Methods Of Integrated Scheduling For Steelmaking-Continuous Casting-Hot Rolling Production Processes

Steelmaking,continuous casting,and hot rolling,which works one after another,are three main processes of iron and steel industry.Since hot rolling is inconsistent with the step of melting shop,which leads a large number of slabs restored in the slab yard.The slabs,whose temperature sharply decline,need to be reheated by the furnace in the hot rolling shop,thus a lot of energy is wasted.Therefore,this paper analyzes the problem of integrated scheduling of steelmaking,continuous casting,and hot rolling production process.To intensify the connection among the three main processes,reduce the storage time that slabs remain in the slab yard,make full use of the slabs' heat to achieve continuous production and energy saving.This paper is supported by the National Natural Science Fund Project of "The modularized method and application of steelmaking-continuous casting process production scheduling and coordinated process controlling optimization(61333006)".The analysis is about the problem of integrated production scheduling of steelmaking-continuous casting-hot rolling.The main contents are as follows:(1)A large amount of papers are accessed;the integrated production process of steelmaking-continuous casting-hot rolling and the connection mode of this three processes are mastered,and the status of research,the characteristics and the existing difficulties of this problem are understood.(2)An integrated static scheduling method of steelmaking-continuous casting-hot rolling is proposed.This method divides the production process into two stages,melt shop and hot rolling shop.Then,a mathematical programming model with the goal of minimizing the makespan of the two stages and the waiting time of DHCR slabs in slab yard is established which can be solved by CPLEX.A large number of experiments indicate that this method is realistic,and can find the optimal scheduling scheme quickly.(3)A dynamic scheduling method of hot rolling shop is proposed to solve the problem of disqualified slabs that can occur in the production process.First,choose a substitutive slab of the similar specification with the bad slab to be rolled.Then,quickly repair the scheduling scheme of the left rolling through a heuristic algorithm.At last,compare the result with the rescheduled and original scheduling.The experiment proved that this method can quickly repair interference,and obtain a dynamic scheduling scheme that has similar objective with the initial scheduling program.