MATHEMATICAL MODELS OF CRITERIA TECHNOLOGICAL PROCESSES OPTIMIZATION CRITERIA OF THE BLAST FURNACE SMELTING

Abstract

The mathematical models of optimality criteria of blast, fuel additives and steam consumption for blasting moisture have been developed. The criterion for optimal blast consumption is the furnace performance, which should be maintained at the highest possible level. The maximum possible level of performance varies over time, even at a constant value of blasting. Therefore, optimal amount of blasting search is carried out continuously every 5 to 10 minutes. The mathematical model of furnace efficiency has been developed. It is determined by information on the amount of combined blast and its content of reducing gas, the oxidation of the charge, the amount of gasified oxygen of the charge from one filing, the amount of cast iron, which is smelted from the charge of one feed, the output of the dry blast furnace gas. The mathematical model of the optimization criterion of fuel additives consumption includes mathematical models: the coke coefficient of substitution by a fuel additive; the amount of coke replaced by a fuel additive; the amount of profit from the additive use. The coefficient of coke substitution is defined as the ratio of the heating power in the blast furnace to of coke combustion heat, based on information on the composition of the blast furnace gas, the composition of the fuel additive and coke. The amount of coke substituted by a fuel additive is determined by the value of the substitution coefficient and the fuel additive consumption. The amount of profit from the additive use is determined by the information on the consumption of fuel additive and oxygen, fuel additive price, oxygen and coke, the furnace efficiency. The mathematical model of the optimization criterion of steam consumption for blas-ting moisture includes models; the amount of heat consumed for steam decomposition; the heat input at the expense of improving the degree of hydrogen and carbon monoxide use; the intensity change of carbon combustion in the tuyeres; required mass of coke for heat compensation expended on the decomposition of the blow moisture in the furnace; total savings or over-consumption of coke mass when humidity changes; increase in the furnace's efficiency due to changes in the moisture content of the blast; money saving from steam using for moistening.