Impact-abrasion between moving and stationary parts in 2×600 MW air-cooled units of one power plant has frequently occurred in the start-up process

and the said impact-abration being eliminated through repair and runing-in measures.At the same time

during the process of taking load

the shaft vibration at bearing no.7 of the said two units had a substantial fluctuation with the load change.By using the dynamic balancing method in the field

the trial weights are simutanuously added onto coupling between LP rotor and generator

as well as onto two LP rotors

thereby

the vibration of units can be controlled to a satisfied level.