Condensate recovery for reversible solid oxide fuel cells

Patent metadata

Field	Value
Publication number	US-10026982-B2
Application number	US-201615213628-A
Country	US
Kind code	B2
Filing date	Jul 19, 2016
Priority date	Jul 19, 2016
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

Embodiments described herein provide for water reclamation from the exhaust stream of a RSOFC while the RSOFC operates in fuel cell mode. The reclaimed water is stored for use by the RSOFC while in electrolysis mode. An embodiment includes a RSOFC, a condensate tank, a condenser, and a controller. The RSOFC generates electrical power and water vapor by consuming hydrogen gas in the fuel cell mode, and consumes electrical power and water to generate the hydrogen gas in the electrolysis mode. The condenser condenses the water vapor into water, and directs the water to the condensate tank. The controller, responsive to transitioning the RSOFC from the fuel cell mode to the electrolysis mode, supplies the water to the RSOFC from the condensate tank, and supplies the electrical power to the RSOFC to electrolyze the water and to generate the hydrogen gas.

First claim

The invention claimed is:

1. An apparatus comprising:
a Reversible Solid Oxide Fuel Cell (RSOFC) configured to operate in a fuel cell mode and in an electrolysis mode, wherein the RSOFC generates electrical power and water vapor by consuming hydrogen gas in the fuel cell mode, and consumes electrical power and water to generate the hydrogen gas in the electrolysis mode;
a condensate tank;
a deionizer in fluid communication between the condensate tank and the RSOFC that is configured to deionize the water prior to supplying the water to the RSOFC;
a condenser configured to condense the water vapor into water, and to direct the water to the condensate tank; and
a controller, responsive to transitioning the RSOFC from the fuel cell mode to the electrolysis mode, is configured to supply the water to the RSOFC from the condensate tank, and to supply the electrical power to the RSOFC to electrolyze the water and to generate the hydrogen gas.

2. The apparatus of claim 1 further comprising:
a connection to a municipal water supply that is coupled to the deionizer;
wherein the controller, responsive to determining that a water level in the condensate tank is below a threshold, is configured to terminate the supply of water to the RSOFC from the condensate tank, and to initiate a supply of water to the deionizer from the municipal water supply to provide the water to the RSOFC.

3. The apparatus of claim 1 further comprising:
a desalinator in fluid communication with the deionizer that is configured to desalinate seawater prior to supplying the seawater to the deionizer;
wherein the controller, responsive to determining that a water level in the condensate tank is below a threshold, is configured to terminate the supply of water to the RSOFC from the condensate tank, and to initiate a supply of seawater to the desalinator to provide the water to the RSOFC to provide the water to the RSOFC.

4. The apparatus of claim 1 further comprising:
a pump in fluid communication between the condensate tank and the deionizer; and
a connection to a municipal water supply that is coupled to the deionizer;
wherein the controller, responsive to determining that an output pressure from the pump is below a threshold, is configured to terminate the supply of water to the RSOFC from the condensate tank, and to initiate a supply of water to the deionizer from the municipal water supply to provide the water to the RSOFC.

5. The apparatus of claim 1 further comprising:
a pump in fluid communication between the condensate tank and the deionizer; and
a desalinator in fluid communication with the deionizer that is configured to desalinate seawater prior to supplying the seawater to the deionizer;
wherein the controller, responsive to determining that an output pressure from the pump is below a threshold, is configured to terminate the supply of water to the RSOFC from the condensate tank, and to initiate a supply of seawater to the desalinator to provide the water to the RSOFC.

6. The apparatus of claim 1 further comprising:
a hydrogen storage system; and
a hydrogen compressor in fluid communication between the hydrogen storage system and the RSOFC;
wherein the controller, responsive to transitioning the RSOFC to the electrolysis mode, is configured to direct the hydrogen compressor to compress the hydrogen gas generated by the RSOFC, and to provide the compressed hydrogen gas to the hydrogen storage system.

7. The apparatus of claim 6 wherein:
the controller, responsive to transitioning the RSOFC to the fuel cell mode, is configured to direct the hydrogen compressor to terminate compression, and to direct the hydrogen storage system to supply the hydrogen gas to the RSOFC.

8. A method for condensate recovery in a Reversible Solid Oxide Fuel Cell (RSOFC) system, the method comprising:
supplying hydrogen gas from a hydrogen storage system of the RSOFC system to a RSOFC of the RSOFC system, wherein the RSOFC is configured to operate in a fuel cell mode and an electrolysis mode, wherein the RSOFC generates electrical power and water vapor by consuming hydrogen in the fuel cell mode, and consumes electrical power and water to generate the hydrogen in the electrolysis mode;
generating the electrical power and the water vapor at the RSOFC;
condensing the water vapor to water;
directing the water to a condensate tank of the RSOFC system;
reducing electrical power supplied by the RSOFC to zero;
applying the water from the condensate tank to a deionizer to deionize the water;
directing the deionized water from the deionizer to the RSOFC;
supplying electrical power to the RSOFC; and
electrolyzing the water at the RSOFC to generate the hydrogen gas.

9. The method of claim 8 further comprising:
determining that a water level in the condensate tank is below a threshold;
terminating the supply of water to the RSOFC from the condensate tank; and
initiating a supply of water to the deionizer from a municipal water supply to provide the water to the RSOFC.

10. The method of claim 8 further comprising:
determining that a water level in the condensate tank is below a threshold;
terminating the supply of water to the RSOFC from the condensate tank; and
initiating a supply of seawater to a desalinator to provide the water to the RSOFC.

11. The method of claim 8 further comprising:
determining that an output pressure from a pump supplying water from the condensate tank is below a threshold;
terminating the supply of water to the RSOFC from the condensate tank; and
initiating a supply of water to the deionizer from a municipal water supply to provide the water to the RSOFC.

12. The method of claim 8 further comprising:
determining that an output pressure from a pump supplying water from the condensate tank is below a threshold;
terminating the supply of water to the RSOFC from the condensate tank; and
initiating a supply of seawater to a desalinator to provide the water to the RSOFC.

13. The method of claim 8 further comprising:
compressing the hydrogen gas;
supplying the compressed hydrogen gas to the hydrogen storage system.

14. The method of claim 13 further comprising:
transitioning the RSOFC to the fuel cell mode;
terminating compression of the hydrogen gas;
supplying the hydrogen gas to the RSOFC from the hydrogen storage system.

15. An apparatus comprising:
a Reversible Solid Oxide Fuel Cell (RSOFC) configured to operate in a fuel cell mode and an electrolysis mode, wherein the RSOFC generates electrical power and water vapor by consuming hydrogen gas in the fuel cell mode, and consumes electrical power and water to generate the hydrogen gas in the electrolysis mode;
a hydrogen storage configured to supply the hydrogen gas to the RSOFC;
a hydrogen compressor configured to compress hydrogen gas generated by the RSOFC, and to provide the compressed hydrogen gas to the hydrogen storage;
a condensate tank;
a deionizer in fluid communication between the condensate tank and the RSOFC that is configured to deionize the water prior to supplying the water to the RSOFC;
a condenser configured, responsive to the RSOFC being in the fuel cell mode, to condense the water vapor into water, and to direct the water to the condensate tank;
the condenser configured, responsive to the RSOFC being in the electrolysis mode, to direct the hydrogen gas generated by the RSOFC to the hydrogen compressor; and
a controller, responsive to operating the RSOFC in fuel cell mode, configured to supply the hydrogen gas from the hydrogen storage to the RSOFC to generate the electrical power and the water vap

Assignees

• Boeing Co

Inventors

• Mermelstein Joshua M
• Cannova Catherine

Classifications

• H01M2008/1293

  Fuel cells with solid oxide electrolytes · CPC title

• H01M2250/10

  Fuel cells in stationary systems, e.g. emergency power source in plant · CPC title

• H01M8/04291

  Arrangements for managing water in solid electrolyte fuel cell systems (H01M8/04119 takes precedence) · CPC title

• H01M8/186

  by electrolytic decomposition of the electrolytic solution or the formed water product · CPC title

• H01M8/04753

  of fuel cell reactants · CPC title