Abstract:

In this paper, the mixing process of the catalyst ink for proton exchange membrane fuel cell is investigated. The relationship between the rheological properties and density of the ink and the volume fraction of platinum-carbon particles is experimentally determined. A three-phase multiphase flow model for the mixing process is developed specifically for the preparation of polymer electrolyte fuel cell ink. Numerical simulations are performed to analyze the flow field and dispersion characteristics of platinum-carbon particles considering the influence of both blade stirring and high-speed shear dispersion. The results suggest that the large-scale flow structures generated by the mixing blade are ineffective in preventing the settling of platinum-carbon particles. However, by introducing a high-speed shear dispersion device, the settling of platinum-carbon particles can be alleviated to some extent. Additionally, the dispersion characteristics of platinum-carbon particles in the flow field can be improved due to the mixing effect of this device. The results could provide an important guide for the design and improvement of ink-mixing devices, and offer substantial theoretical support for the efficient preparation of catalyst ink for proton exchange membrane fuel cells.

Key words: fuel cell, computational fluid dynamics, multiphase flow, mixing, rheology

摘要：

对质子交换膜燃料电池催化剂浆料制备工艺中浆料的混合过程进行了深入研究。通过实验测量获得了浆料流变特性、密度与铂-碳颗粒体积分数之间的关联关系，并建立了浆料混合过程的“液-固-气”三相流动模型。在此基础上，结合桨叶搅拌和高速剪切分散作用，对浆料混合过程中混浆装置内部的流场结构和铂-碳颗粒分散特性进行了数值模拟。结果表明，在搅拌桨叶作用下，混浆装置内形成的大尺度流动结构未能有效抑制铂-碳颗粒的沉降现象。然而，引入高速剪切分散装置后，不仅能够通过抽吸作用缓解铂-碳颗粒的沉降，还能通过狭缝喷射流动增强混合效果，从而显著改善铂-碳颗粒在流场中的分散特性。上述结果为混浆装置结构设计与改进提供了重要的指导，为质子交换膜燃料电池催化剂浆料的高效制备提供有力的理论支撑。

关键词: 燃料电池, 计算流体力学, 多相流, 混合, 流变学