Patent ID: 7820333
Filing Date: 2010-10-26
Classification: H01M,Y02E

Abstract:
1. A fuel cell system comprising: a plurality of fuel cells, each of said fuel cells including a membrane electrode assembly, an anode catalyst layer on a first side of said membrane electrode assembly and a cathode catalyst layer on a second side of said membrane electrode assembly, said plurality of fuel cells arranged in at least two stages, said plurality of fuel cells in each of said at least two stages are arranged in a parallel configuration and said stages are arranged in a series configuration, a first stage having a first plurality of fuel cells and a second stage having a second plurality of fuel cells, said first plurality of fuel cells comprising a greater number of fuel cells than said second plurality of fuel cells; an anode gas inlet manifold in communication with said first stage; at least one anode gas inlet/exhaust manifold, said anode gas inlet/exhaust manifold allowing anode exhaust gas to exit said first stage and allowing said anode exhaust gas to enter said second stage; an anode gas exhaust manifold in communication with said second stage; a cathode gas inlet manifold in communication with said second stage, said cathode gas inlet manifold including a first cathode gas inlet in direct communication therewith; at least one cathode gas inlet/exhaust manifold, said cathode gas inlet/exhaust manifold allowing a cathode exhaust gas to exit said second stage and allowing said cathode exhaust gas to enter said first stage, said at least one cathode gas inlet/exhaust manifold further including a second cathode gas inlet in direct communication therewith; a cathode gas exhaust manifold in communication with said first stage, wherein said anode gas inlet, said anode gas inlet/exhaust and said anode gas exhaust manifolds are positioned such that an anode gas flows in a first direction through said at least two stages, said cathode gas inlet, said cathode gas inlet/exhaust and said cathode gas exhaust manifolds positioned such that a cathode gas flows in a direction generally opposite said first direction; a first cathode gas inlet valve in communication with said cathode gas inlet manifold providing said cathode gas to said second stage and via said cathode gas inlet/exhaust manifold to said first stage; and a second cathode gas inlet valve in communication with said second cathode gas inlet providing additional cathode gas mixing with said cathode exhaust gas exiting said second stage prior to entrance into said first stage, said first and second cathode gas inlet valves together reducing a pressure drop across said cathode gas inlet, said cathode gas inlet/exhaust and said cathode gas exhaust manifolds.