VARIABLE FUEL PRESSURE CONTROL FOR A FUEL CELL

摘要

A fuel cell includes a cathode having an air flow field. An anode includes an inlet and an outlet for providing unused fuel to a fuel recycling line. A pressure regulator is arranged upstream from an ejector and communicates with the air flow field for adjusting a fuel pressure at the motive inlet in response to an air pressure associated with the air flow field. The cathode and/or anode includes a porous water transport plate adjacent to the air flow field and/or fuel flow field respectively. A back pressure valve is arranged downstream from the air flow field for producing an air back pressure that generates a desired differential pressure across the water transport plate. The back pressure valve is controlled to achieve the desired differential pressure across the water transport plate so that the fuel cell maintains water balance.