Continuous Time Modeling And Production Scheduling Of Metallurgical Hot Rolling

As one of the deep manufacturing in the metal smelting industry,rolling process is a very significant working stage,which is closely related to the previous continuous casting process and provides materials for the subsequent process.Therefore,a reasonable production planning and scheduling scheme can not only reduce energy consumption but also have an important impact on the quality of products.The important contents of scheduling problem in rolling process include production planning and scheduling of heating furnace&hot rolling.This thesis studies on the production planning problem of rolling process and production scheduling of heating furnace&hot rolling.The research on mathematical modeling and design optimization algorithm is based on the actual production situation of steel and aluminum enterprises.1)For the aluminum production scheduling of heating furnace&hot rolling problem,with minimizing makespan and residence time in the heating furnace as the objective,considering the capacity constraint of the heating furnace,the residence time of slabs in the furnace,the process conversion time,the capacity constraint of the hot rolling mill,and so on,a continuous time model is formulated.CPLEX is used to solve this model.2)An improved DE algorithm is proposed to solve the problem of aluminum production scheduling of heating furnace&hot rolling.A new local search strategy is proposed to improve the problem that the classical DE algorithm is easy to fall into the local optimal while the adaptive parameter selection strategy is used to speed up the speed of algorithm.Numerical experiments show that the optimal solution can be obtained quickly for the small-scale problem.When the scale is larger,the near-optimal solution can be obtained in a faster time,which can meet the actual needs of production.3)For the production planning problem,with minimizing the penalty values and the number of rolling units as the objective,considering the rolling schedules,a model is formulated and attributed to the VRPTW problem,while a heuristic algorithm based on data analysis is proposed.Computation results indicate that the heuristic algorithm is feasible.Compared with the improved DE algorithm,the penalty values and the rate of DHCR of the heuristic algorithms are similar,while the heuristic algorithm has a significant advantage in solving time.4)The rolling production planning optimization system is developed.The system can analyze the production data and generate production plans automatically.Manual adjustments can be made to improve the results.