Research On Establishment And Application Of Water Supply Network Hydraulic Model Based On Leakage Control

As an important infrastructure for urban construction,the urban water supply network has made great contributions to social and economic development.With the continuous improvement of urban water conservation,the problem of pipe network leakage has become increasingly prominent.The leakage of water supply network not only caused the waste of water resources,but also had a huge impact on social economic development and the environment protection.A hydraulic model that can reflect the leakage of the water supply network is the premise and key to control the leakage.This study aims at the problem that the traditional hydraulic model cannot reflect the leakage of the pipe network,and puts forward the construction and checking method of pressure-driven node flow hydraulic model.In order to build pressure-driven node flow hydraulic model,this paper first studies the relationship between pressure and flow,and considers that the node flow should be divided into two parts: node water consumption and node leakage,what's more,the influences of pressure on the two kinds of water quantity of nodes are determined and written into a formulation.A fitness function for calculating the difference between the calculated leakage and actual leakage.The genetic algorithm was used to determine the leakage coefficient of the pipe network and the node leakage was simulated in the EPANET software.In the distribution process of the node flow,according to the relationship between flow and pressure,Node Flow Analysis method is used to update it.At last,by comparing and analyzing the traditional hydraulic model and pressure-driven nodal flow hydraulic model based on a certain example of pipe network,it is found that the pressure-driven nodal hydraulic model is better than the traditional hydraulic model in terms of accuracy or leakage water simulation.The model can be used as a basis for the analysis of leak age in water supply networks and the implementation plan of pressure management.By verifying the pipe network model for the Hazen-Williams coefficient,the feasibility and applicability of the pipe network model to the actual water supply pipe network are checked.In view of the fact that the investigation of the friction coefficient only focused on the consistency between the model simulation data and the measured data of the water supply network and neglected the rationality of the value of the Hazen-Williams coefficient,the model of the Hazen-Williams coefficient based on the support vector machine was established.The target function is constructed by minimizing the sum of the squared difference between the measured value and the calculated value of the pressure measurement point of the water supply network under multiple working conditions.The verification of the Hazen-Williams coefficient is converted into the solution of the optimization problem,and the particle swarm optimization algorithm is used to solve it.Finally,a whole set of water supply network modeling and checking method based on leakage control was applied to the pipe network of HX development area in Central China,and the model simulation data was compared with the 24-hour pipe network actual measurement data.The results show that the simulation model of the pressure-driven node flow hydraulic model constructed in this paper not only has a high degree of agreement with the actual pipe network,but also can simulate the leakage.It can be applied to the water supply network pressure management implementation plan.