CIESC Journal ›› 2021, Vol. 72 ›› Issue (4): 2276-2282.DOI: 10.11949/0438-1157.20201184

• Energy and environmental engineering • Previous Articles     Next Articles

Study on freezing characteristics of water in gas diffusion layer of proton exchange membrane fuel cells

UTAKA Yoshio1,2(),XU Jingying1,WANG Guozhuo1,CHEN Zhihao1,2()   

  1. 1.School of Mechanical Engineering, Tianjin University, Tianjin 300350, China
    2.Key Laboratory of Efficient Utilization of Low and Medium Grade Energy (Tianjin University), Ministry of Education, Tianjin 300350, China
  • Received:2020-08-19 Revised:2020-10-22 Online:2021-04-05 Published:2021-04-05
  • Contact: CHEN Zhihao

质子交换膜燃料电池内含水气体扩散层的冻结特性研究

宇高义郎1,2(),许竞莹1,王国卓1,陈志豪1,2()   

  1. 1.天津大学机械工程学院,天津 300350
    2.中低温热能高效利用教育部重点实验室(天津大学),天津 300350
  • 通讯作者: 陈志豪
  • 作者简介:宇高义郎(1949—),男,博士,教授,utaka@ynu.ac.jp
  • 基金资助:
    国家重点研发计划项目(2018YFB0105405)

Abstract:

To study the freezing characteristics of the water-containing gas diffusion layer (GDL) and the law of water migration, a visual observation system of the freezing process of the water-containing GDL was designed and built. The freezing process of the water-containing GDL was studied by visual experiment research. The temperature change during the freezing process of the water-containing GDL was analyzed. The influence of wettability and supercooling degree on freezing probability were analyzed. Experimental results show that the sudden freezing at a nucleation point of the GDL causes the release of the supercooled state of the water inside the entire GDL, and then the supercooled water is squeezed out of the GDL pores under the volume expansion force of liquid-solid phase change. Water inside the hydrophobic GDL freezes at higher supercooling degree. With the decrease of GDL temperature, the freezing probability of supercooled water inside GDL increases continuously. This study explores the freezing characteristics of the water-containing GDL, which can lay a foundation for solving the problem of the water-containing GDL freezing during the cold start-up of the proton exchange membrane fuel cell (PEMFC) in the future.

Key words: fuel cell, nucleation, gas diffusion layer, freezing characteristic, wettability, porous media

摘要:

为了研究含水气体扩散层(GDL)的冻结特性及水分迁移规律,设计并搭建了含水GDL冻结过程的可视化观测系统。制备了不同润湿性的含水GDL,并对含水GDL的冻结过程进行了可视化实验研究,分析了含水GDL冻结过程中的温度变化,以及润湿性和过冷度对于结冰概率的影响。实验结果表明:含水GDL中的某点突然结冰引发整个GDL内水的过冷状态释放,随后在液固相变的体积膨胀作用下,尚未冻结的过冷水被挤压到GDL孔隙外;疏水性GDL会在更高过冷度下产生冻结现象;随着含水GDL温度的降低,内部过冷水的冻结概率不断增加。本研究探索了含水GDL的冻结特性,可为今后解决质子交换膜燃料电池(PEMFC)冷启动过程中GDL低温冻结问题奠定基础。

关键词: 燃料电池, 成核, 气体扩散层, 冻结特性, 润湿性, 多孔介质

CLC Number: