两导半伞式立轴混流式水电机组上机架振动超标原因分析

Cause Analysis on Excessive Vibration of Upper Bracket of Two-Guide Half-Umbrella Vertical Shaft Francis Type Water Turbine-Generator Unit

某水电站两导半伞式立轴混流式水轮发电机组在全负荷范围内上机架振动均比国标报警限值大100μm以上,存在明显超标现象。针对该机组上机架振动超标现象,结合机组稳定性试验和动平衡配重试验进行了多方面分析,得出上机架支撑松动是导致上机架振动超标的主要原因的结论。

In the full load range of a hydropower station,the vibration of the upper bracket of the two-guide half-umbrella vertical shaft francis type water turbine-generator unit is more than 100μm larger than the alarm limit of national standard GB,which is obviously out of limits.In view of the phenomenon of excessive vibration of the upper bracket of the unit,multi-analysis is carried out combined with the stability test of the unit and the dynamic balance weight test.It is concluded that loose support of the upper bracket is the main cause of excessive vibration of the upper bracket.