Oxy-Fuel Combustion of Methane in a Rapidly Mixed Tubular Flame Burner

Oxy-fuel combustion of methane was conducted by using an inherently safe technique of rapidly mixed tubular flame burner, in which the fuel and oxidizer were individually injected from four tangential slits. The influences of carbon dioxide assignment, flow rate and burner inlet width on flame structure were analyzed. The results illustrate that by assigning CO₂ to both oxidizer slit and fuel slit so as to maintain the same oxidizer/fuel injection velocity, the flame structure became more uniform. The mixing rate was intensified by increasing the flow rates of fuel and oxidizer. By reducing the inlet width of injection slit, the mixing was intensified, and in addition, the diffusion flame was prohibited under the ultrahigh oxygen mole fraction condition. Therefore, the stoichiometric combustion under pure oxygen condition was achieved. The flammable range at the equivalence ratio expanded with an increase of oxygen mole fraction, and the inlet width merely affected the flammable range.