Experimental investigations on laminar burning velocity variation of CH4+H2+air mixtures at elevated temperatures

• Published in: International journal of hydrogen energy 2022-04, Vol.47 (37), p.16686-16697
• Main Authors: Berwal, Pragya, Solagar, Saran, Kumar, Sudarshan
• Format: Article
• Language: English
• Subjects: Diverging channel; Engine relevant conditions; Laminar burning velocity; Methane-hydrogen-air mixture; Temperature exponent
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2022.03.155

The present work reports experimental investigations on laminar burning velocity variation of CH4+H2+air mixtures at elevated temperatures (300–650 K) using an externally heated diverging-channel method. The effect of mixture equivalence ratio (ϕ = 0.7–1.3) and H2 fraction (0–50% by volume) on burning velocity have been reported at elevated temperatures. The experimental measurements are compared with numerical simulations using GRI Mech 3.0 and FFCM-1 kinetic models. The obtained results exhibit an increase in the laminar burning velocity with H2 fraction due to the formation of H-atom as an intermediate. The temperature dependency is established through a power-law correlation. The temperature-exponent shows a parabolic variation with a minimum value at ϕ = 1.1. Reaction pathway diagram interprets the major oxidation paths followed by reactants for higher carbon-consumption with varying H2 fraction. The P2 pathway involving ethane breakdown plays a major role in enhancing the burning velocity at rich mixture conditions. •Laminar burning velocity of CH4+H2+air flames measured at elevated temperatures.•Burning velocity dependency on temperature established for elevated temperatures.•H2 addition raises burning velocity with increased presence of H, O, and OH species.•Reaction pathway elucidates the role of P2 pathway in C atom consumption.