Numerical Simulation Research On Furnace Body Heat Transfer Of Electric Arc Furnace Steelmaking Process Under Multiple Charges

As the core of short process steel production route,the electric arc furnace（EAF）steelmaking is characterized by diversified charge structure and product types.Which is the main process of high quality clean steel smelting.However,the EAF smelting process is sensitive to hyperthermal,multiphase,and complex chemical reaction,interaction of multiple energy inputs,irregular structure of the furnace body.Which lead to the confusion of quantitatively describing the material and energy conversion process.Moreover,there is still a lack of consciousness of the important role of the heat transfer behavior of the furnace body on the energy utilization efficiency played.In this paper,the 90 ton EAF steelmaking process（EAF SP）in the selected mill located in Hunan province was investigated.By theoretical analysis,numerical simulation and industrial process data detection,the relationship between metal material consumption and energy input output in EAF SP under multiple charge structure was researched.The heat loss of 2250k Wh per heat driven by convection heat transfer of cooling water and air,and radiation heat transfer of high temperature furnace body was calculated and quantized.The quantified value and variation tendency of heat loss of 20 schemes in hot metal distribution process（HMDP）and 16schemes in EAF SP under different slag thickness,air velocity,air temperature,wall temperature and surface emissivity were simulated and analyzed by ANSYS Fluent 18.2 software.Combined with the heat loss of1551.632 k Wh of cooling water,the temperature drop data of12.596～32.703℃in HMDP and the quantified data of heat loss of2065.937～2451.727k Wh per heat in EAF SP were obtained.Which was advantageous for stabilizing the temperature of hot metal while charged into the EAF,and provided theoretical and analytical basis for reducing the heat loss in the process.To further explore and quantify the characteristics and variation trend of heat loss in HDMP and EAF SP,the mathematical fitting,single factor analysis,and multi factor coupling analysis were adopted to establish the quantitative relationship of heat loss under the influence of multiple factors based on the results of numerical simulation experiment.Among them,the quantitative mathematical expression of heat loss in HDMP was shown as Q_{H M} 00.044h_sla² _g 6.184h_{sla g} 2.290v_ai² _r 13.952v_{ai r} 0.142t_{ai r}+9.622ε_{wa ll}+0.364t_top +0.058t_{u p}+0.072t_down+376.816.Furthermore,the quantitative mathematical expression of heat loss in EAF SP was shown asQ_{EA F}0 22.683v_EAF²+62.162 v_{EA F} 0.678t_up^{EA F}+205.858ε_wa^EA _ll^F+0.153t_{ro of}+0.068t_up^{EA F}+0.595t_do^EA _wn^F+0.820t_bottom +191.130.According to the above equations and numerical simulation results,the quantitative evaluation software for heat loss in EAF SP under multiple charges was constructed.Which served as the theoretical basic and assistant tool of energy efficient utilization,waste heat recovery,energy saving and emission reduction,process consumption reduction,and temperature prediction in EAF SP.