Study On Planning Methods Of Integrated Production Based On Hot-rolling

Steel-making, Continuous Casting, Hot Rolling are the three important working procedures in Steel Manufacturing Enterprise. With the large-scale of production technology, fierce market competition and diverse of market demand, enterprises faces large order situations of multi-species, low-volume and high-quality currently, and iron and steel enterprises follows the organization pattern of produce according to sales, production plan is also made in the order of hot rolling-continuous casting-steelmaking based on Just In Time. Hot rolling is regarded as the last key process of iron and steel production, the quantity of production plan not only relates to smooth process of hot rolling but also affects the running results of iron and steel production processes, Under this mode of production planning. Hot rolled strip is the most important products of iron and steel enterprises, its yield is more than half of all steel products, and it is an important factor for measure a country's level of development of the iron and steel industry. So the production planning of hot rolled strip is researched.The production planning of hot rolled strip is a complex combinatorial optimization problem of multi-objective and multi-constraint. The informed research focus on production contract and use a single model to make hot rolled strip production plan. Lots of constraints should be considered so that the model is too complex. In order to reduce the complexity of the model, hot rolled strip production planning will be broken down into two sub-problems---hot rolled strip daily production planning and hot rolled strip production lot planning. Firstly, determine delivery time of production contracts using the model and a hybrid optimization algorithm of genetic algorithm and ant colony optimization algorithm for daily production planning, and then draw up daily production plan. this model's target is minimizing the punishment value of earliness/tardiness delivery and is restrained by unit capacities etc, at the same time, the hybrid optimization algorithm of genetic algorithm and ant colony optimization algorithms is used to solve this model, the self-organizing evolutionary function of ant colony optimization algorithm is used to improve the weaknesses that GA under-utilized the information on the evolution process. Secondly, work out hot rolled strip lot production plan using the model and an improved ant colony algorithm for lot production planning. This model is restrained by unit capacity and rolling regulars etc, and target is minimizing the penalties of broken rolling rules and improve the utilization of rollers.On the basis of above-mentioned studies, a model-based production planning optimization system for hot strip rolling have been developed using Microsoft Visual C # 2005 programming language and SQL Server 2000 database management software. The simulation result, which is based on real production data of hot strip plant in one large domestic iron and steel enterprise within a month, shows this system can improve production efficiency and reduce production costs for iron and steel enterprise, and the correctness and validity are proved.