Systems and methods for detecting leaks in a fuel cell system

Patent metadata

Field	Value
Publication number	US-10050288-B2
Application number	US-201514589777-A
Country	US
Kind code	B2
Filing date	Jan 5, 2015
Priority date	Jan 5, 2015
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

Systems and methods for detecting and validating a leak in a fuel cell system are presented. In certain embodiments, various fuel cell stack set points may be adjusted such that adequate H 2 flow data may be obtained to identify and validate an H 2 leak and/or a location of such a leak. In some embodiments, H 2 flow data may be obtained by adjusting certain fuel cell system operating parameters under a variety of operating conditions and/or modes and measuring flow data under such various operational conditions.

First claim

The invention claimed is:

1. A method for validating a leak in a subsystem of a fuel cell system, the method comprising:
determining that a first measured leak flow rate in the anode subsystem exceeds a first reference flow rate threshold;
adjusting an anode-to-cathode pressure bias and a current density of the fuel cell system to reference levels;
after adjusting the anode-to-cathode pressure bias and current density to the reference levels, measuring a second measured leak flow rate;
comparing a plurality of measured leak flow rates obtained at a plurality of anode-to-cathode pressure bias levels with the second measured leak flow rate;
identifying a leak based on the comparison; and
identifying a leak location in the fuel cell system, wherein identifying the leak location comprises:
increasing a pressure in the cathode subsystem of the fuel cell system;
after increasing the pressure in the cathode subsystem, measuring a third measured leak flow rate; and
identifying whether the leak location is one of an air leak from the cathode subsystem or a fuel leak from the anode subsystem based on a comparison between the third measured leak flow rate with the second measured leak flow rate,
wherein identifying a leak location in the cathode subsystem comprises determining that the third measured leak flow rate is substantially similar to the second measured leak flow rate and, based on the determination, identifying an air leak location in the cathode subsystem, and
wherein identifying a leak location in the anode subsystem comprises determining that the third measured leak flow rate is greater than the second measured leak flow rate and, based on the determination, identifying a fuel leak location in the anode subsystem.

2. The method of claim 1 , wherein comparing the plurality of measured leak flow rates obtained at the plurality of anode-to-cathode pressure bias levels further comprises:
increasing the anode-to-cathode pressure bias;
after increasing the anode-to-cathode pressure bias, determining that a fourth measured leak flow rate exceeds the second measured leak flow rate;
decreasing the anode-to-cathode pressure bias; and
after decreasing the anode-to-cathode pressure bias, determining that a fifth measured leak flow rate is less than the second measured leak flow rate and fourth measured leak flow rate.

3. The method of claim 1 , wherein the method further comprises:
confirming the identified leak, wherein the confirming comprises:
monitoring a pressure decay rate of the anode subsystem during a shutdown operation of the fuel cell system;
determining that the decay rate is faster than a reference threshold decay rate; and
confirming the identified leak based, at least in part, on the determination.

4. The method of claim 1 , wherein the method further comprises implementing at least one protective action in response to identifying the leak to mitigate damage to the fuel cell system.

5. The method of claim 4 , wherein the protective action comprises initiating a shutdown operation of the fuel cell system.

6. The method of claim 4 , wherein the protective action comprises terminating injection of hydrogen in the fuel cell system.

7. A non-transitory computer-readable storage medium storing instructions that, when executing by a processor, cause the processor to perform a method of validating a leak in a subsystem of a fuel cell system, the method comprising:
determining that a first measured leak flow rate in the anode subsystem exceeds a first reference flow rate threshold;
adjusting an anode-to-cathode pressure bias and a current density of the fuel cell system to reference levels;
after adjusting the anode-to-cathode pressure bias and current density to the reference levels, measuring a second measured leak flow rate;
comparing a plurality of measured leak flow rates obtained at a plurality of anode-to-cathode pressure bias levels with the second measured leak flow rate;
identifying a leak based on the comparison; and
identifying a leak location in the fuel cell system, wherein identifying the leak location comprises:
increasing a pressure in the cathode subsystem of the fuel cell system;
after increasing the pressure in the cathode subsystem, measuring a third measured leak flow rate; and
identifying whether the leak location is one of an air leak from the cathode subsystem or a fuel leak the anode subsystem based on a comparison between the third measured leak flow rate with the second measured leak flow rate,
wherein identifying a leak location in the cathode subsystem comprises determining that the third measured leak flow rate is substantially similar to the second measured leak flow rate and, based on the determination, identifying an air leak location in the cathode subsystem, and
wherein identifying a leak location in the anode subsystem comprises determining that the third measured leak flow rate is greater than the second measured leak flow rate and, based on the determination, identifying a fuel leak location in the anode subsystem.

8. The non-transitory computer-readable storage medium of claim 7 , wherein comparing the plurality of measured leak flow rates obtained at the plurality of anode-to-cathode pressure bias levels further comprises:
increasing the anode-to-cathode pressure bias;
after increasing the anode-to-cathode pressure bias, determining that a fourth measured leak flow rate exceeds the second measured leak flow rate;
decreasing the anode-to-cathode pressure bias; and
after decreasing the anode-to-cathode pressure bias, determining that a fifth measured leak flow rate is less than the second measured leak flow rate and fourth measured leak flow rate.

9. The non-transitory computer-readable storage medium of claim 7 , wherein the method further comprises:
confirming the identified leak, wherein the confirming comprises:
monitoring a pressure decay rate of the anode subsystem during a shutdown operation of the fuel cell system;
determining that the decay rate is faster than a reference threshold decay rate; and
confirming the identified leak based, at least in part, on the determination.

10. The non-transitory computer-readable storage medium of claim 7 , wherein the method further comprises implementing at least one protective action in response to identifying the leak to mitigate damage to the fuel cell system.

11. The non-transitory computer-readable storage medium of claim 10 , wherein the protective action comprises initiating a shutdown operation of the fuel cell system.

12. The non-transitory computer-readable storage medium of claim 10 , wherein the protective action comprises terminating injection of hydrogen in the fuel cell system.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Pace Stephen D
• Cai Jun
• Sinha Manish

Classifications

• H01M8/04104 Primary

  Regulation of differential pressures · CPC title

• H01M8/04432

  Pressure differences, e.g. between anode and cathode · CPC title

• H01M8/04388

  of anode reactants at the inlet or inside the fuel cell · CPC title

• H01M8/04952

  of fuel cell stacks · CPC title

• H01M8/04679

  of fuel cell stacks · CPC title