Structural Characteristic in Prototype Runner of Francis Turbine Analysis

摘要

Fatigue and cracks at the blade of Francis runner seriously affect the safe operation of the power stations. It is important to analyze the structural characteristic in order to avoid fatigue and cracks of runner and ensure the safe operation of power stations. Since there are always filled with water in clearance around the runner structure, the structural characteristic of runner would be changed. The whole flow passage including the spiral case, stay vane, guide vane, runner with clearance around it and draft tube was established. The modal of runner in air, flow passage and flow passage with clearance was analyzed. The static stress characteristic of runner based on one-way fluid-solid coupling was calculated. The results show that the natural frequency of runner would be reduced due to the effect of clearance. Flow field calculation with clearance has little impact on the statics stress of runner while the water pressure load at the surface of clearance would change the location of the maximum stress point and reduce the static stress of runner.