质子交换膜燃料电池内含水气体扩散层的冻结特性研究  

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

作　　者：宇高义郎 许竞莹 王国卓 陈志豪[1,2] UTAKA Yoshio;XU Jingying;WANG Guozhuo;CHEN Zhihao(School of Mechanical Engineering,Tianjin University,Tianjin 300350,China;Key Laboratory of Efficient Utilization of Low and Medium Grade Energy(Tianjin University),Ministry of Education,Tianjin 300350,China)

机构地区：[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

出　　处：《化工学报》2021年第4期2276-2282,共7页CIESC Journal

基　　金：国家重点研发计划项目(2018YFB0105405)。

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。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.

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 

分 类 号：TK124[动力工程及工程热物理—工程热物理]