Investigation of erosion influence in distribution system and nozzle structure of pelton turbine

Abstract

Pelton turbine, with its unique advantages in high mountainous region especially in the southwest of China, has received more and more attention. This paper focuses on the erosion influence to the hydraulic characteristics by Euler particle tracking model. Two-phase numerical simulation results are compared with the model experiment results and are proved to be accurate. Solid particle is then added in the flow and three-phase flow is solved. Particle parameters (silt particle size, concentration) were considered to investigate the mechanism of silt erosion on Pelton turbine distribution system including distributor, bifurcation tubes, and nozzle structure. It proves that erosion destroys the vortex structure in bifurcation tubes. As the particle's diameter increases, discharge in different bifurcations appear more uniform. With the particle flow, a strong collision phenomenon appears at nozzle seat. As the particle's diameter increases, the erosion strengthens accordingly. This study reveals that the particle influence induces erosion which is important to be considered during the design and operating procedures in the whole life of Pelton turbine.