Study On The Vibration Characteristics Of Bulb Turbine Hydropower Stations

China has a lot of low-head hydropower resources , and most of them are in the eastern part of the high energy demand in economically developed areas. With the rapid exploitation of high-head hydropower resources in China, there are seldom high-head hydropower resources left to be developed, so people have pay an increasing attention on the development of low-head hydropower resources. Theory and practice have proved that tubular turbine is the most suitable units for the development of low-head hydropower. Bulb turbine hydropower station is one type of run-of-river power plants, and the building itself is not only power building but also retaining structures, therefore structural stability of the plant is very important. Structure and unit coupled vibration problem has been the focus of the study, besides, water is also very important factors in the local oscillator, so it is necessary to study the interaction of flow and structure.Therefore, in this paper, the study is based on a bulb turbine hydropower station, uses ANSYS which is three-dimensional finite element software to build the model of the station, analysis the influence of water on structural vibration characteristics, and analysis the stress condition of the structure under static and dynamic loads. And the main studies are as follows:(1) In the calculation of the vibration characteristics of the hydropower plant structure, the dry modal and wetting modal is calculated. In the wetting mode calculation, three conditions are calculated, flow channel water-filled, spillway over the water and both of them with water. According to the fluid-solid coupling method to calculate the values, and based on the results and shapes, using the mass added method to calculate the modal again and again, and do not stop the simulation until two methods income similar frequency value and the same vibration mode shape, and then get the mass added formula which is suitable for the bulb turbine hydropower station.(2) According to the calculation of the vibration characteristics of plant structures, analysis the vibration sources which is lead to the vibration of the hydropower station, and then get the main vibration source. According to the standard, check the resonance of the hydropower station.(3) This paper calculates the static of the structure with eight sections of three condition, and analysis the press condition of these sections. Considering the influence of earthquake to the hydropower station, calculates the spectrum of the three condition with eight sections. To reflect the actual situation, overlay the spectral analysis results and the results of static, and then analysis the stress of every section.(4) Calculates the structural support harmonic of the tubular turbine. The foundation loads is regarded as the harmonic loads, and calculates the amplitude when the structure is under a certain frequency , specified frequency and fly to escape frequency, and get the frequency - amplitude curve of the main parts of the force structure, and then study on the stress conditions.