厂顶溢流式水电站振源特性研究

Vibration source characteristics of a roof overflow hydropower station

以某水电站灯泡贯流式机组厂顶溢流布置型式为对象,研究该新型结构的振源组成及对厂房结构影响。通过理论分析结合原型观测数据,对机组运行及泄流产生的厂房结构振动频率进行识别,确定其动荷载来源。分别统计厂房结构主要部位振动达峰值时不同频率所占比重,计算实测工况频带能量对总振动响应的贡献,分析分频振动随负荷的变化规律。结果表明:狭缝射流、转轮叶片振动与协联关系不正确引起的振动为主要振源。泄流诱发厂房振动微弱,对厂房结构运行与安全无影响。该结果可为量级评估该型式水电站厂房振动提供依据。

Vibration source compositions and their effects on powerhouse were investigated for a roof overflow hydropower station with a bulb tubular unit. Based on the theoretical analysis and prototype observation data, powerhouse structure vibration frequencies excited by the unit operation and flow discharge were identified, and dynamic load sources were determined. Furthermore, the contributions （ % ） of different frequencies were calculated when the vibrations of the main measured points reached the maximum values. The contributions of the measured frequency bands energy to whole vibration response were also examined. The change laws of different frequency vibrations versus the load were presented. The results showed that the slot jet impingement, the vibration of the runner blade and the vibration due to the incorrect connection relationship are the main vibration sources; the powerhouse vibration induced by flow discharge is small, and it has no effect on the powerhouse structure＇s operation and safety. The results provided a basis for evaluating this model hydropower station＇s powerhouse vibration with a certain level.