Research And Application Of Advanced Control Technology In The Smelting Process Of EAF

The electric arc furnace (EAF) steelmaking is the main method used to produce special steel and alloy steel. Compare with basic oxygen furnace (BOF) steelmaking, the EAF have advantages such as the temperature of steel liquid can be grasped flexibly, thermal efficiency is high, the atmosphere in the furnace can be controlled, the equipment is simple and the technological process is short. In addition, because of the rich craft resources and the enhanced environmental consciousness, the countries all over the world are developing steelmaking of the electric stove steadily. The effectively operation, high efficiency and high quality, saving energy and reducing the cost are essential to the steel and iron industry. The automatic control system, that influences the quality and output of the products directly, is an important part of an EAF process. The key research of this thesis is the application of advanced control technology in the EAF, and the main content is as follows:(1) Economic objective-based optimizing setting for the smelting process of EAFIn order to realize the systematic control goal of reliable and steadily quality and lowest cost, an optimal method of process parameters setting values during production has been proposed based on the economic objective in this thesis. Analyzed to the process parameters of EAF, We propose the smelting optimizing goal and determine the optimization setting value. A technological model aimed at the maximum of the process benefit is established based on the analysis of the energy demanded by EAF and the lost, the demand for oxygen and the period of smelt process. The quantity of craft, molten iron, oxygen, powdered carbon and electric power can be optimized by this model, In addition, the linear programming model based on the fuzzy number for craft mating optimization, the power supply model based on the Mixed Integer nonlinear programming and the alloy component control model based on the grey model which is used for correcting the element yield are established to decrease the cost of the smelting process.(2) Endpoint prediction of EAF smelting process based on the case-based reasoning (CBR)An endpoint prediction model based on the CBR technology is established in this thesis. A case similarity measuring method and a case utilization method are proposed. In order to remedy the deficiency of the CBR, combining the advantages of the increment model, a compensation modeling method of multiple support vector machines (SVM) is proposed to correct the prediction result of CBR which can improve the precision of the endpoint prediction. The emulation conclusion shows that the CBR model compensated by multiple...