300MW机组锅炉MFT关键原因分析与现场改造措施研究

Cause Analysis on MFT of a 300MW Boiler and Research on Field Transformation Measures

针对某发电厂发生MFT事件,从引风机电流、净烟气压力等方面进行了深入分析,在烟囱入口烟气挡板门开、关状态不清楚的情况下,找到了锅炉MFT事件的原因,主要结论如下:由于机组运行期间,烟囱入口烟气挡板门处于近乎关闭状态,导致烟道憋压,引风机运行工况点处于失速区,引起引风机喘振,最终导致MFT,建议将烟囱位置挡板门状态接入DCS系统,完善锅炉MFT后机组启动运行规程。

In view of the MFT(main fuel trip)event in a power plant,this paper makes a thorough analysis from the aspects of the induced fan current and the net flue gas pressure.Under the condition of unclear opening and closing of the flue gas baffle door at the entrance of the chimney,the causes of MFT are detected and main conclusions are as follows:during the operation of the unit,the flue gas baffle door at the chimney entrance is in a close state,which results in the flue shutoff pressure,and the running point of the induced fan is in the stall area,which leads to surge of the induced fan and MFT.It is suggested that the chimney position baffle door state be connected to the DCS system to improve the operation rules of the unit after MFT.