The Optimization Study Of Self-pressure Water Backbone Pipe Network System In Xinjiang

Compared with other water-saving irrigation methods,irrigation of the self-pressure water pipe network system has many advantages,such as remarkable water-saving benefit,high land use rate,strong adaptability to the terrain,fast water transport speed,high irrigation efficiency,convenient operation and management.However,there are many problems in pipe network such as disposable investment big,complexity of planning and design,the filter in the backbone pipe network is easy to be blocked,and leakage and explosion problems exist in the operation of the network.Therefore,systematic optimization research has important practical significance for ensuring safe and effective operation of pipeline network and saving engineering investment.In this paper,the typical self-pressure water backbone network system in Xinjiang was selected as the research object,in the case of summarizing and drawing lessons from the research results of pipe network optimization at home and abroad,in view of the problems existing in the self-pressure backbone pipe network,such as leakage,bursting of pipes,and so on.The research method combining theoretical analysis with engineering example was used to systematically study three aspects of the pipe material,pipe diameter and filter equipment of the self-pressure backbone pipe network system to save investment and ensure reliable operation of the pipeline network.The main research results of this paper are as follows:(1)According to the characteristics of self-pressure water pipe material,the comprehensive evaluation index system of self-pressure water pipe material was established from four aspects of economic,physical properties,reliability and adaptability.6 kinds of pipe materials are used for glass pipe,steel tube,prestressed concrete pipe,ductile iron pipe,PCCP pipe and PVC-U pipe,and the fuzzy comprehensive evaluation mathematical model is used to optimize the pipe material.The results show that the PVC-U pipe should be selected for the water conveyance pipe in DN160～DN600,and the glass tube should be selected in the DN800～DN1400 water conveyance pipe.(2)After determining the pipe network path,according to the optimization problem of pipe diameter,the minimum annual conversion value of investment and operation management cost of pipe network was taken as the objective function,the hydraulic performance of the pipe network and the water volume of the pipe network node were as the constraint conditions,the optimization model of the pipe diameter of the farmland pipe network was established,and the improved particle swarm algorithm was used to solve the model,the results show that when the node water reliability is R_i=0.7,the pipe diameter combination scheme is the best one.(3)According to the hydrological data of the measured flow from 2001 to 2008 in wuluwati hydrological station of the irrigation area and the sediment transport rate formula of the river prototype at all levels of traffic,the suspended sediment volume data from 2001 to 2008 was obtained by 3%bed-suspension ratio,and the main period of the change of suspended sediment in the whole time domain was obtained by the wavelet analysis;the suspended sediment load was predicted by applying the BP neural network model,according to the selection of common filters under different mineral content or particle size,the selection of filter in irrigation area is sedimentation tank+screen filter(laminated filter).