配SCR的锅炉空气预热器适应性改造实践

Modification practice of the air preheater in the boiler with SCR

宝钢电厂1、2号350 MW机组锅炉因环保需要增设的烟气脱硝装置(简称SCR)所产生的硫酸氢氨,将引发空气预热器的腐蚀和堵灰现象,从而严重影响锅炉机组的安全运行,因此必须对空气预热器进行适应性改造。对空气预热器适应脱硝改造的设计原则和技术注意事项进行了研究。改造后锅炉排烟温度下降了5~8℃,平均漏风率降低了1%~2%。烟气流动阻力基本维持在800 Pa以下,且未出现明显的积灰堵塞情况。该项目改造取得了预期目标,为行业提供了成功的案例经验。

1#and 2#350 MW boiler units in Power Plant of Baoshan Iron&Steel Co.,Ltd.were modified with adding the selective catalytic reduction(SCR)for the requirements of environmental protection.The generated NH4HSO4 after the modification could cause corrosion and ash clogging in the existing air preheater,which seriously affected the safe operation of the boiler units.Therefore,the adaptive modification of air preheater should be conducted.The design principles and technical considerations for the modification practice were analyzed in this paper.After the modification,the flue gas temperature dropped by 5~8℃,and the average air leakage rate reduced by 1%~2%.The flow resistance of flue gas in the air preheater maintained below 800 Pa.Furthermore,no obvious ash clogging happened.The expected objectives could be achieved,which could provide the successful experience for the industry.