300MW机组低汽温保护的改造方案

Retrofitting Option for Low Steam Temperature Protection of 300 MW Units

马鞍山第二发电厂因煤质下降,锅炉燃烧不稳定,致使2004年发生非计划停运3次。因此实施了低汽温保护改造,锅炉MFT(除“汽包水位高高”或“2台空预器跳闸”之外)后,不联跳汽轮机,通过快速降负荷,利用锅炉余热,机组带少量负荷维持运行。锅炉吹扫完成后,重新点火,机组恢复正常运行,达到提高经济效益,降低非计划停运次数的目的。

3 times of unplanned shutdown of units in Maanshan No. 2 Power Plant occurred in 2004 because of reduction of coal quality and unstable combustion of the boilers. The retrofitting for low steam - temperature protection has to be carried out. After MFT of boilers the turbine should not be tripped in series. Through the quick load reduction the unit continues to run under less load using the residual heat of the boiler. After blowing up the boiler it is ignited again and the unit recovers to normal operation. In this way the economic benefits will be increase and number of unplanned shutdown can be reduced.