چكيده لاتين
The steel industry, due to its unique characteristics such as strength, flexibility, recyclability, etc.... As a strategic material, it plays a key role in economic development and industrial infrastructure. Steel coils are used as a raw material in construction, automotive, machinery, equipment and various industries This industry, due to the increasing needs for steel products, is constantly expanding and improving production processes in order to meet market demand and increase
productivity. Therefore, proper and optimal planning in the various stages of steel coil production is of great importance in achieving practical goals in this industry, including reducing coil production time and costs, Customization was carried outconsidering operational constraints and system capacity, with the aim of reducing the maximum execution time of production steps in the daily planning interval (operational scope), increasing the number of production melts in a given planning interval, and reducing the number of continuous casting machine shutdowns. In this study, first a mixed integer programming (MIP) model was developed, is presented for the problem. This model has been validated on small scales. Considering the inefficiency of the presented model in solving large-scale problems, a two-stage approach has been designed to solve the problem. In this approach, first the allocation and sequence of melts on steelmaking furnaces and refining furnaces are determined; and then, taking these allocations into account, the melting schedule inThe different steelmaking stages, continuous casting and hot rolling, are determined integrally, as well as the sequence of slabs in the hot rolling stage. To solve the first stage, a metaheuristic algorithm for cooling simulation is developed by adjusting its parameters using the Taguchi method. The second stage is formulated using a MIP model; and is solved using the GAMS software. This approach is used in solving First, the allocation and sequence of melts on steelmaking furnaces and refining furnaces are determined; and then, taking into account these allocations, the timing of melts in different stages of steelmaking, continuous casting and hot rolling, as well as the sequence of slabs in the hot rolling stage, are determined integrally. To solve the first stage, the metaheuristic algorithm of cooling simulation withIt has been developed by adjusting its parameters using the Taguchi method. The second stage is formulated using a MIP model; and it is solved using the GAMS software. This approach has been tested and validated in solving various sample problems. The scheduling has achieved the desired goals in a very short time, given the existing constraints. The results show that the models presented in two different approaches in this research have been able to achieve integrated planning and simultaneous scheduling of steel coil production stages in different dimensions, along with the existing constraints to optimizeThe desired goals are achieved in four stages. The modeling designed in the mathematical model of the problem used in small dimensions, the optimal solution with a long time and the two-stage approach model used in high dimensions, due to the use of the meta-heuristic algorithm of the refrigeration simulation, has achieved a solution close to the optimal in a ver