Iron&Steel Metallurgical Reheating Process Modelling And Integrated Optimal Control

Reheating furnace is an important facility in the producing line of steel's hot-rolling. The reheating furnace should provide qualified billets gratifying the request of the rolling process. A great deal of research work has been done to reduce the energy consumption of the reheating furnace. Some useful achievements were presented in the literature, including the optimal setting method and combustion control for the reheating furnace.However, up to now the reheating process and the rolling process have been controlled separately, which can not bring along the optimizing of the total energy consumption of the hot-rolling process, the facility usage and the production quality, although the optimizing of the energy consumption of the reheating furnace were considered by several control methods.In order to reduce the total energy consumption of the reheating process and the rolling process, and to decrease producing accidents at the same time, this paper presents a new object-oriented integrated optimal control strategy of the hot-rolling process based on the modeling of reheating process with rolling process cooperatively, which provides a better solution to the above-mentioned problem.The billet temperature is an important parameter that connects the reheating process and the rolling process, and this paper establishes a mathematical model of the variety of the billet temperature using mechanism analysis and discrete state space method. The mathematical model establishes the stable foundation for the integrated optimal control of the reheating process and reheating process.The issues of reheating furnace temperature optimal setting and combustion control method design are important to achieve the integrated optimal control of the reheating process and the rolling process. This paper analyzes deeply the question of how to determine and optimize the objective function in the reheating furnace temperature setting, and improves the existing method to make the temperature setting accord with the aim of producing process better. Also, this paper presents a new combustion control method by means of the optimizing of air-fuel ratio, which is realized by combining the feedforward of fuel analysis with feedback of surviving oxygen analysis.In order to solve the question of furnace temperature optimizing on line, this paper presents an integrated optimal control strategy of the hot-rolling process based on the abstraction of fuzzy rule and neural network. This strategy can feed the productioninformation of the rolling process back to the reheating process in time, and can give the presetting value of the furnace temperature corresponding dynamic compensation.In order to apply the integrated optimal control method for the hot-rolling process, this paper establishes a temperature-feedback-oriented and rolling-load-feedback-oriented integrated optimal control model respectively and simulation results are given to demonstrate the effectiveness of the scheme.