Research On Dynamics Of Shaft System Of Hydro-electric Generating Set

With development of the hydro-electrical in china, the scale of the hydropower station is becoming bigger and bigger, at the same time the hydro-electric generating set also trends large-scale, high-capacity and high-parameter. At this point the vibration problems of hydro-electric generating set has become more prominent, it requires not only found them and solve them in the course of the operation, but also avoid them in the design process. Dynamic characteristics and stability of shaft system is an important indicator of safe operation, not only directly affects the quality of the operating hydro-electric generating set, but also affect its life.Based on actual hydro-electric generating set, this paper studies horizontal dynamic Characteristics and dynamic response under the unbalanced force, analyses the stability and the position of the most adverse reaction. The content of specific research as follows:1. Introduces how to compute dynamic response of hydro-electric generating set based on the finite element method, analyses the nicety of ANSYS simulation and choices reasonable model units, establishes the finite element model which can express the actual structure of hydro-electric generating set based on ANSYS.2. Analysis of dynamic characteristics: Based on the theory of rotor dynamics, analyses the influence of dynamic characteristics on shaft system by the gyroscopic effect; Bearing is Boundary conditions of the shaft system, Selects a reasonable guide bearing stiffness and analyses the change of dynamic characteristics of shaft system with the guide bearing stiffhess;Analyses the influence of the magnetic pull of the imbalance on the shaft system.3. Analyses imbalance load which on the shaft system, According to all of the phase difference, computes the dynamic response of shaft system, to identify the most disadvantaged of the load composition and phase difference. When the imbalance loads acting on the shaft system are the most disadvantaged phase, computes changes which the whirl of shaft system under different running speed.Through the analysis of the maximum dynamic response which in the most disadvantaged phase, finding the low of the whirl of the shaft system under different running speed.Through calculating and analyses example, finding the low of changes of the dynamic characteristics and maximum response, which provides a reasonable reference for the design and analysis of stability of the hydro-electric generating set.