储能科学与技术 ›› 2023, Vol. 12 ›› Issue (11): 3361-3368.doi: 10.19799/j.cnki.2095-4239.2023.0477

• 储能系统与工程 • 上一篇    下一篇

基于科赫曲线的PEMFC新型流道设计

刘轲轲1(), 刘永峰1(), 裴普成2, 姚圣卓1, 张璐1   

  1. 1.北京建筑大学,北京 100044
    2.清华大学,北京 100084
  • 收稿日期:2023-07-12 修回日期:2023-07-21 出版日期:2023-11-05 发布日期:2023-11-16
  • 通讯作者: 刘永峰 E-mail:15666037489@163.com;liuyongfeng@bucea.edu.cn
  • 作者简介:刘轲轲(1998—),男,硕士研究生,研究方向为质子交换膜燃料电池,E-mail:15666037489@163.com
  • 基金资助:
    清华大学汽车安全与节能国家重点实验室开放基金(KFY2218)

Design of a novel flow channel structure of PEMFC based on Koch snowflake

Keke LIU1(), Yongfeng LIU1(), Pucheng PEI2, Shengzhuo YAO1, Lu ZHANG1   

  1. 1.Beijing University of Civil Engineering and Architecture, Beijing 100044, China
    2.Tsinghua University, Beijing 100084, China
  • Received:2023-07-12 Revised:2023-07-21 Online:2023-11-05 Published:2023-11-16
  • Contact: Yongfeng LIU E-mail:15666037489@163.com;liuyongfeng@bucea.edu.cn

摘要:

质子交换膜燃料电池流道结构对反应气体流动、热交换、电化学反应具有重要影响。目前,常见流道集中在蛇形、叉指形、点状形、波浪形、平行直流道以及相关改进流道,且在气体均匀性、水管理性能和输出性能上仍有待改进。受数学几何领域的科赫曲线启发,本团队提出了一种新型流道结构,即以圆心为中心向四周辐射,并在6条主干流道的基础上依次添加不同级别的分支流道,最终形成30个流道出口。建立三维稳态单向等温的燃料电池模型,在工作温度为60 ℃,进气相对湿度为100%工况下,搭建燃料电池测试平台进行实验,并借助ANSYS Fluent 2020进行仿真,模型仿真结果与实验结果基本吻合,验证了模型的有效性。将新型流道与传统蛇形流道仿真结果进行比较,分析膜电极电流密度、流道氧气质量分布、流道与气体扩散层交界面水质量分布、膜水含量、流道压力等,结果表明,相比蛇形流道,新型流道的进排气口压降较小、流速较慢,但具有反应气体分布更均匀、水管理效果更好和膜电流密度、输出功率更高等优势,且峰值电流密度增加9.60%、峰值功率密度增加12.70%,有望为燃料电池流道结构创新提供新的思路。

关键词: 质子交换膜燃料电池, 科赫曲线, 新型流道, 数值模拟

Abstract:

The flow channel structure of a proton-exchange membrane fuel cell (PEMFC) has an important influence on the reaction gas flow, heat exchange, and electrochemical reactions. Common flow channels are concentrated in serpentine, interdigital, point-shaped, wavy, parallel, and related improved channels. However, their gas uniformity, water management, and output performance require improvement. Inspired by the Koch snowflake in the field of mathematical geometry, a new channel structure is proposed, i.e., taking the center of the circle as the center to radiate around. Based on six main channels, different levels of branch channels are added in turn to form 30 channel outlets. A three-dimensional steady-state unidirectional isothermal fuel-cell model was developed. Under an operating temperature of 60 ℃ and inlet relative humidity of 100%, a fuel cell testing platform was built for the experiments and simulated using ANSYS Fluent 2020. The model simulation results were consistent with the experimental results, thereby verifying the effectiveness of the model. The simulation results of the new channel and the traditional serpentine channel were compared, and the current density of the membrane electrode, oxygen mass distribution in the channel, water mass distribution at the interface between the channel and gas diffusion layer, membrane water content, and channel pressure were analyzed. The results showed that, compared with the serpentine channel, the new channel has a lower inlet and outlet pressure difference and slower flow rate but has advantages such as a more uniform distribution of reaction gas, better water management effect, and higher membrane current density and output power. The peak current density increased by 9.60%, and the peak power density increased by 12.70%, which is expected to provide new ideas for the innovation of fuel cell flow channel structure.

Key words: proton exchange membrane fuel cell, koch snowflake, new flow channel, numerical simulation

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