COMBINED FUEL CELL SYSTEM

Abstract

A fuel cell system comprises a combination of a first fuel cell of a first type and a second fuel cell of a second type, arranged downstream of the first fuel cell. The anode side of the first fuel cell is coupled with a cathode side of the second fuel cell; allowing the purge gas emanating from the first fuel cell to be fed to the cathode side of the second fuel chamber, rather than to outside air.

Description

BRIEF DESCRIPTION OF THE FIGURES

The drawings show examples of the present invention, which is not limited to the specific examples as represented in the drawings.

FIG. 1 illustrates an example of a fuel cell system for use in transportation, especially in aircraft.

Claims

1. A fuel cell system comprising: a combination of a first fuel cell of a first type and a second fuel cell of a second type, different than the first type, arranged downstream of the first fuel cell, each fuel cell having an anode side and a cathode side, wherein the anode side of the first fuel cell communicates with the cathode side of the second fuel cell.

2. The fuel cell system of claim 1, wherein the first fuel cell is a low-temperature proton exchange membrane fuel cell of the low temperature type or the high-temperature type.

3. The fuel cell system of claim 1, wherein a coolant of the first fuel cell is air.

4. The fuel cell system of claim 3, wherein the coolant is drawn in from an environment.

5. The fuel cell system of claim 1, wherein the second fuel cell is a high-temperature fuel cell type.

6. The fuel cell system of claim 5, wherein the second fuel cell is a solid oxide fuel cell.

7. The fuel cell system of claim 1, wherein the second fuel cell is combination of a combustion chamber and a catalytic burner providing thermal energy.

8. The fuel cell system of claim 1, wherein the second fuel cell is a combination of a combustion chamber and a solid oxide fuel cell.

9. The fuel cell system of claim 8, wherein a plurality of combustion chambers are arranged, so as to alternate with a plurality of solid oxide fuel cells arranged in a ring-shape combination on a shaft which connects a compressor stage on the cathode side of the second fuel cell to a turbine stage on the anode side of the second fuel cell.

10. The fuel cell system of claim 9, wherein a suction side of the compressor stage of the second fuel cell may be used to draw in a coolant of the first fuel cell.

11. The fuel cell system of claim 1, wherein the first fuel cell and the second fuel cell are supplied with hydrogen on the anode side.

12. The fuel cell system of claim 11, wherein the hydrogen for supplying the first fuel cell and the second fuel cell are regulated separately.

13. The fuel cell system of claim 9, wherein the hydrogen for supplying the anode side of each of the first and second fuel cells is preheated by waste heat from the ring-shape combination.

14. The fuel cell system of claim 11, wherein the hydrogen for supplying the anode side of each of the fuel cells is preheated by waste heat of a turbine stage of the second fuel cell.

15. The fuel cell system of claim 11, wherein the hydrogen for supplying the anode side of each of the fuel cells may be transformed from a liquid state to a gaseous state.

16. The fuel cell system of claim 1, wherein an exhaust gas from the second fuel cell may be fed to a cooler/heater combination that preheats supplied cabin air using a portion of waste heat from the exhaust gas.

17. The fuel cell system of claim 16, wherein preheated cabin air may be fed to the cathode side of the first fuel cell using a compressor.

18. The fuel cell system of claim 17, wherein the compressor is mechanically connected or magnetically coupled to a compressor stage and to a turbine stage of the second fuel cell.

19. The fuel cell system of claim 18, wherein the compressor is mechanically connected using a coupling or a gear arrangement.

20. The fuel cell system of claim 18, further comprising a motor that is connected by a shaft to the compressor for generating an angular momentum during starting of the system.

21. The fuel cell system of claim 20, wherein the motor is mechanically connected or magnetically coupled to the compressor stage and to the turbine stage of the second fuel cell.

22. The fuel cell system of claim 1, wherein residual gas from the first fuel cell is added to suction air of the second fuel cell using a venturi nozzle.

23. The fuel cell system of claim 1, wherein water contained in cathode outlet air of the first fuel cell condenses out using a cooling circuit.

24. The fuel cell system of claim 23, wherein the cooling circuit comprises a condenser.

25. The fuel cell system of claim 23, wherein the condensed-out water is fed for further utilisation to a water system or to a reformer that produces hydrogen from hydrocarbon.

26. The fuel cell system of claim 25, wherein hydrogen produced from the hydrocarbon using the reformer is fed to the second fuel cell.

27. The fuel cell system of claim 23, wherein the outlet air of the cathode of the first fuel cell after condensing out the water is added to suction air of the second fuel cell using a venturi nozzle.

28. The fuel cell system of claim 23, wherein the cooling circuit uses a heat pump process and the heat produced by the heat pump process is transferred to outlet air of the cathode side of the first fuel cell.

29. The fuel cell system of claim 1, wherein a cooled-down exhaust gas stream from the second fuel cell is fed to a wing de-icing system.

30. The fuel cell system of claim 1, further comprising an electronic sensor technology-/control unit for regulating the system.

31. The fuel cell system of claim 30, wherein the sensor technology-/control unit is supplied with energy from an on-board electricity network.

32. The fuel cell system of claim 30, further comprising an independent energy source, connected to the sensor technology-/control unit, for starting the system.

33. The fuel cell system of claim 32, wherein the energy source is a battery, a storage battery and/or a super cap high-performance capacitor.

34. An aircraft using the fuel cell system of claim 1.