600MW机组轴系过临界振动故障处理措施

Treatment on Vibration Fault Occurring in the Shaft System of a 600MW unit When Crossing Critical Speed

针对某亚临界600MW机组存在2号、3号瓦过临界振动过大影响机组启动的问题,对比了施加配重之后中压转子两端的影响系数,分析了轴承衬环及轴承座的结构,认为2号、3号瓦支承系统的等效刚度相对较弱是主要原因之一。采用轴瓦衬环优化、轴承座增加三角支承、提高出厂动平衡要求三项针对性措施后,实现了启动过程中轴振能通过临界转速,为同类型机组处理该问题提供一定的参考。

To deal with the excessive vibration of No. 2 and No. 3 tile in a subcritical 600 MW unit affecting the startup of unit when crossing the critical speed, the influence coefficient of both ends of the medium-pressure rotor was analyzed after balancing weight was applied, while the structure of bearing ring gasket and pedestal was analyzed. One of the main reasons is considered to be the relatively low equivalent stiffness of the supporting systems for No. 2 and No. 3 tile. The shaft vibration was able to pass through the critical speed when following three optimization measures were taken, such as optimizing the structure of bearing ring gasket, adding a triangular support to the bearing pedestal, and setting higher requirements for dynamic balancing before delivery, etc. , which may serve as a reference for treatment of similar problems occurring in same type of units.