Numerical simulation of the transient heat transfer in a blast furnace main trough during its complete campaign cycle

Abstract

To achieve higher blast furnace (BF) main trough availability and to minimize the frequency of reparations is a key concern in the steelmaking industry. For this purpose, strategies to assess refractory wear are required, which is heavily influenced by the temperature in the refractory linings. In this work, a mathematical model to assess the transient behaviour of the temperature in a cross-section of a BF main trough during a complete campaign is presented. The scope is to investigate the effect that the casting stops have on the temperature in the trough. A sequence of problems corresponding to each BF tapping and the subsequent stop is determined using process data of a BF.The open-source finite element computing platform FEniCS is employed to solve the model. The discretization and the numerical algorithm have been presented and validated with a manufactured solution test in a previous work. The numerical results show that the effect of the stops during these campaign cycles is non-negligible, preventing the bulk of the solid layers from reaching a steady state. Qualitative agreement with temperature measurements obtained with thermocouples embedded in the trough is observed. Since there is a significant degree of uncertainty concerning the placement of the devices, a minimization problem to adjust their positions within the corresponding feasible regions is proposed. At the identified positions, good levels of fit between the measured and the computed temperatures are achieved. The agreement decreases towards the end of the campaign cycle, being suggestive of severe refractory wear, especially at the laterals of the trough.