Patent ID: 8445157

Claim:
A method of operating a fuel cell stack comprising a plurality of fuel cells and a plurality of interconnects, wherein each of the plurality of the interconnects comprises: an inlet fuel distribution plenum; a single fuel inlet opening, the fuel inlet opening substantially centered in the inlet fuel distribution plenum; an outlet fuel distribution plenum; a single fuel outlet opening, the fuel outlet opening substantially centered in the outlet fuel distribution plenum; a first set of fuel flow channels in a first portion of the interconnect; a second set of fuel flow channels in a middle portion of the interconnect, wherein the middle portion of the interconnect is aligned with the single fuel inlet opening and the single fuel outlet opening, and wherein the channels of the first set are located in peripheral portions of the interconnect on the two sides of the second set of channels; wherein: the first and second sets of fuel flow channels are connected to the inlet fuel distribution plenum and the outlet fuel distribution plenum; the first and second sets of fuel flow channels comprise passages between continuous ribs which extend between the inlet and outlet fuel distribution plenums; and the fuel flow channels of the first set have a different cross sectional area than the fuel flow channels of the second set; and wherein the method comprises providing fuel through the single fuel inlet opening in each of the plurality of the interconnects such that the fuel flows from the single fuel inlet opening through the inlet fuel distribution plenum, and from the inlet fuel distribution plenum through the first and second sets of fuel flow channels to the plurality of the fuel cells.