Research On Optimization Of Pressure Regulating Tank Of Large-scale Self-pressing Pipe Network Based On Genetic Algorithm

The large-scale self-pressure irrigation pipe network has the characteristics of large headto-tail height difference,long pipeline length,large water supply flow rate,etc.Sometimes the working pressure of the pipeline exceeds its pressure-bearing capacity,which is easy to cause pipe explosion and cause greater economic losses.Pressure to ensure the safe operation of the pipe network.This article considers the arrangement of a pressure regulating tank on the main pipe of the pipe network,and pressure relief and flow adjustment by means of arranging pressure reducing valves in the main pipe and branch pipes.The arrangement of the main pipe for pressure regulating tank tank has a direct impact on the total investment of the system and the operation safety of the pipe network system.Therefore,it is necessary to carry out optimization research on the number and position of pressure regulating tank arrangement and the size of pressure regulating tank.Irrigation pipe network system layout pressure regulating tank belongs to a branch of pipe network system optimization research,which has important value and significance for saving irrigation system investment,improving irrigation quality,and enriching pipe network research.This article takes the pressure regulating tank and the self-pressure irrigation pipe network as the research objects,and explores the layout optimization and body shape optimization of the pressure regulating tank respectively.In view of the shortcomings of the current research on the self-pressure pipe network,firstly based on the MATLAB platform,taking the sum of the cost of the main pipe and pressure regulating tank as the objective function,and establishing the large-scale irrigation with the constraints of the flow rate,flow rate,and node pressure of the pipeline The mathematical model of the pipeline network pressure regulating tank optimization is solved based on genetic algorithm combined with a self-pressure tree-like pipeline network in the northwest,which realizes the simultaneous optimization of the layout of pressure regulating tank and the main pipe diameter;then based on the results of the genetic algorithm and based on the FLUENT platform The pressure regulating tank is numerically simulated,and the discrimination parameters are the length-towidth ratio of the pressure regulating tank,the width of the pressure regulating tank and the shape of the outlet wall of the pressure tank.The objective function is the uniformity of the flow rate of the outlet pipe of the pressure regulating tank The best geometric solution.The main results are as follows:(1)Simultaneous optimization of the layout of the pressure regulating tank and the diameter of the main pipe takes the sum of the cost of pressure regulating tank and the cost of the main pipe as the objective function,and uses the penalty function method to deal with the constraint conditions.The double coding method using integer coding is solved using genetic algorithm.The synchronous optimization method avoids the shortcomings of the step-by-step optimization method that is difficult to achieve the global optimal solution.The optimization results show that the pipeline network system has a total of two pressure regulating tanks and divides the pipeline network into 3 zones.The total length of the main pipeline is 10973.7 m,which is The artificial experience method(12473.0 m)reduced by 12.02%,and the total investment of the system was 4.648 million yuan,a decrease of 17.23% compared with the artificial experience method(561.58 million yuan),and the pressure of each water distribution node was more balanced.(2)The shape optimization of the pressure regulating tank takes the uniformity of the flow rate of the outlet pipe of the pressure regulating tank as the objective function,and the single-factor analysis method is used for numerical simulation,using 6 kinds of length-towidth ratio,4 kinds of pressure regulating tank width,and 3 kinds of side wall shapes Optimize in turn.The research shows that,under certain conditions of design flow,for a pressure regulating tank with the same volume,it is not that the longer the length of the tank is,the better the hydraulic performance of the outlet pipe is.The resulting size plan with the highest uniformity of flow velocity at the outlet of the pressure regulating tank is: aspect ratio 7,width of pressure regulating tank 6 m,and the shape of the side wall of pressure regulating tank is a rectangle with rounded corners.