电窑制备SiC结合Si_3N_4材料加热阶段的数值模拟

Numerical Simulation on Heating Process of SiC-Si_3N_4 Material Fabricating in Electrical Furnace

电窑中SiC-Si3N4耐火砖的烧制过程按时间可分为三个阶段,即加热阶段、化学反应烧结及冷却阶段。用数值仿真的方法模拟加热阶段,分析窑内温度场的均匀性。发现窑内热棒的位置及供热功率变化对温度分布影响较大;窑内的对流换热对改善温度场,减小砖坯的表面温差有一定作用;由于发热棒的不合理布置,使得窑内的温度场均匀性较差,升温速率较慢,电窑热效率偏低。

There are three time sections for SiC-Si3N4 firebrick processing in electrical resistance furnace, which is called heating, chemical reaction-sintering and cooling section. This paper simulates the heating section and analyses the temperature field uniformity. It finds that the setting and input power of heating rod has much affection to temperature distribution. And it finds that the heat convection in furnace can weak the temperature difference on stock surface, and improve temperature field. Because of the uneven temperature field, the stock temperature increasing rate is slow, so the thermal efficiency of electrical furnace is lower.