Development of stepwise thermal model for annealing line heating furnace

Knowledge of the steel strip temperature throughout the length of the annealing line continuous heating furnaces is important to guarantee the physical properties of the metal produced. Given that online temperature measurement is difficult, a stepwise model has been developed that considers the furnace as being divided up into enclosures. This model is easy to implement and has a short run time. The steel strip is considered to be subject to convection and radiation mechanisms, and surface and overall heat balances are conducted in the enclosures. The model has been applied to the conditions of an industrial furnace. The following values have been obtained throughout the length of the furnace: strip and wall temperatures; distribution of convective and radiative heat transfer rates in the strip; and heat transfer rate losses through the walls. The overall heat balances are conveniently fulfilled and the solution is obtained in only a few iterations.