Study On Vibration Transfer Path Of Large Hydropower Plant Structure

Powerhouse vibration research is a very important research topic, it involves the structure safety, staff comfort, generator operation and many aspects during the runtime. It is an important objective of hydropower house design to control vibration at a safe range. The structural vibration problem should be considered in the early days of the hydropower house design. Aimed at the hydraulic,mechanical,electromagnetic vibration source, it is necessary to study the production, transmission and attenuation rule to make vibration satisfied structural safety. This subject will take this as the starting point.The main work and results obtained from the researches of this paper are summarized as follows:(1)Vibration sound intensity expression is deduced through a combination of the equations of elasticity and finite element theory. The ansys APDL function is used to write the parametric design program, the visualization of sound intensity vector is achieved. The vibration transfer characteristics of beam-slab structure are analyzed under different modeling, stiffness, damping and loads. The method of applying power-flow-method to complex construction is explored in advance.(2)The vibration transfer characteristics of a dam-rearpower plant are studied on basis of the power-flow-method. Research shows that the second quadrant of generator floor, cowling, beam column, metal spiral case and socket ring are the main vibration transfer path. Reinforcement detailing, changing structure properly, using high damping and stiffness stuff are the effective measures of vibration reduction.(3)Focused on the impact of hydro-power plant for hydraulic machinery, this paper optimized the hydro-power material properties through combination of structural intensity theory and finite element method, the vibration intensity was taken as index. Results of comparison indicated that the optimized weaken effect of changing structural stiffness and damping is obvious.(4)On the basis of vibration measurement data, the FOAGRNN method is proposed regardless of the accurate mechanical model. The method is used to predict vibration of the stator on the main vibration transfer path. The forecasting error is 3.28%. The result shows that FOAGRNN can predict thepowerhouse vibration well.The article reveals the vibration transfer law of a dam-rear power plant on basis of theoretical derivation and numerical computation from the perspective of structural intensity visualization,it also offers the support to further study of complex construction vibration.