Fuel cell system configurations

• US 4,276,355 A
• Filed: 04/28/1980
• Issued: 06/30/1981
• Est. Priority Date: 04/28/1980
• Status: Expired due to Term

• Current Assignee: United States Department of Energy
• Original Assignee: Westinghouse Electric Company LLC (Brookfield Asset Management Incorporated)
• Inventors: Kothmann, Richard E., Cyphers, Joseph A.
• Primary Examiner(s): LeFevour, Charles F.
• Application Number:
  US06/144,089
• Time in Patent Office: 428 Days
• Field of Search: 429/26, 429/35
• US Class Current: 429/435
• CPC Class Codes: H01M 8/04014 Heat exchange using gaseous fluids; Heat exchange by combustion of reactants
• CPC Class Codes: H01M 8/2485 Arrangements for sealing external manifolds; Arrangements for mounting external manifolds around a stack
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

Fuel cell stack configurations having elongated polygonal cross-sectional shapes and gaskets at the peripheral faces to which flow manifolds are sealingly affixed. Process channels convey a fuel and an oxidant through longer channels, and a cooling fluid is conveyed through relatively shorter cooling passages. The polygonal structure preferably includes at least two right angles, and the faces of the stack are arranged in opposite parallel pairs.

Claims

1. An electrochemical cell system comprising:

a plurality of electrically connected fuel cells and at least one cooling module disposed between selected fuel cells, said fuel cells and cooling module arranged in a stack and shaped in cross section as an elongated polygon having pairs of oppositely disposed peripheral faces, at least one pair of peripheral faces being longer than the remaining pairs and disposed such that the distance between said opposite longer pair of peripheral faces is shorter than the distance between the opposite peripheral faces of the remaining pairs;

each said fuel cell having an electrolyte positioned between a pair of bipolar plates, said bipolar plates defining oxidant channels for transporting an oxidant in reacting communication with said electrolyte, and fuel channels for transporting a fuel in reacting communication with said electrolyte, said fuel and oxidant channels each having an inlet on one shorter peripheral face of said polygon and an outlet on an opposite shorter peripheral face;

said cooling module having cooling passages, said passages having an entry on one peripheral face of said polygon and an exit on an opposite peripheral face, said entry and exit being disposed on said longer peripheral faces of said polygon.

2. The electrochemical cell system of claim 1 further comprising a plurality of conduit structures each sealed to a peripheral face of said stack and forming an ingress manifold common to each fuel channel inlet, an egress manifold common to each fuel channel outlet, an ingress manifold common to exit oxidant channel inlet, an egress manifold common to each oxidant channel outlet, an ingress manifold common to each cooling passage entry, and an egress manifold common to each cooling passage exit.

3. The electrochemical cell system of claim 2 wherein said elongated polygon is an elongated hexagon having six peripheral faces and six corners, and wherein each of said manifolds is sealed to a different one of said six peripheral faces.

4. The electrochemical cell system of claim 3 wherein each said manifold is sealed to a respective peripheral face by gaskets disposed at said corners.

5. The electrochemical cell system of claim 2 wherein said elongated polygon is a rectangle having four peripheral faces and four corners, said cooling passage ingress and egress manifolds being sealed to said longer peripheral faces, said fuel channel ingress manifold being sealed to the same peripheral face as said oxidant channel egress manifold, and said fuel channel egress manifold being sealed to the same peripheral face as said oxidant channel ingress manifold.

6. The electrochemical cell system of claim 5 wherein said cooling passage ingress and egress manifolds are sealed to said respective peripheral faces by gaskets disposed at said corners and each said fuel channel and oxidant channel manifold is sealed to said respective peripheral face by a gasket disposed at one corner and by another gasket disposed at an intermediate position along the respective peripheral face.

7. The electrochemical cell system of claim 1 wherein said elongated polygon is a hexagon having two 90°

angles.

8. An electrochemical cell system comprising:

a plurality of electrically connected fuel cells and a cooling module disposed between selected fuel cells, said fuel cells and cooling module arranged in a stack and shaped in cross section as an elongated hexagon having three pairs of oppositely disposed, substantially parallel peripheral faces, the faces of one of said pairs being longer than the faces of the remaining pairs and disposed such that the distance between the faces of said one pair is shorter than the distance between the faces of the remaining pairs;

each said fuel cell having an electrolyte positioned between a pair of bipolar plates, said plates defining oxidant channels and fuel channels, said oxidant channels having an inlet on one face of one of said remaining pairs and an outlet on the oppositely disposed face, said fuel channels having an inlet on one face of the other of said remaining pairs and an outlet on the oppositely disposed face;

said cooling module defining cooling passages having an entry on one face of said longer pair and an exit on the oppositely disposed face.

9. The system of claim 8 wherein said elongated hexagon has two 90°

angles.

10. The system of claim 8 wherein said oxidant channels comprise three segments, a first segment generally perpendicular to the face of said oxidant inlet, a second segment generally parallel to said longer faces, and a third segment generally perpendicular to the face of said oxidant outlet.

11. The system of claim 10 wherein said fuel channels comprise three segments, a first segment generally perpendicular to the face of said fuel inlet, a second segment generally parallel to said longer faces, and a third segment generally perpendicular to the face of said fuel outlet.

12. An electrochemical cell system comprising:

a plurality of electrically connected fuel cells and a cooling module disposed between selected fuel cells, said fuel cells and module arranged in a stack and shaped in cross section as a rectangle having two pairs of oppositely disposed, substantially parallel peripheral faces, the faces of one of said pairs being longer than the faces of the other shorter pair,

each said fuel cell having an electrolyte positioned between a pair of bipolar plates, said plates defining oxidant channels and fuel channels, said oxidant and fuel channels each having an inlet and an outlet, said oxidant inlet and said fuel outlet being positioned on one of said shorter faces, separated along said one shorter face by an intermediate gasket, and said oxidant outlet and fuel inlet being positioned on said other shorter face, separated along said other shorter face by an intermediate gasket,

gaskets for sealing, in conjunction with said intermediate gaskets, manifolds to said shorter faces including a manifold common to said oxidant inlets, a manifold common to said oxidant outlets, a manifold common to said fuel inlets and a manifold common to said fuel outlets,

said cooling module defining cooling passages having an entry on one of said longer faces and an exit on the oppositely disposed face, and

manifolds sealed to each of said longer faces, one of said manifolds being common to said entries of said cooling passages and another one of said manifolds being common to said exits of said cooling passages.

13. The system of claim 12 wherein said fuel channels comprise three segments, a first segment substantially parallel to said longer faces, a crossover segment substantially perpendicular to said longer faces, and a third segment substantially parallel to said longer faces.

14. The system of claim 13 wherein the cross sectional area of said crossover segment is larger than the cross-sectional area of either of said other segments.

15. The system of claim 12 wherein said oxidant channels comprise three segments, a first segment substantially parallel to said longer faces, a crossover segment substantially perpendicular to said longer faces, and a third segment substantially parallel to said longer faces.