Prediction of furnace heat transfer and its influence on the steel slab heating and skid mark formation in a reheating furnace

Abstract

In this work, a mathematical heat transfer model of a walking-beam type reheating furnace has been developed. The model can predict the heat flux distribution within the furnace and the temperature distribution in the slab throughout the reheating furnace process by considering the heat exchange between the slab and its surroundings in the furnace, including the radiant heat transfer among the slabs, the skids, the hot gases and the furnace wall as well as the gas convection heat transfer In the furnace. The furnace filled with hot combustion gases such as H2O, CO2, O2, and N2 Is modeled as radiating medium with spatially varying temperature. After the predictions of the present model were compared with the data from an in situ measurement in the furnace, the effect of the skids on the slab heating, the heat transfer characteristics and temperature behavior of the slab were investigated by changing such parameters as residence time and emissivities of the slab and the furnace wall. © 2008 ISIJ.