Method and apparatus for disposing of water and/or inert gas from a fuel cell block

A method for cathode-side water and inert gas disposal and/or anode-side inert gas disposal from a fuel cell block having a number of fuel cells, includes increasingly concentrating a water and an inert gas component in a cathode-side gas mixture and an inert gas component in an anode-side gas mixture, in flow direction of the gas mixtures. The water and inert gas components are at least partially discharged from the fuel cell block. In an apparatus for performing the method, the fuel cells are subdivided into cell groups through which a flow of gas mixtures can be conducted in parallel. The cell groups include a cell group disposed last as seen in gas mixture flow direction. Lines connect the cell groups for conducting at least a fraction of the gas mixtures successively through the cell groups, and for discharging another fraction of the gas mixtures, being dependent on an electric current, from the fuel cell block after flowing through the last cell group.

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Claims

1. A method for cathode-side water and inert gas disposal and anode-side inert gas disposal from a fuel cell block having a number of fuel cells,

which comprises increasingly concentrating a water and an inert gas component in a cathode-side gas mixture in a flow direction of the gas mixture, and increasingly concentrating an inert gas component in an anode-side gas mixture in a flow direction of the gas mixture, in a fuel cell block having a number of fuel cells; and at least partially discharging the water and inert gas components from the fuel cell block.

2. The method according to claim 1, which comprises discharging from the fuel cell block a portion of the applicable gas mixture being dependent on an electric current of at least one of the fuel cells, for regulated disposal of at least one of water and inert gas.

3. The method according to claim 1, which comprises at least partially recirculating the cathode-side gas mixture into the fuel cell block, with water being separated in the process.

4. The method according to claim 1, which comprises directing the flow of the anode-side and the cathode-side gas mixtures through the fuel cell block in opposite directions.

5. The method according to claim 1, which comprises subdividing the fuel cell block into at least two cell groups through each of which the flow is parallel,

increasing the concentration of the water and the inert gas component in the cathode-side gas mixture, and increasing the concentration of the inert gas component in the anode-side gas mixture, by a successive flow through the cell groups,
withdrawing water from the cathode-side gas mixture before it enters the next cell group, and discharging the gas mixture from the fuel cell block as it leaves the last cell group, as seen in the flow direction of the gas mixture.

6. The method according to claim 1, which comprises subdividing the fuel cell block into at least two parallel cell groups through each of which the flow is parallel,

partially recirculating the cathode-side gas mixture after flowing through a cell group with water separation, into the same cell group, and partially introducing the cathode-side gas mixture into the next cell group, and
discharging a fraction of the gas mixture leaving the cell group disposed last, as seen in the flow direction of the gas mixture, in dependence on the electric current of at least one fuel cell.

7. The method according to claim 1, which comprises carrying out water separation in cathode chambers of the fuel cells.

8. The method according to claim 1, which comprises discharging the water from the gas flow from cathode chambers of the fuel cells, and separating the water outside the fuel cells.

9. The method according to claim 1, which comprises humidifying the gas mixtures flowing into the fuel cells with separated water.

10. The method according to claim 1, which comprises discharging a fraction of the anode-side and the cathode-side gas mixture from the fuel cell block, in dependence on an electric current,

wherein the current is a current flowing through one of two electrically parallel-connected fuel cells, and the two fuel cells are disposed last in the fuel cell block, as seen in the flow direction of at least one of the two gas mixture, and
delivering fuel and oxidant in a mutually stoichiometric ratio.

11. The method according to claim 1, which comprises

directing the anode-side and the cathode-side gas mixtures in opposite directions through the fuel cell block, and
discharging the anode-side or the cathode-side gas mixture from n fuel cells from the fuel cell block, if 2I.sub.H /I.gtoreq.0.70 and 2I.sub.O /I.gtoreq.0.60, wherein I is the current flowing through the total fuel cell block, I.sub.H is the current flowing through one of two electrically parallel-connected fuel cells which together form the last fuel cell of the block through which the anode-side gas mixture flows, and I.sub.O is the current flowing through one of two electrically parallel-connected fuel cells which together form the last fuel cell of the block through which the cathode-side gas mixture flows.

12. A fuel cell assembly, comprising:

a fuel cell block having an anode side for an anode-side gas mixture, a cathode side for a cathode-side gas mixture, and a number of fuel cells,
said fuel cells being subdivided into cell groups through which a flow of gas mixtures can be conducted in parallel, said cell groups including a cell group disposed last as seen in gas mixture flow direction, and
lines connecting said cell groups for conducting at least a fraction of the gas mixtures successively through said cell groups, and for discharging another fraction of the gas mixtures, being dependent on an electric current, from said fuel cell block after flowing through said last cell group.

13. The assembly according to claim 12, wherein the number of said fuel cells through which a parallel flow occurs within one of said cell groups decreases as seen in the flow direction of the anode-side gas mixture and in the flow direction of the cathode-side gas mixture.

14. The assembly according to claim 12, wherein said lines connect said cell groups to one another for conducting the entire anode-side gas mixture successively through said cell groups on said anode side, and for conducting the entire cathode-side gas mixture successively through said cell groups on said cathode side,

including a water separator connected in one of said lines conducting the cathode-side gas mixture between two successive cell groups, and
the gas mixture leaving said last cell group can be discharged from said fuel cell block as a function of the electric current.

15. The assembly according to claim 12, including water disposal lines connected to said cell groups on said cathode side, and a common water separator into which each of said water disposal lines discharges for water disposal purposes.

16. The assembly according to claim 12, including a water separator and a condenser, said cell groups on said cathode side include a first cell group having an inlet side, and said lines connected to said cell groups on said cathode side discharge through said water separator and said condenser into the inlet side of said first cell group for water and inert gas disposal, except for said line connected to said last cell group.

17. The assembly according to claim 12, wherein said fuel cells have plates and radial conduits extending in a plane of said plates for disposal of the anode-side and the cathode-side gas mixtures, and including hydrophilic inserts built into said radial conduits as a throttle resistance.

18. The assembly according to claim 12, including a humidifier receiving separated water for humidifying the gas mixtures flowing into said fuel cell block.

19. A fuel cell assembly, comprising:

a fuel cell block having an anode side for an anode-side gas mixture, a cathode side for a cathode-side gas mixture, and a number of fuel cells, for cathode-side water and inert gas disposal and anode-side inert gas disposal from said fuel cell block,
said fuel cells being subdivided into cell groups through which a flow of the gas mixtures can be conducted in parallel, said cell groups including a cell group disposed last as seen in gas mixture flow direction, and
lines connecting said cell groups.
said lines conducting at least a fraction of the gas mixtures successively through said cell groups, while increasingly concentrating a water and an inert gas component in the cathode-side gas mixture in the flow direction of the gas mixture, and increasingly concentrating an inert gas component in the anode-side gas mixture in the flow direction of the gas mixture, and
said lines discharging another fraction of the gas mixtures, being dependent on an electric current, from said fuel cell block after flowing through said last cell group, while at least partially discharging the water and inert gas components from said fuel cell block..Iadd.

20. A method for inert gas disposal from a fuel cell block having a number of fuel cells, which comprises increasingly concentrating a water and an inert gas component in an anode-side gas mixture in a flow direction of the gas mixture, in a fuel cell block having a number of fuel cells; directing the flow of the anode-side and the cathode-side gas mixtures through the fuel cell block in opposite directions;

and at least partially discharging the water and inert gas components from the fuel cell block..Iaddend..Iadd.

21. The method according to claim 20, which comprises discharging from the fuel cell block a portion of the applicable gas mixture being dependent on an electric current of at least one of the fuel cells, for regulated disposal of at least one of water and inert gas..Iaddend..Iadd.22. The method according to claim 20, which comprises at least partially recirculating the anode-side gas mixture into the fuel cell block, with water being separated in the process..Iaddend..Iadd.23. A method for inert gas disposal from a fuel cell block having a number of fuel cells, which comprises increasingly concentrating a water and an inert gas component in an anode-side gas mixture in a flow direction of the gas mixture, in a fuel cell block having a number of fuel cells;

subdividing the fuel cell block into at least two cell groups through each of which the flow is parallel;
increasing the concentration of the water and the inert gas component in the anode-side gas mixture, by a successive flow through the cell groups;
withdrawing water from the anode-side as mixture before it enters the next cell group, and discharging the gas mixture from the fuel cell block as it leaves the last cell group, as seen in the flow direction of the gas mixture; and
at least partially discharging the water and inert gas components from the

fuel cell block..Iaddend..Iadd.24. A method for inert gas disposal from a fuel cell block having a number of fuel cells, which comprises increasingly concentrating a water and an inert gas component in an anode-side gas mixture in a flow direction of the gas mixture, in a fuel cell block having a number of fuel cells;

subdividing the fuel cell block into at least two parallel cell groups through each of which the flow is parallel;
partially recirculating the anode-side gas mixture after flowing through a cell group with water separation, into the same cell group, and partially introducing the anode-side gas mixture into the next cell group; and
discharging a fraction of the gas mixture leaving the cell group disposed last, as seen in the flow direction of the gas mixture, in dependence on

the electric current of at least one fuel cell..Iaddend..Iadd.25. The method according to claim 20, which comprises carrying out water separation in anode chambers of the fuel cells..Iaddend..Iadd.26. A method for inert gas disposal from a fuel cell block having a number of fuel cells, which comprises increasingly concentrating a water and an inert gas component in an anode-side gas mixture in a flow direction of the gas mixture, in a fuel cell block having a number of fuel cells; and at least partially discharging the water and inert gas components from the fuel cell block by discharging the water from the gas flow from anode chambers of the fuel cells, and separating the water outside the fuel cells..Iaddend..Iadd.27. The method according to claim 20, which comprises humidifying the gas mixtures flowing into the fuel cells with separated water..Iaddend..Iadd.28. A method for inert gas disposal from a fuel cell block having a number of fuel cells, which comprises increasingly concentrating a water and an inert gas component in an anode-side gas mixture in a flow direction of the gas mixture, in a fuel cell block having a number of fuel cells;

and at least partially discharging the water and inert gas components from the fuel cell block by discharging a fraction of the anode-side and the cathode-side gas mixture from the fuel cell block, in dependence on an electric current;
wherein the current is a current flowing through one of two electrically parallel-connected fuel cells, and the two fuel cells are disposed last in the fuel cell block, as seen in the flow direction of at least one of the two gas mixtures; and
delivering fuel and oxidant in a mutually stoichiometric ratio..Iaddend..Iadd.29. The method according to claim 28, which comprises directing the anode-side and the cathode-side gas mixtures in opposite directions through the fuel cell block, and
discharging the anode-side or the cathode-side gas mixture from n fuel cells from the fuel cell block, if 2IH/I>0.70 and 2IO/I>0.60, wherein I is the current flowing through the total fuel cell block, IH is the current flowing through one of two electrically parallel-connected fuel cells which together form the last fuel cell of the block through which the cathode-side gas mixture flows, and I.sub.O is the current flowing through one of two electrically parallel-connected fuel cells which together form the last fuel cell of the block through which the anode-side gas mixture flows..Iaddend..Iadd.30. A fuel cell assembly, comprising:
a fuel cell block having an anode side for an anode-side gas mixture, a cathode side for a cathode-side gas mixture, and a number of fuel cells,
said fuel cells being divided into cell groups through which a flow of gas mixtures can be conducted in parallel, said cell groups including a cell group disposed last as seen in gas mixture flow direction, and
lines connecting said cell groups for conducting at least a fraction of the gas mixtures successively through said cell groups, and for discharging another fraction of the gas mixtures, being dependent on an electric current, from said fuel cell block after flowing through said last cell

group..Iaddend..Iadd.31. The assembly according to claim 30, wherein the number of said fuel cells through which a parallel flow occurs within one of said cell groups decreases as seen in the flow direction of the anode-side gas mixture and in the flow direction of the cathode-side gas mixture..Iaddend..Iadd.32. The assembly according to claim 30, wherein said lines connect said cell groups to one another for conducting the entire anode-side gas mixture successively through said cell groups on said anode side, and for conducting the entire cathode-side gas mixture successively through said cell groups on said cathode side,

including a water separator connected in one of said lines conducting the anode-side gas mixture between two successive cell groups, and the gas mixture leaving said last cell group can be discharged from said fuel cell block as a function of the electric current..Iaddend..Iadd.33. The assembly according to claim 30, including water disposal lines connected to said cell groups on said anode side, and a common water separator into which each of said water disposal lines discharges for water disposal purposes..Iaddend..Iadd.34. The assembly according to claim 30, including a water separator and a condenser, said cell groups on said anode-side include a first cell group having an inlet side, and said lines connected to said cell groups on said anode-side discharge through said water separator and
said condenser into the inlet side of said first cell group for water and inert gas disposal, except for said line connected to said last cell group..Iaddend..Iadd.35. The assembly according to claim 30, wherein said fuel cells have plates and radial conduits extending in a plane of said plates for disposal of the anode-side and the cathode-side gas mixtures, and including hydrophilic inserts built into said radial conduits as a throttle resistance..Iaddend..Iadd.36. The assembly according to claim 30, including a humidifier receiving separated water for humidifying the gas mixtures flowing into said fuel cell block..Iaddend..Iadd.37. A fuel cell assembly, comprising:
a fuel cell block having an anode side for an anode-side gas mixture, a cathode side for a cathode-side gas mixture, and a number of fuel cells, for cathode-side water and inert gas disposal and anode-side water and inert as disposal from said fuel cell block,
said fuel cells being divided into cell groups through which a flow of the gas mixtures can be conducted in parallel, said cell groups including a cell group disposed last as seen in gas mixture flow direction, and
lines connecting said cell groups,
said lines conducting at least a fraction of the gas mixtures successively through said cell groups, while increasingly concentrating a water and an inert gas component in the anode-side gas mixture in the flow direction of the gas mixture, and
said lines discharging another fraction of the gas mixtures, being dependent on an electric current, from said fuel cell block after flowing through said last cell group, while at least partially discharging the water and inert gas components from said fuel cell block..Iaddend.
Referenced Cited
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3455773 July 1969 Huebschem et al.
3553026 January 1971 Winsel
4317864 March 2, 1982 Strasser
4407904 October 4, 1983 Uozumi et al.
4533607 August 6, 1985 Soderquist
4555452 November 26, 1985 Kahara et al.
4593534 June 10, 1986 Bloomfield
5149599 September 22, 1992 Kamoshita
Foreign Patent Documents
1187697 February 1965 DEX
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2729640 November 1979 DEX
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4004896 August 1991 DEX
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Other references
  • VDT Reports, No. 912, 1992 (Strasser) "Brennstoffzelen fuer ELektrotraktion", pp. 125-145. Fuel Cell Handbook (Appletby et al.) pp. 1-7, 440-455 and 544-551, Van Nostrand Reinhold, New York (Date Unknown). Patent Abstact of Japan No. JP40-95356 (Yasutaka) Mar. 27, 1992.
Patent History
Patent number: RE36148
Type: Grant
Filed: Aug 1, 1996
Date of Patent: Mar 16, 1999
Assignee: Siemens Aktiengesellschaft (Munich)
Inventor: Karl Strasser (Erlangen)
Primary Examiner: Caridad Everhart
Attorneys: Herbert L. Lerner, Laurence A. Greenberg
Application Number: 8/691,121
Classifications
Current U.S. Class: 429/13; 429/14; 429/17; 429/23
International Classification: H01M 804; H01M 824;