Research On Model Of Water Supply Network Update And Optimization Based On Evaluation Of Network Performance

As the update and optimization of water supply network is a complicated and huge project, it is significant to evaluate the network status scientifically and reasonably. In addition, the establishment of optimization model of the water supply network is also based on selecting and sorting for upgrading pipeline section.In this paper, experts grading method, fuzzy analytic hierarchy process, optimality theory and particle swarm optimization were used to screen indexes for network performance evaluation and propose evaluation system. Based on this, the optimization model of the network was established, and its solution was determined. The model was successfully verified by examples. The main conclusions of this paper were as follows:Firstly, a set of comprehensive performance evaluation system of water supply pipe was established, which was on the basis of hydraulic reliability, water quality security, structural stability and economy. And the weights of each index were determined using fuzzy analytic hierarchy process. The hydraulic respectively was evaluated by network reliability of each node's degrees of freedom, water quantity and water pressure. Security of water quality was evaluated by residual chlorine and water age. Structural stability was evaluated by tube stock, pipe age, lining and load conditions. The economy of network was evaluated by using value engineering method to calculate the cost of water supply pipe network unit.Secondly, based on the comprehensive performance evaluation system of pipeline, the comprehensive performance evaluation method was established. And the selection and sorting of pipes were completed. In the method of EPA, the hydraulic model was established to evaluate and sort the property of each tunnel. When the network upgrade costs are under certain conditions, the pipes which are needed to be upgraded are selected.Thirdly, a set of optimal network comprehensive performance optimization model of water supply network upgrading was set up. The model was used to optimize the retrofit design of the selected pipes and determine the diameter combination of upgrading section pipes when the upgrade costs were under certain conditions. Then Particle Swarm Optimization was used to achieve the optimum comprehensive performance of network. Besides, the organic combination of pipe network calculation and optimization algorithm was realized by means of EPANET-toolbox written by MATLAB.At last, a development zone of the city in north China was selected as the research object to evaluate the comprehensive performance of network. Then the retrofit optimization section set was determined and solved by using the optimization model of water supply network.