Characteristics of Laminar Flame Propagation and NO Emission for NH3-H2-Air Flame

Abstract

氨气作为一种可持续和可再生燃料近年来引起研究者广泛的兴趣，然而由于较低的层流火焰传播速度和较高的NO排放，需要对此进行进一步研究。本文通过数值研究的方法，计算了NH3-H2-空气火焰的火焰传播速度和NO排放量，并且进行了火焰的详细反应敏感性分析，研究了化学当量条件下氢气对于火焰传播速度以及NO影响的原因。结果表明，随着燃料中H2成分的增加，改变了火焰中自由基的浓度，提升了火焰中重要反应的反应速率，同时对反应路径有着较为明显的影响，从而增强了火焰传播速度以及NO的摩尔分数。 Ammonia, as a sustainable and renewable fuel, has aroused widespread interest among researchers in recent years. However, due to its low laminar flame propagation velocity and high NO emissions, it needs to be further studied. In this paper, the flame propagation velocity and NO emission of NH3-H2-air flame are calculated by numerical method, the detailed response sensitivity analysis of flame is also carried out, and the reasons for the effect of hydrogen on flame propagation velocity and NO under chemical equivalent are studied. The results show that with the increase of H2 composition in the fuel, the concentration of free radicals in the flame is changed, the reaction rate of the important reaction in the flame is increased, and the reaction path is obviously affected, thus the flame propagation speed and the mole fraction of NO are enhanced.