Investigation on flashback propensity of fuel blends: Oscillation effect

Deepthi Davu, University of Texas at El Paso

Abstract

The primary objective of the proposed research was to develop fundamental understanding of the flashback propensity of syngas at different compositions. Through experimental measurements the proposed study generated critical boundary velocity gradient maps of different compositions of syngas with or without the presence of combustion oscillation. The influence of mixture composition and combustion oscillation (externally driven) on the flashback propensity was quantified. Of special interest of the project was to understand the effect of higher concentrations of hydrogen in syngas on flashback. ^ The report presents the effects of composition and external excitation on the flashback propensity of hydrocarbon (methane-propane and methane-ethane) and hydrogen (carbon monoxide-hydrogen and methane-hydrogen) fuel blends. The flashback propensity of hydrocarbon fuel blends generally correlates with the flame velocity and stoichiometry of the fuel mixtures. The flashback propensity of hydrocarbon fuel blends is susceptible to the presence of external excitation. Flashback occurs at much leaner conditions in acoustically forced flames. The flashback characteristics of hydrogen fuel blends (especially syngas: carbon monoxide-hydrogen) are generally dominated by the kinetics of the hydrogen. The effects of external excitation on the flashback propensity of carbon monoxide-hydrogen flames with more than 5% hydrogen are not significant. For low frequency (0-700Hz and an average amplitude of 95dB) externally driven forcing range the kinetic time scale of hydrogen is prevalent over the forcing time scale. (Abstract shortened by UMI.) ^

Subject Area

Engineering, Chemical|Engineering, Mechanical

Recommended Citation

Davu, Deepthi, "Investigation on flashback propensity of fuel blends: Oscillation effect" (2005). ETD Collection for University of Texas, El Paso. AAI1430267.
http://digitalcommons.utep.edu/dissertations/AAI1430267

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