Determination of laminar flame speed of methane-air flames at subatmospheric conditions using the cone method and CH* emission

Experimental measurements of laminar fl ame speed for premixed methane-air fl ames were carried out for different equivalence ratios at subatmospheric conditions, 852 mbar and 298 K. The fl ames were obtained using a rectangular port burner with a water cooler system necessary to maintain the temperature of the mixture constant. An ICCD camera was used to capture chemiluminescence emitted by OH-CH radicals present in the fl ame and thus defi ne the fl ame front. Laminar fl ame speed was calculated using the cone method and experimental results were compared with those reported by other authors and the numerical simulations made with the software CHEMKIN using the GRIMECH 3.0 mechanism. In this work it was found that decreasing the barometric pressure from 1013 mbar to 852 mbar generated an increase of 7% in the laminar fl ame speed.

[1]  F. Egolfopoulos,et al.  Measurement of laminar flame speeds through digital particle image velocimetry: Mixtures of methane and ethane with hydrogen, oxygen, nitrogen, and helium , 2002 .

[2]  T. Lieuwen,et al.  Laminar Flame Speeds of Synthetic Gas Fuel Mixtures , 2005 .

[3]  Javier Ballester,et al.  Diagnostic techniques for the monitoring and control of practical flames , 2010 .

[4]  C. S. Marques,et al.  Experimental Study of OH*, CHO*, CH*, and C2* Radicals in C2H2/02 and C2H2/O2/Ar Flames in a Closed Chamber , 2001 .

[5]  A. Amell,et al.  Laminar burning velocities and flame stability analysis of syngas mixtures at sub-atmospheric pressures , 2011 .

[6]  B. Dlugogorski,et al.  Propagation of laminar flames in wet premixed natural gas-air mixtures , 1998 .

[7]  Alexander A. Konnov,et al.  Effects of hydrogen enrichment on adiabatic burning velocity and NO formation in methane + air flames , 2007 .

[8]  G. Cabot,et al.  Impact of H2 addition on flame stability and pollutant emissions for an atmospheric kerosene/air swirled flame of laboratory scaled gas turbine , 2009 .

[9]  De Goey,et al.  The laminar burning velocity of flames propagating in mixtures of hydrocarbons and air measured with the heat flux method , 2004 .

[10]  Serguei Zelepouga,et al.  OH and CH luminescence in opposed flow methane oxy-flames , 2007 .

[11]  F. Halter,et al.  Characterization of the effects of pressure and hydrogen concentration on laminar burning velocities of methane–hydrogen–air mixtures , 2005 .

[12]  F. Egolfopoulos,et al.  Chain mechanisms in the overall reaction orders in laminar flame propagation , 1990 .

[13]  Jan Baeyens,et al.  Progress in Energy and Combustion Science , 2015 .

[14]  The effect of simplified transport modeling on the burning velocity of laminar premixed flames , 2003 .

[15]  T. Poinsot,et al.  Experimental and numerical study of the accuracy of flame-speed measurements for methane/air combustion in a slot burner , 2011 .