Analysis Of Abrasion In Kaplan Turbine Runner

The sediment concentration in the rivers in the north of China is relatively large.On the contrary,it is relatively low in the southern river,but the amount of the sediment is large.The turbines running on these rivers are vulnerable to the combined effect of abrasion and cavitation,which generates the very serious abrasion.So the hydraulic performance of the turbine is greatly reduced,and the safety and stability of the turbine are threatened to a great extent.In order to study the abrasion performance of turbines under the sediment concentration,this paper firstly analyzes the abrasion mechanism of a Kaplan turbines,combines the actual case of the disposal about the runner envelope in the capacity increase of power station.And analyzes the effect of silt-carrying flow on axial flow Abrasion Effect of the Runner of the Slurry Hydraulic Turbine.The nano-WC-10Co-4Cr coating was prepared by high velocity oxy-fuel method and its abrasion resistance was tested in the slurry abrasive grinding machine.The main contents of this paper as follow:?1?The analysis and discussion of the erosion mechanism of the axial Kaplan turbine which made form some methods,such as a reasonable operation,reducing the sediment concentration of the machine,optimizing the axial flow of the Kaplan turbine anti-wear coating processing technology,and some other methods from comprehensive analysis.?2?The anti-abrasion effect of nanometer WC-10Co-4Cr coating and Cr3C2-NiCr coating was studied by using the method of experiment.The effect of different content and different size of sediment on the erosion was studied.The experimental results showed that nanometer WC-10Co-4Cr coating anti-abrasion effect is better than the Cr₃C₂-NiCr coating.The relationship between the weight of abrasion loss and time on test-piece can be divided into three processes: incubation period,acceleration phase and stable phase.From this experiment,the greater the sediment particle size,the greater the impact on the erosion;the greater the concentration of sediment,erosion will be more serious.