超超临界压力切圆燃烧锅炉掺煤高钠煤NO_x排放特性试验研究

Experimental Study on NO_x Emission of an Ultra-Supercritical Pressure and Tangentially-Fired Boiler with Mixture of High Sodium Coal

以660 MW超超临界压力切圆燃烧直流锅炉为对象,对掺烧高钠煤时的NO_x排放特性进行了试验研究。结果表明:NO_x排放值随SCR入口处氧量的增加而增加,100%额定负荷下,高钠煤掺烧比例为80%时,O_2体积分数控制在3%为宜; 50%额定负荷下,高钠煤掺烧比例为50%时,O_2体积分数控制在4.7%为宜;随着分离式燃尽风(SOFA)的增加,NO_x排放值降低;调节燃烧器摆角可改变分级燃烧效果,提高高钠煤掺烧比例和采用下5台磨运行组合方式能有效降低NO_x排放浓度。

With a 660 MW ultra-supercritical pressure once-through boiler,a series of experiments on NOx emission were conducted with coal-feed composed of certain proportion of Shenhua coal.The experiment results revealed that NOx emission increases with O2(measured at SCR entrance).O2 content is recommended to be 3% at 100% load with the proportion of Shenhua coal being 80%,and 4.7% at 50% load with proportion of Shenhua coal being 50%.NOx emission increases with seprate-over-fire(SOFA) as expected.The angle of combustor can also alter air-staged combustion,facilitating the control of NOx emission.I Increasing proportion of Shenhua coal and using bottom group of coal mill could reduce NOx emission as while.