Solid oxide fuel cell generator with mid-stack fuel feed

1. A solid fuel oxide fuel cell generator comprising:

a housing defining a plurality of chambers including a generator chamber and first and second combustion zones located adjacent to opposite ends of said generator chamber;

said generator chamber including first and second generator sections, said first and second generator sections located between said first and second combustion zones;

a plurality of elongated fuel cells, each said fuel cell extending through said first and second generator sections and including opposing open ends wherein each said open end opens into one of said chambers defined within said housing;

an oxidant supply supplying oxidant to said housing;

a fuel distribution plenum extending transversely to said elongated fuel cells through said generator chamber and located between and distributing fuel to said first and second generator sections; and

wherein said first and second combustion zones receive a portion of the fuel passing through said first and second generator sections, respectively, said portion of the fuel comprising depleted fuel from said generator chamber.

2. The generator of claim 1 , wherein each of said fuel cells open into at least one of said combustion zones.

3. The generator of claim 2 , including first and second oxidant chambers located adjacent each of said combustion zones, each said oxidant chamber receiving oxidant from said oxidant supply and supplying oxidant to a predetermined number of said fuel cells.

4. The generator of claim 2 , wherein said first combustion zone receives vitiated oxidant from a first set of said fuel cells and mixes said vitiated oxidant with a fraction of said depleted fuel from said generator chamber, and a second set of fuel, cells conveys said vitiated oxidant and depleted fuel to said second combustion zone.

5. The generator of claim 2 , wherein said second combustion zone comprises an oxidant chamber receiving oxidant from said oxidant supply where said depleted fuel from said generator chamber mixes with said oxidant prior to entering said fuel cells.

6. A fuel cell generator comprising:

a housing defining a plurality of chambers including a generator chamber having first and second generator sections;

a plurality of elongated fuel cells, each said fuel cell extending through said first and second generator sections and including opposing open ends wherein each said open end opens into one of said chambers defined within said housing;

an oxidant supply supplying oxidant to said housing;

a fuel distribution plenum extending transversely to said elongated fuel cells through said generator chamber and located between and distributing fuel to said first and second generator sections; and

wherein said oxidant passes through a first set of said fuel cells in a first direction and each of said first set of fuel cells includes an exhaust end that opens into a first combustion zone, and said oxidant passes through a second set of said fuel cells in a second direction opposite to said first direction and each of said second set of fuel cells includes an exhaust end that opens into a second combustion zone.

7. The generator of claim 6 , wherein one or more of said chambers comprise a combustion zone, and oxidant entering said housing is caused to pass through at least one of said one or more combustion zones prior to passing through said generator sections.

8. The generator of claim 6 , wherein at least two of said chambers comprise oxidant chambers located at opposite ends of said housing for receiving oxidant from said oxidant supply and supplying oxidant to said open ends of said fuel cells.

9. The generator of claim 8 , including a chamber defining each said combustion zone located between each of said oxidant chambers and one of said first and second generator sections, and each of said fuel cells open into one of said combustion zones chambers where a fraction of depleted fuel from said generator sections reacts with vitiated oxidant exiting said fuel cells.

10. The generator of claim 9 , including a recirculation plenum adjacent each of combustion zones and connected to a recirculation circuit for recirculating depleted fuel to said fuel distribution plenum.

11. The generator of claim 6 , wherein at least one of said chambers comprises an oxidant chamber receiving oxidant from said oxidant supply and including a first combustion zone located at an end of said housing opposite from said oxidant chamber, and said oxidant passing through said second set of fuel cells comprises an oxidant from said first set of fuel cells that has partially reacted with depleted fuel from said first generator section within said first combustion zone.

12. The generator of claim 11 , including a second combustion zone located between said oxidant chamber and one of said first and second generator sections wherein said oxidant passing through said second set of fuel cells exits said second set of fuel cells into said second combustion zone and reacts with depleted fuel from said second generator section.

13. The generator of claim 12 , including a recirculation plenum adjacent each of combustion zones and connected to a recirculation circuit for recirculating depleted fuel to said fuel distribution plenum.