Effect of inner dehumidification technique on the performance of a dead-ended proton exchange membrane fuel cell stack

Water management is important for proton exchange membrane fuel cell (PEMFC). To maintain highly efficient and stable operation of PEMFC, water generated in PEMFC needs to be migrated in time. An inner dehumidification technique is proposed to remove the water inside the PEMFC stack. Two inner condensing units are set near the cathode outlet to cooling the moisture gas. Water vapor in the flow channel will transfer directly to the outlet to supplement the vapor loss due to condensing. As a consequence, water flooding is sufficiently mitigated inside PEMFC. The experimental results show that the output voltage of the dead-ended fuel cell stack increases by 9.77% at 1000 mA center dot cm(-2) when the condensing temperatures is 5 degrees C. When the condensing temperature decreases from 20 degrees C to 5 degrees C, the average stack voltage can be increased by 14.3% at 500 mA center dot cm(-2), and the average temperature difference decreases from 3.2 degrees C to 1.8 degrees C. Moreover, the performance and temperature distribution uniformity are all increased with the increasing of the operation temperature due to inner moisture dehumidification.

Automated summary

Water management is crucial for the efficient and stable operation of PEMFC. The implementation of the inner dehumidification technique successfully mitigates water flooding inside the PEMFC, resulting in increased performance and temperature distribution uniformity.