Study on optimization of reduction temperature of hydrogen-based Shaft Furnace—Numerical simulation and multi-criteria evaluation

Under the background of carbon neutralization at present, the green and low-carbon development of the iron and steel industry has become an inevitable trend, and the hydrogen-based shaft furnace involving hydrogen metallurgy has attracted wide attention. As an important method to study shaft furnace, numerical simulation can quantitatively analyze the law of energy and mass transfer in shaft furnace. In this study, a three-dimensional CFD mathematical model of reduction zone of hydrogen-based shaft furnace is established, and the influence of reduction gas temperature on various physical quantities in shaft furnace is studied in order to better understand and optimize the operating conditions of hydrogen-based shaft furnace. The results show that the gas and solid temperature are close to each other and can be divided into six regions along the height, in which the range of IV and V determines the mass fraction of Fe; increasing the reducing gas temperature can reduce the proportion of low velocity zone in the furnace, improve the thermochemical state in the furnace, increase the gas utilization degree and DRI metallization degree, and reduce the CO2 emissions; calculated by the Multi-criteria VIKOR evaluation model, the ideal temperature of reducing gas is about 1173 K.