基于N元素标记的NH3燃烧识别NOx生成来源OA
Identification of NOx formation based on nitrogen element labeled NH3 combustion
NH3燃料是一种具有应用前景的零碳燃料,但点火困难、反应性低及NOx排放高限制了其实际应用.为了精确区分NH3燃烧过程中,由于燃料和氧化剂均含N元素,导致NOx的生成源难以明确区分,且不同燃烧模式下NH3燃料的NOx生成差异显著性,本文基于已有研究的NH3燃烧详细机理,通过一种类似于同位素标记的化学反应机理建立方式,构建了包含N元素标记的化学反应新机理,给出了详细的数学表达;并通过在仅涉及化学反应过程的均相反应器中,比较验证了区分(NH3/N2/O2)和不区分(NH3/N2/O2)下模拟结果的有效性.研究结果表明:标记后的机理与未标记的机理相比,组分最大摩尔分数和燃烧产物摩尔分数的平均误差在0.1%以内,且组分最大反应速率预测误差低于0.3%,证明了标记方式的有效性;均相反应器模拟结果显示,随着反应温度的升高,NO的生成源逐渐由以NH3为主转向以N2为主,说明NH3燃烧在不同温度下生成NO的还原机理存在差别.
NH3 fuel is a promising zero-carbon fuel,but its difficult ignition,low reactivity and high NOx emission limit its practical application.In order to accurately distinguish the source of NOx formation in the NH3 combustion process,due to the fact that both fuel and oxidant contain N elements,it is difficult to clearly distinguish the source of NOx formation,and the significant difference of NOx formation in NH3 fuel under different combustion modes.Based on the detailed mechanism of NH3 combustion,this paper constructs a new chemical reaction mechanism containing N element labeling by a chemical reaction mechanism similar to isotope labeling,and gives a detailed mathematical expression.The effectiveness of the simulation results under distinguishing(NH3/N2/O2)and non-distinguishing(NH3/N2/O2)was verified by comparison in a homogeneous reactor involving only chemical reaction processes.The results show that compared with the unlabeled mechanism,the average error of the maximum mole fraction of the component and the mole fraction of the combustion product is less than 0.1%,and the prediction error of the maximum reaction rate of the component is less than 0.3%,which proves the effectiveness of the labeling method.The simulation results of homogeneous reactor show that with the increase of reaction temperature,the generation source of NO is gradually shifting from NH3 to N2 as the main source,indicating that the reduction mechanism of NO generated by NH3 combustion at different temperatures is different.
李爽;刘祥涛;李雨钊;司济沧
大连海事大学轮机工程学院,辽宁 大连 116000北京大学工学院,北京 100871
能源与动力
氨燃烧氮氧化物数值模拟均相反应器
ammoniacombustionnitrogen oxidenumerical simulationhomogeneous reactor
《电力科技与环保》 2024 (005)
495-503 / 9
中央高校基本科研业务费专项资金资助项目(3132024218)
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