摘要
等离子弧加热技术被广泛应用于冶金领域,采用磁流体动力学理论(Magnetohydrodynamic theory,MHD)建立直流电弧等离子体的数学模型,利用Fluent软件求解电磁场、温度场、速度场的耦合过程,研究不同弧长大小,不同入口速度对电弧温度分布、形貌、轴向速度分布和电流密度分布的影响。研究结果表明,弧长大小和入口速度对电弧特征分布有明显影响,但不是线性相关。电弧温度沿轴向降低,径向温度分布是以轴线为中心沿两侧径向逐渐降低,等离子弧温度呈“钟型”分布。电弧中心轴线速度在阴极处急剧增加然后逐渐降低。沿轴向方向,电流密度呈指数下降趋势。当入口速度为10 m/s时,随着弧长的增加,电弧有效作用面积范围也增加,当弧长为20 mm或25 mm时,射流现象最明显,轴向最大速度可达到约408 m/s。研究结果解释了不同弧长和入口速度对电弧特征的影响规律,为电弧等离子体加热工艺的应用提供了理论依据。
Arc plasma heating technology is widely used in metallurgy filed.The mathematical model of DC arc plasma is established by using magnetohydrodynamic(MHD) theory.The coupling process of electromagnetic field,temperature field and velocity field are solved by Fluent to investigate the influence of different arc length and inlet velocity on temperature distribution,shape and axial velocity and current density of arc plasma.The results show that the characteristics distribution of arc plasma is affected by arc length and inlet velocity,but they are not linear.The temperature of arc plasma decreases along the axial direction and the radial temperature distribution is centred on the axis and gradually decreases along the radial direction of both sides.The temperature of arc plasma is distributed in a bell type.The velocity of arc plasma sharply increases in axial direction and then decreases gradually.The current density decreases exponentially along the axial direction.When the inlet velocity is 10 m/s,the effective area of arc plasma increases with the increase of arc length.When the arc length is 20 mm or 25 mm,the jet phenomenon is the most obvious,and the maximum axial velocity is about 408 m/s.The results explain the influence of different arc length and inlet velocity on arc plasma characteristics and provide a theoretical basis for the application of arc plasma heating technology.
作者
赵梦静
王勇
杨树峰
段卫平
刘威
李京社
ZHAO Mengjing;WANG Yong;YANG Shufeng;DUAN Weiping;LIU Wei;LI Jingshe(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083;Tianjin Iron Works Co.,Ltd.,Handan 056404)
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2022年第8期153-159,共7页
Journal of Mechanical Engineering
基金
国家自然科学基金资助项目(52074030,51734003)。
关键词
电弧等离子
温度场
数值模拟
电流密度
弧长
arc plasma
temperature filed
numerical simulation
current density
arc length
