基于Fluent多晶硅还原炉内部辐射换热的模拟分析

The simulation analysis on internal radiation heat transfer simulation of polysilicon reduction furnace based on fluent

针对多晶硅还原炉内部三氯氢硅发生的化学沉积反应内部换热能耗复杂,测定相关传热系数难度较大的问题,为进一步还原炉生产工艺节能减排提供理论依据,本研究通过建立实际生产中的还原炉三维模型,利用计算流体动力学方法,在考虑对流和辐射传热损失的条件下,对还原炉内部进行数值模拟及其场协同分析,探究流体流动与传热特性规律。结果表明:湍动能较大处发生在进气喷口处,流场稳定均匀性较差;硅棒周围温度明显高于其他区域,2-2.5 m处截面温度均匀分布,入射辐射能量最大达到3.35×10~5 W/m^2;硅棒直径增大,Nu数逐渐增加,协同角θ减小,使得壁面速度梯度增加,内壁发射率与材料的表面粗糙度有关,发射率越小,硅棒辐射能量损失减少,内部热量相对集中,有利于强化传热。

Aiming at the polysilicon reducing furnace internal chemical deposition reaction of trichlorosilane,the internal heat exchange energy consumption is complex and the relative heat transfer coefficient is difficult to measure.In this research,the three-dimensional model of the reduction furnace was established in the real production process,under the condition of considering the heat convection and radiation losses and under the condition of the model,numerical simulation and field synergy analysis are used to research on the laws of the fluid flow and heat transfer characteristics.The results show that the place with larger turbulent kinetic energy is in the intake vents,and with the less stable flow field uniformity.The ambient temperature of silicon rod is significantly higher than other regions.Uniform temperature distribution is at the 2-2.5 m cross section and the maximum energy of the incident radiation can reach to 3.35 x 10~5 W/m^2.When the diameter of silicon rodincreases,Nu increases gradually and synergy angle decreases,resulting in the increasing of wall velocity gradient.Inner wall emissivity is associated with the surface roughness of materials,and the smaller rate of emission,resulting in the reducing of silicon rods radiation energy loss and the relative concentration of internal heat,which is conducive to the enhancement of heat transfer and can providing a theoretical basis for the further reduction furnace production process energy saving.