本文基于“火焰控制连续算法”对掺氢天然气层流平面预混火焰传播极限进行了高精度的数值模拟，揭示了掺氢比对可燃极限的影响机制，并基于化学爆炸模式分析(CEMA)方法深入揭示了可燃极限的形成机制与主导控制因素。研究发现:ωH2对贫燃传播极限的影响很微弱，而在富燃极限处由于剩余氢气热解所产生的H基、以及氢气的优先扩散效应拓宽了富燃区的可燃极限。整体而言，氢气的优先扩散特性对甲烷传播极限的影响是比较微弱的，而氢气的化学特性对贫燃和富燃极限都会产生显著影响，并且对富燃极限的影响更大。氢气的化学特性主要在贫燃极限处起主导作用，而扩散特性主要在富燃极限处发挥主导作用。对于掺氢甲烷预混传播火焰，尽管预热区上游的燃料初始裂解反应放热很微弱，但此区域内EXTC模式的出现控制着火焰整体稳定性，利用多孔介质燃烧器能够显著拓宽贫燃/富燃传播极限。对贫燃与富燃极限，导热都是最重要的因素，其次是N2(贫燃)与H2(富燃)的扩散传输过程。

This paper employed the “flame-controlling” continuous method to perform an accurate simulation of the propagation limit of methane/hydrogen laminar planar premixed flame, and then revealed the impacting mechanism of hydrogen addition on flammability. The chemical explosive mode analysis (CEMA) method was used to identify the flammability mechanism as well as the underlying physics of governing importance. It was found that the role of hydrogen addition ratio (ωH2) in the lean flammability limit was ignorable, while with respect to the rich flammability limit, it impact became rather remarkable due to production of H radicals at rich stoichiometry and hydrogen’s preferential diffusion effect. In overall, the role of hydrogen diffusion in flammability limit was fairly weak, however hydrogen reactions can affect the lean/rich limits remarkably, especially for the rich limit. The hydrogen reactions are important for the lean limit, while hydrogen diffusion plays the governing role in the rich limit. Although the incipient fuel-pyrolysis reactions occurring ahead of the leading preheating zone was indiscernible, the pop up of local extinction (EXTC) mode in this area plays the governing role in the global flame stability. However, the employment of porous plate burner can effectively inhabit the EXTC mode and thus extend the lean/rich flammability limits. Heat conductivity is always the most important sub-process for the propagation limit; N2 and H2 play the secondary significance for the lean and rich limit respectively.