Konferensartikel

This paper proposes the numerical analyses on performance for PEMFC in the aspects of water management and distribution of current density were performed to compare serpentine channel flow field of 5 passes 4 turns serpentine and 25cm2 reaction surface between with and without sub-channel at rib. Through the supplement of sub-channel flow field; the improvement of water removal characteristic inside channel was confirmed from the numerical results because the flow direction of under-rib convection is changed into the sub-channel. Reacting gases supplied from entrance disperse into sub-channel flow field and electrochemical reaction occurs uniformly over the reaction surface. Therefore; it was also known that total current density distributions become uniform because retention time of reacting gases traveling to sub-channel flow field is longer than main channel. At the averaged current density of 0.6 A/cm²; the results show that output power for the serpentine flow-field with sub-channel is 8.475 W which is decreased by about 0.35 % compared with 8.505 W for the conventional-advanced serpentine flow-field; whereas the pressure drops on the anode and cathode side for the serpentine flow-field with sub-channel are 0.282 kPa and 1.321 kPa which are decreased by about 22.95 % and 17.12 % compared with 0.366 kPa and 1.594 kPa for the conventional-advanced serpentine flow-field; respectively.

PEM Fuel Cell; Current density; Water management; Under-rib convection; Sub-channel