应用小波变换提取输油管道泄漏突变信号

为减少输油管道泄漏事故造成的损失，需及时发现泄漏并判断出泄漏 的准确位置。依据负压波检测输油管道泄漏的基本原理，分析了压力信号的突变点以及噪声在小波变换下的不同特性，认识到突变信号的小波变换模极大值具有随尺度的增加而增加，而噪声的小波变换模极大值随尺度的增加而减小的特点，因此可以应用小波变换精确地检测到负压波到达输油管道两端传感器的时间差，结合负压波传播速度就可以算出泄漏点位置。针对具体数据给出了计算算例。应用结果表 明：小波变换法能准确的提取瞬态负压波的突变值，实现对输油管道的泄漏检测与定位。

APPLICATION OF WAVELET TRANSFORM IN DETECTING LEAKAGE IN PIPELINES

The oil pipeline leaking accident occurs for many reasons.In order to reduce the loss which the accident results in,the leakage and leaking position should be discovered promptly.In this paper,the basic theory of applying negative wave to detect leakage is introduced,then the characteristic of pressure signals singularity and the different characteristics between signals and noises are analyzed based on their wavelet transform,the sudden change signal wavelet transformation mold maximum value increases along with the criterion increases,but the noise wavelet transformation mold maximum value reduces along with the criterion increases.Therefore,the leaking point position can be figured out by using the time difference and propagation velocity of the negative pressure wave,which may arrive at the both ends of the oil pipeline.The case study indicates that,the wavelet transform method of transformation can be used to accurately withdraw the sudden change value of the transient negative pressure wave,thus the leakage location can be detected.