Numerical study of the effect of hydrogen addition on methane–air mixtures combustion
Numerical study of the effect of hydrogen addition on methane–air mixtures combustion
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DOI：
10.1016/j.ijhydene.2008.11.010
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发表时间：
2009
影响因子：
7.2
通讯作者：
Jinhua Wang;Zuo-hua Huang;Chenglong Tang;H. Miao;Xibin Wang
中科院分区：
文献类型：
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作者：
Jinhua Wang;Zuo-hua Huang;Chenglong Tang;H. Miao;Xibin Wang
采用CHEMKIN II程序中的PREMIX程序和GRI-Mech 3.0机理，对常温常压下化学计量比甲烷-氢气-空气自由传播的层流预混火焰进行了计算。得到了甲烷-氢气-空气火焰中主要组分和部分中间组分的摩尔分数分布和主要反应的生成速率。通过对甲烷生成速率的分析，并根据特定物种的主导基元反应，分析了氢气添加对甲烷-空气混合物燃烧反应的影响。结果表明，随着氢气的加入，主要组分CH 4、CO和CO2的摩尔分数降低，而其归一化值增大。随着氢气的加入，主要反应产生CH 4、CO和CO2的速率显著增加。当混合物中氢含量超过20%时，H2在火焰中的作用将由中间物转变为反应物。氢的加入使火焰中氢、氧和羟基的含量显著增加，从而促进了燃烧。随着氢气的加入，CH 2 O和CH 3CHO的摩尔分数降低，表明随着氢气的加入，甲烷燃烧的醛类排放量降低。当氢气可用时，甲烷氧化反应途径将向低碳反应途径移动，这具有减少烟灰形成的潜力。氢气添加的化学动力学效应对甲烷掺氢燃烧NO生成影响不大。
The stoichiometric methane–hydrogen–air freely propagated laminar premixed flames at normal temperature and pressure were calculated by using PREMIX code of CHEMKIN II program with GRI-Mech 3.0 mechanism. The mole fraction profiles and the rate of production of the dominant reactions contributing to the major species and some selected intermediate species in the flames of methane–hydrogen–air were obtained. The rate of production analysis was conducted and the effect of hydrogen addition on the reactions of methane–air mixtures combustion was analyzed by the dominant elementary reactions for specific species. The results showed that the mole fractions of major species CH4, CO and CO2were decreased while their normalized values were increased as hydrogen is added. The rate of production of the dominant reactions contributing to CH4, CO and CO2shows a remarkable increase as hydrogen is added. The role of H2in the flame will change from an intermediate species to a reactant when hydrogen fraction in the blends exceeds 20%. The enhancement of combustion with hydrogen addition can be ascribed to the significant increase of H, O and OH in the flame as hydrogen is presented. The decrease of the mole fractions of CH2O and CH3CHO with hydrogen addition suggests a potential in the reduction of aldehydes emissions of methane combustion as hydrogen is added. The methane oxidation reaction pathways will move toward the lower carbon reaction pathways when hydrogen is available and this has the potential in reducing the soot formation. Chemical kinetics effect of hydrogen addition has a little influence on NO formation for methane combustion with hydrogen addition.