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氧燃烧方式下由于高浓度CO2介质的存在对煤中氮的析出以及氮氧化物的多相转化有重要影响。该文基于化学动力学分析软件CHEMKIN对O2/CO2及O2/N2气氛下甲烷燃烧均相反应体系中NO的转化行为进行模拟计算,探讨了温度、过氧系数λ、CO2浓度、O2浓度、初始含N污染物组分等因素对NO形成及其还原的影响规律,采用生成率分析和敏感性分析工具分析了不同气氛富燃及贫燃条件下NO的反应机理。结果表明,2种气氛富燃及贫燃条件下NO的还原率变化规律相反,与空气气氛相比,富燃条件下O2/CO2气氛不利于NO的还原,而贫燃条件下O2/CO2气氛有利于NO还原。生成率分析表明高浓度CO2气氛能够促进NO还原并对NO的生成具有一定的抑制作用。敏感性分析表明2种不同气氛下NO的反应历程区别不大,但所发生的重要反应有明显差别;在富燃及贫燃条件下,NO反应历程有明显区别,富燃条件下NO的主要反应历程为NO→HNO→NH→N2,贫燃条件下NO的主要反应历程为NO→N→N2。
Oxygen combustion mode has the important influence on the precipitation of nitrogen and the multi-phase conversion of nitrogen oxides due to the presence of high-concentration CO2 medium. In this paper, based on chemical kinetics analysis software CHEMKIN, the NO conversion behavior in homogeneous reaction of methane combustion in O2 / CO2 and O2 / N2 was simulated. The effects of temperature, peroxide coefficient λ, CO2 concentration, O2 concentration, Containing pollutants and other components on the formation and reduction of NO. The reaction mechanism of NO under different atmosphere rich and lean burn conditions was analyzed by means of formation rate analysis and sensitivity analysis tools. The results show that the reduction rate of NO under the two kinds of rich atmosphere and lean burn is the opposite. Compared with the air atmosphere, the O2 / CO2 atmosphere is not conducive to NO reduction under rich conditions, while the O2 / CO2 atmosphere under lean conditions NO reduction is conducive The generation rate analysis showed that the high concentration of CO2 atmosphere can promote the reduction of NO and inhibit the formation of NO. Sensitivity analysis showed that there was no significant difference in the reaction course of NO under the two different atmospheres, but the important reactions that occurred were obviously different. Under rich and lean conditions, the reaction course of NO was obviously different. The reaction course is NO → HNO → NH → N2. The main reaction course of NO under lean-burn condition is NO → N → N2.