汽轮发电机组振动故障分析及处理

C25-8.83/0.981是一台抽汽供热式汽轮发电机组。该机组在启动调试过程中,发现其存在四号轴承轴向振动超标故障、发电机转子热不平衡故障和汽轮机动静碰磨故障等问题。本文通过启动运行过程中对机组参数监控及轴系振动的监测,经过对现象及相关数据的分析,并在停机过程中多次进行调整。最终确定四号轴承轴向振动超标的主要原因是由于该轴承球面与球面座定位销错位,引起定位销卡涩,从而使激振力投影点与轴承几何中心不重合,致使四号轴承轴向振动过大。而发电机转子热不平衡和汽轮机动静碰磨的故障现象是在机组并网带负荷运行过程中四号轴承和二号轴承相继振动过大。经分析判断,主要是由于发电机转子在运行过程中发生了热弯曲,从而造成发电子转子热不平衡,产生较大的轴向振动,进而影响到汽轮机转子并致使动静碰磨造成二号轴承振动过大。最终通过现场动平衡,加配重,才使这一问题得到较好的解决。

C25-8.83%.981 is a extraction steam heating type turbo-generator set. The unit in the process ot start debugging, no. 4 bearing axial vibration have been found to exceed bid failure, heat generator rotor unbalance fault and the problem of steam turbine with ground fault movement.By starting in the process of running the unit parameter monitoring and vibration in shaft system of monitoring, through the analysis of the phenomenon and the related data, and many times in the process of downtime to adjust. Eventually determine the no. 4 bearing axial vibration exceeds the main reason is because of the spherical bearing and ball seat positioning pin, cause dowel unsmooth, so that the vibration force projection points do not overlap with bearing geometric center, no. 4 bearing axial vibration is too large. And heat balance and the steam turbine generator rotor movement to touch the ground fault phenomenon is in the process of grid load operation of no. 4 bearing and the no. 2 bearing vibration. Via the analysis judgment, is mainly due to the rotor of the generator hot bending happened in the process of operation, leading to send the rotor heat imbalance, produce bigger axial vibration, which affect the steam turbine rotor and the action is no. 2 bearing vibration grinding. Finally through the field dynamic balance, add weight, makes the problem to get a better solution.