Computational Fluid Dynamics Modeling of Supersonic Coherent Jets for Electric Arc Furnace Steelmaking Process

This paper presents a three-dimensional numerical investigation of pulverized dry lignite in a 100 kW oxyfuel furnace. A computational fluid dynamics (CFD) code was used to model four different combustion scenarios. One air-fired combustion case and three oxy-fuel-fired cases, known as OF25 (25 vol. % O2 concentration), OF27 (27 vol. % O2 concentration), and OF29 (29 vol. % O2 concentration), were modelled. User-defined functions (UDFs) for the multistep reaction schemes were written and incorporated to the CFD code. Under oxy-fuel combustion, the appropriate mathematical models were implemented to calculate the flame temperature distributions and species concentrations (O2 and CO2). The multi-step chemical reaction schemes were used for the gas-phase and solid-phase coal particle reactions. In addition to the one-step (reference) reaction scheme, twostep and three-step reaction schemes were considered in this numerical study. Compared to the one-step and twostep reactions, the three-step reaction results showed a reasonably good agreement against the experiments for all combustion cases. This numerical investigation of the oxyfuel combustion scenarios might probably provide significant information towards modelling of large-scale oxy-fuel-fired coal tangentially furnaces/boilers.