A Detailed Chemical Kinetic Modelling Study on High Temperature Ignition of Methane / Air Mixtures Doped with C3f7h

C3F7H (FM-200) has recently been introduced as an alternative for Halon 1301 (CF3Br) fire suppression agent. In this paper, as part of an effort to study the effects of C3F7H on high temperature ignition of gaseous fuels, we are expanding on our earlier evaluations of ignition inhibition characteristics of C3F7H. Of particular interest is a better or improved understanding of the fundamental mechanisms by which C3F7H functions as an inhibitor. We found that the ignition delay is primarily controlled by the initial C3F7H decomposition kinetics, which releases active species into the system. At low temperatures (below1000 K) these active species increase the overall reaction rate by initiating new chain reactions. However, at higher temperatures, due to competition between the main chain branching reaction of CH4 combustion and reactions involving C3F7H derivatives (e& C3F7 and C3F& the heat release rate of the overall combustion reaction is substantially decreased leading to a longer ignition delay time.