Title |
Humidity Distribution and Performance Variation of a PEMFC Multi Stack System According to the Direction of Anodic Supply |
DOI |
https://doi.org/10.6110/KJACR.2018.30.3.143 |
Keywords |
고분자 전해질 연료전지 ; 습도분포 ; 평행류 ; 대향류 PEMFC ; Humidity distribution ; Parallel flow ; Counter flow |
Abstract |
In this study the performance and humidity variation for 2 unit cells connected in series were experimentally measured. The relative flow direction of hydrogen and air was changed from parallel flow to counter flow. Internal humidity distribution was then measured by 5 embedded sensors on each channel. In all experimental conditions, the former unit cell showed a better performance and the gap is noted to be higher when counter flow is applied. The performance was noted to be higher at high humidification case in the parallel flow. However, in the counter flow, the difference of performance according to the humidification is negligible. Hydrogen and air are discharged from the PEMFC unsaturated with water vapor at parallel flow/low humidification condition, which explains lower performance of the PEMFC than other conditions. The humidities in hydrogen and air streams of counter flow were noted to increase rapidly even at low humidification condition and the consequential even hydration of membrane is the reason of higher performance. |