Resurch On Structure Vibration Of Hydropower House Excitated By Large-Sized Francis Turbine-Generator Set

Today, the capacity of the water turbo-generator set is larger gradually. The phenomenon of excessive vibration in some load area is founded ubiquitously. This kind of vibration not only affects the reliability of generator unit, but also arouses violence vibration of powerhouse structure, the most outstanding is hydraulic resonance in large-sized Francis turbine. It is discussed elementarily in this paper, that the probability of the fluctuation of waterpower arouses the vibration of generator unit so much as the vibration of powerhouse structure. And the following research is made on the structure vibration of the Three Gorges Hydropower House: Using Large Eddy Simulation method of unsteady turbulent flow numerical analysis to make hydro vibration source simulation for interflow unit of the Three Gorges Hydropower; using frequency spectrum analysis method to analyze the frequency spectrum features; Analyzing structure self-vibration features and dynamic response (harmonic response) under the effect of hydro excitation load. Through comprehensive consideration to above results, we can conclude the worst frequency and space location of the Three Gorges Hydropower house under the effect of hydro excitation load.The research result can be applied on other hydropower house whose turbine-generator set has the same type as Three Gorges Hydropower House' sThe main contents of this paper are listed as below:In chapter 1, current research situation on hydropower house vibration11and main contents of this paper are introduced.In chapter 2, turbulent simulation theory is introduced. Through comparing different simulation methods on result precision, resolving consumption and result purpose adaptability, After simulated the the curved tube we can say that Large Eddy Simulation(LES) is regarded as the best method at present to simulate the pulsation information in turbulent field.In chapter 3, three dimensions unsteady turbulent flow numerical simulation is used for tail tube of the Three Gorges Hydropower, and frequency spectrum analysis is made for pulsation pressure, therefore frequency and corresponding amplitude of pulsation pressure is concluded.In chapter 4, precise modal analysis is carried out for the Three Gorges Hydropower House structure. By using the result from turbulent field simulation in tail tube chamber, harmonic response analysis are carried out respectively on vertical excitation load , transverse excitation load in 16Hz~40Hz frequency sect.