水口水电站发电机层楼板振动分析

Vibration Analysis of Generator Floor Slab of Shuikou Hydroelectric Station

通过建立三维有限元模型对水口水电站发电机层楼板进行振动分析,研究了厂房的自振特性并进行共振校核,分析了发电机层楼板各象限和机墩周围上、下游及左、右侧在机械振动荷载和蜗壳水流脉冲压力作用下的振动响应,并对发生较强烈响应对应频率下的荷载进行时程分析。结果表明,发电机层楼板未发生共振,楼板在蜗壳水流脉冲压力荷载作用下的响应较强烈,机墩周围在机械振动荷载作用下的响应较强烈,在楼板某些区域处振动响应的放大倍数接近10倍,部分振动响应值超出允许范围,在机组正常运行中应避免不利频率出现,并加强对该区域的监测和预警。

The vibration characteristics of generator floor slab of Shuikou hydroelectric station are analyzed by setting up three-dimensional finite element model.The vibration property of power house is studied and its resonance checking is conducted.The vibration response of all quadrants and generator piers of generator floor slab are analyzed under the action of mechanical vibration loads and pressure pulsation in spiral case.The corresponding time-history analysis is carried out under the strong response load.The results show that the generator floor slabs do not appear resonance;all quadrants of floor slabs response strongly under pulse pressure in spiral case;it appears strong response around generator piers under mechanical vibration loads;the magnification of vibration response is closed to 10 times in some areas of floor slabs;some vibration response values are beyond allowed range;in order to ensure the normal operation of generator units,it should avoid appearing adverse frequency and enhance monitoring and early warning in this area.