TY - JOUR
T1 - Influence of cell temperature on water removal mechanism during shutdown purge in proton exchange membrane fuel cells
T2 - Experimental and simulation analysis
AU - Zhang, Zhenya
AU - Wei, Houyu
AU - Lou, Taishan
AU - Zhang, Jun
AU - Xiao, Yanqiu
AU - Jin, Tingxiang
AU - Tian, Jiean
AU - Li, Xuewei
AU - Liu, Zhengxuan
PY - 2024
Y1 - 2024
N2 - The internal temperature of proton exchange membrane fuel cells significantly influences their shutdown purge process a key factor for ensuring operational stability and longevity. This study explores how cell temperature impacts water removal mechanisms during shutdown purge, emphasizing its importance for the operational stability of fuel cell. High-temperature purge experiments were conducted using an integrated stack experimental platform, revealing that prolonged high-temperature purging increased the high frequency resistance of a single cell to 639.44 mΩ∙cm2 and caused severe perforation of the membrane electrode assembly. To delve deeper into the mechanisms of cell temperature influence and the cause of perforation, an isothermal, transient, two-phase flow fuel cell model was developed. The cell temperature during purge was incrementally raised from 303.15 K to 358.15 K in 5 K steps. Detailed analyses of membrane desorption and water phase changes during purge processes were performed. At cell temperatures ranging from 338.15 K to 358.15 K, a 120-s purge reduced the membrane water content to below 4.8, with only a 5 % variation in residual membrane water. When the cell temperature exceeded 323.15 K, water activity increased with temperature, intensifying evaporation and leading to desorption of vapor from the membrane. Consequently, higher temperatures facilitated the removal of liquid water, with no liquid water remaining within cell above 323.15 K. Elevated cell temperatures accelerated the purge, resulting in lower liquid water content and increased vapor, but with minimal difference in membrane water content. The intense evaporation process and rapid purge at high temperatures were identified as direct causes of membrane electrode assembly perforation. This study highlights the critical role of cell temperature in the shutdown purge process, providing innovative insights into optimizing proton exchange membrane fuel cell operations for enhanced performance and durability.
AB - The internal temperature of proton exchange membrane fuel cells significantly influences their shutdown purge process a key factor for ensuring operational stability and longevity. This study explores how cell temperature impacts water removal mechanisms during shutdown purge, emphasizing its importance for the operational stability of fuel cell. High-temperature purge experiments were conducted using an integrated stack experimental platform, revealing that prolonged high-temperature purging increased the high frequency resistance of a single cell to 639.44 mΩ∙cm2 and caused severe perforation of the membrane electrode assembly. To delve deeper into the mechanisms of cell temperature influence and the cause of perforation, an isothermal, transient, two-phase flow fuel cell model was developed. The cell temperature during purge was incrementally raised from 303.15 K to 358.15 K in 5 K steps. Detailed analyses of membrane desorption and water phase changes during purge processes were performed. At cell temperatures ranging from 338.15 K to 358.15 K, a 120-s purge reduced the membrane water content to below 4.8, with only a 5 % variation in residual membrane water. When the cell temperature exceeded 323.15 K, water activity increased with temperature, intensifying evaporation and leading to desorption of vapor from the membrane. Consequently, higher temperatures facilitated the removal of liquid water, with no liquid water remaining within cell above 323.15 K. Elevated cell temperatures accelerated the purge, resulting in lower liquid water content and increased vapor, but with minimal difference in membrane water content. The intense evaporation process and rapid purge at high temperatures were identified as direct causes of membrane electrode assembly perforation. This study highlights the critical role of cell temperature in the shutdown purge process, providing innovative insights into optimizing proton exchange membrane fuel cell operations for enhanced performance and durability.
KW - Cell temperature
KW - Proton exchange membrane fuel cell
KW - Shutdown purge mechanism
KW - Water content
KW - Water phase change
UR - http://www.scopus.com/inward/record.url?scp=85203869629&partnerID=8YFLogxK
U2 - 10.1016/j.icheatmasstransfer.2024.108071
DO - 10.1016/j.icheatmasstransfer.2024.108071
M3 - Article
AN - SCOPUS:85203869629
SN - 0735-1933
VL - 159
JO - International Communications in Heat and Mass Transfer
JF - International Communications in Heat and Mass Transfer
M1 - 108071
ER -