Numerical Simulation of High Temperature Combustion in CO-H₂ Mixture with O₂ Jet

Abstract

In this study, numerical simulation of high temperature combustion in CO-H₂ mixture with oxygen jet has been conducted to consider post combustion in a converter for steel making process. In the numerical model, a coaxial flow diffusion flame was simulated, and the flammability characteristics and flame structure were examined. The influence of H₂ content in the mixture and the reaction mechanism of the combustion were discussed. When H₂ content in the mixture is high, the position of the highest temperature moves more upstream, and consumption of the oxygen is promoted. The total heat release rate in the combustion region becomes the maximum when H₂ content in the mixture is 2% in volume. When the molar hydrogen concentration is over 20% in CO-H₂ mixture, CO₂ is decomposed around the edge of combustion zone, where the endothermic reaction occurs. Resultantly, the temperature in the downstream region is reduced. In the CO-H₂ combustion, water vapor is also decomposed by the shift reaction of CO + H₂O → CO₂ + H₂.