TY  - EJOU
AU  - Shao, Qianqian 
AU  - Wang, Min 
AU  - Xu, Nuo 

TI  - Influences of Co-Flow and Counter-Flow Modes of Reactant Flow Arrangement on a PEMFC at Start-Up
T2  - Computer Modeling in Engineering \& Sciences

PY  - 2024
VL  - 139
IS  - 2
SN  - 1526-1506

AB  - To investigate the influences of co-flow and counter-flow modes of reactant flow arrangement on a proton exchange membrane fuel cell (PEMFC) during start-up, unsteady physical and mathematical models fully coupling the flow, heat, and electrochemical reactions in a PEMFC are established. The continuity equation and momentum equation are solved by handling pressure-velocity coupling using the SIMPLE algorithm. The electrochemical reaction rates in the catalyst layers (CLs) of the cathode and anode are calculated using the Butler-Volmer equation. The multiphase mixture model describes the multiphase transport process of gas mixtures and liquid water in the fuel cell. After validation, the influences of co-flow and counter-flow modes on the PEMFC performance are investigated, including the evolution of the current density, flow field, temperature field, and reactant concentration field during start-up, as well as the steady distribution of the current density, reactant concentration, and membrane water content when the start-up stabilizes. Co-flow and counter-flow modes influence the current density distribution and temperature distribution. On the one hand, the co-flow mode accelerates the start-up process of the PEMFC and leads to a more evenly distributed current density than the counter-flow mode. On the other hand, the temperature difference between the inlet and outlet sections of the cell is up to 10.1°C under the co-flow mode, much larger than the 5.0°C observed in the counter-flow mode. Accordingly, the counter-flow mode results in a more evenly distributed temperature and a lower maximum temperature than the co-flow case. Therefore, in the flow field design of a PEMFC, the reactant flow arrangements can be considered to weigh between better heat management and higher current density distribution of the cell.
KW  - PEMFC; full coupling model; Butler-Volmer equation; multiphase mixture model; co-flow mode; counter-flow mode

DO  - 10.32604/cmes.2023.044313