Feedback modeling of blast furnace cooling system based on numerical analog simulation

Abstract

Efficient operation of the cooling system is essential to control the heat generated in the blast furnace during the ironmaking process. Suitable cooling conditions enable the formation of a stable slag crust on the cooling stave of the blast furnace, which helps to slow down the erosion of refractory materials and improve production efficiency. However, there is a lack of scientific guidance in the regulation of the current blast furnace cooling system, which leads to problems such as slag crust thickness variation and unstable furnace conditions. This paper proposes a slag crust thickness calculation formula based on the heat transfer principle. In order to further verify the validity of the formula, the three-dimensional steady-state heat transfer model of the blast furnace cooling system is constructed by using Fluent software to simulate and analyze the temperature distribution of the cooling system under different working conditions. The results show that the stable existence of slag crust is the key to the efficient operation of the cooling system, and the error between the calculated and simulated values of slag crust thickness is within the range of ±5%, which is able to better reflect the furnace conditions. When the gas velocity increases by 3.76 m/s or the gas temperature increases by 63°C, the slag crust thickness decreases by about 10 mm. At this time, the cooling should be strengthened to make the slag crust thicker to achieve the effect of protecting the cooling stave. In addition, when the melting point of slag increases by 48.69°C, the thickness of slag crust increases by about 10 mm. Predicting the melting point of slag crust based on the composition of the charge can also help to adjust the cooling system in time to stabilize the slagging on the cooling stave.