低NO_x燃烧与脱硝经济运行的实践

吴泾热电厂2×300MW级燃煤供热机组脱硝设备,采用低NOx燃烧加选择性催化还原法(SCR)脱硝系统。介绍了SCR的化学反应机理、反应器安装位置、分段配风燃烧技术,分析了低NOx燃烧工况和运行参数,结果证实了:对分段配风的低NOx燃烧器来说,有效控制主燃烧区的风量,在总风量不变的条件下,加大可水平摆动的分离燃烧器(SOFA)配风量和加大SOFA配风距离是有效降低NOx的生成、减轻SCR的负载、降低耗NH3的有效方式;当燃用低值煤和可磨性差煤,使相对一次风量增加时,应降低二次风的配风量,用一次风总量自动实时修正二次风的配风量是实现自动低NOx燃烧调整的有效途径;适当降低二次风与炉膛的差压是防止二次风配风不均和控制主燃烧区风量的有效方法。

Practice on Economical Operational of Low NO_x Combusting and Denitrification

SCR denitrification system with low NOx combusting applies to 2×300 MW fuel heat addition units’denitrification mechanism in Wujing Thermal Power Plant of Shanghai Electric Power Co.,Ltd.By introducing Chemical reaction mechanism of SCR,reactor installation position,sectional air combustion technology and low NOx combustion conditions and operating test,this essay proves an effective way for sectional air low NOx burner to reduce NOx production,the load of SCR and consumption of NH3,which is control air volume in primary combustion zone effectively,and under the same air flow conditions,increasing air volume and air distribution distance of SOFA of being horizontally swing.When burning low value coal and the coal of poor grindability,it needs to low secondary air volume for improving primary air relatively.With a primary air automatic real-time correction for secondary air is an effective way to realize automatic adjustment of low NOx combustion.Reducing difference between secondary air and furnace pressure properly could effectively prevent secondary air distributing unevenly and control the primary combustion zone air volume.