Study On Flow Pattern And Hydraulic Optimization Of X-Type Two Way Pump System

X-type two-way pump system can meet the dual needs of urban construction and agricultural irrigation,and is widely used.However,the water flow in the inlet and outlet channels is complicated,and due to the immature technical means and improper value of the channel size,some pump stations were built in the early stage.Therefore,the flow pattern analysis and hydraulic optimization of the inlet and outlet channels of X-type two-way pump system are carried out in this paper,and the optimization hydraulic design results are applied in combination with the pump station engineering example.The research contents include:（1）Three-dimensional turbulence numerical simulation method is used to analyse the flow pattern of the inlet and outlet channels of the X-type two-way pump system.The flow pattern in the inlet channel is complex,with a large range of low-speed reflux areas at the blind end of the channel and wall vortices easily generated at the back wall on both sides of the flapper tube;the water rotates into the channel formed by the diffuser tube and the water cone,and turns and spreads sharply in all directions from the exit of the diffuser tube,and the flow pattern at both sides and the blind end of the outlet channel is poor.（2）This paper investigates the inlet channel length,height,width and flapper geometry parameters of the X-type two-way pump system,and the results show that the inlet channel length has little effect on its hydraulic performance,and its value can depend on the layout needs of the pump room superstructure;With the height of the inlet channel increasing,the flow velocity distribution at the outlet of the flow channel increases gradually and evenly,the water flow into the pump angle changes very little,the head loss of the flow channel is significantly reduced;As the width of the inlet channel increases,the uniformity of the flow velocity distribution and the angle of water flow into the pump increases,the head loss tends to decrease,the diameter of the vortex tube attached to the wall in the flow channel gradually decreases.When the channel is wider than 2.96 D₀,the vortex attached to the wall on both sides of the blind end of the flow channel disappears;As the diameter of the entrance to the hornpipe increases,the uniformity of flow rate distribution increases significantly,the angle of water flow into the pump gradually decreases but the change is small,the head loss of the flow channel loss is significantly reduced;At a certain channel height,increase the overhang height of the hornpipe,the height of the f hornpipe decreases correspondingly,the uniformity of flow velocity distribution is increasing first and then slightly decreasing trend,the angle of water flowing into the pump gradually decreases but the change is not large,the head loss is obviously reduced,and the change is small since the overhang height is larger than 0.65 D₀;In the same horn tube overhang height,gradually increase the height of the horn tube,water flow velocity distribution uniformity began to improve after tending to basically unchanged,the water flow into the pump angle and flow channel head loss increased;In a certain height of the horn tube,with the increase in overhang height,flow velocity distribution uniformity and into the pump angle increased,head loss reduced.（3）The study analyzed the influence of the length,height,width and geometric parameters of the diffuser tube on the hydraulic performance of the X-type two-way pump system.The height and width of the outflow channel have a significant effect on the head loss of the runner,the higher the height,the lower the head loss,with less variation for heights greater than 1.94 D₀;the greater the width,the smaller the head loss,with the width greater than 2.90 D₀,the head loss is basically unchanged;the head loss of the outflow channel increases with the diameter of the diffusion tube outlet,there is an increasing trend followed by a decreasing trend,reaching a minimum at around 2.01 D₀;When the outflow channel height is certain,with the outflow channel diffusion tube outlet to the top plate distance increases,the diffusion tube height correspondingly decreases,the flow channel head loss shows a trend of first decreasing and then increasing,the top plate distance in 0.45 Do when the head loss is the smallest;when the outflow channel diffusion tube outlet to the top plate distance is certain,with the increase in diffusion tube height,the outflow channel head loss gradually decreases;when the outflow channel diffusion tube height is certain,with the increase in the top plate distance,the outflow channel head loss decreases.When the outflow channel diffusion tube height is certain,as the top plate height increases,the outflow channel head loss decreases.（4）Numerical simulation and model test were carried out to verify the accuracy of the numerical calculation method for the energy performance of the X type two-way pump system with the original control size scheme.Based on the inlet and outlet channel design parameters research,with orthogonal test method to the inlet and outlet channel hydraulic performance influence factor for sorting,get without constraints port further optimization;The flow pattern in the flow channel of the pump in the further optimization scheme is better,the head and the efficiency of the pump system are increased by 1.54%and 0.14m respectively than the original control size value scheme.This article reveals the X type two-way pump system inlet and outlet channel in the movement of water,analysis the influence of different design parameters on hydraulic performance,improved the water flow movement flow and the efficiency of the pump.The research results can provide reference for the hydraulic design of inlet and outlet channels of the same type pump system.