Study On Relationship Between River Turbidity And Sediment Wear Of Turbine Runner In Yingxiuwan Hydropower Station

In China’s sediment-laden river basins,sediment particles in large and medium-sized hydropower stations have different wear effects on hydraulic turbines.Especially,in flood season,the sediment transport capacity of rivers is more than 77% of the whole year,so the problem of sediment wear of hydraulic turbines on rivers with heavy sediment is very serious in flood season.As the core equipment of hydropower station,sand wear will cause vibration,reduce efficiency and shorten maintenance cycle.Especially after Wenchuan earthquake,soil erosion along the Minjiang River has intensified,and sediment transport in the Minjiang River has increased rapidly,resulting in further serious sediment wear of hydraulic turbines in the Minjiang River Basin.Therefore,the research on the sediment wear of hydraulic turbine is very important for seeking the technical methods and measures to effectively reduce the sediment wear of the overflow parts of hydraulic turbine,as well as the design and reconstruction of hydraulic turbine in hydropower station,which has great economic benefits.The main research of this paper is as follows:1.The flow of sand and water in the whole channel of HLA982a-LJ-418 hydraulic turbine of yingxiuwan hydropower station in Minjiang river basin is numerically simulated.The calculation results show that the pressure distribution in the flow-through parts area of hydraulic turbine is uniform under various working conditions,and the pressure decreases gradually along the centripetal direction from the water inlet of guide vane to the water outlet of runner,so the flow pattern is better.Sediment concentration at the bottom of volute,the lower end of guide vane and near the lower ring of runner are slightly higher than other sections.With the direction of inflow,the velocity of sediment flow around the water edge of runner blade is the largest.2.The sediment wear test of turbine runner blades of Yingxiuwan Hydropower Station was carried out by using the flow around test method,and the sediment wear on the blade surface was measured by using 3D topography tester.3.The relationship between turbidity and sediment concentration in Yingxiuwan Hydropower Station is established.4.According to the calculation and test data,the calculation formula of turbine runner blade wear rate of Yingxiuwan Hydropower Station is obtained by multivariate linear analysis method,and the service life of the turbine is predicted according to the national standard,and some suggestions for the reconstruction and reasonable operation of the hydropower station turbine are put forward.