三相电极电渣重熔过程温度场与流场研究

A study on the temperature field and flow field in the electroslag remelting process of three-phase electrode

基于有限体积法发展了三相电极电渣重熔过程的瞬态多场耦合数学模型.通过简化麦克斯韦方程组得到适用于电渣重熔体系的电磁场输运方程,计算出了洛伦兹力和焦耳热的分布,并将两者分别耦合到动量与能量方程中.同时采用RNG k-ε湍流模型计算湍流粘度,通过自定义函数描述电极的集肤效应.研究结果表明:焦耳热主要集中在渣池内,其最大值在电极底部内侧与渣的交界处.渣池内温度较高,分布比较均匀,温度的最大值出现在三根电极中心的渣层区域.渣池内的流动由重力、洛伦兹力和浮升力引起的.三电极的金属熔池是一个U型剖面,相较于单电极的V型金属熔池剖面更浅、更平缓.

Based on finite volume method, the transient multi-field coupling mathematical model of the electroslag remelting process of three-electrode was developed. The magnetic field transport equations which could be applied to electroslag remelting system were obtained by simplifying Maxwell’s equations, and Lorentz force and Joule heat distribution were calculated and respectively coupled into the momentum and energy equations. Meanwhile, the RNG k-ε turbulence model was used to calculate the turbulent viscosity, and the skin effect of these electrodes was described by a custom function. The results showed: Joule heat mainly concentrated in the slag pool and its maximum appeared at the intersection of the inner side of the electrode bottom and the slag. Besides, the temperature in the slag pool was relatively high and heat distribution was even. The maximum temperature appeared in the slag layer at the center of these three electrodes. The flow in the slag pool was caused by gravity, Lorentz force and buoyancy force. The U-shaped profile of the three-electrode molten metal pool was shallower and gentler than the V-shaped profile of the single-electrode molten metal pool.