FUEL CELL HAVING INTERDIGITATED FLOW CHANNELS AND WATER TRANSPORT PLATES

摘要

The present invention is a fuel cell power plant (10) that includes a fuel cell (12) having a membrane electrode assembly (16), which is disposed between an anode support plate (17) and a cathode support plate (19), and porous water transport plates (84', 86') adjacent the anode and cathode support plates. The porous water transport plates have interdigitated flow channels for the reactant gas streams (110) to pass therethrough and conventional flow channels for a coolant stream (98) to pass therethrough. The fuel cell power plant also has means for creating a pressure differential between the reactant gas streams and the coolant stream such that the pressure of the reactant gas streams is greater than the coolant stream. Incorporating the interdigitated flow channels into the porous water transport plates and operating the fuel cell at a pressure differential allows the coolant water to saturate the water transport plates thereby forcing the reactant gases into the anode and cathode support plate. This, in turn, increases the mass transfer of such gases into the support plates, thereby increasing the electrical performance of the fuel cell. Current densities of about 1.6 amps per square meter are achieved with air stochiometries of not over 2.50.