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

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. The presence of slag crust 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, and uses Fluent software to construct a three-dimensional steady-state heat transfer model of the blast furnace cooling system. The stable existence of slag crust is the key to the efficient operation of the cooling system. The increase in gas temperature and gas velocity will lead to an increase in the intensity of heat flow in the cooling system, at which time the cooling should be strengthened to prevent the thickness of the slag crust from decreasing. In addition, the prediction of the melting point of the slag crust based on the composition of the charge is also helpful for the timely adjustment of the cooling system to stabilize the slagging on the cooling stave.在炼铁过程中，冷却系统的高效运行对管控高炉内部产生的热量至关重要。适宜的冷却工况可使高炉冷却壁（cooling stave）形成稳定的渣壳（slag crust）。渣壳的存在能够延缓耐火材料的侵蚀，提升生产效率。然而当前高炉冷却系统的调控缺乏科学指引，由此引发了渣壳厚度不均、炉况不稳定等问题。本文基于传热原理提出了渣壳厚度计算公式，并采用Fluent软件构建了高炉冷却系统的三维稳态传热模型。渣壳的稳定存续是冷却系统高效运行的核心关键。煤气温度与气流速度的升高会增大冷却系统的热流强度，此时需强化冷却以避免渣壳厚度减薄。此外，基于炉料成分预测渣壳熔点，也有助于及时调整冷却系统，以稳定冷却壁上的结渣工况。