重泥沙条件下冲击式水轮机的冲蚀及磨损特性OA

To investigate the erosion characteristics of flow components in a Pelton turbine induced by sediment-laden three-phase flow,a numerical simulation of a four-nozzle Pelton turbine was conducted.The influence of sediment particle size on the erosion rate of the injector and the bucket was analyzed,with a particular focus on comparing erosion under the optimal operating conditions using single,doub-le,and four nozzles.The results indicate that as the mechanism for guiding fluid to each nozzle,the water distribution ring pipe exhibits low-pressure and high-pressure zones on the inner and outer sides of the bifurcation,leading to the formation of Dean vortices.These vortices enter the injector with the fluid flow.Additionally,due to the presence of the injector's internal deflector,significant local erosion occurs on the jet needle.Erosion on the injector and the bucket working surface primarily occurs at the jet needle,the water edge of bucket,and the splitter edge.Both the average and maximum erosion rates increase with larger sediment particle sizes,and the velocity profile of the bucket becomes more regular.Among the various working conditions,the single-nozzle condition produces the highest jet ve-locity,resulting in the most severe erosion on both the injector and the bucket compared to other condi-tions.This finding demonstrates that fluid velocity plays a critical role in the erosion process.