The Operation Scheduling System For Blooming Mill In Continuous-casting And Finishing-rolling Stages

The bloom production line is a typical production line in iron and steel enterprises, which is characterized as multi-process, multi-object and crossing of material flow. With the development of information, it is essential of applying intelligent management method to the bloom production operation scheduling such that the efficiency of the overall production line is improved. Efficient operation scheduling is an important approach to balance the material flow of the bloom production line, to improve production efficiency and product quality. Moreover, it also significant in improving resource unitization, reducing production cost and energy consumption. This dissertation takes the bloom production as research backgrounds, and studies cold bloom configuration problem, reheat furnace sequencing problem and continuous-casting and finishing integrated scheduling problem. The decision supported system of the bloom production line is developed. The main research contents of this dissertation are as follows:(1) The cold-bloom configuration problem is to determine how insert the cold blooms into the idle time once the sequence of hot blooms on rolling machine is given, so that production capacity of rolling machine is sufficiently unitized. In this paper, a mathematical programming model, which takes the changeover of blooms specification and the tardiness of orders as the objective, is proposed for the cold bloom configuration problem. For the characteristics of large scale and complicated constraints, an intelligent optimization algorithm based on neighborhood search and scatter search is proposed to solve the model. The experimental results verify the effectiveness of the proposed algorithm.(2) Reheat furnace sequencing problem is to determine the processing sequence of blooms which arrive on the reheat furnace through different routes. The reheat furnace sequencing problem is NP-hard problem. In this paper, a mixed-integer nonlinear programming model is developed. The objective of the model is to minimize the waiting time before reheat furnace, the tardiness of orders, the changeover of blooms specification and the makespan as objects. Due to the complication of the problem and the requirement of quick response in practical application, a heuristic is constructed so that this problem can be quickly solved in a reasonable computation time.(3) The continuous-casting and finishing integrated scheduling problem is to determine the timetable of blooms on each machine. In this paper, a linear programming model is developed to solve the problem. Its objective is to minimize the waiting time before machines and the tardiness of orders. Based on the combination of time-forward and time-backward idea, an effective heuristic algorithm is designed to solve this model. The result of running verifies the efficient of this algorithm.(4) After analysis the requirements of bloom production scheduling system, the different modules of the system is designed and developed. The simulation simulates the production process of each machine, so that an intuitive understanding of each machine of bloom production line can verify the reasonability and affectivity of the plan and schedule. The system is trial running in an iron and steel enterprise of China, and the reply of planner shows that the system is stabilized and favorable.