Prediction of sediment wear of francis turbine with high head and high sediment content

Abstract

Wear of runner blades is a common problem affecting the operational reliability of turbines with high head and high sediment content. In order to accurately predict the wear of the turbine runner blade, based on the solid-liquid two-phase flow equation and turbulence model, the full channel numerical simulation of the internal water and sediment flow was carried out, and the sediment volume distribution and sand water velocity on the turbine runner blade were obtained. Then, according to the digital simulation results and the operating parameters of the turbine runner, the sediment wear test scheme for the turbine blade material specimen is designed, and the sediment wear test is carried out on the runner material. According to the test results, the sediment wear curve of runner blade material is obtained and applied to numerical simulation, and the main position and wear degree of turbine blade sediment erosion are predicted. The inspection results of the runner blade wear after the unit has operated for a flood season show that obvious wear can be seen at the outlet edge of the lower band of the runner blade, and the wear position and wear amount are basically consistent with the simulation values. The study is of great importance for predicting the wear of turbine runner blades with high drop height and high sediment content, and for turbine maintenance under complex conditions.