Optimal Slab Heating Control for Reheating Furnaces

A new optimal heating control has been developed for reheating furnaces into which both hot and cold slabs are charged in a mixed manner. The main features of the control system are as follows: 1) Online simulation with an analytic model (nonlinear, parameter-distributed model) 2) Optimization of reference trajectories of slab temperature by the steepest descent method using the above online simulation 3) High-speed optimal processing by the weighted residual method to heat-transfer calculation, and parallel processing 4) Tracking control to the reference trajectories by the Generalized Predictive Control using a linear simplified model The control has been proved effective through simulation and is now being installed and tested on a real plant at Oita Works of Nippon Steel Corporation.