Study on sediment erosion of pump turbine guide vane head with V-shaped structure

Abstract

During pump turbine operation, sediment particles typically erode and damage the surface of the guide vanes. In this study, Euler–Lagrange numerical calculations and sediment erosion tests are employed to comprehensively analyze the wear characteristics and particle trajectories of guide vane heads with different V-shaped structures. The mechanism of sediment erosion of the guide vane head is identified. The findings indicate that a guide vane head with a V-shaped structure significantly reduces sediment particle aggregation, with the turbulent Reynolds number in the test flow channel ranging from 0 to 18 954. Sediment particles in the boundary layer region of the wall experience viscous forces, leading to considerable viscous dissipation of sediment particle momentum. Maximum turbulent vortex dissipation occurs at the tail of the guide vane, reaching 3086 m2/s3. The impact velocity of sediment particles at identical positions increases by about 25% on average. The V-shaped structure intensifies particle wear at the head, decreases the velocity impact angle of sediment particles, and reduces the frequency of particle collisions. The rate of wear of the guide vane head by sediment particles increases with time. Wear testing reveals that impact and wear form S-shaped pits on the guide vane head, with the maximum wear groove depth measuring about 0.2 mm. Surface wear manifests as smooth, silver-gray striped scratches. Wear calculations show that when the deformation rate Δ = 1.68, the sediment particle distribution becomes denser, the wear erosion rates increases to 1.5 × 10−6 kg/m2, and head wear becomes more severe. These results clarify the effects on liquid–solid two-phase flow characteristics and wear mechanism associated with different shapes of the guide vane head.

Topics & Concepts