Visualization of initial evolution of flooding in proton exchange membrane fuel cells with parallel flow channels

초록

To maintain optimal performance and extend the lifespan of proton exchange membrane fuel cells (PEMFCs), it is essential to monitor the generation and movement of liquid water and detect flooding at an early stage. This study utilizes transparent single cells with parallel channels and confirms that fog formation is confined to specific areas of the channel. Subsequently, the area of water droplets was quantified, revealing that 82% of all droplets were located within the fog area. The simulation results reveal that the region consistently encompasses areas with relative humidity (RH) of 1.8 or higher and a current density of 0.4 A/cm2 or less. Simultaneously, flooding in the corresponding area is detected through high-frequency resistance (HFR) measurements, revealing that the HFR fluctuation cycle shortens, and the magnitude of HFR variation decreases as relative humidity (RH) increases or voltage decreases.

키워드