50 MW背压机组缸体偏心摆动问题的分析及对策

Analysis and Countermeasure of 50MW Back Pressure Units’Cylinder Swing off Center Position

当前,50 MW背压式供热机组被广泛应用于现代工业生产中,其安全稳定运行非常重要。在多台50 MW背压式机组的实际启动过程中,发现了一种新的故障形式,并给出了“缸体偏摆”的定义;当机组冷态启动或大幅变工况时,汽轮机上半缸体出现严重偏离中心线的摆动问题。分析结果表明:该缸体偏摆问题受进汽不均、管道振动等因素影响,会引发机组轴振突增现象;甚至导致轴振超限停机,并伴随轴承磨损、大轴弯曲等严重问题。最后,在给出问题针对性预防措施的同时,还设计了可实时监测汽缸偏摆状态的装置。实际应用效果显示:该方案可有效应对此类50 MW汽轮机缸体偏摆问题。本文对改善同类型机组运行的安全稳定性具有极大的借鉴价值。

At present,the 50 MW back pressure heating unit has been widely used in modern industrial production,and its safe and stable operation is very important.During the actual start-up of several 50 MW back pressure units,a new form of failure was found and defined as“the cylinder swing off center position”:when the unit was started or the operating conditions were changed drastically,the upper half of the steam turbine severely deviated from the centerline and wobbled.Analysis results show that the cylinder swing off center position is affected by factors such as uneven steam intake and pipeline vibration,which will cause the sudden increase of the shaft vibration of the unit;it will even cause the shaft vibration to exceed the limit and be accompanied by severe bearing wear and large shaft bending problem.Finally,the corresponding preventive measures are given,and the device that can real-time monitor the cylinder’s swing off center position is also designed at the same time.The practical application results show that the scheme can effectively deal with the problem of cylinder body deflection of 50 MW steam turbine.This paper has great reference value for improving the safety and stability of the same type of unit operation.