Research On Location Of Pipe Burst And Diameter Inversion Of Burst Orifice Based On Transient Flow

At pessent,pipe burst occasionally appears in urban water supply network.It is difficult to realize pipe burst recognition and location and obtain the information of the burst pipe quickly by the existing location method,which brings great difficulties to the repair decision of the burst pipe.After experimental pipe network platform was built,the pipe burst experiments were carried out under different conditions,and the water pressure anomalous features of the pipe bursts were analyzed and summarized.According to the propagation theory,the propagation law of the transient flow,which was generated by pipe burst,was studied.On this basis,a pipe burst location method and a diameter inversion method of burst orifice based on transient flow were proposed.The two methods were realized using the pressure data with reducing sampling frequency,and then,they were applied to the pipe burst location and diameter inversion method of burst orifice in actual pipe network.In view of the low frequency sampling characteristics in the monitoring of actual pipe network,a burst pipe location method based on system anomaly was proposed.The main The main research results are as follows:(1)Butterworth band-stop filtering method was applied to process the highfrequency pressure data,and the abnormal characteristics were summarized: When the pipe burst happens,a system abnormity with sudden decrease appears,accompanied by a negative transient flow,whose amplitude is usually greater than or close to 3 times the root-mean-square error.(2)By studying the propagation law of transient flow,a software about propagation and simulation of transient flow,i.e.,Tran＿Flow software,was developed to realize the visual display of transient flow in each pipe and at each monitoring point.(3)By analyzing the variation character and law of transient flow,a transient flow model of complex pipe network was established,and a pipe burst location method based on transient flow,transient flow simulation method,was proposed,which realized the recognition of pipe burst event,the identification of burst pipe,the location of pipe burst.(4)On the basis of pipe burst location,a diameter inversion method of burst orifice based on transient flow,transient flow reverse propagation inversion method,was proposed,which realized the inversion of excitation signal caused by pipe burst and the diameter calculation of burst orifice.(5)In order to reduce the monitoring cost,through reducing sampling frequency,the pipe burst location and diameter inversion of burst orifice were realized at the frequency of 100 Hz using the transient flow simulation method and the transient flow reverse propagation inversion method,and their accuracies were hardly affected.(6)In view of the low-frequency sampling characteristics in the monitoring of actual pipe network,only system anomalies could be observed under such conditions,a pipe burst location method based on system anomaly was proposed,and the pipe burst was located in a certain pipe in the experimental pipe network.(7)The transient flow simulation method and transient flow backward propagation inversion method were applied to the water supply pipe network in an industrial park,and the methods could realize the location of pipe burst point and the diameter inversion of pipe bursting orifice when the sampling frequency was only 100 Hz.The pipe burst location method based on system abnormity was also applied to the pipe network,and depending on the data from the current monitoring system of the pipe network,it could also realize the accurate location of the burst pipe.