Flow Pattern Improvement And Outlet Pipe Optimization Of Dongxingang Pumping Station

Pumping stations,whose function is to promote the benign development of the national economy and help people resist natural disasters and other aspects are widely used in all walks of life,especially in irrigation and drainage,water transfer etc.Intake basin pool and the water pipe are important inflow components of the pump station,whose main role is to furtherly adjust the water from the forebay,flow instability in the intake basin could influence inlet conditions of the pump,thereby reduce the water pump cavitation performance,envn could affect the safe operation of the pump station,cause problems such as pump unit vibration.The main function of the outlet pipe is to ensure the smooth flow into the outlet pool and reduce the hydraulic loss as much as possible.So,the flow state of the inlet pool will be improved by the comprehensive rectifying facilities,and on this basis,the straight-pipe outlet channel of the original scheme will be optimized.Firstly,a three-dimensional solid model was established.Two working conditions of drainage operation and diversion operation were explored.And,the flow state of original scheme for the two working conditions was simulated.Then,for the drainage operation condition,better flow patterns of the intake pool is achieved by adding guide piers in the forepool to extend the length of the barrier piers.After determining the optimal guide piers parameters,the vortex elimination beam is added on the surface of the intake pool to successfully eliminate the surface vortex.For the water diversion operation condition,the original flow patterns is good,but after the addition of rectification measures,the flow pattern of the inlet pool is disturbed,so for the water diversion operation condition,the original design scheme is maintained.For drainage operation condition,when the length,width and height of the diversion pier is 5 m,1.2 m,and9.5 m respectively,the shape of the pier head issemicircle(radius of which is 0.6 m),the section length of added extincting-vortex beam is 0.2 m,while the space and the length of which is 5 cmand 3.3 m respectively,the flow patterns in the intake pool are the best.Compareing with the original scheme,the velocity uniformity at section a-a of the original scheme is increased by 1.48%,the weighted average angle increased by 4.09°.the velocity uniformity of section b-b is increased by 3.19 percentage points,and the weighted average Angle is increased by 1.14°Finally,the outlet pipe of the pump station is optimized,and the straight pipe outlet pipe is changed to the low hump outlet pipe.The parameters of the low hump outlet pipe are designed.The hydraulic loss between the inlet and the outlet of the outlet pipe is taken as the index,and the schemes are analyzed.The results show that the low hump outlet pipe can effectively reduce the hydraulic loss of the outlet pipe and improve the bad flow state of the outlet pipe.When the section diameter s is equal to 1400mm,the hydraulic loss in the drainage condition is 0.612m lower than the original scheme,and the hydraulic loss in the water diversion condition is 0.583m lower than the original scheme.Through the scheme design and numerical simulation calculation analysis,the improvement measures for the poor flow state of the inlet pool of the gate station combined with the engineering pump station and the optimization scheme for reducing the hydraulic loss of the straight pipe outlet channel are obtained.It is proved that the measure and scheme are effective and reasonable,and the research results could provide some reference value for similar engineering design.