Nonlinear model predictive control of a continuous slab reheating furnace

A nonlinear model predictive controller is designed for a continuous reheating furnace for steel slabs. Based on a first-principles mathematical model, the controller defines local furnace temperatures so that the slabs reach their desired final temperatures. The controller is suitable for non-steady-state operating situations and reaching user-defined desired slab temperature profiles. In the control algorithm, a nonlinear unconstrained dynamic optimization problem is solved by the quasi-Newton method. The design of the controller exploits the fact that the considered slab reheating furnace is a continuous production process. Long-term measurement results from an industrial application of the controller demonstrate its reliability and accuracy.

Graphical AbstractFigure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► A first-principles model for a continuous slab reheating furnace is developed. ► A nonlinear model predictive controller for the slab temperatures is designed. ► The control design exploits the special structure of the continuous process. ► Input constraints are adapted depending on the state of subordinate control loops. ► An industrial application demonstrates the accuracy of the controller.