Research On Water Supply Networks Residual Chlorine Decay Modeling Base On Hydraulic Modeling In C City

The water supply network is an important water transportation facility in the city.However,the rapid development of the city and the increasing number of people make the water supply network increasingly heavy load,resulting in the water supply pipe aging,leakage,burst pipe and water pollution and other incidents commonly occur,the water body at the end of the pipe network residual chlorine content is low,the water quality of the pipe network water safety is not effectively guaranteed.Therefore,in order to be able to grasp the hydraulic and water quality conditions of the entire water supply network in a timely,accurate and comprehensive manner,the establishment of hydraulic and water quality models of the urban water supply network is of paramount importance,and the establishment of the model can effectively ensure the safety of water quality in the urban water supply network.In this paper,the hydraulic model and the residual chlorine decay model of the City C water supply network are studied in depth.First,the basic principles of the hydraulic model of the water supply network are systematically elaborated,and the set of equations of the network in the hydraulic model and its solving methods are described in detail.Subsequently,GIS data and CAD graphics were used to collect static and dynamic data of the City C water supply pipeline network,and field surveys and manual monitoring were used to supplement the missing data,and the coarse coefficient of the pipe section,node flow distribution,water consumption patterns of typical users and the change of water consumption curve of the City C water supply pipeline network were initially determined.In order to improve the accuracy of the hydraulic model of the City C water supply network,real data from six typical pressure monitoring points were used to perform multiple checks on the hydraulic model and to correct the relevant parameters of the hydraulic model.The calibration results show that the hydraulic model has a high degree of accuracy and meets the minimum permissible error requirements of hydraulic modeling,and the pressure error at all the calibration pressure monitoring points is≤±4 m.The pressure error≤±2 m accounts for 93.75%of all the calibration monitoring points and the pressure error≤±1 m accounts for 63.20%of all the calibration monitoring points.Secondly,the problem of residual chlorine decay in the City C water supply network was solved by using the residual chlorine decay primary response model and the Lagrangian time drive method.Subsequently,the main water reaction coefficient（K_w）and wall residual chlorine decay coefficient（K_b）of each pipe section in the C city water supply network were preliminarily determined,in which the main water reaction coefficient was determined by the offline beaker test,and the initial value of K_b was determined to be-0.20 d^-1,while the wall residual chlorine decay coefficient was determined based on the reported research results and the actual situation of the C city water supply network,and the pipe sections were divided into three groups according to the number of years of pipe laying.Finally,to ensure the accuracy of the residual chlorine decay model for the City C water supply network,the model was calibrated using real values of residual chlorine from 15 water quality monitoring points.In the calibration process,MATLAB genetic algorithm toolbox combined with EPANET toolbox was used to automatically optimize the attenuation coefficients of the residual chlorine decay model of City C water supply pipeline network.68 iterations of the algorithm,the optimal solution of the attenuation coefficients for each group of the model was obtained,in which the first group of the calibrated K_w11 value is-0.03 m/d,the second group of K_w22 value is-0.053 m/d、,the third group of K_w33 value is-0.124 m/d,and the K_b value is-0.247 d^-1.The comparison of the calibrated model with the true value of water quality monitoring points found that the calibrated model has a high degree of accuracy,the difference between the calibration value and the true value of 15 water quality monitoring points in the model is small,the calibration accuracy of all water quality monitoring points is less than 30%,which meets the calibration accuracy requirements of the residual chlorine decay model.Through the establishment of the C city water supply network hydraulic model and residual chlorine decay model,you can comprehensively understand the hydraulic and water quality conditions of the entire C city water supply network,so as to promptly discover the problems of the water supply network,can effectively guarantee the safety of the water quality of the pipeline network,so that users can drink safer drinking water,can also provide auxiliary management for the water supply group,which is conducive to strengthening the safety of the water supply system,the water quality maintenance of the pipeline network has played a certain guiding role.Figure [16] Table [17] Reference [81]...