Computational Fluid Dynamics Simulation of Industrial Electric Arc Furnace Operation: Validation and Performance of Melting Phenomena

Abstract

A tap‐to‐tap operation conducted in a 150 t AC electric arc furnace (EAF) by NLMK Indiana is used to validate a computational fluid dynamics (CFD)‐EAF solver. Model validation is conducted by comparing the electrodes position and melting rates obtained by CFD model against those reported in actual operation. Comparison demonstrates close alignment between simulation and actual process. Namely, electrode position is predicted with less than 5% error. Electrode bore‐in after the first bucket charge is predicted to within 3% of industrial data, whereas bore‐in prediction after the second bucket charge deteriorates due to arc instabilities driven by cave‐ins, not currently included in the CFD solver. At the beginning of the refining stage, the predicted ratio of solid to molten steel mass is 6% higher than that expected by industry. Validated tap‐to‐tap results are further analyzed to determine main features of the melting process. Specifically, in the results, reduction of molten steel temperature after each scrap charge and a temperature rise after electrode bore‐in are shown. Molten steel temperature further increases during the refining/melting stage due to reduction of arc heating losses. In the thermal analysis, it is shown that heating losses increase with pit size, reaching 25% right before charging of second bucket and 20% at the beginning of refining.