Research On Slab Selecting And Reheating Scheduling In Hot Rolling Production

The steel industry that is high energy consumed in China's Process Industries,has some obvious problems compared with the international industry,such as large energy consumption and high production cost.How to realize saving energy,reducing consumption,shortening production period,and reducing the production cost is worth to explore and research in the process of iron and steel production.This paper mainly studies the problem of selecting slabs and scheduling reheating furnaces in the process of reheating furnace charging and hot rolling.According to the production process and constraints in the process of reheating furnace charging and hot rolling,a multi-objective mathematical model is developed,and some optimization algorithms are designed to solve the problem.The main research is as follows:1)Study the problem of selecting slabs and scheduling reheating furnaces in the process of reheating furnace charging and hot rolling.According to the production process and constraints in the process of reheating furnace charging and hot rolling,a multi-objective mathematical model is developed which aims to minimizing the total shuffle number,the practical reheating time and the duration of the reheating process.2)Design a multi-objective ant colony optimization algorithm to solve the problem of selecting slabs and scheduling reheating furnaces.In this algorithm,several ant colony systems which the ants in each system travelling independently was set up.At the same time the heuristic value computation and the local search strategy were designed according to the characteristics of the problem.After the ants in each individual ant colony system travel several times,communication between different ant colony systems was conducted.The ants used the communication information to adjust the rule of pheromone updating,and then continued to travel.3)Design the non-dominated sorting genetic algorithm-II(NSGA-II)to solve the problem of selecting slabs and scheduling reheating furnaces.In these algorithms,the doubly linked was used to design the chromosome,a condition restriction model in the process of generating the initial population was developed which was used to determine the feasibility of individual,and the adaptive adjustment strategy to change the mutational rate based on the quantity of optimal solution in the Pareto Front was designed.Then we used several local search strategies to improve the optimization algorithm NSGA-II.4)Do several verification experiments based on the practical instances to compare and analyze the merits of the algorithm performance.Simulation experiment results showed that all the algorithms could solve the small problems very well,and with the problem size increasing,the optimization algorithm NSGA-? which was improved with local search strategies is more effective.5)Design and develop a hot rolling scheduling plan module.According to the original hot rolling plan,the module could provide a rational hot rolling scheduling plan for the decision makers by system simulation.