基于PBM模型的狭缝模头内颗粒行为分析

Behavior analysis of particle in slot-die head based on PBM model

为探究用于氢燃料电池生产的狭缝模头内部流场中固液两相流动与催化剂颗粒聚并、破碎的情况,使用修正过的PBM(群体平衡模型)针对颗粒行为进行数值模拟,研究流场内及出口的颗粒分布情况及不同条件对出口粒径的影响。结果表明:离散相与连续相的体积分数与速度均匀。聚并形成的大颗粒主要分布在近壁处,而中央区以较小的颗粒为主;通过增大进口速度、减小固含量可以削弱聚并现象,出口处的粒径明显降低。模拟结果可以为氢燃料电池催化剂膜的生产工艺优化提供理论参考。

In order to investigate the flow of solid and liquid phases in the internal flow field of the slot-die head for hydrogen fuel cell production and the aggregation and breakage of catalyst particles,numerical simulations were performed with a modified PBM(population balance model)to investigate the particle distribution within the flow field,outlet and the effect of different conditions on particle size of outlet.The results show that the volume fraction and velocity of discrete and continuous phases are equal.The large particles formed by aggregation are mainly distributed near the wall,while the central zone is dominated by smaller particles.By increasing the inlet velocity and decreasing the sloid content,the aggregation phenomenon can be weakened,the particle size of the outlet is obviously reduced,and the distribution is improved.The simulation results can provide theoretical reference for the optimization of the production process of hydrogen fuel cell catalyst membrane.