Oxy-fuel combustion with low NO_x emission has been received more attention in recent years. In this work, a series of oxygen-staged experimental investigations of Shenmu bituminous coal with the preheated combustion technology was carried out under O₂/CO₂ atmosphere to obtain the effect of oxygen-staged on combustion and NO_x emission. The results showed that the increase of excess oxygen coefficient of the primary air(λ_Pr) decreased the temperature difference at each measuring point in the circulating fluidized bed, promoted the production of coal gas, facilitated the release of elements, and improved the mass conversion ratio of volatile matter up to 92.3%. Besides, the increase of λ_Pr inhibited the conversion process of N-5 to N-6. At the same time, the release of nitrogen-containing volatile matter during the partial gasification process was also reduced. As the λ_Pr increases, reducing the excess oxygen coefficient of the secondary air(λ_Se) or increasing the oxygen partial pressure of primary air were beneficial to reduce the emissions of NO_x to a certain extent.

近年来，低NO _x排放的富氧燃烧受到越来越多的关注。本工作在O ₂ /CO ₂气氛下利用预热燃烧技术对神木烟煤进行了一系列氧气分级实验研究，以获得氧气分级对燃烧和NO _x排放的影响。结果表明，一次风过量氧系数λ _{Pr 的}增加减小了循环流化床各测点的温差，促进了煤气的产生，促进了元素的释放，提高了质量转化率。挥发分比例高达92.3%。此外，λ _Pr的增加抑制了 N-5 到 N-6 的转化过程。同时，也减少了部分气化过程中含氮挥发物的释放。随着λ _{Pr 的}增加，降低二次风的过量氧系数（λ _Se）或提高一次风的氧分压有利于在一定程度上减少NO _x的排放。