有芯感应炉熔沟焦耳热与流场数值模拟

Numerical simulation on Joule heating and flow field in melting channel of channel type induction furnace

以某厂1 t双环式熔沟有芯感应炉为研究对象,通过ANSYS仿真软件耦合k—ε模型和磁流体力学模型(MHD)建立了数值仿真模型。研究了熔沟内流场状态与温度分布,不同熔沟间距与不同宽厚比对熔沟功率密度和熔沟顶面流速的影响。结果表明:熔沟间距在275~345 mm变化时,熔沟热值最大,约为410 kJ,功率密度为0.018 W/mm^(3);随着宽厚比增加,熔沟热值逐渐下降。流场结果显示:熔沟两侧沟道内熔体流速较快,并以螺旋式从熔沟两侧流向炉膛,到达熔沟顶面时速度最高达到0.297 m/s,炉膛内熔体在重力作用下流入中心沟道,下行熔体受到两侧熔沟射流的影响,在熔沟上部形成纵向涡心。从熔沟中心沟道上方开始,沿着熔沟方向向熔沟两侧移动,熔体温度逐渐升高,在熔沟两侧拐角处最大,最大温差为12.9℃。

Taking the 1-ton double-loop channel type induction furnace as the research object,a numerical simulation model were built by the ANSYS simulation software coupled Realizable k-ε model and the magnetohydrodynamic model(MHD).The flow field and temperature distribution in the melting channel were calculated.The effect of different channel intervals,the aspect ratios on the power density of the channel,and the flow velocity on the channel top surface were investigated.The results indicated that the joule heat of the channel reached 410 kJ when the channel intervals varied from 275 mm to 345 mm,and the power density reached 0.018 W/mm^(3).As the aspect ratio increased,the joule heat of the melting channel gradually decreased.The flow field results indicated that the melt flow rate in the end channels was faster,and flew from end channel in a spiral flow to the furnace,the maximum outflow rate on the channel top surface reached 0.297 m/s.Metal melt in the furnace flew into the center channel under the action of gravity,and the downward melt was affected by the jets from the end channel to form a longitudinal vortex center on the upper part of the melting channel.The temperature of the melt gradually increased from the top of the center channel along the direction of the melting channel,then reached the maximum level at the corners of the end channel,and the maximum temperature difference was 12.9℃.