本文采用详细化学反应机理，建立氧煤燃烧气固反应模型，分析煤在富氧燃烧条件下NOx生成机制，研究不同O2浓度和分级燃烧对NOx排放的影响。富氧燃烧时，NOx生成主要路径为：HCN→CN→NCO→NO和HCN→CN→NCO→HNCO-HN2→NH—HNO→NOX初始O2增大，挥发分和HCN析出时间提前，高的O2初始浓度对燃料N转化率有促进作用；煤富氧分级燃烧时，主燃区还原气氛有利于NO还原为N2，其主要还原路径如下：NO＋CO→N＋CO2、NO＋H→N＋OH和NO＋N→N2＋O，当主燃区过量空气系数SR1从1．15减小到O6，N最终转化率（t1000111S）只是从0．379减小到0．339，相对于未分级燃烧时变化了10．55％，与煤空气分级燃烧相比，煤富氧分级燃烧对N转化率影响较小。
Gas-solid reaction model of pulverized coal was established based on detailed chemical reac- tiou mechanism, the NOx formation mechanism in oxy-coal combustion was analyzed, and the effects of 02 concentration and air staged combustion on NOx emission were investigated. NOx formation paths in oxy-coal combustion are HCN→CN→NCO→NO and HCN→CN→NCO→HNCO→HN2 →NH→HNO →NO. The increase of initial O2 concentration makes the release of volatile and HCN ahead, and increasing initial concentration of O2 promotes the conversion rate of fuel N. In Oxy-coal staged combustion, the reducing atmosphere in primary combustion zone is conducive to NO reduction to N2, and the main reaction paths are NO+CO→N+CO2, NO+H→N+OH and NO+N→N2+O. N conversion rate decreases from 0.379 to 0.339 when the excessive air rate decreases from 1.15 to 0.6, and it decreases 10.55% as compared that of unstaged combustion. Oxy-eoal combustion has slightly influence on N conversion rate as compared that of air-coal combustion.
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