| Popis: |
This systematic study is focused on the influence of the addition of several halogenated fluorocarbon compounds (CF4, CF3H, CF3Cl, CF3Br, CF2Cl2, CFCl3) on the burning velocities and final temperatures of stoichiometric CO/O2/Ar/H2 flames. The inhibiting strength decreases along the sequence CF3Br > CFCl3 > CF2Cl2 > CF3Cl > CF3H > CF4 Moreover, the inhibition effect is more pronounced for CO/O2/Ar flames either containing low quantities of H2, or in lean mixtures. The competition between the reaction of the inhibitor scavenging hydrogen atoms and the branching reaction (H + O2 OH + O) is the main process for inhibition. The rate constants and the activation energy of the individual trapping reactions of the inhibitor must be in between specified limits. The efficiency of the inhibitor is closely related to the rate constants and the activation energy of the primary trapping process. Nevertheless, the occurrence of Br or Cl atoms in the inhibition molecule enhanced the inhibition effect by subsequent scavenging reactions. |
