台。将三只相同参数的声发射传感器分别安装在阀门上游、本体和下游,并在不同的泄漏率工况下同时采集泄漏声发射信号。采用小波包分解重构、提取信号平均能量均方根(RMS)和线性拟合等方法,对采集信号进行特征提取分析。提取结果表明,三个位置传感器输出信号幅值随泄漏率的变化均接近线性关系。其中:安装在阀门下游处的声发射传感器输出信号能量更加集中,且幅值随泄漏率变化的线性度最好;安装在阀门上游处的声发射传感器输出信号幅值随泄漏率变化的线性度最差。在已有研究基础上,通过试验对比阀门上游、本体和下游传感器所测数据。试验结果表明,将传感器安装在下游靠近阀门处,可有效提高阀门内漏率声发射检测精度,并为预估阀门剩余寿命提供依据。

To research the influence of sensor layout on the acoustic emission detection effect of valve internal leakage,a test platform for valve internal leakage acoustic emission detection is built.Three acoustic emission sensors with the same parameters are installed in the upstream,body and downstream of the valve respectively,and the leakage acoustic emission signals are collected simultaneously under different leakage rate conditions.Wavelet packet decomposition and reconstruction,extracting the average energy of the signal root mean square(RMS)and linear fitting and other methods are used to analyze the collected signals for feature extraction.The extraction results show that the output signal amplitudes of the three position sensors are close to linear with the change of the leakage rate.Among them,the acoustic emission sensor installed at the downstream of the valve has more concentrated output signal energy and the best linearity of amplitude with the change of the leakage rate;the acoustic emission sensor installed at the upstream of the valve has the worst linearity of output signal amplitude with the change of the leakage rate.Based on existing research,the measured data of the upstream,body and downstream sensors of the valve are compared through the experiment.The experimented results show that,by installing the sensor at the downstream near the valve,it can effectively improve the accuracy of the acoustic emission detection of the internal leakage rate of the valve and provide a basis for the estimation of the remaining life of the valve.