Battery-Boosted, rapid startup of frozen fuel cell
AssigneeUTC Fuel Cells, LLC
InventorCarl A. Reiser
Life of this patent
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Abstract
A fuel cell stack (7) has an auxiliary load (30) in series with a battery (29) which can selectively (25) be connected across the fuel cell stack in place of a main load (24). A method includes connecting the battery and auxiliary load across the fuel cell stack while providing fuel (13) to the anode flow fields (8, 10); in one embodiment, oxidant (17) is provided to the cathode flow fields (16) initially; in a second embodiment, oxidant is withheld from the cathode flow for a predetermined time or until a threshold voltage is reached.
Claims16
A fuel cell system comprising:
- a fuel cell stack including a plurality of contiguous fuel cells, each cell having an anode with a fuel flow field;
- a source of fuel;
- a main load;
- a series circuit including a DC power source in series with an auxiliary load, said source and said load selected to cause an initial current density of at least a predetermined magnitude in said fuel cell stack during startup;
- a switch for alternatively connecting either said main load or said series circuit electrically across said fuel cell stack;
- and
- a controller for applying fuel from said source to said fuel flow fields and subsequently causing said switch to connect said series circuit across said fuel cell stack.
A fuel cell system which will start up when frozen, comprising:
- a fuel cell stack including a plurality of contiguous cells, each cell having an anode with a fuel flow field;
- means for applying fuel to said fuel flow field;
- and
- means for externally forcing current through said fuel cell stack to initially provide current density in said cells of at least a predetermined magnitude.
A startup method for a frozen fuel cell stack including a plurality of contiguous cells, each cell having an anode with a fuel flow field, said method comprising:
- applying fuel to said fuel flow fields;
- and
- then externally forcing current through said fuel cell stack to initially provide current density in said cells of at least a predetermined magnitude.
A method for startup of a frozen fuel cell stack comprising:
- providing fuel to said fuel cell stack;
- and
- then connecting a DC source in series with an auxiliary load electrically across said fuel cell stack, said source and said load selected to initially provide a predetermined current density in said fuel cell stack.
Dependencies are inferred from the claim text.