Simulation Research On Pipeline Leakage Location Based On Acoustic Signal Processing

As an important resource,natural gas is widely used in power generation,chemical industry,people’s livelihood and other fields.However,natural gas pipeline leaks due to various reasons in long-term use,which is easy to cause environmental pollution and casualties.Therefore,it is of great significance to carry out research on pipeline leakage location.This paper takes the natural gas leakage pipeline as the research object,studies the propagation law and time-frequency characteristics of the leakage acoustic signal,and carries on the feature extraction of the acoustic signal for the leakage pipeline location analysis.The main research contents include:First of all,this paper takes straight pipe and three-way pipe as the research object to carry out numerical simulation analysis of the pipeline under different pressure and leakage aperture conditions.The changing rules of pipeline flow field distribution under different influence conditions were obtained,and the sound field distribution of leakage pipeline was studied according to this,and the propagation rules and time-frequency characteristics of sound signals on both sides of leakage holes under different conditions were obtained.Secondly,an improved empirical wavelet transform method is proposed to extract the features of the original acoustic signal,aiming at the problem that the original acoustic signal cannot accurately identify the location of pipeline leakage.The traditional empirical wavelet transform needs to set the decomposition scale and divide the frequency band manually.It can be improved by using wavelet packet decomposition and wavelet packet multi-scale information entropy theory.The decomposition scale is determined by the ratio of information entropy and original signal entropy,and the signal frequency band is divided based on the local minimum value of the selected frequency band energy as the boundary.The acoustic signal spectrum is divided by the wavelet filter bank composed of the empirical scale function and the empirical wavelet function,so as to achieve the purpose of reasonable signal division.Finally,in order to verify the accuracy of leakage pipeline location.Through the establishment of the positioning model of the straight pipe and the three-way pipe natural gas leakage pipeline,the improved empirical wavelet transform is used to extract the features of the collected pipeline acoustic signals,and the acoustic signal components are selected to analyze the cross-correlation positioning based on the correlation coefficient.The accuracy of locating leakage positions of straight pipe and three-way pipe is 99% and 94.8%,respectively.The results verify the accuracy of the proposed method in locating leakage pipes.