Research And Development Of Leakage Transient Flow Detection Technology And Experimental System For Water Supply Network

Leakage is the most common fault of water supply network.The running,falling,dripping and leaking of water supply network are always hot issues in the global water supply industry,resulting in a large number of resource losses,energy waste and environmental pollution.Therefore,the theoretical research and solve the problem of water supply network leakage detection and localization method and implementation technology,not only conducive to the safe operation and management of the water supply network,but also has important significance to the national economy and people's life.Here,the leakage control of water supply network mainly studies the theory and method of leakage warning,monitoring and rapid and accurate positioning,as well as the related technology of controlling and reducing pipeline leakage or poor production and marketing,which provides theoretical basis and technical reference for the management,maintenance,efficient and stable operation of water supply pipelines.This is not only a hot demand of the current society,but also one of the key problems to be solved urgently in building a water-saving society in China.Based on the technology of transient leakage flow detection in water supply network,this paper systematically studies the theory and application of transient leakage flow detection in water supply network.The work involves transient flow,leakage detection theory,transient hydraulic analysis of water supply network,research and development of low intensity transient flow exciter,hydraulic transient detection experimental platform for pipeline network fault and related software.Some technical problems in practical application are solved.Exploratory research has been carried out from different perspectives.The main research work and achievements of this paper include:(1)The causes of leakage in pipeline system are analyzed,and the research progress and main problems faced by the pipeline network at home and abroad are summarized from four aspects:pipeline network leakage monitoring and early warning technology and equipment,leakage location and identification,signal identification and algorithm optimization,and health management of water supply network.(2)The basic assumptions and equations of fluid flow in pipelines are elaborated.Several kinds of unsteady friction models are summarized and studied,and their characteristics are introduced.The interpolation grid of characteristic lines and the solution method are given.The calculation of transient process in complex pipeline network is based on the calculation of single-pipe transient process.Therefore,the hydraulic analysis of the transient condition of single-pipe is carried out and summarized.The calculating steps of single pipe transient process are introduced.The mathematical model of transient hydraulic analysis and boundary condition equation for complex pipe network system are established and solved.The transient hydraulic process in different sizes of water supply network is calculated with several examples.The transient inverse problem analysis model is introduced,and the method of solving the inverse problem of system identification is illustrated with examples.(3)Firstly,in the field of water diversion or water supply engineering,the typical layout of pipeline system is classified,and then the traditional excitation methods and detection methods of leakage detection and the difficulties faced are expounded.In order to overcome the difficulties and problems faced by traditional detection methods,a low-intensity transient flow exciter and its parameter design method for leak detection of water supply pipelines and pipeline networks are proposed.The water hammer shut-off model tests under two working conditions are carried out in the laboratory using the device,and the basic variation law of the water hammer wave excitation on the experimental platform is obtained.(4)An experimental platform system for pipeline network fault detection is developed,which can simulate different leakage holes and local blockages.It is mainly used to support and verify the digital management platform of water supply network,including equipment,technology and methods for health assessment and intelligent management scheme determination.At the same time,an experimental platform for pipeline network fault hydraulic detection is developed based on RSView configuration software.SCADA system is used to calibrate the pipeline roughness of the test platform.According to the test platform,the corresponding pipeline fault detection methods are proposed.Three leakage conditions and one blocking condition are designed to simulate the excitation effect and detect the fault.The results show that the above experimental platform not only realizes the excitation of controllable transient water hammer wave,but also can be used to detect and locate faults with high positioning accuracy,which verifies the validity of the detection method.