Modeling And Life Loss Analysis On Torsional Vibration Of Steam Turbine-Generator Shafts

To meet the needs of online monitoring and analysis on torsional vibration of steam turbine-generator, a multistage lumped-mass model considering influence of damping is established in this paper. The detailed modeling principle and calculation method of structural parameter are put forward. The effects of damping on torsional vibration characteristics are analyzed. Torsional stiffness of shafts has been adjusted based on shaft temperature distribution. Contrasting actual response of monitoring points, a dynamic correction method of stiffness and damping in response model is put forward. Moreover, the calculation method of shaft fatigue life is determined under complex stress condition. Combining actual parameters of a 200MW turbine-generator, nature frequencies calculation, parameter correction, response calculation and fatigue life analysis of some kinds of simulated faults, are carried out.Finally, a practical and reliable online monitoring and analyzing system for the torsional vibration of steam turbine-generator is designed. The system can provide continuous real-time monitoring on torsinal vibration of shafts, online analysis on response of torsional vibration, historical data tables, fault reports, and life loss of shafts. The system can also exchange data with remote diagnosis center to achieve remote faultdiagnosis.