Open The Gate To The Cross-flow Pumping Station Study On The Influence Of Hydraulic Characteristics During Starting Process

Tubular pumping stations are widely used in important water conservancy fields such as flood control,drainage,and water resoLrces improvement dispatching.For example,the Yangtze River Delta and the Pearl River Delta have used pumping stations for pumping stations in several pumping stations.Although the cross-flow pump has advantages that other low-lifl pumping stations cannot match in terms of hydraulic performance,plant efficiency,and engineering cost,there are some problems similar to other forms of low-lifl pumping stations,that is,during the starting process of the pumping station,The structure of the shaft of the outlet flow channel of the tubular pumping station is small,the water level rises rapidly in the shaft,and the pump head increases rapidly,so that the load torque of the motor is large,which easily leads to overload of the motor and causes failure of starting.Therefore,studying how to inprove the hydraulic characteristics of the starting process of the tubular pumping station is one of the problems that the design and operation unit needs to consider and solve.A quick gate is usually provided at the outlet passage of the cross-flow pumping station.During the starting process,the space in the outlet passage of the tubular pumping station is small If the lifting speed of the gate is too slow,the pump head will increase rapidly,which will easily lead to the motor.Overloading causes failure to start;but if the gate is lifted faster,not only does the requirements for the fast gate opening and closing equipment are high,but also the pump outflow collides with the original water flow in the outlet pool,and the pump lift rises sharply in a short period of time,thus causing the motor Overloaded,failed to start To this end,based on the previous research,the idea of adding a gate on the fast gate is proposed to slow down the increase rate of the pump lift and further improve the hydraulic characteristics of the cross-flow pump station during the transition process.This paper focuses on the analysis of the hydraulic characteristics of the tubular pumping station after adding the gate on the fast gate.It is verified that adding the gate on the fast gate can better improve the starting process and find the hydraulic characteristics that affect the starting process,factor.In this paper,the Tubular Pumping Station is taken as the research object.According to the characteristics of the pump and the characteristics of the motor and the cooperation of the motor and the pump during the starting process of the pumping station,the dynamic torque balance equation of the hydraulic characteristics of the starting transition process is added to the fast gate.The starting point of the pumping station is divided into different stages by the preset lifting height,the water level of the outlet pool and the top elevation of the chest wall.According to the starting characteristics of the motor,the characteristics of the pump,the opening and closing characteristics of the quick gate and the overcurrent characteristics of the gate.The dynamic mathematical model of the start-up process of the cross-flow pumping station with the open gate on each stage is established,and the corresponding initial conditions and boundary conditions are given.According to the Huai'an three-station calculation example,the shots are taken without the gate.Each of the optimal values within the allowable range of the hydraulic characteristics of the starting process is calculated,and the starting process of the normal pumping situation is calculated,and the variation of each physical quantity with time after the addition of the gate is obtained;in the case of normal pumping,Take different gate lifting speeds and different delay opening times respectively,and start the mathematical model of the opening process.The calculation is earmed out to analyze the influence of the two orn the hydraulic characteristics of the start-up process.Under the normal pumping situation,the size of the different gate areas is taken,and the mathematical model of the starting process is solved and the starting process under different gate areas i5 obtained.The law of the change of physical quantity in time.The calculation results show that adding the gate on the fast gate has obvious effect on improving the hydiaulic characteristics of the starting transition process.After adding the gate on the fast gate,increasing the gate lifting speed can improve the hydraulic characteristics during the starting process and prolong the delay opening time to start.The process is unfavorable;after the opening of the gate is increased,the increase in the area of the gate can be increased,and the hydraulic characteristics of the pumping station can also be improved.