Research On Optimizational Control Strategy Of The Regenerative Reheating Furnace With Distributed Changing-Direction

Reheating furnace, as the key equipment in the hot rolling production line, takes on the assignment of providing billets which are used to supply the heating quality. At the same time, the study of saving energy and reducing consumption of this high energy consumption equipment is regarded as the focus of metallurgical automation.There are still some problems in optimal control strategy of reheating furnace. The first is the temperature distribution of the billet can’t be measured directly. The second is that the optimization index of the setting of furnace temperature is unreasonable. The third is that the heating quality of the billet is poor because of the uncertainty of the heating process. To solve these problems, the present study attempts to explore the optimizational setting of furnace temperature on the basis of certain reheating furnace. Firstly, one dimensional mathematical model is built by means of mechanism analysis and the discrete state space. And its effectiveness is validated by simulation. Secondly, the objective function of the minimum fuel consumption is built. Meanwhile, the constraints are designed according to the slab temperature difference of section, heating rate and temperature setting value. Then the optimal distribution of furnace temperature can be obtained by the Flexible Tolerance Method(FTM). The solution process is simplified by the reasonable simplification on optimization index. Finally, the method of testing heating quality of the billet by mill current is proposed and a neural-fuzzy controller which is used for dynamic compensation for furnace temperature setting online is designed. By using the controller, the heating quality of billets can be optimized in real time. What’s more, the productivity of the mill is improved, and the whole energy consumption of the hot rolling production line is reduced. The simulation results showed that the controller is able to compensate for the furnace temperature set value, to improve the heating quality and to achieve production targets of saving energy and reducing consumption.