Steam Turbine and Gas Turbine
HE Guo-an, MIN Chang-fa, ZHANG Xue-yan, ZHANG Wei-jun, WANG Yan-bo
2012, 32(4): 282-288.
Aiming at the vibration problems frequently occurring in operation of domestic 600 MW turbo-generator sets, an analysis has been carried out on the vibration phenomenon, feature, mechanism and the causes, while various countermeasures for on-site dynamic balancing summarized. Results show that large vibration disturbance exists in domestic 600 MW high- and medium-pressure rotors due to their asymmetric structures, to overcome which, the disturbance coefficient of various vibration modes and orders should be considered during on-site dynamic balancing process of rotors, especially the influence of one-order weighing on two-order vibration mode. The abnormal vibration occurring in low-pressure cylinder of some domestic sets are caused by insufficient rigidity of supports for relevant bearing seats, which may be handled by fine dynamic balancing on site. The vibration of generator rotor is mainly of the three-order mode, which may be corrected by adding balancing weight on the shaft coupling between low-pressure rotor and generator rotor, or on the shaft coupling between generator rotor and exciter rotor, in consideration of the distortion of vibration mode. The vibration of electricity gathering shaft is highly affected by the installation quality of the shaft coupling between generator rotor and exciter rotor, for which attention should be paid to the influence of weighing response at bottom opening of the shaft coupling between generator rotor and exciter rotor, during corresponding dynamic balancing analysis on site.
