An innovative scheduling coordination method for improved productivity and energy efficiency of a large-scale integrated steel plant

Energy efficiency will play an important role in improving the heavy industry's environmental and economic performance. In this work, an innovative scheduling coordination method to coordinate two consecutive production sections in an integrated steel plant - melt shop and hot rolling mill - is discussed. Between the two sections a slab yard acts as a buffer for intermediate products – slabs. Planning and scheduling of the two sections are currently solved independently by two industrial optimization solutions, observing complex production rules and different objectives. The proposed coordination method reuses the existing optimization modules and minimizes the storage time in the slab yard. Furthermore, the coordinated schedule enables some slabs from the melt shop to be charged directly into the reheating furnace of the hot rolling mill without losing considerable thermal energy (hot charging). The challenges and the approaches to coordinate two industrial schedulers incorporating several optimization steps, for instance mixed integer linear programming (MILP) and heuristics are presented. The coordination approach is validated by testing it with real production data from a real life steel plant and the potential to save energy and reduce production time is demonstrated.