在不同α下，λ=20％可有效降低炉内的最高温度，而对炉内平均温度的影响相对较小。在T₀=823 K、α=1.2、燃烧负荷为84％时，λ从0增大至20％左右时，NOx排放浓度从161 ppm降低至83 ppm，相比于无烟气外循环，NOx排放浓度可减少48％，接着增大λ，NOx排放浓度变化缓慢。

Under different α, λ= 20% can effectively reduce the maximum temperature in the furnace, but has relatively little influence on the average temperature in the furnace. When T0= 823K, α=1.2 and combustion load is 84%, the NOx emission concentration decreases from 161 PPM to 83 PPM when λ increases from 0 to about 20%. Compared with no external flue gas circulation, the NOx emission concentration can be reduced by 48%. Then, the NOx emission concentration changes slowly with the increase of λ.