超微粉制备中的感应等离子炬温度场数值模拟

摘要

为了得到超微粉制备中的感应等离子炬温度场,根据传热学Navier-Stocks方程及电磁理论,在高频感应等离子炬中建立了电热以及流体耦合控制方程.利用有限元方法对制粉过程中的电热效应及流体-热交互耦合进行数值模拟,得到高频等离子炬气动过程中的速度分布及温度场分布.结果表明:在等离子体加热部分存在涡流,温度的最高点不在轴线上,输入功率越高,距离线圈越近;在相同进气流量条件下,输入功率为2 kW时,温度最高点距离线圈0.062 m,输入功率为5 kW时,温度最高点距离线圈0.039 m.%To obtain the temperature field of the radio frequency induction plasma torch in preparation of superfine powder, the governing equations for the coupled electric field, temperature field and flow field were set up based on heat transfer, electromagnetic theory, and incompressible Navier-Stocks equations. A numerical simulation of the electrothermal effect and fluid-thermal interaction in powder preparation were simulated using the finite element method, to obtain the velocity distribution and temperature distribution of the plasma torch in the flow process. The results show that a vortex exists in the plasma heating region, and the highest temperature point is not on the axial line of the region. The higher the power input, the smaller the distance between the highest temperature region and the coil for skin effect. Under the same gas flux condition, the distance between the highest temperature point and the coil is 0.062 m when the power input is 2 kW, and 0.039 m when the power input is 5 kW.