Study On Optimal Design Of Irrigation Pipe Network

Our country is a large agricultural country,the amount of water used for agricultural irrigation accounts for about 75% of the total amount of water used in the country.The development of advanced irrigation technology,improving irrigation efficiency,is one of the effective measures to alleviate the contradiction between supply and demand of water resources in our country.In the current water-saving irrigation technology,the pipeline irrigation technology with the advantages of high transmission and distribution efficiency,leakage evaporation loss and small water loss along the route,rapid,uniform and precise irrigation,and water-saving,land saving and energy saving advantages,which can increase the rate of field irrigation water and crop yield,and easy to realize automatic control and management,has been widely used.In the pipeline irrigation system,water distribution system cost accounted for about 70% of the total investment of pipeline system,planning and design of the part is reasonable or not will directly affect the safety and reliability of water quality and total investment,operation system,but its design theory is still relatively lagging behind,especially in hilly areas related to optimization theory can not meet the demand of efficient agricultural production.Therefore,it is necessary to further develop the theory of optimal design of irrigation pipe network.Based on the analysis of network optimization at home and abroad,this paper mainly studies the following two aspects.1.research on optimal design of irrigation pipe network in plain area.Through systematic analysis of pipeline irrigation planning and design theory and methods,including piping irrigation system layout principle,pipe network design flow calculation,pipe diameter determination method and pipe network hydraulic calculation and other aspects.A pump pressure mathematical model of optimal design of irrigation pipe network based on the minimum annual cost as the goal,then with the Yicheng project,using economic velocity method and boundary flow method and Excel programming method of pipeline optimization design was carried out,results show that the use of Excel programming method to optimize the design of irrigation pipe network can not only save a lot of investment,but also can guarantee the reliability of the irrigation network system,compared with the traditionalmethod and the new economic flow algorithm,this method is simple and easy to grasp,improve the design efficiency,is a method for optimization design of high practical value,can provide a feasible design scheme for pipeline irrigation engineering.2.Study on partition optimization in hilly areas of irrigation pipe network.The purpose of the division of the irrigation network in hilly area is to reduce the energy consumption of the water supply from the economic point of view.The technical reason is to make the water pressure of the pipe network smaller than the pressure capacity of the pipeline,so as to protect the pipes and fittings from being damaged.This study by assuming uniform slope in hilly areas,irrigation area zoning rules,irrigation area is equal,each partition is provided with a pumping station,and only consider with matching pump station flow head related to a water pipe network system,establish the cost minimum partition in hilly areas in the objective function of the optimization model,and an example analysis shows that different height should be used to partition network in different ways,namely,reasonable setting the number of partitions,so that the network of minimum annual cost.