瀑布沟水电站地下厂房机墩组合结构刚度分析

Analysis on Stiffness of Generator Pedestal Structure of Underground Powerhouse in Pubugou Hydropower Station

机墩组合结构是水电站厂房中水轮发电机组的主要支撑结构,其刚度的大小对机组的稳定运行起着至关重要的作用。以瀑布沟水电站工程为例,建立地下厂房结构三维有限元模型,计算机墩结构的水平向静力刚度和动力刚度以及竖向静力刚度和动力刚度,并进行了刚度复核。计算结果表明,机墩各方向静力刚度和动力刚度均满足要求;随着机组动荷载频率的变化,机墩各方向最小动力刚度值及对应计算工况或出现的位置均随之变化,说明机墩动力刚度与动荷载频率存在相关性,对动力刚度进行校核是很必要的。

The generator pedestal structure is the main supporting structure of the hydro generator set in a powerhouse,whose stiffness plays an important role on the stability of generating unit.Taking Pubugou hydropower station project as an example,the study on the static stiffness and dynamic stiffness in various directions of the generator pedestal structure is conducted by a three dimensional finite element model of underground power house.The results indicate that the static stiffness and dynamic stiffness in various directions of the generator pedestal structure can meet the design requirements.The minimum dynamic stiffness value in various directions and calculation condition or placement are all changed with the change of the dynamic load frequency of generating unit,which could explain that the dynamic stiffness of the generator pedestal structure has close correlation to the dynamic load frequency,so it is necessary to check the dynamic stiffness.