AVOIDING FUEL STARVATION OF ANODE END FUEL CELL

摘要

The fuel flow channels (20a) of the end fuel cell (9a) at the anode end (34) of a fuel cell stack are significantly deeper than the fuel flow field channels (20) of the remaining fuel cells (9) in the stack, whereby fuel starvation caused by ice in the fuel flow channels is avoided during cold startup. The fuel flow field channels of the end cell (9) at the anode end of the stack is between about 0.15 mm and about 1.5 mm deeper than the fuel flow field channels in the remaining fuel cells of the stack, or between about 35% and about 65% deeper than the fuel flow field channels in the remaining fuel cells of the stack.

主权项

1. Apparatus comprising:
a fuel cell stack (31) including a plurality of contiguous fuel cells (9) compressed between a pair of end plates (32), each of said fuel cells comprising an electrolyte (10) with an anode catalyst layer (13) on one surface of the electrolyte and a cathode catalyst layer (14) on a second surface of the electrolyte, an anode gas diffusion layer (16) adjacent the anode catalyst and a cathode gas diffusion layer (17) adjacent the cathode catalyst, an anode water transport plate (21) having a fuel flow field adjacent the anode gas diffusion layer and a cathode water transport plate (28) having to an oxidant flow field adjacent the cathode gas diffusion layer; said stack having an anode end (34) characterized by: the depth of fuel flow field channels in the fuel flow field of the fuel cell at the anode end of the stack being either a) between about 35% and about 65% deeper than the fuel flow field channels in the fuel flow plates of the remaining fuel cells in the stack, or b) being deeper than the fuel flow field channels in the fuel flow plates of the remaining fuel cells in the stack by about 0.15 mm to about 1.5 mm, or preferably from about 0.15 mm to about 0.5 mm, or more preferably from about 0.15 mm to about 0.25 mm.