烟气外循环率对立火道内温度场、燃烧情况和NOx排放量有很大影响。外循环在一定程度上有助于实现火道高向加热均匀,增加烟气外循环可以明显降低立火道出口NO浓度。
The external circulation rate of flue gas has a great influence on the temperature field, combustion and NOx emission in the flue. To some extent, the external circulation is helpful to realize the uniform heating in the high direction of the flame path. Increasing the external circulation of flue gas can significantly reduce the NO concentration at the outlet of the vertical flame path.