汽轮机组转子抱死事故的处理与防范措施

汽轮机转子抱死事故时有发生,某汽轮发电机组通流部分改造后,因发电机轴承振动超标进行了现场动平衡。现场动平衡结束后,机组热态启动,发生了汽轮机盘车电机超电流,转子抱死的事故。经过分析认为,转子抱死的原因为启动过程中轴封压力偏低,抽真空后,冷空气由轴封进入汽轮机,引起缸体或汽封部分变形,造成局部动静间隙消失。为了避免该事故再次发生,根据事故分析,制定了监视盘车电流波动及振动幅值变化量的措施。

Treatment of Shaft Locked Accident for a Turbine and Preventive Measures

Dynamic balance was carried out on the spot because the generator bear’s vibration over-proof, after the flow passage of a steam turbine reformed. The hot start resulted an accident of rotor locking after the dynamic balance. It was considered that the reason of rotor locking was the low pressure of shaft seal before vacuum pump started through analysis. Cold air entered the turbine from shaft seal, which caused partial deformation of cylinder or seal, resulted in the disappearance of dynamic and static clearance. According to the accident, relevant measures to prevent the rotor from locking during the start-up process were worked out.