Optimal Control Of Reheat Furnace Temperature

Reheat furnace is not only one of the most important equipment., but also a large energy consumer on steel rolling line. The technology of slabs heating directly affects strip steel product quality, energy consumed and mill life. So it is important to extend optimal setting control technology for reheat furnaces of steel enterprises. The purpose of reheat furnace production is to acquire the slab temperature distribution rolling required, and achieve the fewest stock scale loss and energy consumption. Because reheat furnace is of non-linearity, uncertainty and coupling, so mathematical model of its dynamic characteristics is difficult to be developed. It is difficult to achieve the ideal result by the classical optimized control, which depends on the experience of the personnel operator to control the set values of lower level control loops. When the boundary conditions change, which usually makes the technical specification actual values deviate the scope of target, and results in the product quality descending, and gaining consumption. Aiming at above problems, this paper includes the main work as follows:1. Based on state space, the slab temperature prediction model is established, which solves the problem that slab temperature is immeasurable and makes important foundation for optimal setting control of reheat furnace.2. A kind of optimal setting control method based on production targets is provided. This method adopts feedforward control, feedback control, adaptive control, fuzzy control and soft measurement technologies, and adjusts setting temperature of reheat furnace with expert rules, realizes combination of modeling and control.3. Object-Oriented method is adopted to design program for optimal setting control of reheat furnace. A lot of simulations have been done to demonstrate that the technology can achieve the effective control for rough rolling temperature of slabs, where the temperature is limited in ±10℃.