Effect of wall emissivity on slabs temperature uniformity in double-row walking-beam reheating furnace
DONG Kexin1, LI Baokuan1, XU Jianxiang1, HUANG Song2, GAO Jun2
1. School of Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China; 2. Anshan Steel Iron and Steel Group Co., Ltd., Anshan 114021, Liaoning, China
Abstract：The reheating furnace accounts for 15%-20% of the total energy consumption for enterprise and 70% of the energy consumption of slab rolling process, which is of great value to research. A mathematical model based on the computational fluid dynamics method was developed to study the heating process of slabs in double-row walking-beam reheating furnace. The feasibility of the model was validated by comparing the simulation results with the black box data. The effect for emissivity of furnace wall areas and furnace chamber on the heating process of slabs were investigated according to the variation of each heat flux in the slabs along the furnace length. The results show that increasing the furnace wall emissivity has small effect on average slabs temperature but significant effect on the slabs temperature difference. While the wall emissivity is increased from 0.75 to 0.95, the optimum residence time of slabs can be reduced by 5%-12%. The increase of wall emissivity in the flue gas preheating zone, preheating zone and second heating zone has greater impact on the slabs heating process than the first heating zone and the soaking zone. Taking into account economic costs and production efficiency, the quality of slabs heating can be improved in industrial processes by applying emissivity of 0.85 coating to the walls of flue gas preheating zone, preheating zone and second heating zone to enhance radiative heat exchange in the furnace. The study results provide theoretical basis for the practical production of reheating furnaces.
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2023, Vol. 33 
