Vibration Characteristics Of The Overflow Powerhouse With Bulb Tubular Unit

Vibration source compositions as well as effects on the powerhouse have been investigated for the roof overflow hydropower station with bulb tubular unit. This is a new type of construction in China in recent years. In this type of structure, flood-releasing surface hole through between the powerhouse operation layer and host layer, and sediment flushing outlet through from the turbine flow channel sidewalls. During flood discharging, the unit also operating, thus, powerhouse has not only become the support of the bulb tubular unit, but also a carrier of flow-induced vibration. Unit operation and discharge induced powerhouse vibration may impact on the stability and reliability of the structure. And this may become a new project. Based on prototype observation data of a roof overflow hydropower station with bulb tubular unit, and using technology of processing dynamic signal, finite element analogy and intelligence algorithm, the paper studies the problem of hydropower plant vibration. The principal contents and achievement of this dissertation are as follows:(1) Based on a subsistent vibration source theory and prototype observed data, statistical analysis the frequency of vibration source and dynamic loads of the roof overflow hydropower station with bulb tubular unit. The modals of the model of powerhouse structure are calculated by the three-dimensional finite element numerical analogy. Then check the source of resonant excitation of the generator units.(2) Through a prototype observation data that combine of hydraulic, mechanical, structural response while testing, analyse on bulb unit operating characteristics, vibration characteristics of the powerhouse and dam structure while unit operation, characteristics of the powerhouse and dam structure during flood discharge, vibration characteristics of powerhouse and unit stability both flood discharge and unit operation. Hope to grasp the characteristics of bulb unit hydropower station.(3) Segment of the original signal through the theory and prototype observation data, analyze the vibration source of the powerhouse, come out the dynamic response of major bands. And hope the results can help understanding the effect of dynamic load on an order of magnitude.(4) In accordance with the coupling effect between vibration of units and powerhouse, two models for forecasting response of the vibration of the powerhouse are built based on radial basis function network and LS-SVM respectively. Then verify the precision of the two forecasting models through the testing data of vibration in the hydropower station.