Journal of Hebei University of Science and Technology (Dec 2021)
Numerical simulation of scrap preheating in EAF steelmaking
Abstract
In order to make full use of waste heat of electric arc furnace (EAF) flue gas to preheat scrap steel,a three-dimensional unsteady random distribution local model of scrap preheating process was established on the platform of computational fluid dynamics software Fluent,and the distribution law of preheating temperature of different types of scrap steel was investigated by numerical simulation method.The simulation results show that the preheating temperature of scrap steel increases obviously with the increase of preheating time,and the thickness of scrap steel has a significant effect on the preheating temperature.Under the same preheating conditions,the average temperature of light and thin scrap steel is about 1 600 K,medium scrap steel is about 1 000 K and heavy scrap steel is about 700 K.Increasing specific surface area can improve the preheating temperature of all types of scrap steel to a certain extent.Considering the influence of scrap melting on the quality of steel output during preheating,the specific surface area of bottom scrap should be controlled below 1.5 m2/m3,and the specific surface area of heavy scrap should be controlled above 0.25 m2/m3.The high temperature flue gas will preferentially pass through the area with large voidage and good patency,and the dense accumulation of sheet steel scrap blocks the flue gas flow,leading to the reduction of the preheating temperature in this area.Therefore,the proportioning ratio of heavy scrap can be reduced relatively in production,and medium scrap can be used more often.The research results can provide preheating analysis data for manufacturers using scrap preheating technology,improve the preheating process of EAF steelmaking,and have a certain theoretical reference value for the efficient smelting of industrial scrap.
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