有限要素法と特性曲線法による高炉のガス流れと伝熱の同時解析

抄録

An attempt was made on the simultaneous analysis of the gas flow and heat transfer in the blast furnace by a mathematical model which considered complex structure and nonuniform sink and source terms for both heat and mass. ERGUN'S equation was used for the equation of motion of gas and potential flow approximation was used for the equation of solid flow. Two dimensional distribution for the velocities of gas and solid was obtained numerically by applying the finite element method with quadratic elements. Fundamental equations of heat transfer on gas and solids were composed of the terms for convection, heat exchange and heat source. Numerical computation of the fundamental equations was carried out in accordance with the method of characteristics. In this analysis, sink and source terms regarding fusion of ore in the cohesive zone and combustion of coke in the raceway were incorporated in the mathematical model as well as radial distributions of particle size and void fraction. It was consequently found that the temperature distribution was affected principally by nonuniform gas flow and thermal flow ratio. Within the cohesive zone, strong consumption of heat by fusion of ore and decrease in the solids velocity appeared. These phenomena affected significantly the temperature distribution in the lower region of the blast furnace together with the generation of heat in the raceway region.