铝电解槽焦粒焙烧过程中热应力场数值模拟

Numerical Simulation of Thermal Stress Field of Aluminum Reduction Cell during Coke Preheating

用大型商业有限元分析软件ANSYS建立三维瞬态1/4槽热和结构应力场模型,对铝电解槽焦粒焙烧过程中热应力场进行数值模拟,分析了焦粒焙烧所引起的阴极温度分布和热应力分布。选择均匀一致、条形和环形3种类型的焦粒床结构,对比分析了3种结构中所产生的热和应力场分布。研究结果表明,在阳极平均排列时,环形焦粒床所产生的热梯度最小,为最佳的焦粒焙烧方案。此模型从数值上避免了由焙烧启动而带来的阴极内较大温度梯度,能有效地减少铝电解槽早期破损,提高铝电解槽的寿命。

The three-dimension transient thermal and structural ANSYS finite element model of quarter aluminum reduction cell was developed to predict the temperature profile due to coke preheating and evaluate the resulting thermal stresses in the cathode. The uniform, strip and ring coke beds were considered in this model and thermal stresses in the cathode of the three different coke bed were studied and evaluated. The computational results show that the ring coke bed is the best method of the coke preheating which has the least thermal stress in the cathode when anodes are arranged averagely. This model can decrease the early damage of aluminum reduction cell and prolong the life of aluminum reduction cell by avoiding thermal gradient in the cathode resulting from the preheating and the start-up of aluminum reduction cell.