Research On The Settlement To Avoid Sediment Deposition In The Forebay Of A Pumping Station Built On The Sediment-laden River

The forebay of a pumping station is a segment that connects intake channel and intake sump, and it can make the flow in the intake channel spread smoothly into the intake sump, so that each pump unit has a more smooth flow pattern. If a pumping station is built on the sediment-laden river, because hydraulic conditions of the forebay are changed due to sediment deposition, the flow pattern of the forebay and flow conditions of the pump deteriorate which can decrease the efficiency of pump system and bring great difficulties in operation and management of the pumping station. Dregding in the forebay is usually not very effective, because a new deposition forms soon after dredging. Therefore, using project measures to solve the sediment deposition of forebay is important to save water and energy, improve economic benefit of the pumping station.This paper takes an example of number six Guhaikuoguan pumping stations in Ningxia whose water resources is the Yellow River. The numerical simulation and model experiment are combined to do research. Based on these, preventing the sediment deposition of forebay is researched.In aspect of model experiment, the similarity criterion of water movement and suspended sediment movement is used, the model scale is determined. According to the model scale and the features of model sediment, electric sawdust is selected as model sediment. Based on the experiment of clear water, the flow pattern of the original design and the design after the flow pattern modifying technology is observed. The area of sediment deposition is analyzed, and preliminary schemes of modifying the flow pattern is put forward. Furthemore, the experiment of muddy water is done in the condition of the original design and the design after the flow pattern modifying technology, and the sediment distribution of every section is measured. Then, preventing the sediment deposition of forebay is presented.In aspect of numerical simulation, GAMBIT is used to set up the three dimension solid model of forebay in the condition of the original design and the design after the flow pattern modifying technology. The mesh generation of three models is done, local refinement is also done to improve the quality of the grid. Based on the standard k-ε, RNGk-εand Realizablek-εturbulence model respectively, the three-dimensional numerical simulation of forebay in the condition of the original design using clear water is obtained. Moreover, the numerical simulation results and experimental results are quantitatively compared, and Standard k-εturbulence model is closer to the experiment results. So, this paper uses Standard k-εturbulence model to do numerical simulation of the single phase flow and homogeneous multiphase in the condition of the original design and the design after the flow pattern modifying technology. Besides that, this paper analyzs the sediment impact on the flow pattern in the forebay. the sediment distribution in the forebay in the condition of the original design and the design after the flow pattern modifying technology is compared, and preventing the sediment deposition of forebay is presented.The numerical simulation results and experimental results have been quantitatively compared, and a more rational solvement to prevent the sediment deposition of forebay is put forward.