使用格子博尔兹曼法和计算机断层扫描扫描技术对气体扩散层内部突破的定量测量和比较
Hossein Pourrahmani1, Milad Hosseini2, Hamza Moussaoui3
1Group of Energy Materials, École Polytechnique Fédérale de Lausanne, 1951, Sion, Switzerland. hossein.pourrahmani@epfl.ch.
Scientific reports
|April 26, 2024
概括
质子交换膜燃料电池 (PEMFC) 中的剩余水阻碍了冷启动. 本研究使用格子博尔茨曼法 (LBM) 建模来量化气体扩散层 (GDL) 中的水分去除,比较原始和老化的样本.
科学领域:
- 电化学 电化学 电化学
- 材料科学 材料科学 材料科学
- 计算流体动力学的流体动力学.
背景情况:
- 质子交换膜燃料电池 (PEMFC) 的气体扩散层 (GDL) 中的残留水对冷启动性能和耐用性产生负面影响.
- 在GDL中了解水资源管理对于优化PEMFC运行和寿命至关重要.
研究的目的:
- 开发和验证一种计算方法来定量评估GDLs的去水性能.
- 为了比较原始与老年GDL样本的水分保留特性,没有进行广泛的实验测试.
- 调查衰老对GDLs微结构性质和水运行为的影响.
主要方法:
- 使用格子博尔茨曼方法 (LBM) 开发了一个计算模型,以模拟GDL中的水运输.
- 该模型结合了毛细血管压力效应,并分析了从计算机断层扫描 (CT) 扫描中获得的GDL几何.
- 对原始和老化的GDL样本进行了水柱形成 (突破) 的定量分析.
主要成果:
- 该研究量化了原始和老化的GDL样本中的残留水柱体体积:分别为6.32%和10.12%.
- 与原始样本相比,老化的GDL样本表现出更高的水分保留倾向.
- 微结构分析揭示了衰老对GDL特性,如连接性和有效扩散性的重大影响.
结论:
- 开发的基于LBM的方法提供了一种有效的手段,可以量化地比较GDL的去水性能.
- 衰老明显改变了GDL的微观结构,导致水的积累增加,并可能损害燃料电池的功能.
- 这种方法在PEMFC开发中为GDL材料选择和耐久性评估提供了有价值的工具.
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