Research On Integrated Scheduling Problem Of Continuous Casting-Heating Furnace-Hot Rolling

With the rapid development of the industrial structure and technology for steel manufacturing,the problem of resources and energy consumption has drawn more attention.At the same time,the issues including the improvement of product quality,energy consumption saving,and the reduction of production cost have become major factors in enhancing the core competitiveness of steel companies.The production scheduling of steel enterprises is characterized as high complexity,high coherence,and multiple constraints,which is a hot and difficult problem for domestic and foreign experts.The continuous casting-reheating furnace-hot rolling process is a cohesive production process.It has crucial theoretical significance and economic significance to analyze the main energy consumption facture and technological constrains,formulate reasonable production scheduling plan and establish energy optimization model which is in line with enterprise practical situation.In this thesis,the integration optimization scheduling problem for continuous casting-reheating furnace-hot rolling process is researched.The scheduling task contains the allocation of processing equipment for slabs,the confirmation of slab processing sequence and the scheduling time during the process of continuous casting-heating furnace-hot Rolling.Considering the constraint condition including process constraint of continuous casting and hot rolling process and self limitation of heating furnace,a non-linear mathematical programming model of scheduling problem is established.In order to save energy consumption as much as possible,minimizing the interval time of slabs between continuous casting and hot rolling process and the residence time during reheating furnace period is considered as the optimization objective.Through taking full advantage of the accuracy of hybrid integer programming and constraint programming which can reduce the search space,a hybrid algorithm combined integer programming and constraint programming is designed to solve the problem.Several sets of experimental tests with different scale are performed.The experimental results show that the hybrid integer programming and constraint programming algorithm proposed is suitable to solve the scheduling problem in this thesis.