330MW机组低压旁路控制系统优化改造

达拉特发电厂4号机组原低压旁路控制系统采用瑞士苏尔寿公司生产的AV6控制系统,系统不开放,故障不易查找和排除,而且元件老化,备件价格高。其伺服阀多次出现卡涩现象,导致系统无法正常投入等问题。针对上述问题,取消原AV6控制系统,在4号机组主DCS控制系统的基础上,扩展网络结构,增加部分卡件;旁路控制系统纳入新华XCU-800控制系统,与DCS融合为一体;系统可以实现快关、闭锁和超驰,运行模式保持原来的手动、半自动、自动3种运行方式;控制回路中用比例阀代替伺服阀,保证了低压旁路控制系统的正常投入;用PVR定位器代替RK10伺服卡。通过优化改造,提高了低压旁路控制系统的稳定性、可靠性和精确性。

Optimal Reforming to LP-bypass Control System of 330 MW Unit

The original LP-bypass control system of unit 4 in Dalate Power Plant adopted the AV6 control system manufactured by Sulzer Ltd. of Swiss. It was not so open to users that the users were hard to find and remove the hitchs. What＇s more, the components were getting older and prices were higher. The servovalve of this control system was often blocked, which resulted that the systems cannot operate normally. Therefore, adopted the several following optimal measures to improve it. Cancelling the original AV6 control system; expanding the network structure and increasing partial accessories based on the main DCS of unit 4; bringing the bypass control system into Xinhua XCU-800, integrated with DCS as a whole. With the above improvement, the system can achieve fast closing, locking and override. Operation mode can keep three kinds of operation ways such as original manual, semi-automatic, and automatic. Instead of the servovalve with proportional valve, control loop ensures the normal input of low pressure bypass control system. And also, the RK10 servo card was replaced by the PVR locator. Through the optimization, improve the stability, reliability and accuracy of the low pressure bypass of the control system.