株溪口水电厂机组转轮室结构安全数值分析

Analysis on structural safety value of unit runner chamber of Zhuxikou Hydropower Station

建立了株溪口水电厂灯泡贯流式机组转轮室的三维模型,采用有限元法,对转轮室的动静力特性和疲劳进行了分析。结果表明:模态计算显示机组正常运行时,转轮室的固有频率应在37~47 Hz,现场试验测点转轮室振动频率为叶片频率,转轮室无共振风险。转轮室的振动属于水力作用下的强迫振动,转轮室刚度偏小,引起振动偏大。转轮室结构强度可以满足机组运行要求,出现疲劳破坏的可能性较低。计算结果为保障转轮室安全运行提供了重要技术支持。

A 3D model of runner chamber of bulb tubular unit of the Zhuxikou Hydropower Station has been established to analyze dynamic/static characteristics and fatigue characteristics o f runner chamber by means o f finite element method. The results indicate that when units are in normal operation as indicated by modal calculation, the inherent frequency o f runner chamber shall be 37~47 Hz. According to field test points, the vibration frequency of runner chamber is the blade frequency, so the runner chamber is free of resonance risk. The vibration o f runner chamber belongs to forced vibration under hydraulic actions, and becomes stronger under lower rigidity o f runner chamber. Since the structural strength o f runner chamber can meet operation requirements of units, there is relatively low possibility of fatigue failure. The calculation results provide important technical support for the safe operation of runner chamber.