Li Shuanglong, Liu Qianqian, Zhang Feng, Sun Jingyun, Wang Yang, Gu Mingyan
School of Energy and Environment, Anhui University of Technology, Ma'anshan 243002, China.
Molecules. 2024 Aug 24;29(17):4003. doi: 10.3390/molecules29174003.
The formation of soot and NOx in ammonia/ethylene flames with varying ammonia ratios was investigated through experimental and numerical analysis. The spatial distribution of the soot volume fraction and NOx concentrations along the flame central line were measured, and the mechanism of soot and NOx formation during ammonia/ethylene co-combustion was analyzed using CHEMKIN 17.0. The experimental results indicated that the soot volume fraction decreases with an increase in ammonia ratio, with the soot peak concentration occurring in the upper region of the flame. The distribution of NOx is complex. In the initial part of the flame, a higher concentration of NOx is generated, and the lower the ammonia ratio, the higher the concentration of NOx. As the combustion process progresses, the concentration of NOx initially decreases and then subsequently increases rapidly, with higher ammonia ratios leading to higher concentrations of NOx. The addition of ammonia results in a decrease in CH, CH, and CH, and an increase in CN concentration. This leads to a transformation of carbon atoms within the combustion system, reducing the available carbon for soot formation and suppressing its generation. A higher ammonia ratio increases the likelihood that NH will be oxidized to N, as well as increasing the probability that any generated NO will undergo reduction to N through the action of the free radicals NH and NH.
通过实验和数值分析研究了不同氨比的氨/乙烯火焰中碳烟和氮氧化物的形成。测量了沿火焰中心线的碳烟体积分数和氮氧化物浓度的空间分布，并使用CHEMKIN 17.0分析了氨/乙烯共燃烧过程中碳烟和氮氧化物的形成机理。实验结果表明，碳烟体积分数随氨比的增加而降低，碳烟峰值浓度出现在火焰的上部区域。氮氧化物的分布较为复杂。在火焰的初始部分，会产生较高浓度的氮氧化物，氨比越低，氮氧化物浓度越高。随着燃烧过程的进行，氮氧化物浓度先降低，随后迅速增加，氨比越高，氮氧化物浓度越高。氨的加入导致CH、CH和CH减少，CN浓度增加。这导致燃烧系统内碳原子的转化，减少了用于形成碳烟的可用碳并抑制了其生成。较高的氨比增加了NH被氧化为N的可能性，同时也增加了任何生成的NO通过自由基NH和NH的作用被还原为N的概率。
