Electric modelling and image analysis of channel flow in bipolar plates

Bipolar plates are an essential part of Polymer Electrolyte Membrane Fuel Cells (PEMFC) and are related to fluid conduction. The topology of a bipolar plate is critical to the homogeneous distribution of the feeding gases over the accessible zone of the electrode. An electric model that simulates flow in bipolar plates and permits the optimisation of gas feeding in PEMFCs is proposed. As a first approach, an analogy is made between the gas pressure P and an electric voltage U in a circuit and a gas flow F and an electric current I. The fluidic resistance in a bipolar plate channel is thus R = P / F and is equivalent to the electric resistance R = U / I in a branch of a circuit. Computer image processing techniques allow the validation of the present flow estimation approach based on electrical variables. Separate plates were developed to experimentally implement a complete parallel bipolar topology.