Numerical analysis of the optimum membrane/ionomer water content of PEMFCs: The interaction of Nafion® ionomer content and cathode relative humidity
Numerical analysis of the optimum membrane/ionomer water content of PEMFCs: The interaction of Nafion® ionomer content and cathode relative humidity
复制标题
DOI：
10.1016/j.apenergy.2014.10.011
复制
发表时间：
2015-01
期刊：
影响因子：
11.2
通讯作者：
L. Xing;P. Das;Xueguan Song;M. Mamlouk;K. Scott
中科院分区：
文献类型：
--
作者：
L. Xing;P. Das;Xueguan Song;M. Mamlouk;K. Scott
建立了质子交换膜燃料电池（PEMFC）的二维跨通道等温两相流模型，研究了干态Nafion®离聚物体积分数（L-M-dry）与阴极相对湿度（RHc）的相互作用.团聚体模型用于描述催化剂层的性质，其中团聚体被离聚物和液态水膜覆盖。最佳离聚物水含量建议通过最大化氧扩散速率通过离聚物膜。研究了LMdry和RHc对膜和离聚物溶胀及电池性能的影响。在固定的电池电压的预测电流密度进行了分析的克里格代理模型，并用于优化的L M干和RH c的基础上分析它们的相互作用。模拟结果表明，最佳离聚体含水量随着离聚体含量的增加而增加。在更高的电流密度下，例如1.0 A cm− 2，最佳的电池性能是在10%的L M dry下实现的，对应于0.3 mg cm− 2，具有完全加湿的入口气体。当LM干度为40%时，最佳相对湿度c在60%~ 80%之间。模拟结果还表明，在较高的电流密度，最佳RH c最初降低，然后增加，作为L M干增加。最适相对湿度c随干重从10%增加到30%而从76%下降到73%，随干重增加到50%而上升到85%。
A two dimensional, across the channel, isothermal, two-phase flow model for proton exchange membrane fuel cells (PEMFCs) is developed to investigate the interaction of dry Nafion® ionomer volume fraction (L M dry) and cathode relative humidity (RH c) in PEMFCs. The agglomerate model is used to describe the catalyst layers properties, in which the agglomerate is covered by ionomer and liquid water films. The optimum ionomer water content is suggested by maximising the oxygen diffusion rate through the ionomer film. The effects of L M dry and RH c on membrane and ionomer swelling and the cell performance are studied. The predicted current densities at fixed cell voltages are analysed by the Kriging surrogate model and used to optimise the L M dry and RH c based on analysing their interaction. The simulation results show that the optimum ionomer water content increases as the ionomer content increases. At higher current densities, eg 1.0 A cm− 2, the best cell performance is achieved with L M dry of 10%, corresponding to 0.3 mg cm− 2, with fully humidified inlet gases. The optimum RH c is between 60% and 80% for L M dry of 40%. The modelling results also show that at higher current densities, the optimum RH c initially decreases then increases as L M dry increases. The optimum RH c decreases from 76% to 73% as L M dry increases from 10% to 30% then it increases up to 85% as L M dry increases to 50%.