Research And Application Of Integrated Scheduling Of Steelmaking-Continuous Casting-Hot Rolling

In this dissertation, the importance of the MES in the CIMS of Iron & Steel enterprise and the main role of production scheduling in the MES are reviewed. The sate of art of the steelmaking production scheduling is also reviewed and the characters of integrated production scheduling are analyzed. The research of this dissertation is supported by National High-Tech. R&D Program. Some problems existed in steelmaking production integrated scheduling are studied and solved by considering the actual production process in Iron & Steel enterprises. This dissertation has mainly carried on the following research.A mathematical model and an algorithm for hot rolling lot planning in integrated production scheduling system are proposed. The model is proposed with the aims of promoting average rolling length of rolling turn and increasing hot charge rate, and the time constraint and temperature constraint in industrial practices are considered. According to the fact that the average rolling length of rolling turn is considered as more important than hot charge rate, a two-stage variable neighborhood search algorithm is designed to solve the problem. The algorithm solves the problem by optimizing the average rolling length firstly and optimizing hot charge rate secondly.Mathematical models for steelmaking and continuous casting planning are formulated. An integrated method is proposed for the two planning problems considering the close relationship between steelmaking and continuous casting, so that the steelmaking plans and continuous casting plans are not solved separately, and global optimization is achieved. Firstly a set of potential furnace charge plans are obtained through solving a multi-objective model of furnace charge planning. Then the casting plans can be obtained by the solutions of mathematical model of continuous casting planning with the objective of minimizing the number of casting plans. Finally the furnace charge plans can be confirmed according to the casting plans. Multi-objective simulated annealing algorithm and variable neighborhood search algorithm are designed to solve the problems.Reheat furnace is important equipment between continuous casting machine and hot rolling machine. The reheat furnace scheduling problem is researched and mathematical model for the problem is formulated. Objective of the model is to minimize total extra time of slabs kept in reheat furnace after reaching the rolling temperature. As a result the energy...