| The water transfer project is a major strategic measure to alleviate the serious shortage of water resources in some areas of my country,and the cascade pumping station is the most common water transfer method in the water transfer project.The cascade pumping station water delivery project generally has a large total installed capacity,a long running time,and a large energy consumption of the pumping station.During the operation,some pumping stations switch on and off more frequently;the operating efficiency of some pumping stations is not in the peak range of operating efficiency,resulting in resources Waste and other issues.In order to realize the safe and effective operation of the cascade pumping station,it is necessary to study the optimal operation of the cascade pumping station water delivery system.In this study,hydraulic simulation was used as a means to study the hydraulic characteristics of the cascade pumping stations in the two lakes;the pumping stations at all levels in Changgou,Denglou and Baliwan were optimized to solve the pump station switch with the best efficiency The combination of the machine and the flow of the unit;focusing on the optimization of the water level between the cascades and the water flow between the cascades,to solve the optimal water flow and water level combination between the cascades.The optimization results can provide scientific guidance for the safe and effective operation of the East Route of South-to-North Water Transfer Project,which has certain theoretical and practical significance.The results achieved include the following parts:(1)(1)Build a hydraulic simulation model of the cascade pumping stations of the NanSiHu~DongPingHu,and analyze the flow-water level-storage relationship of each step in the constant flow state;study the self-balancing capacity of each section under the unsteady flow state;focus on the analysis When there is a certain flow difference between the upper and lower water levels,the pump station reaches the range of flow difference in a self-balanced state.(2)Taking Changgou,Baliwan and Denglou pumping stations as the research objects,establish a single-stage pumping station model to solve the optimal switchgear combination of each pumping station and the flow operation scheme of each unit;take Denglou pumpingstation as an example For example,the optimized solution is better than the sub-optimal solution,and the optimization efficiency is increased by 0.12%.(3)Taking Changgou~Denglou~Baliwan pumping station as an example,based on the optimization results of single-stage pumping station,taking the operating efficiency of cascade pumping station as the target,and taking the water level of each station as the constraint condition,the optimization model of water level between cascades was built,Solving the water level combination of water flow rate of 110 m3/s and net head of 9 m,the combination of water levels between steps and the combination of switchgears at all levels of pumping stations,etc.,increased by 0.08% compared with the sub-optimal scheme efficiency;compared with other net head optimization schemes In comparison,the operating efficiency is the highest when the net head is 10 m,which is 31.95% more than the optimal scheme with a net head of 6 m.(4)Taking the scheduling of Changgou~Denglou~Baliwan pumping station as an example,based on the optimization results of single-stage pumping station and the optimization of water level between cascades,the operational efficiency of cascade pumping station is taken as the goal,and the water flow of pumping stations at all levels is the constraint Build an optimized model of water flow between the two cascades of the two lakes,and solve the water level combination between the cascades corresponding to the optimal water delivery flow rate at a net head of 7 m,and the combination of the on and off machines at all levels of the pump station.%;Compared with other net-lift water flow optimization schemes,the operating efficiency of net-lift 10 m is the largest,which is an increase of25.99% compared with the net-lift 6 m.(5)For the same net head,the efficiency of the interstage water transfer optimization scheme is greater than the efficiency of the interstage water level optimization scheme,and the net head and the operating efficiency have a positive growth relationship.The larger the head,the slower the efficiency growth trend.(6)The two-stage pumping station joint dispatching scheme is superior to the three-stage pumping station joint dispatching scheme.When the net head is 7 m,the maximum optimization rate of the water level between the steps is 5.25%,and the maximum optimization rate of the flow rate between the steps is 18.2%.Therefore,under the conditionof meeting the scheduling requirements,priority can be given to the two-stage pumping station scheduling. |
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