Kinetic incentive of hydrogen addition on nonpremixed laminar methane/air flames

• Published in: International journal of hydrogen energy 2021-04, Vol.46 (27), p.14813-14823
• Main Authors: He, Yituan, Liang, Mengqing, Liu, Chunzhi, Liao, Shiyong, Yang, Rundai, Qin, Liheng, Jian, Xiaochun, Shao, Yiming
• Format: Article
• Language: English
• Subjects: Active radical; Chemical reactivity; Hydrogen addition; Nonpremixed flame; Physical transport
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2021.01.230

In order to find out the respective influences of chemical reactivity and physical transport of hydrogen additive on nonpremixed flame, two fabricated hydrogen additions were introduced into nonpremixed methane/air flame modeling. Hydrogen addition was assumed as inert gas or partial reactivity fuel to respectively explore the kinetic reasons by the three aspects: the elementary reaction route, heat release, and physical diffusion of hydrogen addition. The analyses were implemented in terms of OH and H production. Results showed that, hydrogen addition can enhance OH and H production via elementary reactions, and causes flame reaction zone migration through the coupling interaction between the low-temperature heat enthalpy release and diffusion behavior of hydrogen addition. R84 (OH + H2=H + H2O) and R38 (H + O2=O + OH) are the most important elementary reactions related to OH and H production. The physical incentive of hydrogen addition can hardly work without the chemical effects of hydrogen addition. [Display omitted] •Fabricated fuel method used to study effects of hydrogen reactivity and transport.•Hydrogen reactivity shows effects on OH and H production by elementary reactions.•Hydrogen enthalpy release and diffusion cause flame reaction zone migration.•Hydrogen diffusion cannot play effects without chemical effects of hydrogen.