Parametric Analysis of Coke Conversion Characteristics in the Static Raceway Zone of Blast Furnace: Numerical Investigation

Abstract

The ironmaking industry is responsible for approximately 7% of global CO2 emissions and consumes substantial fossil fuels. Enhancing efficiency and reducing emissions through fuel switching, process optimization, and thermodynamic improvements is crucial to addressing climate concerns. The blast furnace (BF), the primary method for ironmaking, is highly efficient but energy-intensive. Improving the energy efficiency of BFs is essential to reduce energy consumption and emissions. The thermochemical conversion inside the BF involves complex physical and chemical changes occurring simultaneously. Computational fluid dynamics (CFD) is a valuable tool for understanding the intricate processes within the BF, particularly where direct measurements of key physical variables are challenging due to limited accessibility in experiments. This study focuses on analyzing heat and temperature distribution near the tuyere, where coke combustion creates a cavity known as the raceway zone. Various parameters, such as blast and coke properties, influence the coke conversion characteristics, including species concentration and production or consumption rates. A Eulerian-Eulerian framework is adopted to model gas and solid phases. The multiphaseEulerFoam solver, part of the open-source CFD toolbox OpenFOAM is employed for the modeling study. A 2D simulation domain is implemented to validate the results against experimental data. This study aims to compare the effects of homogeneous and heterogeneous reactions on combustion characteristics within the BF to deepen the understanding of the process.