300 MW机组低负荷下脱硝连续运行的研究与实践

Research and Practice of Continuous Denitrification Operation of 300 MW Unit under Low Load

电厂SCR型脱硝系统,在机组启停或低负荷运行时,脱硝装置入口烟气温度低于催化剂的正常使用温度(295℃)导致脱硝系统无法正常运行,造成排污超标。未反应的逃逸氨与SOX易生成硫酸氢铵,堵塞催化剂和空气预热器元件,甚至出现加速腐蚀脱硝后端设备等现象。着重介绍了首钢京唐公司2×300MW机组煤-煤气混烧锅炉的低负荷脱硝系统烟气旁路实际改造案例。

The entrance smoke temperature at startup and shutdown or low-load operation of SCR denitrifying system in power plants would be lower than normal operating temperature(295℃),which caused the denitrifying system unable to operate normally resulting in standard-exceeding emission.Unreacted escaping ammonia and SOX are easy to form ammonium hydrogen sulfate,to block elements in catalyzer and air preheater,or even accelerate corrosion on the denitrifying rear equipment.The paper focuses on the flue gas by-pass transformation project of the low-load denitrifying system for the coal-gas mixed burning boiler of Shougang Jingtang Steel’s 2×300 MW unit.