670MW超临界直流锅炉硬性金属密封改造

Non-flexible metal seal modification of 670MW supercritical once-through boiler

670MW超临界直流锅炉炉顶采用二次密封形式,护板为耐热、耐腐蚀、延展性好的材料,但由于炉顶棚面积过大,各处膨胀复杂,机组投运后护板容易拉裂,加之护板下部耐火可塑料、耐火浇注料受热松散,造成烟气泄漏。为了解决锅炉炉顶受热膨胀造成的漏烟、漏灰问题,提高锅炉效率,在原有二次密封基础上,采用环保非金属立体柔性密封技术,对锅炉炉顶密封进行改造修复。机组投运后,效果良好,解决了锅炉受热膨胀造成的漏烟、漏灰问题,提高了锅炉效率,改善了生产环境。

670 MW supercritical once -through boiler roof adopts twice sealing forms, and guard plate material is heat -resisting, anti -corrosive, ductility material. However, due to the oversized ceiling area and complex expansion, guard plate is easily to be ripped; besides, the heat -resisting plastic and refractory tastable material will become loose due to heat, which will lead to flue emission. In order to solve the problems and increase the boiler efficiency, on the base of twice sealing forms, environmental nonmetallic three - dimensional flexibility seal technology is adopted, and the boiler furnace top seal situation is modified. It is not only solving flue gas leakage, ash leakage, but also improving boiler efficiency and unit operation environment.