Abstract The flame ionization characteristic is a key point to realize the combustion diagnosis and control of hydrocarbon flame based on electric fields. In this paper the effects of hydrogen addition on the ionization of partially premixed methane flame were investigated experimentally and computationally. The flame current was measured by applying a small electric field across the partially premixed methane flame with different hydrogen addition and the effects of hydrogen addition on the ionization intensity and the flame ionization structure were analyzed. Furthermore, the intrinsic reaction mechanism of hydrogen addition affecting the ionization of partially premixed methane flame was studied based on a comprehensive reaction mechanism, which combines GRI 3.0 for neutral species and an 85-steps flame ionization reaction for 13 kinds of charged species. The results show that hydrogen addition can promote the ionization of partially premixed flame by affecting the chemical ionization process. However, when the hydrogen content reaches 50% of the total fuel amount, the promotion effect will be significantly weakened. Moreover, for partially premixed methane flame, the effect of hydrogen addition on the flame ionization was affected by the amount of primary premixed air. The larger the amount of primary premixed air, the more significant the promotion of hydrogen addition. What’s more, the hydrogen addition mainly affects the concentration of e− in the flame through the reactions H + CH3 (+M) ⇔ CH4 (+M) and H + O2 ⇔ O + OH while affects the concentration of H3O + through the reactions OH + CH3 ⇔ CH2 (S) + H2O and H3O+ + e− ⇔ OH + 2H.

中文翻译：

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加氢对部分预混甲烷火焰电离的影响

摘要 火焰电离特性是实现基于电场的烃类火焰燃烧诊断与控制的关键。在本文中，通过实验和计算研究了氢气添加对部分预混甲烷火焰电离的影响。通过在具有不同氢添加量的部分预混甲烷火焰上施加小电场来测量火焰电流，并分析氢添加对电离强度和火焰电离结构的影响。此外，基于综合反应机理，结合GRI 3，研究了加氢影响部分预混甲烷火焰电离的固有反应机理。0 为中性物种，85 步火焰电离反应为 13 种带电物种。结果表明，加氢可以通过影响化学电离过程促进部分预混火焰的电离。但当氢含量达到总燃料量的50%时，促进作用将明显减弱。此外，对于部分预混甲烷火焰，加氢对火焰电离的影响受一次预混空气量的影响。一次预混空气量越大，对加氢的促进作用越显着。更重要的是，