抽水蓄能电站地下厂房振因仿真分析

利用三维有限元分析方法,对某抽水蓄能电站主厂房两台机组进行了动力特性及动力响应仿真分析研究。根据地下厂房整体自振频率、局部构件自振频率与厂房振动主频的错开度分析结果,厂房的剧烈振动是由局部支撑构件在振源激励频率下发生共振引起的。通过对比现场试验振动加速度分布规律和有限元模型时间历程响应数值计算得到的振动加速度分布规律的对比分析,发现引起厂房振动的主要水力振源为导叶后与转轮之间的压力脉动,频率为2倍叶片过流频率(100Hz)。对该抽水蓄能电站的振因分析的研究结果为今后抽水蓄能电站设计阶段的抗振校核和运行阶段振动原因分析提供了参考。

Simulation Analysis of the Vibration Causes of Underground Powerhouse in Pumped Storage Power Station

The three-dimensional finite element analysis method was used to simulate the dynamic characteristics and dynamic response of two units in the main powerhouse of the pumped storage power station. According to analysis results of the natural vibration frequency of the whole powerhouse structure, natural vibration frequency of the partial structures, and the staggered degree of main vibration frequency of the powerhouse, resonance does not occur for the whole structure of powerhouse, and the severe vibration of the powerhouse is caused by the resonance of the partial support components under the excitation frequency of vibration source. With the comparative analysis of vibration acceleration distribution patterns obtained from the field tests and the time history response of the finite element model, the main hydraulic vibration source stimulating the powerhouse vibration is the pressure pulsation between the rotor and the vanes. The frequency of pressure pulsation (100 Hz) is twice of the blade overcurrent frequency. The analysis of the vibration causes of the pumped storage power station can provide references for the anti-vibration check during the design stage and vibration cause analysis during the operation period of the pumped storage power station.