This article discussed the vibration cause of a 660 MW turbine during start-up process after unit class-A repair

incident handling and effect. Through the characteristic of vibration spectrum

found that the cause of vibration is the thermal bending of rotating shaft caused by rub-impact of steam seal and rotor

which is obtained by take measures such as dynamic and static friction under the premise of controlling the amplitude of vibration. It’s provided reference for finding out such vibrations causes of other units.