Research On The Mechanism Of Sediment Deposition And Optimum Structural Design In The Forebay Of The Pumping Station In Large Scale Irrigation Area

With the rapid development of economy and the improvement of science and technology in China, the engineering construction of large pumping more, the pumping stations in the development of national economy and the people's all aspects of life play an important role. In order to promote the construction and operation management of pumping station, the level of field investigation, and mathematical subject adopts hydraulic model test and theoretical analysis, the analysis method of sediment deposition in the pool, before the improvement mechanism of effective and reasonable structure, reduce the previous pool in the process of flow pump hydraulic losses and improve the efficiency and reduce the consumption of pumping unit, reduce the cost of pumping stations, and has important theoretical significance and practical value.Based on landscape irrigation in gansu and ningxia electric pumping irrigation fixed sea water before the big pool and positive side before water pool as research object, the main research contents include:1 Study on irrigation water pumping flow sediment energy and hydraulic unit operation efficiency, reduce the influence of sediment technical measures;2 Field investigation data of hydraulic model test and analysis, the research results of the sediment deposition in the pool of pumping station site before model and mechanism of sediment deposition in the pool;3 According to the pool of pumping station, sediment deposition mechanism of pumping station is effective and reasonable structure optimization design scheme.The main innovation of a paper:1 Through field investigation and analysis of the test method of the Yellow River region high head before the pumping irrigation sediment deposition in the pool.2 Monte Carlo method with the sedimentation tank before pumping stations, according to data model to establish the appropriate hydraulic model, objectively Sedimentation forebay pumping experiment in minutes3 Using the formula Ne=γQH and J.M.N eilson and A.Gildris function of sediment abrasion on the pump operating efficiency and the impact of erosion on the turbine.4 Analysis of pumping station sediment deposition in the pool of water and sediment mechanism of influencing factors, put forward the corresponding measures to improve the structure.The main conclusion:1.Flow sediment and water pump units have a direct relationship between efficiency. The water and sediment, the lower the efficiency, water consumption is higher. Therefore, this article puts forward the importance of cascade pumping irrigation to build system of the desilting basin.2.Sediment silting mechanism: Sediment-carrying concentrations in two-phase flow into the pool of backflow before sediment deposition badly regional, Don't always open, feed water pump near the pool area before and mainstream backflow regional deposition lighter.3. Monte carlo method and simulation of pumping station pool sediment particle movement of computing, sediment concentration distribution, regional distribution of sediment deposition.4. And puts forward the change of pumping station, adjusting the structure of local pool pumping unit arrangement etc, effectively improve the engineering measures to water flow mode, prior to reduce sediment deposition.