Fuel cell power plant having improved operating efficiencies

摘要

A fuel cell power plant (10) includes an oxidant stream controlled to enter a fuel cell (12) of the plant at a pressure of between about 0.058 pounds per square inch gas (‘psig’) and about 4.4 psig and the oxidant stream passes through the fuel cell (12) at an oxidant stoichiometry of between about 120% and about 180%, and preferably between about 150% and 170%. A macro-pore cathode gas diffusion layer (36) is secured between a cathode catalyst (16) and a cathode flow field (28). A porous coolant plate (44) is secured in fluid communication with and adjacent the cathode flow field (28). The gas diffusion layer (36) and coolant plate (44) facilitate removal of product water to eliminate flooding and to permit operation at low oxidant stoichiometry and high water balance temperature, thereby minimizing need for water capture and heat rejection apparatus.