Combustion enhancement and inhibition of hydrogen-doped methane flame by HFC-227ea

摘要

Hydrogen enriched with compressed natural gas is an efficient and environment-friendly gaseous fuel. However, the safety issues of mixture and the method to control or weaken their combustion are highly concerned. To explore the inhibition effect of halogenated fire suppressants on the mixture, the effect of HFC-227ea on the laminar premixed methane/air flames, with different fractions of H-2, have been studied. Burning velocities have been measured with constant-volume combustion chamber and kinetically modelled a recently assembled kinetic mechanism. The fractions of H-2 influence the enhancement and inhibition effect of HFC-227ea, and it is less effective with the lean mixture. In stoichiometric condition, HFC-227ea showed good inhibition effect on the mixture flames. The HFC-227ea increased the burning velocities of CH4-0% H-2-air and CH4-10% H-2-air flames at leanest condition, whereas the increased burning velocity arising from HFC-227ea not occurred as the addition of H-2 above 20%. Experimental results coincided well with numerical results, however the agreement was poor for the leanest flames at low agent loading. Lastly, kinetic mechanism analysis was used to interpret the combustion enhancement and inhibition effect of hydrogen-doped methane flame by HFC-227ea. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.