Experimental and Modeling Study of the Effect of CF3CHFCF3 on the Chemical Structure of a Methane-Oxygen-Argon Flame

• Published in: Combustion science and technology 1997-01, Vol.122 (1-6), p.33-62
• Main Authors: Sanogo, OUMAR, Delfau, JEAN-LOUIS, Akrich, ROBERT, Vovelle, CHRISTIAN
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemistry; Combustion of gaseous fuels; Combustion. Flame; Energy; Energy. Thermal use of fuels; Exact sciences and technology; laminar flames; nalons: flame inhibition; Theoretical studies. Data and constants. Metering
• ISSN: 0010-2202; 1563-521X
• DOI: 10.1080/00102209708935604

The chemical structure of stoichiometric methane-oxygen-argon flames seeded or not with 1% heptafluoropropane (CF 3 CHFCF 3 ) was measured by the molecular beam-mass spectrometry technique. Both flames were stabilized on a water-cooled flat-flame burner under low pressure (4.2 kPa). Mole fraction profiles were computed by a simulation code as well. Modeling of the unseeded flame was performed with an updated version of a mechanism issued from Warnatz. Two submechanisms were considered to model the chemistry of fluorinated species: (i) a mechanism proposed by Westbrook to model flame inhibition by CF 3 Br, (ii) a modified version of (i) validated recently by Sanogo in a modeling study of the effect of C 2 F 6 on a methane flame. Both submechanisms were compared on the basis of their reaction pathways. They have in common a key role played by CF 2 in the consumption of the fluorinated additive. The consumption of this radical forms CF that is consumed very slowly with Westbrook mechanism,in contradiction with experimental results. A better agreement is obtained with the modified version so that this study extends and confirms its validation.