Eccentricity design for the coolant distribution optimization of a practical commercial-size proton exchange membrane fuel cell stack using a novel proper orthogonal decomposition based analysis model

Abstract

The uniform distribution of coolant among different coolant flow field plates is of critical importance to the thermal management of proton exchange membrane fuel cell (PEMFC) stacks. Herein, the coolant distribution uniformity is optimized using an eccentric end socket structure based on the computational fluid dynamic (CFD) method. Firstly, the grid systems are comprehensively tested for the refined simulation requirements under a well-distributed condition and a high current density. Then, to reduce the heavy burden of computing resources, a novel analysis model is proposed to further establish the explicit mathematical expression between the coolant distribution curve (CDC) and the eccentricity based on the CFD results and proper orthogonal decomposition (POD). Finally, the coolant distribution uniformity is optimized according to the above explicit expression. Results suggest that for the studied cases, the grid systems with the manifold cross section grid numbers take 4 480 and 8 385 can be regarded as the grid-independent ones under the eccentricity ranges of 0 ∼ 0.7 and 0.7 ∼ 1.0 respectively. The simulated stack pressure drops show a high consistence with the experimental ones with a maximum relative deviation of 10%, validating the reliability of the CFD model. With the increase of the eccentricity, the coolant distribution non-uniformity decreases firstly and finally increase. The CDCs are similar if the eccentricity vector points to the same side of the transverse eccentricity axis. The optimized coolant distribution non-uniformity (1.58%) reduces 4.04 times compared with that in the benchmark case (6.38%) when the eccentricity takes 0.8856.