The two major challenges for ammonia combustion in gas turbines are its high NO_x emission and low burning velocity. Recently, while H₂ doping has been proved as an effective means of improving the NH₃ burning velocity, there is a knowledge gap on the emissions characteristics of NH₃/H₂ fuel mixture in gas turbine conditions. This paper presents a kinetics modeling study on the NO_x emission characteristics of a staged rich-lean combustor cofiring NH₃/H₂ mixture. A chemical reaction network was set up to model the staged combustor. Emission characteristics were obtained at various operating parameters, including equivalence ratio, residence time, and H₂ doping ratio. The rich-burn stage equivalence ratio was found to be the primary factor influencing NO_x emissions. The key to reduce NO_x emissions is to balance the NO production and the unburnt NH₃ in the rich-burn stage. Extending the residence time of its post-flame zone and increasing H₂ doping ratio also benefit NO_x reduction by decreasing unburnt NH₃ content, but with a secondary impact. NO reaction pathway analyses showed that NO is formed mainly through the HNO pathway in the flame zone of the rich-burn stage, while NH_i decomposition in the post-flame zone plays a key role in NO reduction. Depending on the NH_i concentration, different mechanisms dominate NO reduction in the post-flame zone.

在燃气涡轮机的燃烧氨的两大挑战是它的高NO _X排放和低燃烧速度。近来，尽管已证明H ₂掺杂是改善NH ₃燃烧速度的有效手段，但是在燃气轮机条件下，关于NH ₃ / H ₂燃料混合物的排放特性存在知识差距。本文对NH ₃ / H ₂分级富浓燃烧室的NO _x排放特性进行了动力学建模研究。混合物。建立了化学反应网络以模拟分级燃烧器。在各种工作参数下获得了发射特性，包括当量比，停留时间和H ₂掺杂比。发现富燃级当量比是影响NO _x排放的主要因素。减少NO的关键_X排放量是平衡NO生产和未燃NH ₃在浓燃烧阶段。其延伸后火焰区中的停留时间和提高ħ ₂掺杂率也受益NO _X通过降低未燃烧NH还原₃内容，但具有次要影响。NO反应路径分析表明，NO的形成主要是通过浓燃烧阶段火焰区的HNO路径形成的，而火焰后区NH _i的分解在NO还原过程中起关键作用。取决于NH _i的浓度，不同的机理主导着火焰后区NO的减少。