Optimization And Effect Evaluation Of Pressure Management Strategy In Water Supply Network

With the development of urbanization,the scale of urban water supply network is increasing.At present,the total annual water supply in China has exceeded 60 billion cubic meters.At the same time,the leakage problem of water supply network has been paid more and more attention by the water supply industry.At present,it is generally believed that the leakage of water supply network has a positive correlation with pressure.Pressure management is a leakage control method which takes regulating and controlling the pressure of water supply network as the main means,which has been verified in engineering practice,recognized by the industry and gradually put into use.This paper will systematically focus on the study of pressure management,the establishment and characteristics of the hydraulic model of pressure management,the optimization of pressure management control,and the optimization and evaluation of different control modes in the model.At the same time,for the water supply network which is difficult to establish a micro hydraulic model,the establishment and application of macro model are studied.In the study of pressure management oriented hydraulic model,the similarities and differences between water demand driven hydraulic model and pressure driven hydraulic model in node demand and leakage model are compared.The water quantity and hydraulic characteristics of the two models under different conditions are compared by setting up an example water supply network.It is considered that in the establishment of hydraulic model for pressure management research,pressure driven hydraulic model has better performance and applicability due to its pressure related characteristics of water demand and leakage.In the study of pressure management control in model,based on the established model of urban water supply network,a step-by-step iterative method based on the greedy algorithm is proposed.The method is applied to the optimization of the control sequence of the pressure reducing valve,which can solve the optimal control sequence of pressure reducing valve quickly.At the same time,the relationship between the valve flow and the head loss from the back of the valve to the most unfavorable point in the simulation process is studied.The relationship between them accords with the conic curve and can be used in the PRV control which acts according to the valve flow.In the study of pressure management control and evaluation,a set of evaluation indicators is proposed,and the realization of four control modes in the model is studied.Among them,in the research based on time segmented control,a preselection index is proposed for the multi scheme selection problem,and its advantages in the process of scheme selection are verified.On the basis of realizing four control modes in model,the paper compares them according to the evaluation index proposed above,and analyzes the applicable scenarios of the control way.In the study of pressure management of water supply network,the macro model of water supply network which is difficult to establish micro hydraulic model is studied.Based on the historical data,the pressure regulation strategy of pressure management is established,and the effect of the strategy is discussed by using the macro model.