Traditional steelmaking is a major source of carbon dioxide emissions, but green steel production offers a sustainable alternative. Green steel is produced using hydrogen as a reducing agent instead of carbon monoxide, which results in only water vapour as a by-product. Midrex is a well-established technology that plays a crucial role in the green steel supply chain by producing direct reduced iron (DRI), a more environmentally friendly alternative to traditional iron production methods. In this work, we model a Midrex blast furnace and propose a parallel multi-physics simulation tool based on the coupling between Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD). The particulate phase is simulated with XDEM (parallelized with MPI+OpenMP), the fluid phase is solved by OpenFOAM (parallelized with MPI), and the two solvers are coupled together using the preCICE library. We perform a careful performance analysis that focuses first on each solver individually and then on the coupled application. Our results highlight the difficulty of distributing the computing resources appropriately between the solvers in order to achieve the best performance. Finally, our multi-physics coupled implementation runs in parallel on 1024 cores and can simulate 500 seconds of the Midrex blast furnace in 1~hour and 45~minutes. This work identifies the challenge related to the load balancing of coupled solvers and makes a step forward towards the simulation of a complete 3D blast furnace on High-Performance Computing platforms.

peer reviewed