Heat Transfer Calculation for Numerical Simulation of Thermal Mode of Slag–Splashing Lance in the Forecasting System

Increasing the efficiency of converter steel production requires the implementation and widespread utilization of computer decision support systems based on mathematical modeling methods. A methodology for calculating complex radiation-convection heat exchange has been developed, forming the foundation for the mathematical description of an information-modeling system used to predict top water-cooled slag-splashing lance life employed in the hot repair of converter linings through the slagging method. Approximate calculations of heat exchange components were conducted for the operating conditions of the lance during slag splashing for lining BOFs of typical capacities of 160 tons and 250 tons. Heat flow densities were computed for heat exchange on the outer surface of the lance with the exhaust gases, heat exchange on the inner surface of the device with cooling water, and the density of resulting radiation flow on the outer surface of the lance. It was determined that as the velocity of the exhaust gases increases within the operational range, the heat flow density on the lance surface increases approximately sixfold while increasing the water velocity enables an increase in the cooling intensity of the lance by over sevenfold. The obtained results can also be applied in the design of water-cooled slag-splashing lance and for optimizing their operation process.