Study On Rectifying Measures Of Basin Before Inlet Of Hushu Drainage Pumping Station

The forepool is an important building in the pumping station project.It is a hydraulic structure used to connect the upstream river with the pumping station’s inlet pool or water inlet channel.The water flow in the upstream river will be adjusted after entering the forepool to be uniform.The smooth diffusion allows the water flow to enter the inlet pool steadily,creating a foundation for the safe,stable and efficient operation of the water pump.Due to the acceleration of the process of urbanization in my country,a large number of drainage pumping stations play an important role in urban development,but at the same time,the land resources in the city are relatively limited,and sometimes it is necessary to use a large-angle lateral inflow method to arrange the forepool.As a result,some undesirable flow patterns such as large-scale reflux and vortex will be generated in the front pool.Relying on a pumping station in Hushu as an example,this paper mainly uses three-dimensional numerical simulation to calculate the original plan of the pumping station’s inlet forepool,and calculates the optimized plan by adding rectification measures:setting diversion barriers,sills,and sills.The rectification analysis is carried out by combining the measures of the diversion pier and the bottom sill,through the comparative study of the results of the three-dimensional flow numerical simulation calculation of different rectification schemes,and combining the actual needs of the project,the optimal scheme is selected.In this paper,the three-dimensional modeling software UG is selected.The first step is to model the forepool of the pump station of the original scheme without any rectification measures,and then import the three-dimensional model into the meshing software to divide the grid and specify the appropriate boundary.Conditions:Finally,import the Fluent software for three-dimensional numerical simulation,export the data for analysis after the calculation is completed,and use the professional post-processing software Tecplot to complete the final post-processing to obtain the flow patterns of the surface layer,middle layer and bottom layer.In the improvement of the flow pattern in the fore-pool,this paper first performs three-dimensional numerical simulations on the diversion partitions with two different arrangements,and then sets up a sill in the fore-pool to rectify;finally,the diversion partitions are connected to the bottom.Combining the rectification measures with the ridge to study the rectification effect.By comparing and analyzing the flow pattern,the uniformity of the flow velocity distribution of each section and the weighted average angle,the optimal rectification measures are selected.Finally,the calculation results of each rectification measure are analyzed and compared,and the flow patterns of the surface,middle,and bottom layers of each measure and the simulation calculation results of the uniformity of the flow velocity distribution and the weighted average angle of each typical section are integrated,and the optimal measure is selected.The flow pattern of the water flow in the forepool of the pumping station is optimized to prevent large-scale backflow,vortex and sedimentation in the forepool,which has important practical engineering significance for improving the safe,stable and efficient operation of the pumping unit.The main research conclusions of the thesis are as followsIn this paper,the RNG k-ε model is used to numerically simulate the engineering design water level conditions.It is found that due to the large-angle lateral water inlet arrangement,there are two large-scale vortex areas in the water inlet front pool.The flow barrier,the guide grid,the bottom sill,and the combination of the guide grid and the bottom sill are rectified according to the design water level conditions,and the flow line cloud diagram,three-dimensional trace diagram and the flow velocity of the longitudinal characteristic section in the front pool are obtained.Distribution cloud map,and related calculations in the inlet tank to obtain two quantitative indicators of flow velocity distribution uniformity and weighted average angle.By analyzing streamline diagrams,velocity cloud diagrams,etc.,as well as calculating the uniformity of velocity distribution and weighted average angle of characteristic sections,it is found that the water flow in the front pool is smooth and without vortices and other undesirable flow patterns in the improvement scheme 6,which is the best scheme.