Numerical simulation and experimental measurement of transport phenomena for coherent jet with CH4 + N2 mixed fuel gas

Coherent jet technology has been widely used in EAF steelmaking process because of the longer potential core length and stronger impacting power of the supersonic oxygen jet. However, more oxygen and fuel gas are consumed to achieve excellent characteristics of coherent jets, which causes the increase in steelmaking cost. Computational fluid dynamics simulation and experimental measurement of the coherent jets with CH4 + N2 mixed fuel gas were carried out aiming at reducing the consumption of fuel gas. The numerical simulation results showed good agreement with the experimental data. As a result, high proportion of N2 negatively affects the combustion of CH4, which is not good for the protection of oxygen jets. While the gas composition is 75% CH4 + 25% N2, the N2 addition to the CH4 leads to an expanding of CH4 combustion zone, and the energy generated by the combustion reaction could be delivered to the molten bath more efficiently, which is one control scheme with high performance–price ratio.