Research On Acoustic Leak Detection And Location Of Urban Water Supply Pipeline Network

Urban water supply pipeline network is an essential infrastructure of urbanexistence and development. Leakage phenomenon of our urban water supplypipeline network is serious, resulting in substantial waste of water resources.Faced with this situation, the exact location of the leak point is particularlyimportant.Currently, long-distance oil and gas pipeline leak detection and locationtechnology has matured, and obtained good results in the actual testing. Urbanwater supply pipeline network is different from the oil and gas pipelines. It hasthe characteristic of complex spatial distribution, a lot of branch and nodes,different leakage forms and complicated pipeline conditions. The differentconditions include pressure,tubing, pipe diameter, pipe thickness, pipe interfaceforms and buried conditions. Therefore, the oil and gas detection method can notbe applied on the city water supply pipeline network directly.The acoustic leak detection methods of urban water supply pipeline network are numerous. We get the leakage signal by piezoelectric accelerometersensor which are mounted on the outside of the pipes and determine the leaklocation by processing and analyzing the signal. My research advanced someimprovement and innovation about mechanism of leak acoustic signal,signalde-noising,optimization of time delay estimation localization algorithm,localization algorithm of different shaped pipes and to build intelligent detectionand location system.Specific contents:(1) My study analyzed the types and causes of pipeline leakage and takecategory talk of leak source.(2) The paper studyed the characteristics of leak acoustic signal, which arepropagation characteristics, frequency and attenuation characteristics. Itanalyzed the characteristics and impact with different conditions of acousticsignal.(3) The paper studyed the theory of wavelet denoising, wavelet transformand wavelet de-noising method based on threshold. Aiming at the defects of softand hard thresholding method,my study proposed an improved method.(4) The paper studyed the theory of LMS adaptive time delay estimationmethod, advantages, disadvantages and improved methods. Due to acousticwave propagation velocity affected by diameter and pipe material and otherfactors, so the paper proposed positioning algorithm of different materials pipes.(5) The paper studyed the composition and function of intelligent detection and location system of water supply pipeline network. Based on the powerfulfunction of MATLAB software, the paper designed positioning software ofurban water supply pipeline network.The main conclusions:(1) The main sound sources of the leak pipe are caused by pipe leak, highpressure water crash and medium friction. The study chosen the sound of leakpoint as research object.(2) The characteristics of leakage acoustic signal are influenced by thefactors of propagation distance, leak size, tubing pressure, material elasticmodulus,viscosity absorption of medium,absorption of heat absorption andscattering of bubbles in the water.(3) Wavelet denoising has the characteristics of adaptability andmulti-resolution analysis.Wavelet denoising is an effective denoising method.The study proposed a new threshold method that was adaptive function ofhigh-order approximation.Adaptive function of high-order approximation madeup of soft and hard thresholding defects,with excellent denoising effect.(4) The study taken leak location with LMS adaptive time delay estimationmethod.For the different materials pipes in the water supply network, the studyproposed an appropriate method of leak location.(5) The study constructed a system of pipeline leak detection and location,combined software and hardware to achieve the function.