Flow Analysis in PEMFC Stack for Variation of Channel Width between Cells

Proton exchange membrane fuel cells (PEMFCs) continue to attract significant attention because of their various advantages, such as a high power density, clean energy source, and operation at a relatively low temperature and pressure. Generally, a single PEMFC can provide a voltage of 0.6 to 0.7 V, and several single cells are serially connected to build a stack for a high voltage. The uniform flow distribution in the stack is vital for high performance and stable operation. The more the number of cells stacked, the more is the pressure drop produced in the manifold, which is the main reason for the uneven flow distribution. An uneven flow distribution causes performance loss and malfunction of the stack. In this study, the pressure variation and the flow distribution in a fuel cell stack are simulated by FLUENT. Moreover, the gradient of the channel width between the cells is suggested to prevent uneven flow distribution.