System for regenerating a fuel cell and regeneration method

Patent metadata

Field	Value
Publication number	US-12021282-B2
Application number	US-202217809378-A
Country	US
Kind code	B2
Filing date	Jun 28, 2022
Priority date	Jun 30, 2021
Publication date	Jun 25, 2024
Grant date	Jun 25, 2024

Abstract

A fuel cell and a method for regenerating this fuel cell, including a supply of the fuel cell by the main supply conduit by a fluid having a nominal flow rate and a nominal molar fraction of combustion agent, during a regeneration phase of a given group, a switching of the inlet, outlet and recirculation switches of the fluid circuit so as to supply the given group from the recirculation line of the given group and from a fluid discharge line of at least one other group, an application of a regeneration voltage Ve to the cells of the given group, Ve being less than or equal to 0.3V.

First claim

The invention claimed is:

1. A fuel cell, comprising:
a first group of electrochemical cells and a second coup of electrochemical cells, each having an inlet and an outlet capable of receiving a fluid, and
a fluid circuit configured to guide the fluid and composing, for each group of electrochemical cells:
(i) a fluid supply line connected to the inlet of a respective group of electrochemical cells, the fluid supply line comprising an inlet switch configured to enable or block a flow of the fluid,
(ii) a fluid discharge line connected to the outlet of the respective group of electrochemical cells,
(iii) a recirculation line configured to fluidically connect the inlet and the outlet of the respective group of electrochemical cells, the recirculation line comprising a recirculation switch configured to enable or block the flow of the fluid,
wherein each fluid supply line (i) is connected to a main supply conduit common to the groups and each fluid discharge line (ii) is connected to a main discharge conduit common to the groups, the main discharge conduit comprising an outlet switch configured to enable or block the flow of the fluid,
wherein the inlet, outlet, and recirculation switches of the fluid circuit are configured to enable, during a regeneration phase of the respective group of electrochemical cells, a supply of the respective group of electrochemical cells from a recirculation line (iii) of the respective group of electrochemical cells and from a fluid discharge line (ii) of at least one other group of electrochemical cells,
wherein the fuel cell is configured such that the fluid has a first flow direction in the respective group of electrochemical cells dining the regeneration phase of the respective group of electrochemical cells, and
wherein the fuel cell is configured such that the fluid has a second flow direction in the respective group of electrochemical cells during a nominal production phase of the respective group of electrochemical cells,
wherein the first flow direction is opposite the second flow direction, and
wherein the nominal production phase is separate from the regeneration phase.

2. The fuel cell of claim 1 , wherein the recirculation line (iii) of a group of electrochemical cells comprises a common section with the recirculation line (iii) of at least one other group of electrochemical cells.

3. The fuel cell of claim 1 , wherein the fluid circuit further comprises a recirculation pump common to each recirculation line (iii) of the fluid circuit,
wherein the recirculation pump is configured to maintain, in the respective group of electrochemical cells during the regeneration phase, a fluid flow rate greater than or equal to 50%, of a nominal flow rate measured in the main supply conduit.

4. The fuel cell of claim 3 , wherein the recirculation pump is confirmed to enable an inversion of a flow direction of the fluid in the respective group of electrochemical cells.

5. The fuel cell of claim 1 , further comprising:
a control/command system configured to command the inlet, outlet, and recirculation switches of the fluid circuit so as to enable or block the flow of the fluid along a chosen fluid path.

6. The fuel cell of claim 1 , further comprising:
a third group of electrochemical cells,
wherein, during the regeneration phase of the respective group of electrochemical cells, the supply of the respective group of electrochemical cells is done from the recirculation line (iii) of the respective group of electrochemical cells and from fluid discharge lines (ii) of the other groups of electrochemical cells of the fuel cell.

7. A method for regenerating the fuel cell of claim 1 , the method comprising:
supplying the fuel cell by the main supply conduit by a fluid having a nominal flow rate and a nominal molar fraction of combustion agent; and
during the regeneration phase of the respective group of electrochemical cells:
switching the inlet, outlet, and recirculation switch of the fluid circuit so as to supply the respective group of electrochemical cells from the recirculation line (iii) of the respective group of electrochemical cells and from the fluid discharge line (ii) of the at least one other group of electrochemical cells,
applying a regeneration voltage Ve to the cells of the respective group of electrochemical cells, Ve being less than or equal to 0.3V.

8. The method of claim 7 , wherein the regeneration phase is configured, such that a molar fraction of combustion agent in the fluid circulating through the respective group of electrochemical cells is less than or equal to 50% of the nominal molar fraction of combustion agent.

9. The method of claim 7 , wherein the fluid circulating through the respective of electrochemical cells has a flow rate greater than or equal to 50% of the nominal flow rate.

10. The method of claim 7 , wherein the regeneration is earned out for a duration less than or equal to 10 s.

11. The method of claim 7 , wherein the regeneration phase is carried out alternatively on each group of electrochemical cells of the fuel cell.

12. The method of claim 7 , wherein the regeneration phase comprises an inversion of the flow direction of the fluid in the respective group of electrochemical cells.

13. The method of claim 7 , wherein the regeneration phase is carried out when the fuel cell does not need to operate in the nominal production phase.

14. The method according to claim 7 , wherein the fuel cell comprises the first, the second, and third group of electrochemical cells, and
wherein the regeneration phase is carried out simultaneously on the respective group of electrochemical cells and on at least one other group.

15. The method of claim 7 , wherein at least one group of electrochemical cells of the fuel cell is in the nominal production phase during the regeneration phase of at least one given group of electrochemical cells.

16. The method of claim 7 , wherein the fluid circulating through the respective group of electrochemical cells has a flow rate greater than or equal to 80% of the nominal flow rate.

17. The method of claim 7 , wherein the regeneration phase is carried out when an electrical production requested to the fuel cell is less than a nominal electrical production of the fuel cell.

18. The fuel cell of claim 1 , configured such that, during the regeneration phase, the first flow direction is inverted through the respective group of electrochemical cells with respect to the second flow direction during the nominal production phase of the respective group of electrochemical cells.

19. The method of claim 7 , comprising, during the regeneration phase, inverting the first flow direction through the respective group of electrochemical cells with respect to and the second flow direction during the nominal production phase of the respective group of electrochemical cells.

20. The fuel cell of claim 1 , wherein the recirculation line (iii) comprises a recirculation pump configured to invert of a circulation direction of air in the respective group of electrochemical cells.

Assignees

• Commissariat Energie Atomique

Inventors

• Micoud Fabrice
• Morin Arnaud
• Poirot-Crouvezier Jean-Philippe
• Vandenberghe Florent

Classifications

• H01M8/04089

  of gaseous reactants · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M8/04223

  during start-up or shut-down; Depolarisation or activation, e.g. purging; Means for short-circuiting defective fuel cells · CPC title

• H01M8/04865

  Voltage · CPC title

• H01M8/04097

  with recycling of the reactants (H01M8/04119, H01M8/04104 take precedence) · CPC title