Study On Sediment Wear Of Guide Vanes For Hydraulic Turbines In Xiate Hydropower Station

When sediment water passing through the turbine passage,the hard sand particles will hit and wear the surface of the flow components causing sediment erosion.The erosion will reduce the efficiency of the turbine,even damage the turbine and lead to severe economic losses.The sediment content in Kezi River Basin is large,and the sand particles have sharp angles and large hardness.Therefore,it will inevitably cause erosion to the flow components s of the turbine operating in these rivers.The sediment erosion of turbines in Xiate hydropower station which will be built on Kezi River was studied.The UG software was used to establish the 3D model of the whole flow passage components of the HLA351-LJ-275 Francis turbine with long and short blade.The CFX software was used to numerically simulate the sediment flow in the turbine.For hydropower stations with high heads,the sediment erosion on the guide vanes is more serious,so the sediment flow in the guide vane mechanism was analyzed in emphasis.And then,the sediment erosion test of guide vanes was conducted on the sediment erosion test stand of hydraulic machinery.The main contents and achievements are as follows:1.According to the two-dimensional design of HLA351-LJ-275 Francis turbine,the water data model of the volute,guide vane mechanism,runner and draft tube was established by using the UG 3D modeling software.2.By adopting the structured grid division method,ANSYS ICEM was used to divide the grid of each component,and the type of boundary was set up.3.The CFX pre-processing was used to set boundaries,select parameters,solve and control,and a series of other operations for each part of the turbine.The CFX solver was used to calculate the three-dimensional turbulent flow of the turbine at different flow rates and sand concentrations.4.The CFD POST was used for post-processing of the calculation results,and the distributions of sediment concentration,velocity and pressure on the components of the guide vane mechanism were obtained at different conditions.5.The sediment erosion test of the guide vane mechanism was conducted on the sediment erosion test stand,and the white light interferometer was used to read the surface morphology and the depth of the specimen before and after erosion.6.The erosion rate of guide vane mechanism with different materials was obtained by using the test data and fitting method,which can provide a reference for engineering design of the hydropower plant.