Research On The Effect Between Disinfectant Corrosion And Leaked Pipes In The Water Supply Network

With the acceleratec advancement of our contry's urbanization,urban water supply system rapidly develop.As main part of this system,water supply network has received more and more attention.Presently,water supply pipe network leakage rate in most cities is still high,which causes great waste of water resources and energy,so it is imperative to carry out the national leakage control.Understand the reason of leakage and build the model of water supply pipe network leakage control are the two keys in the operation of leakage control.This study explores the leakage from two aspects,including disinfection methods and pipes selection,and establishes new FAVAD(Fixed Area and Aariable Area Discharge)model,to guide leakage control work.The object in this research includes three disinfectant(Chlorine,Chloramine,and Chlorine dioxide)and 6 common water supply pipes(UPVC,PE,PPR,Galvanized steel,Welded steel and Cast iron).Corrosion effects of disinfectant on the leaked pipes has been studied by experiment and numerical simulation.There are three main aspects of the experiment.Through the surface analysis technology(SEM-EDS),disinfectant concentration and corrosion time can promot water supply pipes damagement within the limits of municipla water supplies,which has been verified.And this corrosion is mainly the oxidation of dissolved oxygen and permeability of chloride.Build dynamic corrosion test platform and pressure control platform respectively,to test the relationship between leakage flow and pressure.Disinfectant concentration has an impact effect on pipes' leak area that has been demonstrated from the perspective of leakage quantity.The corrosion result is chlorine dioxide disinfection >chloramine disinfection > chlorine disinfection;metal pipes >nonmetallic pipes.Measure pipes' elastic modulus after disinfectant effect.It is concluded that disinfectant concentration and thecorresponding corrosion time are the two important factors to influence the changes of pipe material performance.The trend shows goes up and then down in the process of corrosion.There are two main aspects of the numerical simulation.Analyze the elastic modulus and Poisson's ratio of pipes and the effect between these two material performance parameter and the slope of water head and leakage area(m value)in FAVAD model through ANSYS software platform.The results show that elastic modulus has obvious effect on m value,but Poisson's ratio has little.The relation to elastic modulus and m value is established.Then,1st Opt platform is appled to fit the surface equation of disinfectant corrosion and pipes performance based on the regression analysis.Thus,the improved FAVAD model is built to predict water supply pipe network leakage.