Liquid Water Transport in Gas Diffusion Layer of Polymer Electrolyte Fuel Cells
Liquid Water Transport in Gas Diffusion Layer of Polymer Electrolyte Fuel Cells
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DOI：
10.1149/1.1646148
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发表时间：
2004-03
影响因子：
3.9
通讯作者：
U. Pasaogullari;Chaoyang Wang
中科院分区：
文献类型：
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作者：
U. Pasaogullari;Chaoyang Wang
高电流密度性能的聚合物电解质燃料电池~PEFCs！已知受到反应物和产品运输的限制。此外，在高电流密度下，会产生过量的水并冷凝，使电极的孔洞充满液态水，从而限制了反应物向活性催化剂的传输。这种被称为“泛洪”的现象是PEFC性能的一个重要限制因素。在这项工作中，描述了水在亲水和疏水扩散介质中传输的主导物理以及相关传输过程的一维解析解。结果表明，液态水在气体扩散层中的输运~Gd1！由相饱和度梯度产生的毛细管力控制。导出了液态水在气液两相流中传输的一维解析解，并预测在局部电流密度为1.4A/cm2时，液态水的饱和度将超过10%
High-current-density performance of polymer electrolyte fuel cells ~PEFCs! is known to be limited by transport of reactants and products. In addition, at high current densities, excessive amount of water is generated and condenses, filling the pores of electrodes with liquid water, and hence limiting the reactant transport to active catalyst. This phenomenon known as ‘‘flooding’’ is an important limiting factor of PEFC performance. In this work, the governing physics of water transport in both hydrophilic and hydrophobic diffusion media is described along with one-dimensional analytical solutions of related transport processes. It is found that liquid water transport across the gas diffusion layer ~GDL! is controlled by capillary forces resulting from the gradient in phase saturation. A one-dimensional analytical solution of liquid water transport across the GDL is derived, and liquid saturation in excess of 10% is predicted for a local current density of 1.4 A/cm 2