基于负压波原理的管道泄漏检测技术具有响应快、精度高、成本低的优点,广泛应用于管道泄漏检测,其检测过程分为泄漏判定与泄漏定位两个过程。基于瞬变模型建立了长输水管道仿真模型,模拟了管道泄漏引起的水力瞬变过程。结果表明:泄漏引起了管道水位、流量的变化,其变化幅度随泄漏面积的变大而变大;压力梯度曲线在泄漏点处呈现出明显的突变。由仿真模型得到的压力波形可用于构建模式识别库,再采用基于负压波的模式识别法来判断是否发生了泄漏,泄漏位置的定位则采用压力梯度法。
The pipeline leak detection technology based on negative pressure waves has been used widely in real pipeline, because of its faster response, higher precision and lower cost. The applications include judging leakage and locating leakage points. The simulation model of long-distance water trans- mission pipeline based on transient model was built, and the hydraulic transient process caused by pipe- line leak was simulated using the simulation model. The simulation results showed that the changes of wa- ter level and flow were caused by pipeline leak, and the magnitude of such fluctuation increased as the leakage area increased. The pressure gradient curve showed obvious mutation at leakage points. So the pressure curve obtained by simulation model could be used for building pattern recognition database. The pattern recognition method based on negative pressure waves could be used for judging leakage, and pres- sure gradient method could be used for locating leakage points.