Comparative study on the effects of nitrogen and carbon dioxide on methane/air flames
Comparative study on the effects of nitrogen and carbon dioxide on methane/air flames
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DOI：
10.1016/j.energy.2016.03.087
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发表时间：
2016-07
期刊：
影响因子：
9
通讯作者：
Chi Zhang;Ge Hu;S. Liao;Q. Cheng;Chenxuan Xiang;C. Yuan
中科院分区：
文献类型：
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作者：
Chi Zhang;Ge Hu;S. Liao;Q. Cheng;Chenxuan Xiang;C. Yuan
通过火焰温度场测量和火焰计算，分析了CO2和N2稀释对甲烷/空气火焰的影响。结果表明，除火焰厚度外，CO_2的加入对火焰的热物性影响更为显著。火焰动力学分析，实现了单个反应的热释放。结果表明，燃烧化学计量比主要影响主导反应的放热贡献，而稀释度的影响很小。反应物种的浓度对反应进行速率有重要影响。主导反应的活性组分浓度的峰值乘积可以近似为初始反应物浓度和稀释率的指数表达式，并且对于添加二氧化碳的火焰获得了更大的指数。评价了排放指标和燃烧效率，以评估抑制NO的收益和燃烧恶化的损失。结果表明，燃烧的盈亏比不仅受火焰当量比的影响，而且受稀释气体成分的影响。对于富甲烷/空气火焰，氮气稀释显示出更大的价值，而二氧化碳稀释的化学计量火焰获得更大的好处。
The measurement of flame temperature profile and flame computation were conducted to analyze the effects of carbon dioxide and nitrogen dilution on methane/air flames. Results indicated that carbon dioxide addition shows more significant effects on the thermal properties of flame, except for flame thickness. Flame kinetic analyses were implemented for the heat release of individual reaction. It is suggested that the heat release contribution of dominant reaction is primarily affected by flame stoichiometry, while the dilution shows weak effect. The concentrations of reactive species play important influences on the progress rate of reaction. The peak product of reactive species concentrations of the dominant reactions could be approximated by an exponent expression of the concentration of initial reactants and dilution rate, and a greater exponential index was obtained for the flames with carbon dioxide addition. The emission indices and combustion efficiency were evaluated to assess the profit in NO suppression and the loss in combustion deterioration. Results indicated that the profit-loss ratio is influenced by both flame equivalence ratio and the component of diluent gas. For rich methane/air flame, nitrogen dilution shows a greater value, while a larger benefit is obtained for stoichiometric flame diluted by carbon dioxide.