Method for cooling oxygen sensitive components

• US 20060035122A1
• Filed: 08/13/2004
• Published: 02/16/2006
• Est. Priority Date: 08/13/2004
• Status: Abandoned Application

• Current Assignee: Delphi Technologies, Inc. (Aptiv PLC)
• Original Assignee: Delphi Technologies, Inc. (Aptiv PLC)
• Inventors: England, Diane M., Weissman, Jeffrey G.
• Application Number:
  US10/917,736
• Publication Number:
  US 20060035122A1
• Time in Patent Office: Days
• US Class Current: 429/423
• CPC Class Codes: B01D 2253/10 Inorganic adsorbents
• CPC Class Codes: B01D 2256/10 Nitrogen
• CPC Class Codes: B01D 2257/104 Oxygen
• CPC Class Codes: B01D 2259/402 using two beds
• CPC Class Codes: B01D 2259/416 involving cryogenic temperature treatment
• CPC Class Codes: B01D 53/0407 Constructional details of adsorbing systems
• CPC Class Codes: B01D 53/047 Pressure swing adsorption
• CPC Class Codes: B01D 53/22 by diffusion manufacturing semi-permeable membranes B01D67/00; form, structure or properties of semi-permeable membranes B01D69/00; material for semi-permeable membranes B01D71/00
• CPC Class Codes: C01B 13/0248 Physical processing only
• CPC Class Codes: C01B 2203/066 with fuel cells
• CPC Class Codes: C01B 2210/0046 Nitrogen
• CPC Class Codes: C01B 2210/0082 Argon
• CPC Class Codes: C01B 3/38 using catalysts
• CPC Class Codes: H01M 8/0267 having heating or cooling means, e.g. heaters or coolant flow channels
• CPC Class Codes: H01M 8/04044 Purification of heat exchange media
• CPC Class Codes: H01M 8/04089 of gaseous reactants
• CPC Class Codes: H01M 8/04225 during start-up
• CPC Class Codes: H01M 8/04228 during shut-down
• CPC Class Codes: H01M 8/04231 Purging of the reactants
• CPC Class Codes: H01M 8/04302 applied during start-up
• CPC Class Codes: H01M 8/04303 : applied during shut-down
• CPC Class Codes: H01M 8/0618 : Reforming processes, e.g. autothermal, partial oxidation or steam reforming
• CPC Class Codes: Y02E 60/50 : Fuel cells

Abstract

A system and method for cooling oxygen sensitive components in a fuel cell system comprising supplying air to an air purification device during cool down of a fuel cell system comprising at least one fuel cell comprising an anode, a cathode, and an electrolyte disposed between the anode and cathode; treating the air within the air purification device to produce a flow of nitrogen gas and a waste stream comprising oxygen enriched air; directing a flow of the nitrogen gas through the anode; the anode being in fluid communication with the air purification device and isolated from the fuel reformer and anode exhaust during cool down; the flow of nitrogen gas being directed through the anode in an amount sufficient to balance pressure within the fuel cell cathode and anode during cool down.

Claims

1. A fuel cell system for cooling oxygen sensitive components comprising:

a fuel cell stack comprising at least one fuel cell comprising an anode, a cathode, and an electrolyte disposed between the anode and cathode;

a fuel reformer disposed in fluid communication with the fuel cell stack for supplying a flow of fuel to the anode;

an air supply disposed in fluid communication with the fuel cell stack for supplying a flow of air to the cathode; and

an air purification device for preparing a nitrogen gas stream, the air purification device having an inlet for receiving a flow of air and an outlet in fluid communication with the fuel cell stack anode for discharging the nitrogen gas stream;

a means for supplying a flow of the nitrogen gas stream to the anode during fuel cell cool down and optionally, during fuel cell shut down; and

an outlet for discharging a flow of oxygen enriched air;

wherein the flow of the nitrogen gas stream is sufficient to balance pressure within the fuel cell cathode and anode during cool down.

2. The system of claim 1, wherein the air purification device is a device suitable for preparing a nitrogen gas stream having an oxygen content of less than about 1 part per million oxygen.

3. The system of claim 1, wherein the air purification device is a device providing a nitrogen gas stream flow rate in the range of about 0.01 to about 100 ml/min.

4. The system of claim 1, wherein the air purification device is a device providing a nitrogen gas stream flow rate in the range of about 0.05 to about 5 ml/min.

5. The system of claim 1, wherein the air purification device is a device providing a supply pressure that is close to atmospheric pressure.

6. The system of claim 1, wherein the air purification device is selected from the group consisting of membrane separators, molecular sieve filters, pressure-swing adsorbers, chromatographic separation devices, paramagnetic separators, cryogenic separators, or a combination thereof.

7. The system of claim 1, wherein the fuel cells comprise solid oxide fuel cells, proton exchange membrane fuel cells, phosphoric acid fuel cells, or molten carbonate fuel cells.

8. The system of claim 1, further comprising:

a thermal enclosure;

wherein the fuel cell stack, fuel reformer, and air supply are disposed within the thermal enclosure and wherein the air purification device is located outside of the thermal enclosure.

9. The system of claim 1, further comprising:

a thermal enclosure;

a cold zone enclosure disposed outside of the thermal enclosure;

wherein the fuel cell stack, fuel reformer, and air supply are disposed within the thermal enclosure; and

wherein the air purification device is located within the cold zone enclosure.

10. The system of claim 1, further comprising:

a waste energy recovery device disposed in fluid communication with the cathode for receiving and treating an oxygen depleted air stream from the cathode; and

,

optionally, the waste energy recovery device is further disposed in fluid communication with the anode for receiving and treating an anode waste stream.

11. The system of claim 1, further comprising:

an oxygen removal device disposed in the flow path of the nitrogen gas stream upstream of the anode.

12. The system of claim 11, wherein the oxygen removal device is selected from the group consisting of an oxygen getter containing nickel, copper, iron, manganese, or silver, or a combination thereof, disposed to react with or adsorb oxygen.

13. The system of claim 1, wherein the air purification device is further disposed in fluid communication with additional oxygen sensitive heated components in the system such that the additional oxygen sensitive heated components are cooled by a flow of the nitrogen gas stream from the air purification device.

14. The system of claim 1, further comprising:

an engine having an inlet and an exhaust;

optionally at least one exhaust treatment device disposed in fluid communication with the engine exhaust;

wherein the engine and, if present, the optional at least one exhaust treatment device, are disposed in fluid communication with the air purification device to receive a supply of oxygen enriched air produced by the air purification device.

15. The system of claim 1, wherein one or both of the cathode and fuel reformer are disposed in fluid communication with the air purification device to receive a supply of oxygen enriched air produced by the air purification device.

16. The system of claim 1, further comprising:

means for isolating the anode from the reformer and anode exhaust passage during cool down.

17. A method for cooling oxygen sensitive components in a fuel cell system comprising:

supplying air to an air purification device during cool down of a fuel cell system comprising at least one fuel cell comprising an anode, a cathode, and an electrolyte disposed between the anode and the cathode;

treating the supplied air within the air purification device to produce a nitrogen gas stream and a waste stream comprising oxygen enriched air;

directing the produced nitrogen gas stream through the anode;

the anode being in fluid communication with the air purification device;

the flow of nitrogen gas stream being sufficient to balance pressure within the fuel cell cathode and anode during fuel cell cool down.

18. The method of claim 17, further comprising:

directing the nitrogen gas stream through the anode during fuel cell cool down and during fuel cell shut down.

19. The method of claim 17, further comprising:

supplying a flow of fuel to the anode via a fuel reformer disposed in fluid communication with the fuel cell stack;

supplying a flow of air to the cathode via an air supply disposed in fluid communication with the fuel cell stack; and

isolating the anode from the fuel reformer and from the anode exhaust passage during fuel cell cool down.

20. The method of claim 17, wherein the air purification device is selected from the group consisting of membrane separators, molecular sieve filters, pressure-swing adsorbers, chromatographic separation devices, paramagnetic separators, cryogenic separators or a combination thereof

21. The method of claim 17, wherein the fuel cells comprise solid oxide fuel cells, proton exchange membrane fuel cells, phosphoric acid fuel cells, or molten carbonate fuel cells.

22. The method of claim 17, further comprising:

disposing the fuel cell stack, fuel reformer, and air supply within a thermal enclosure and locating the air purification device outside of the thermal enclosure.

23. The method of claim 17, further comprising:

disposing the fuel cell stack, fuel reformer, and air supply within a thermal enclosure; and

disposing the air purification device within a cold zone enclosure located outside of the thermal enclosure.

24. The method of claim 17, further comprising:

directing an oxygen depleted air stream from the cathode through a waste energy recovery device disposed in fluid communication with the cathode and treating the oxygen depleted air stream therein.

25. The method of claim 17, further comprising:

directing an anode waste stream through a waste energy recovery device disposed in fluid communication with the anode and treating the anode waste stream therein.

26. The method of claim 17, further comprising:

regenerating the air purification device by passing a flow of supply air through the air purification device; and

optionally, heating the flow of supply air so as to provide heated air to aid in the regeneration process.

27. The method of claim 17, further comprising:

during intervals when the fuel cell is operating, supplying the waste stream comprising oxygen enriched air from the air purification device to the fuel cell cathode, a fuel reformer air inlet, a combustion catalyst, an exhaust catalyst, an engine, an internal combustion engine, a spark ignition engine, a direct ignition engine, or a combination thereof.

28. The method of claim 17, further comprising:

removing residual oxygen from the flow of nitrogen gas stream produced by the air purification device via an oxygen removal device disposed in a flow path of the nitrogen gas stream upstream of the anode.

29. The method of claim 28, wherein the oxygen removal device is selected from the group consisting of an oxygen getter containing nickel, copper, iron, manganese, or silver, or a combination thereof, disposed to react with or adsorb oxygen.

30. The method of claim 17, further comprising:

treating supplied air within the air purification device to produce a nitrogen gas stream having an oxygen content of less than about 1 part per million of oxygen.

31. The method of claim 17, further comprising:

treating supplied air within the air purification device to produce nitrogen gas stream having a flow rate in the range of about 0.01 to about 100 milliliters per minute.

32. The method of claim 17, further comprising:

treating supplied air within the air purification device to produce a nitrogen gas stream having a flow rate in the range of about 0.05 to about 5 milliliters per minute.

33. The method of claim 17, further comprising:

treating supplied air within the air purification device to produce a nitrogen gas stream having a supply pressure that is close to atmospheric pressure.

34. The method of claim 17, further comprising:

in a system further comprising additional oxygen sensitive heated components, cooling the additional components in the system with a flow of nitrogen gas produced from the air purification device.

35. The method of claim 17, further comprising:

cooling the fuel cell stack during start up or operating mode with said nitrogen gas stream; and

optionally, purging the fuel cell stack when cool with said nitrogen gas stream prior to start up.

36. The method of claim 17, further comprising:

preheating the nitrogen gas stream prior to directing to the anode.