• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>International Conference on Fuel Cell Science, Engineering and Technology; 20040614-20040616; Rochester,NY; US >INFLUENCE OF POROUS ELECTRODE STRUCTURE ON PEM FUEL CELLS DESIGN AND PERFORMANCE
【24h】

INFLUENCE OF POROUS ELECTRODE STRUCTURE ON PEM FUEL CELLS DESIGN AND PERFORMANCE

机译：多孔电极结构对PEM燃料电池设计和性能的影响

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Gas flow in fuel cell porous electrodes is usually modelled with Darcy's law, which requires the definition of a resistance constant for the material. This can be done directly via experimentation or indirectly via numerical tuning to fit experimental data on cell behaviour. Both methods lack generality, as they do not take into account the particular porous structure of each electrode. In the present work, a numerical procedure for calculating the resistance constant for a given porous structure is presented. This procedure is based on Lattice Boltzmann models, which treat the problem from a microscopic point of view, reproducing collisions between fluid molecules and solid particles. It can be demonstrated that under certain hypotheses, these models yield Navier-Stokes equations on a macroscopic scale, hence obeying fluid mechanics laws. Here the flow in a set of thirty randomly generated porous structures was analyzed, thus obtaining a distribution of values for Darcy's constant. The analysis was repeated for ten different pressure gradients applied to a portion of the electrode and for three different volume porosities. The results showed that, for a given volume porosity, the value of Darcy's constant is strongly affected by the material porous structure. On the other hand, the mean value of resistance remained almost constant while varying the applied load, thus correctly reproducing the linear dependence between velocity and pressure gradient, as stated by Darcy's law.
机译：燃料电池多孔电极中的气体流动通常用达西定律建模，该定律要求定义材料的电阻常数。这可以通过实验直接完成，也可以通过数值调整间接完成，以使实验数据适合细胞行为。两种方法都缺乏通用性，因为它们未考虑每个电极的特定多孔结构。在本工作中，提出了一种计算给定多孔结构电阻常数的数值程序。该程序基于莱迪思·博尔兹曼（Lattice Boltzmann）模型，该模型从微观角度处理问题，重现流体分子与固体颗粒之间的碰撞。可以证明，在某些假设下，这些模型在宏观尺度上产生Navier-Stokes方程，因此遵循流体力学定律。在这里，分析了一组三十个随机生成的多孔结构中的流动，从而获得了达西常数值的分布。对施加到电极的一部分的十种不同的压力梯度和三种不同的体积孔隙率重复分析。结果表明，对于给定的体积孔隙率，达西常数的值受材料多孔结构的强烈影响。另一方面，在改变施加的负载时，电阻的平均值几乎保持恒定，从而正确地再现了速度与压力梯度之间的线性关系，如达西定律所述。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号