Comprehensive Optimizing Control Strategy And Control Method Study Of Reheating Furnace In Hot Rolling Process

The heating process and rolling process of slab are very important procedures in hot rolling production line. Reheating furnace should heat the slab to the temperature distribution that is needed by the rolling technology of roughing mill, and roughing mill should roll the slab into the product with the desired dimension. Reheating furnace and roughing mill are two main energy-consuming facilities in hot rolling production line.Because the practical production and theoretical research in the past treat reheating furnace and roughing mill as two separate facilities, which dissevers the continuity of production process and the interaction on energy consumption of the two facilities, even though the minimal energy consumption may be achieved in a single facility, there is no way to guarantee the total energy consumption minimization of the two facilities as a whole. Now in the condition of world energy resource deficiency, there are still some problems to be solved, such as exceeding energy consumption, low heating quality of slab, the difficulty of guaranteeing rolling security, so this paper tries to give solutions to the mentioned problems from the following several aspects.First of all, start with the heat exchange mechanism, form an objective function whose objective is to make the energy consumption of the reheating furnace, the burning loss of the slab and the slab temperature difference between the expectation value and actual value at the exit of the furnace minimized. A furnace temperature optimizing adjustment strategy based on the expertise of skilled workers is used to hunt the optimal temperature rise curve of the slab and the corresponding optimal furnace temperature distribution curve, and then the optimizing setting of furnace temperature is realized, the energy consumption of heating process is reduced.Secondly, aiming at the difficulty of information sharing between reheating furnace and roughing mill which is brought by the separate control of the two facilities, and the problems of exceeding energy consumption and low security of rolling process given by the difficulty to adjust the heating process of slab dynamically, this paper presents a comprehensive optimizing control strategy of reheating furnace based on the rolling information feedback. In the presented strategy, fuzzy control and neural network are used to feed roll force and slab temperature of therolling process back to reheating furnace and the concrete furnace temperature setting compensation value can be worked out. So that the heating process of slab can be adjusted dynamically according to the heating quality of the slab, and energy consumption can be reduced, the rolling security can be ensured as well.In addition, this paper puts forward a comprehensive optimizing index which combines the quality index with the economy index in hot rolling process, and expounds the fundamental idea of production-oriented comprehensive optimizing control strategy of hot rolling process. Simulation results are provided to prove the effectiveness of the comprehensive optimizing control strategy.