氨燃烧污染物特性的实验研究及动力学分析

The effects of air preheating temperature, heat load and equivalence ratio on the formation characteristics of pollutants in ammonia flameless combustion were studied in a cyclone flameless combustion furnace. The dynamic reason of NO_x formation was analyzed by Chemkin. The experimental and simulation results showed that the flameless combustion can significantly broaden the flammability limit of ammonia, and the stable flameless combustion can be realized above 1 300 K. Equivalence ratio under lean burn condition ϕ=0.6~0.8, NO_x emission reaches the peak, and H₂ emission and ammonia escape are almost zero. With the increase of heat load, the furnace temperature at the far lean burn limit point rises to more than 1 400 K. The reaction rate of the two main no generation paths of NH+O₂=NO+OH and HNO+OH=NO+H₂O is significantly increased, which promotes the rapid increase of no emission at the far lean burn working point, and the peak value of NO_x emission shifts to the far lean burn working condition. Under the condition of rich combustion, the emissions of no and N₂O are almost zero, the emissions of H₂ and ammonia escape increase rapidly. Under micro lean burn condition(ϕ=0.96~0.97), and finally achieved a minimum of 5.6×10^-5 NO_x emissions and 3.7×10^-5 ammonia escape.