摘要
Abstract
During shutdown of the subcritical 600 MW unit turbines,the main steam valve should be closed tightly and rapidly within 300 ms,thus to quickly cut down the high pressure steam source,slow down the turbine speed,and prevent turbine over speed accidents.However,since the commissioning of subcritical 600MW steam turbine unit in Taishan Power Plant,the closing time of high pressure main steam valve al-ways exceeded 300 ms during the shutdown.Especially,this phenomenon aggravated when the steam tur-bine ran at high load.Therefore,the reason was analyzed,and the valve stem bending,insufficient spring force and complicate connection force of horizontal lever were considered as the maj or causes.Finally,sev-eral countermeasures were put forward,such as transforming the mode that the lever is connected to the main steam valve into the one that the servomotor is directly connected the main steam valve,meanwhile, increasing the spring force.关键词
亚临界 600 MW机组/主汽阀/关闭时间/超标Key words
subcritical/600 MW unit/main steam valve/closing time/over standard分类
能源科技
