Systems and method of operating a fuel cell assembly

Patent metadata

Field	Value
Publication number	US-12037124-B2
Application number	US-202217581098-A
Country	US
Kind code	B2
Filing date	Jan 21, 2022
Priority date	Jan 21, 2022
Publication date	Jul 16, 2024
Grant date	Jul 16, 2024

Abstract

A method for operating a propulsion system for an aircraft, the propulsion system including a gas turbine engine and a fuel cell assembly, the fuel cell assembly comprising a fuel cell stack having a fuel cell defining an outlet positioned to remove output products from the fuel cell during operation, the method including: executing a startup sequence for the gas turbine engine, wherein executing the startup sequence comprises initiating the startup sequence for the gas turbine engine; executing a startup sequence for the fuel cell assembly concurrently with, or subsequent to, initiating the startup sequence for the gas turbine engine; and operating the fuel cell assembly to provide output products to a combustion section of the gas turbine engine.

First claim

We claim:

1. A method for operating a propulsion system for an aircraft, the propulsion system comprising a gas turbine engine and a fuel cell assembly, the fuel cell assembly comprising a fuel cell stack having a fuel cell defining an outlet positioned to remove output products from the fuel cell during operation, the method comprising:
executing a startup sequence for the gas turbine engine, wherein executing the startup sequence comprises initiating the startup sequence for the gas turbine engine;
executing a startup sequence for the fuel cell assembly concurrently with, or subsequent to, initiating the startup sequence for the gas turbine engine, wherein executing the startup sequence for the fuel cell assembly comprises initiating operation of a fuel processing unit and providing an off-gas of the fuel processing unit around an anode of the fuel cell to a combustor of a combustion section of the gas turbine engine; and
operating the fuel cell assembly to provide the output products to the combustion section of the gas turbine engine.

2. The method of claim 1 , wherein executing the startup sequence for the gas turbine engine comprises achieving a flame on condition for the gas turbine engine, and wherein executing the startup sequence for the fuel cell assembly comprises executing a startup sequence for the fuel cell assembly concurrently with, or subsequent to, achieving the flame on condition for the gas turbine engine.

3. The method of claim 1 , wherein executing the startup sequence for the fuel cell assembly comprises
operating in a purge state after initiating the startup sequence for the fuel cell assembly;
operating in a first heat-up state prior to a temperature of the fuel cell stack reaching a first fuel cell temperature threshold;
operating in a second heat-up state subsequent to the temperature of the fuel cell stack reaching the first fuel cell temperature threshold and prior to the temperature of the fuel cell stack reaching a second fuel cell temperature threshold; and
operating in a power generation state subsequent to the temperature of the fuel cell stack reaching the second fuel cell temperature threshold.

4. The method of claim 1 , wherein executing the startup sequence for the fuel cell assembly comprises operating in a purge state to provide an airflow from a compressor section of the gas turbine engine to purge an anode and a cathode of the fuel cell.

5. The method of claim 4 , wherein the airflow from the compressor section is at a temperature of at least about 200 degrees C.

6. The method of claim 1 , wherein executing the startup sequence for the fuel cell assembly further comprises:
providing the output products from the fuel cell to a combustor of the combustion section while the gas turbine engine is operating in a flame on condition or faster, wherein the output products comprise hydrogen gas.

7. The method of claim 1 , wherein executing the startup sequence for the fuel cell assembly further comprises providing a heated airflow from the fuel processing unit to a cathode of the fuel cell.

8. The method of claim 1 , wherein executing the startup sequence for the fuel cell assembly further comprises
receiving data indicative of a temperature of the fuel cell stack being greater than or equal to a first fuel cell temperature threshold; and
providing an off-gas of the fuel processing unit to an anode of the fuel cell in response to receiving data indicative of the temperature of the fuel cell stack being greater than or equal to a first fuel cell temperature threshold.

9. The method of claim 1 , wherein executing the startup sequence for the fuel cell assembly further comprises
providing an off-gas of the fuel processing unit to a cathode of the fuel cell in response to receiving data indicative of a temperature of the fuel cell stack being greater than or equal to a first fuel cell temperature threshold.

10. The method of claim 9 , wherein providing the off-gas of the fuel processing unit to the cathode of the fuel cell comprises providing the off-gas of the fuel processing unit to the cathode of the fuel cell at a pressure less than a pressure of the off-gas of the fuel processing unit provided to the anode of the fuel cell.

11. The method of claim 1 , wherein executing the startup sequence for the fuel cell assembly further comprises:
receiving data indicative of a temperature of the fuel cell stack being greater than or equal to a second fuel cell temperature threshold; and
initiating operation of the fuel cell assembly in a power generation mode.

12. The method of claim 11 , wherein the second fuel cell temperature threshold is at least about 400 degrees C.

13. The method of claim 1 , wherein executing the startup sequence for the fuel cell assembly comprises:
operating an air processing unit; and
providing an off-gas of the air processing unit to a cathode of the fuel cell, to an anode of the fuel cell, or both.

14. The method of claim 13 , wherein executing the startup sequence for the fuel cell assembly further comprises
receiving data indicative of a temperature of the fuel cell stack being greater than or equal to a first fuel cell temperature threshold;
operating a fuel processing unit;
providing an off-gas of the fuel processing unit to the anode of the fuel cell in response to receiving data indicative of the temperature of the fuel cell stack being greater than or equal to a first fuel cell temperature threshold; and
providing an off-gas of the air processing unit to a cathode of the fuel cell in response to receiving data indicative of the temperature of the fuel cell stack being greater than or equal to a first fuel cell temperature threshold.

15. The method of claim 1 , wherein executing the startup sequence for the fuel cell assembly comprises providing a flow to an anode of the fuel cell having an oxygen content prior to a temperature of the fuel cell stack being greater than or equal to a first fuel cell temperature threshold.

16. The method of claim 1 , wherein executing the startup sequence for the fuel cell assembly comprises providing a flow to an anode of the fuel cell having an oxygen content prior to a temperature of the fuel cell stack being greater than or equal to a second fuel cell temperature threshold.

17. The method of claim 1 , wherein executing the startup sequence for the fuel cell assembly comprises performing a fuel reforming action at an anode of the fuel cell.

18. The method of claim 17 , wherein performing a fuel reforming action at an anode of the fuel cell assembly comprises providing a flow of hydrocarbon fuel to the anode and a flow of an oxygen-containing gas to the anode.

19. A propulsion system for an aircraft having a gas turbine engine, the aircraft comprising an aircraft fuel supply, the propulsion system comprising:
a fuel cell assembly comprising a fuel cell stack having a fuel cell, the fuel cell defining an outlet positioned to remove output products from the fuel cell;
a turbomachine comprising a compressor section, a combustion section, and a turbine section arranged in serial flow order, the combustion section configured to receive a flow of aviation fuel from the aircraft fuel supply and further configured to receive the output products from the fuel cell; and
a controller comprising memory and one or more processors, the memory storing instructions that when executed by the one or more processors cause the propulsion system to perform operations including
executing a startup sequence for the gas turbine engine, wherein exe

Assignees

• Gen Electric

Inventors

• Wang Honggang
• Benjamin Michael Anthony
• Hong Seung-Hyuck
• Hart Richard L

Classifications

• B64D27/355

  using fuel cells · CPC title

• B64D31/18

  for hybrid-electric power plants · CPC title

• B64D27/026

  comprising different types of power plants, e.g. combination of a piston engine and a gas-turbine (Hybrid electric aircraft B64D27/33) · CPC title

• F02C6/08 Primary

  the gas being bled from the gas-turbine compressor · CPC title

• F02C7/26

  Starting; Ignition · CPC title