Model predictive control of a pusher type reheating furnace

This paper focuses on the design of an Advanced Process Control system for the control and the optimization of a pusher type billets reheating furnace. The controller formulation is based on a two-layer Model Predictive Control strategy. The formulated linear model of the furnace variables and the billets temperature behavior is constituted by a combination of Linear Time Invariant and Linear Parameter Varying models. The basic control mode is based on an adaptive approach. Simulation and field results on a plant located in an Italian steel industry have shown the reliability of the proposed control system and its optimality with respect to the previous control system, based on local PID controllers managed by operators. Significant improvements on process control have been obtained, together with a major and safer approach to process operating limits.