Research On Water Transfer Efficiency And Optimization Analysis Of Water Transmission And Distribution Plan

Inter-basin water allocation and dispatching is an important way to alleviate the regional contradiction between supply and demand of water resources,and improving the operating efficiency of water distribution projects is an effective measure to improve the efficiency of water transfer projects.The Yellow River to Qingdao Project has promoted the optimal allocation of water resources in Shandong Province.The project realized the joint operation of multiple sources of water from the Yangtze River,the Yellow River,and local water resources,and greatly eased the water shortage in Jiaodong.Aiming at the serious water loss along with the water diversion project from the Yellow River to Qingdao Project and the continuous drought in recent years that have caused water shortages in Weifang and Qingdao,this article aims to effectively reduce the water shortage rate in the water receiving area and reduce the loss of water transmission.The hydrodynamic model of the Yellow River to Qingdao Project realizes the simulation of the hydrodynamic conditions of the channel under different flow rates in the whole channel.Based on this,the water delivery efficiency is calculated.At the same time,the empirical formula of Davis Wilson and Kosgakov was used to study the water delivery efficiency under different flow rates,and to compare and analyze the channel water delivery efficiency.On this basis,RiverWare software was used to optimize the current plan,and the channel water distribution optimization plan under different water delivery efficiencies is obtained by controlling the corresponding parameters.The optimization effect of the plan is studied and analyzed,which can be used as a reference for the actual operation of the project.The main research contents and results are as follows:(1)Generalization and simulation of the water transfer system.The Yellow River to Qingdao Project has a huge system.As the basis for the optimal dispatch and analysis,and calculation of water resources,the main elements of the abstract and generalized water transfer project system help to study the relationship between water supply,water consumption,water consumption,and drainage of the system.In order to better implement the optimal scheduling of water resources,comprehensively consider the terrain conditions of the water transfer project,channel hydraulic structures,water source intersections,etc.,nodes and water transmission system connection lines were used to connect the water diversion gates,sluices,and sluices in the water transfer system.Reservoir,river channel junctions,channels,calculation units,etc.to generalize the engineering network,Mike 11 one-dimensional river canal hydrodynamic model coupled with pump station nodes was chosen to analyze and simulate the water transfer process,and complete model construction and parameters.Based on existing data,after calibration,a more accurate engineering dynamic simulation of the channel hydrodynamic conditions under different flow rates in the entire channel was realized,to easily and quickly grasp the channel hydrological conditions,reduce the workload of real-time data measurement and collection,and improve the efficiency of operation and management.(2)Research on water delivery efficiency in the study area.Water transfer efficiency is the basis for efficient water transfer and improvement of water transfer efficiency.Based on the actual water transfer data selected by the water balance method and the actual water transfer situation for many years,according to the check flow,design flow,and actual dispatching flow of the upper sluice of diverting water from the Yellow River to Qingdao,this paper statistically analyzes and divides six different flow intervals,namely the flow rate of the Yellow River to Qingdao Project upper control gate is q>40 m3/s,36 m3/s<q≤40 m3/s,33 m3/s<q≤36 m3/s,30 m3/s<q≤33 m3/s,When 25 m3/s<q≤30 m3/s and q≤25 m3/s.Mike 11 model was used to determine the water conveyance efficiency of the channel under six different flow rates.The water conveyance efficiency of the channel was calculated from the check flow rate.design flow rate and actual dispatching operation data.of the upper control sluice head of the Yellow River water diversion to Qingdao.Among them,40 m3/s is the check flow of the head of the upper control gate of the Yellow River and Jiqing River,36 m3/s is the design flow.Other flows are determined according to the actual dispatching operation data.Based on the model results,the overall water delivery efficiency of the Yellow River to Qingdao Project is 0.8010～0.8794.The greater the amount of water transferred at the upper control gate of the Yellow River to Qingdao Project,the higher the water delivery efficiency of the project.In the actual water transfer process,the large flow of water should be delivered within the scope of conditions.Furthermore,the Davis-Wilson formula,the Kosgakov formula,and other empirical formulas were used to calculate the water delivery efficiency.After comparative analysis,the water conveyance efficiency is determined.Results indicate that the model-based water delivery efficiency calculation result has a smaller error compared with the empirical formula method.It can be used to calculate the water delivery efficiency of the designated target canal section,and can also be used to determine the water delivery efficiency of the entire project.The results are fast,reasonable,and reliable.(3)Determination of optimal scheduling plan.Taking the socio-economic development status of Qingdao and Weifang,and the water delivery efficiency from the head of the canal to the outlets of the water receiving areas,etc.into comprehensive consideration,this paper took month as scheduling period.The goal of the dispatching is to minimize the total water shortage in each outlet of the receiving area during the dispatching period.The optimal water resource dispatching model is established.External water transfer constraints(the head of the canal is allocated to the water distribution of Weifang and Qingdao cities less than or equal to the allocated water),water demand constraints(①Weifang City,Qingdao City each water distribution The total water distribution is less than or equal to the total water demand of the corresponding water-receiving city②The water distribution of each water distribution along the route is greater than or equal to the minimum water demand of the corresponding water distribution),the design flow restriction of the water distribution(the water distribution of each water receiving division is less than or equal to Corresponding design flow),channel water balance constraint,channel flow capacity constraint(the input water volume of each canal section is less than or equal to the design flow of the canal section),the principle of full utilization of dispatched water volume(the dispatched water volume reaches the end of the water transmission line in each dispatch period At this time,all the water in the channel is used to supply the tail water divider,so that the allocated water can be fully utilized),non-negative constraints(all variables appearing in the model do not have negative values)and other constraints are used as scheduling strategies.The simulation model of YRDP based on riverware software is built.By adjusting the optimization objectives and constraints,the model is solved by using the advanced solution system of the software.The optimal scheduling schemes are obtained when the water conveyance efficiency is 0.8755,0.8571 and 0.8210 respectively.The optimal operation results based on three different water conveyance efficiency schemes are analyzed.It can be seen that the higher the water transfer volume at the upper control gate of the Yellow River to Qingdao Project,the higher the channel water transfer efficiency,the smaller the water transfer loss,and the greater the reduction in water shortage.Therefore,in the actual process of water transfer,large flow water should be transported within the allowable range,and different optimal scheduling schemes should be selected according to the size of water transfer to improve the scheduling efficiency.