Study On Improvements Laws Of Flow Conditions To Side-direction Forebay In Pump Station Of Diversion Pier

Forebay is an important influent building whose hydraulic characteristics directly affect the performance of the pump.The arrangement of the pumping station is often restricted by objective factors such as water flow conditions and actual terrain.It has to adopt the arrangement of lateral inflow,and the direction of water flow in the lateral inflow has a certain angle with the direction of the front pool,and in severe cases it will produce severe cavitation and vibration,affecting the normal operation of the pump.Therefore,the use of rectification measures to improve the influent flow state of the pumping station has important practical significance for the design and modification of the pumping station and the economic and safety of the engineering operation.In this paper,the orthogonal test method is used to numerically simulate and analyze the different parameter combinations of the diversion piers.The relevant laws can be used to provide reference for the design of similar projects and improve the flow pattern of side-inlet forebay.Firstly,the model of the forebay of the side-inlet pumping station is established.The lateral bending angle is set to 45°and 60°.The numerical calculation is performed for the two schemes.The numerical simulation results are analyzed and the drainage channel is found to be better.However,after entering the front pool,there is a serious deflection in the mainstream of the 1#inlet flow channel near the side wall.Most of the water flow can flow smoothly into the inflow channel,and a small part of the water flows to the back wall to form a backflow,resulting in a large range of recirculation zones near the left side wall of the front pool,and the flow pattern in the recirculation zone is disordered and affects 1#The water inlet conditions of the water channel.Secondly,a diversion pier rectification is added between the 1#and 2#inlet flow passages,and the geometric parameters of the diversion pier are optimized by orthogonal test method.The factors include the length,width,curvature and relative height of the diversion pier.L16(45)orthogonal table was used,and the test indicators were analyzed by variance and variance to determine key factors,important factors and optimal or better test protocols.Then,through the orthogonal test analysis and the targeted second round of orthogonal experiment,the improvement of the flow parameters of the front pool is improved by the geometric parameters of the diversion pier.When the lateral angle of the current pool is between 45°and 60°,the optimal combination of parameters for the diversion pier to improve the flow pattern in the lateral inlet is:the length of the diversion pier is taken from(0.4?0.6)times of the inlet center to the outlet center of the forebay;the arc of the diversion pier is 0°?15°;the width of the diversion pier is determined by the spacing of the inlet flow channel.The distance between the inlet and the runner is 1.0m;the relative height of the diversion pier is 1.0,that is,the flow state is the best when the height of the diversion pier is flush with the water surface.Finally,the correctness of the calculation and analysis of the orthogonal test and the analysis of the mechanism of the rectification of the diversion pier are further verified.The numerical simulation of the typical schemes of the first and second orthogonal designs is carried out when the lateral 45°and the lateral 60° angle are selected.The results were compared and analyzed.The geometrical parameters optimization design method of the diversion pier combined with the orthogonal experimental design analysis method and numerical simulation technology was obtained.It is reasonable and feasible to improve the hydraulic performance of the lateral inlet water pool.It has engineering application value in multi-parameter optimization in pump station engineering design.