LF精炼过程中通电升温阶段底吹氩方式的优化

doi:10.12068/j.issn.1005-3026.2024.04.007

摘要/Abstract

摘要：

在LF（ladle furnace）精炼过程的通电升温阶段多采用双喷嘴等流喷吹的吹氩方式.本文提出一种双喷嘴差流吹氩的底吹方式，以某钢厂135 t钢包为原型设计1∶4非等温水模型实验平台，在总流量相同的情况下进行底吹比例为1∶1，2∶1和3∶1的温度均匀化实验，结果表明底吹比例为2∶1时的各监测点无量纲温差最小，均匀化效果最好.建立流动-传热耦合数学模型对实验结果进行验证，结果表明在总流量相等的情况下，底吹比例为1∶1，2∶1和3∶1时流动死区占比分别为14.1%，9.1%和9.8%，温度死区占比分别为6.2%，2.6%和0.3%，2∶1差流底吹方式在活跃流场和促进温度均匀化方面具有优势.

关键词: 差流吹氩, 底吹分布, 温度均匀化, 非等温水模型, 流动死区

Abstract:

During the electric heating stage of the LF （lalde furnace） refining process， dual?nozzle equi?flow argon blowing is often used. This paper proposes a bottom blowing method of dual?nozzle non?equi?flow argon blowing. A 1∶4 non?isothermal water model experimental platform was designed based on a 135 t ladle in a steel plant. Under the same total flow rate， temperature homogenization experiments were conducted with bottom blowing ratios of 1∶1， 2∶1 and 3∶1. The results show that the minimum dimensionless temperature difference and the best homogenization effect were observed at each monitoring point when the bottom blowing ratio was 2∶1. The coupling mathematical model for flow and heat transfer was established to verify the experimental results. The results show that under the same total flow rate， the proportion of flow dead zone was 14.1%， 9.1%， and 9.8% respectively when the bottom blowing ratio was 1∶1， 2∶1 and 3∶1， and the proportion of temperature dead zone was 6.2%， 2.6%， and 0.3%， respectively. The 2∶1 non?equi?flow bottom blowing method has advantages in active flow field and promotes the temperature uniformity.

Key words: non?equi?flow argon blowing, bottom blowing distribution, temperature homogenization, non?isothermal water model, flow dead zone

中图分类号:

TF 777

王宁, 秦德越, 李宝宽, 赵家七. LF精炼过程中通电升温阶段底吹氩方式的优化[J]. 东北大学学报（自然科学版）, 2024, 45(4): 507-513.

Ning WANG, De-yue QIN, Bao-kuan LI, Jia-qi ZHAO. Optimization of Argon Bottom Blowing During Electric Heating Stage of LF Refining Process[J]. Journal of Northeastern University(Natural Science), 2024, 45(4): 507-513.

图/表 14

图1 LF简图

Fig.1 Schematic diagram of LF

表1 钢包水模型基本参数

Table 1 Basic parameters of ladle water model

参数	数值
钢包高度/mm	796
底部直径/mm	667
顶部直径/mm	685
钢液深度/mm	746
渣层厚度/mm	45
喷嘴直径/mm	25
入口偏离中心距离/mm	104.5
喷嘴夹角/（°）	117
底部喷嘴中心间距/mm	358

图2 钢包底座氩气入口位置示意图

Fig.2 Schematic diagram of argon inlet position at ladle bottom

表2 底吹流量方案

Table 2 Scheme of bottom blowing flow rate

方案编号	Inlet-1流量/（L·h^-1）	Inlet-2流量/（L·h^-1）	流量比	总流量/（L·h^-1）
1	112.5	112.5	1∶1	225
2	150	75	2∶1	225
3	168.75	56.25	3∶1	225

图3 水模型实验装置简图

Fig.3 Schematic diagram of water model experiment device

表3 钢包数值模拟物性参数 (numerical simulation)

Table 3 Physical parameters for ladle

参数	数值
水密度/（kg·m^-3）	1 000
水黏度/（kg·m^-1·s^-1）	0.001
油层密度/（kg·m^-3）	850
油层黏度/（kg·m^-1·s^-1）	0.008 5
水-氩气表面张力/（N·m^-1）	0.073
初始水温度/K	285
氩气密度/（kg·m^-3）	1.67

图4 网格划分

Fig.4 Grid division

图5 无底吹时的无量纲温度曲线

Fig.5 Dimensionless temperature curves without bottom blowing bottom blowing of 225 L/h total flow rate

图6 底吹总流量为225 L/h时的无量纲温度曲线

Fig.6 Dimensionless temperature curves with

图7 总流量为225 L/h的速度场（a）—速度场选取的截面；（b）—底吹比例1∶1；（c）—底吹比例2∶1；（d）—底吹比例3∶1.

Fig.7 Velocity field at total flow rate of 225 L/h

图8 水模型内流动活跃区和死区体积分数

Fig.8 Volume fractions of flow active zone and dead zone in the water model

图9 总流量225 L/h时不同截面温度分布（a）—截面位置；（b）—底吹比例1∶1；（c）—底吹比例2∶1；（d）—底吹比例3∶1.

Fig.9 Temperature distribution on different sections at total flow rate of 225 L/h

图10 总流量225 L/h时温度死区体积分数

Fig.10 Volume fraction of temperature dead zone at total flow rate of 225 L/h

图11 总流量225 L/h时同一截面温度分布（a）—截面位置；（b）—底吹比例1∶1；（c）—底吹比例2∶1；（d）—底吹比例3∶1.

Fig.11 Temperature distribution at the same section with a total flow rate of 225 L/h

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