基于声发射技术的气体阀门内漏诊断

Internal Leakage Diagnosis for Gas Valve Based on AE Technique

针对石化企业阀门内漏在线诊断中存在的问题,建立了预置缺陷闸阀内漏模拟试验平台,应用声发射检测技术,结合Fluent软件对泄漏状态下流场的模拟,探讨了气体阀门内漏过程中声发射特征参数分布规律。利用小波分析技术,研究了内漏声发射信号频率分布规律。结果表明:随着压差的增大,阀门泄漏率增大,声发射信号特征参数(能量、幅值、平均信号电平等)也随之呈规律性变化,且阀门缺陷尺寸越大,变化趋势越明显。对均方根-泄漏率关系曲线进行最小二乘法拟合,提出阀门内漏定量诊断公式。

Aiming at on-line diagnosis problem about valve leakage in petrochemical enterprises,a simulation test platform of preset defect gates valve leakage is established.By the application of acoustic emission（AE）technology testing means combined with Fluent software simulation of flow field under leakage state,the distribution of AE characteristic parameters are studied in the process of internal leakage.Results show that as the pressure increases,the leakage rate in valve will increase,and the AE signal characteristic parameters（including energy,amplitude,ASL,RMS,etc）will also change regularly.The larger the size of the defect is,the more obvious the change trend shall be.RMS-leakage rate curve is fitting with least squares,and the formula is put forward on quantitative diagnosis for valve leakage.