| In iron and steel industry, reheating furnace is used to heat up the billets transported from continuous casting to be of the right temperature and suit rolling, so furnace plays important role during iron and steel production. At the same time, the energy consumption of furnace also takes a big proportion in the whole energy consumption of iron and steel industry, which is about twenty-five percent of the whole consumption. In this condition, to search a method of enhancing the heating efficiency to decrease energy consumption and reduce the production cost to enhance the competing power of product in market with the right output and quality of product has been the new aim sought by iron and steel corporation.Because furnace is a complex control object in industry, and it has the characteristics of high energy consumption and high temperature, to research the running process of furnace becomes very complex, at present, there exist many difficulties to describe the whole running process of furnace with quite extract mathematical model. Because of the characteristic of subsection of walking beam furnace, this paper plot out furnace into some sections during the optimization of the running process for furnace, through the predigestion for the mathematics model and the solving of differential evolution algorithm, the aim of optimizing the production and reducing the energy consumption has been realized.This paper carries out the research to the problem of furnace temperature setting based on the need of energy saving and cost reducing from iron and steel corporation, taking the techniques process of furnace as the practice background and the mechanism model of furnace as the mathematics support. The main content of this paper is generalized as follows:1) The techniques operation and characteristics of controlling system of walking beam furnace is introduced, which provide practice background and theory support for building mathematics model and rising object function; The transmission peculiarity of quantity of heat an changing characteristics of furnace temperature are researched, and on the basic of the contrast of some mathematics models, balancing and summarizing the excellence and the disadvantage of the models, through the idea of systemic identify, the mathematics mechanism model is upbuilt, according to which, the temperature of billet is predicted. 2) The optimization aim is built according as the characteristics of iron and steel production. The optimization aim of this paper is to save the energy consumption and reduce the cost of production at the precondition of making sure to provide the rough-milling with billets of right status, with the restrictions as follows:(1) The temperature change and sectional temperature dispersion of every section should not higher than some certain value;(2) The sectional temperature dispersion of the outing-time should not larger than limit, and temperature of furnace in every section should not exceed the upper-limit of furnace in that section.3) According to the nonlinear characteristic of furnace designs and improves differential evolution algorithm and the improving strategy could be described as follows:(1) At the prophase of the running of algorithm, the diversity of cluster needs to be kept and the capability of global search needs to be enhanced, thus the crossing-rate is linearly decreased, at the same time, the zoom quotiety is increased to avoid earliness;(2) At the anaphase of the running of algorithm, the crossing-rate needs to be increased and the zoom quotiety in order to enhance the capability of local search and quicken the convergence of the algorithm.4) The improved differential evolution algorithm is used to solve the problem of temperature setting of walking beam furnace, and the data from experiment of C environment shows that both the efficiency and stability of the improved differential evolution algorithm are obviously better than that of classical differential evolution algorithm. |
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