Patent ID: 6979508

Claim:
A PEM fuel cell system, comprising: a membrane/electrode assembly (MEA) including a proton exchange membrane (polymer electrolyte membrane, PEM) between an anode chamber with an anode and a cathode chamber with a cathode; a hydrogen supply network connected to supply hydrogen fuel to said anode, said hydrogen supply network having: a fuel jet pump with an inducing nozzle and a suction input communicating with an anode output of said anode chamber; a two-position pulse-generating hydrogen supply pressure regulator having a hydrogen input and a hydrogen output communicating with said inducing nozzle of said fuel jet pump, feeding an anode fuel reciroulation loop; a hydrogen supply communicating with said hydrogen input of said pressure regulator; wherein said regulator has a first, at least substantially closed position and a second, at least substantially open position for feeding hydrogen to an input of said anode chamber with pulse-fluctuating pressure; and wherein a duration of a cycle and a duration of a pulse within the cycle are variable in dependence on a magnitude of a fuel cell output requirement and the duration of the cycle and the duration of the pulse change under control of said regulator; an air supply network connected to supply air to said cathode, said air supply network having: an air jet pump with an input receiving air from an air supply compressor and a suction input communicating with a cathode output of said cathode chamber; a differential air supply regulator having an input area communicating with said air supply and an output area communicating with an inducing nozzle of said air jet pump; and a connection between said air supply regulator and said hydrogen supply pressure regulator for synchronizing pressure and flow pulses of the cathode air supply with pressure and flow pulses of the anode fuel supply.