Study On The Leak Localization Of The Pipeline With Three Sensors Interrelated Based On Multi-Scale Analysis

Pipeline has become the lifeline of the national economy and the human life, its importance cannot be ignored. But as for so huge pipe network, the leakage occurs frequently and even hard to avoid. So it is necessary to locate the leak accurately and maintain it timely. At present the correlator has introduced from abroad many years, and be more and more extensive applied in pipeline leak detection, especially for the tap water pipe. But the reliability of the leak positioning with the traditional correlator is poor, and the result cannot be verified timely. So the object of this paper is how to improve the positioning performance.1,This paper takes the cast iron pipe as the object of the research. The acoustic characteristics were studied by experiments for the case of with leakage and without leakage separately. And all the spectrum distribution of the acoustic in the pipeline with leakage are illustrated. In order to understand the effect of different hydraulic conditions on the acoustic characteristics of the leakage respectively, the pipe leakage acoustic signals under the influence of different pressures, different distance, and different flow were investigated.2,In the paper, first of all, the shortcomings of the Fourier transform were pointed out in dealing with the non-stationary signal. Then the characteristic of wavelet basis was introduced in detail. Furthermore the advantages of wavelet transform is discussed, especially the wavelet multi-scale decomposition was done a more in-depth analysis. This sets the stage for performing a multi-scale decomposition to the leak noise.3, Through anglicizing the disadvantage of traditional two-sensor correlator and considering the characteristics of the pipeline leak signals, the "three sensor vector matching" and―multi-scale analysis‖was applied to detecting the location of the leakage, innovatively. And finally, a new method of leak localization based on multi-scale analysis with three sensors that interrelated is proposed.4, The experiment results prove the method is practical and feasible. It can not only calculate speed by itself but also make the quality of leak localization greater enhanced.