汽动给水泵调门LVDT固定抱箍脱落导致机组多起异常案例分析

Case Analysis of Faults Caused by the Detachment of the LVDT Fixed Hoop of the Valve of the Steam Feed Pump

描述了小汽机低调阀LVDT抱箍反馈脱落以后的动态过程,介绍了伺服卡接受DEH控制指令及调门位置发送器LVDT位置反馈信号,同时向LVDT差动线圈的初级线圈提供激磁电压。提出了给水泵的指令信号与LVDT的反馈信号在伺服卡中进行求偏差计算,偏差计算结果通过PI运算后输出驱动电压至伺服阀。并提出了相应的改进措施,其对于类似事故的避免与处理有一定的参考意义,对于其他大型汽轮机组的维护也有借鉴作用。

This paper describes the dynamic procedure of the detachment of the LVDT fixed hoop of the valve of the small turbine.The servo card can receive the DEH control command and the LVDT position feedback signal sent by the position transmitter of the valve and then provide exciting voltage to the primary coil of the LVDT differential coil.The deviation between the command signal of the feed pump and the LVDT feedback signal can be calculated in the servo card.The driving voltage can be output to the servo valve after the PI calculation based on the result of the deviation calculation.Finally,relevant measures of improvement are given to provide reference for similar faults and the maintenance of large turbine units.