国产早期300MW机组的振动分析及治理

Vibration Analysis and Handling of Early-made 300MW Steam Turbine-Generator Unit

某发电厂7号机组为早期国产300MW机组,在发电机转子改造后,当升速、降速过发电机临界转速时,出现发电机轴瓦振动一次比一次大的现象,同时该机组低压缸轴瓦振动一直超标。对机组振动的原因为:由于发电机转子改造中装配紧力不当,在离心力作用下发电机部分部件移位或变形,导致一阶不平衡量增大,在两端加重无法将振动降到合格水平,必须在转子中部加重。通过治理,机组振动达到优良水平。

NO.7 steam turrbinegenerator unit in one power plant was a 300 MW unit made in the early stage.After the rotor of generator was retrofitted,when the raising speed and reducing speed passde through the critical speed,the vibration of generator’s bearings became larger and largev,and meantime the vibration of low pressure cylinder’s bearings always exceeded the standard. The vibration causes of unit were： as a result of the improper tightening force of assembly during the retrofit of generator’s rotor ,under the action of centrifugal force,the displacement or deformation phenomena appeared on some parts of generator ,thus leading to incresing of firsrt order unbalance quantity. Throngh to add weight in the rotor,the vibration of unit has teached good level.