Study On Optimal Design And Energy-saving Operation Of Intake Pump Station With Broad Water Level Variation

The primary pump station is one of the core parts of the urban water supply system,and its main function is to transfer raw water to the water supply treatment plant under pressure,and its operating cost mainly comes from the power consumption of the pump unit.According to the actual situation of the project,it is of great significance to select the appropriate water intake structure,and the pump adopts a reasonable joint operation mode,under the premise of ensuring the reliability of water conveyance,to optimize the pump dispatching scheme and to reduce the cost of water conveyance.The research contents of this paper mainly include three parts: one is to put forward the method of finding the best way of water intake,the other is to analyze the operating condition and pump selection of variable frequency speed regulation of water pump,and the third is to establish and solve the mathematical model of energy saving optimization of pump station,and get the best dispatching scheme of water pump under different working conditions.Summarize and sort out the main influencing factors of the location selection of river water intake structures,and analyze the structural composition,advantages and disadvantages and applicable scope of fixed water intake structures(shore type,river bed type)and mobile water intake structures(floating boat type,cable car type).Combined with the construction cost,operation management cost,working conditions,construction difficulty,engineering life and the ability to adapt to sediment,the method of selecting water intake structure is proposed based on decision tree.The Q-H curves,Q-η curves and Q-N curves of fixed speed pumps are fitted by quadratic curve method.According to the proportion rate of pumps,the three characteristic curves corresponding to the speed regulation operation of pump are obtained.According to the graphic method of characteristic curves,the operation of a single pump is analyzed,and its working state is divided into five types: unstable operation,inefficient operation,efficient operation and cavitation operation.This paper discusses the operating conditions of the same type pump in parallel and series,and proves that the full frequency conversion is scientific.The conclusion of pump selection according to pump station working condition is obtained.This paper compares the Q-H curve and Q-N curve under constant speed and speed regulation,and expounds the principle of energy saving in pump speed regulation operation.Based on the comprehensive efficiency of the system,the minimum power consumption of the pump station is determined as the objective function.The constraints are water supply,water supply pressure,pump speed regulation ratio and high efficiency section constraints.The penalty function is used to simplify the multi-constrained nonlinear solution problem to the unconstrained one.This paper introduces the principle and calculation process of lightning search algorithm,compares it with the performance of genetic algorithm,and proves its superiority.According to the actual situation of the project,the water conveyance line and the water intake port of the Yellow River diversion project in Yan’an are determined,the comparison of the water intake scheme is carried out by using the decision tree,and the shore tower and tube type water intake structure is selected.77.05 m span of the pump working head section is divided into three parts,respectively,the pump selection.Compare the objective functions of series and parallel in low-lift section to prove the energy saving of parallel.the parallel mode is used to solve the scheduling scheme and objective function of middle and high lift segments.