Water management system for solid polymer electrolyte fuel cell power plants

摘要

A simplified solid polymer electrolyte fuel cell power plant utilizes porous conductive separator plates having central passages which are filled with circulating coolant water. The coolant water passes through a heat exchanger which rejects heat generated in the power plant. Water appearing on the cathode side of each cell membrane is pumped into the water circulation passages through the porous oxidant reactant flow field plates by a positive DELTA P created between the cathode reactant flow field of each cell and the coolant water circulation passages between each cell. In order to create the desired DELTA P, at least one of the reactant gas streams will be referenced to the coolant water loop so as to create a coolant loop pressure which is less than the referenced reactant gas stream pressure. Excess water is removed from the coolant water stream. The system can operate at ambient or at elevated pressures. Each cell in the power plant is individually cooled on demand, and the power plant does not require a separate cooling section or reactant stream humidifying devices.