小波变换法在输油管道泄漏检测中的应用研究

Application Research of the Wavelet Transform in Oil Pipeline Leakage Detecting

针对管道泄漏诱发的负压波传播到管道泄漏上下游监测点时,会使该点压力信号幅值产生瞬态下降这一现象,对管道监测点采集的压力信号进行小波变换,并根据小波变换模极大值对应着信号突变点这一理论,计算出负压波传播到管道上下游监测点的时间差,根据此时间差计算出泄漏点的位置。对滤波前后的信号对应的数据求标准方差,从数学方面验证小波变换方法对信号中夹杂的噪声的抑制作用。

Leakage accidents in pipeline transportation occur frequently in recent years. In order to guarantee the pipelines work safely and minimize the losses caused by leakage accidents, it is necessary to study leakage detecting technology to raise the sensitivity of detection and accuracy of localization. When the negative pressure wave induced by pipe leakage propagates to two monitoring points of upstream, the pressure amplitudes at these points will decrease instantaneously. Based on this phenomenon, a wavelet transform for the pressure signals acquired from the monitoring points is provided, and the propagating time difference between the two monitoring points is calculated according to the theory that extreme modulus value of wavelet transform responds to the sudden change of the pressure signal. The calculated results indicate that the time difference can be calculated by this way. It offers a base to accurately determine the leakage location.