三维长电弧磁流体动力学数值模拟

Numerical Simulation of Three-dimensional Long Arc Magneto-hydrodynamic

危险废物焚烧产生的飞灰和底渣含有大量的重金属、二噁英等,属于危险废物,采用电弧等离子体熔融技术是当前最为先进的灰渣处置方式之一。开发工业规模的直流电弧等离子体熔融炉难度大、周期长。为此,采用磁流体动力学(MHD)模型对三维自由燃烧长电弧内的流动传热现象进行研究,运用Fluent软件将基于磁矢量势描述的麦克斯韦方程组、N-S方程、能量守恒方程进行耦合迭代求解,得到三维长电弧内部温度场、速度场及电磁场分布。结果清晰地揭示了电弧内部的传热流动规律及对熔池产生的影响,并与同行结果进行对比,对于灰渣等离子体熔融技术装备的开发具有重要意义。

Fly ash and bottom ash produced by hazardous waste incinerators contain a lot of heavy metals and dioxins,which is still hazardous waste.The technology of arc plasma melting is one of the most advanced disposal methods of fly ash and bottom ash.It is very difficult to develop a DC arc plasma melting furnace of industrial scale,and it also costs much time and money.In this work,the Magneto-Hydrodynamic(MHD)model is used to study three-dimensional long free-burning plasma arc.Temperature,velocity and magnetic fields of the arc are obtained by solving Maxwell equations based on the magnetic vector potential description,N-S equation and energy conservation equations with the coupled computation.The simulation results clearly reveal the phenomenon of heat transfer and flow inside the arc.It is of great significance to the development of plasma melting technology and equipment for fly ash and bottom ash.