An experimental study of methane–oxygen–carbon dioxide premixed flame dynamics in non-adiabatic cylinderical meso-scale reactors with the backward facing step

• Published in: Chemical engineering and processing Vol. 95; pp. 105 - 123
• Main Authors: Baigmohammadi, Mohammadreza, Tabejamaat, Sadegh, Farsiani, Yasaman
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-09-2015
• Subjects: Carbon dioxide; Combustion; Flame; Methane; Oxygen; Reactor; Methane; Oxygen; Combustion; Reactor; Carbon dioxide; Flame
• ISSN: 0255-2701; 1873-3204
• DOI: 10.1016/j.cep.2015.05.013

•Blow-out, marginal, stationary, RERI, and flashback flame regimes were observed.•Carbon dioxide has significant influence on the flame shape and dynamics.•Adding carbon dioxide to methane–oxygen mixture could extend RERI flame regime.•Adding CO2 to CH4–O2 mixture decreases the average traveling speed of RERI flames.•Adding CO2 to CH4–O2 mixture reduces the average traveling frequency of RERI flames.
In the present study, we experimentally evaluated the effects of geometrical parameters, Reynolds number, dilution percent, and equivalence ratio on methane–oxygen–carbon dioxide flame dynamics in non-adiabatic cylindrical meso-scale reactors with the backward facing step. Five flame regimes of blow-out, marginal, stationary (asymmetric and spinning), RERI, and flashback were observed during the tests. The results showed that adding carbon dioxide to methane–oxygen mixture could extend RERI flame regimes in the meso-scale reactors. Moreover, it was shown that the presence of RERI flame regime could lead to more uniform temperature distribution on the outer surface of the lengthy meso-scale reactors as compared to the stationary flame regimes. Also, it was demonstrated that increasing the average flow speed in the meso-scale reactors decreased the average frequency of RERI flame regimes.