Near Optimal Scheduling of Steel-making and Continuous Casting Process Based on Charge Splitting Policy

Abstract

The process of steel-making and continuous casting (SCC) is the bottleneck in the iron and steel production, how to take a quick response and make a good scheduling in a computationally efficient manner are the key factors for iron and steel production manufacturing productivity. In this paper, based on the time-index variables, we established a mixed integer-programming model for the scheduling problem considering the four performance indexes. Then, the charge splitting policy based on the relaxation of the no confliction and no break cast are proposed. The polynomial dynamic programming algorithm is presented to solve the corresponding relaxed problems. Based on the above approaches, an approximate optimization method with surrogate subgradient algorithm is proposed to solve the relaxed problem. The method has been tested by using practical data from the Shanghai Baoshan steel plant in China. Computational experiments demonstrate that the model and the algorithms developed can generate the satisfactory solutions and realizes rapidly response for the dynamic change.