The implementation of an online mathematical model of billet reheating in an OFU furnace

We present the implementation of an online mathematical model for billet reheating in the OFU walking-beam furnace at the store Steel d.o.o. steelworks in Slovenia. For the real-time operation of the simulation model the data about furnace charging and real-time measurements in the furnace are needed. The simulation model is connected to the existing information system of the OFU furnace, which can ensure the required data. The simulation is performed for all the billets (up to 125) that are currently charged in the furnace. The modeling of the reheating process in a gas-fired walking-beam furnace consists of descriptions of complex partial mechanisms. For the validation of the model, measurements of the billet reheating in the OFU furnace were made. These measurements involved a test billet and five trailing thermocouples. The comparison of the measurements and the simulation results, which are stored in a local database, shows good agreement across the whole temperature range of the reheating process. For a user-friendly presentation of the simulation-model results we developed a graphical user interface. This GUI allows the selection of particular billet from a visualization on the screen of the billets in the furnace. The temperature field and the history of reheating for individual positions of the billet in the furnace are shown for the selected billet. The system has been used online in the production process since May 2006.