托电1号炉PCV阀控制方式改造

Renovation of PCV Control Mode of Boiler 1 in Tuoketuo Power Generation Co. Ltd.

托电1号机组自2003年投产运行几年来,检修人员发现通过用大量程压力开关检测主蒸汽压力信号来控制PCV阀的动作比较困难。当机组大范围变负荷或异常工况时,主蒸汽压力信号往往变化很大,但压力开关的设定值很容易因为周围振动和高温环境而迁移,从而导致PCV阀误动作或拒动。为了避免PCV的误动作,用压力变送器来取代压力开关,用DCS逻辑实现PCV阀的精确控制,这一改造使PCV阀误动、拒动的问题得以解决。

The No.1 boiler of Inner Mongolia Datang International Tuoketuo Power Generation Co.Ltd.was put into production in May 2003.Through these years of running,the maintenance team discovered that using a large-scale pressure triggered switch which was controlled by the main steam pressure signal to control the PCV valve is difficult.When the unit load was changing in a large scale or working abnormally,the main steam signal changed rapidly,while the pressure triggered switch's set value is easily changed by vibrations or high temperatures,this led to PCV valve's wrong operation or no reaction.To avoid wrong operation of the PCV valve,using a pressure-transmitter instead of a pressure triggered switch and DCS logic to realize PCV valve's precision control.The problem was solved.