Method for determining the starting state of a fuel cell system

Patent metadata

Field	Value
Publication number	US-11489178-B2
Application number	US-201916964526-A
Country	US
Kind code	B2
Filing date	Jan 23, 2019
Priority date	Jan 24, 2018
Publication date	Nov 1, 2022
Grant date	Nov 1, 2022

Abstract

A method for determining the starting state of a fuel-cell system is provided having cathode and anode chambers separated by a membrane-electrode assembly, comprising the steps of initially introducing hydrogen into the anode chamber, measuring the voltage and evaluating whether at least a threshold value has been reached immediately after the start of the introduction of hydrogen into the anode chamber, and determining the starting state as a function of whether the threshold value has been reached.

First claim

The invention claimed is:

1. A method for determining a starting state of a fuel-cell system having cathode and anode chambers separated by a membrane-electrode assembly, comprising:
initially introducing hydrogen into the anode chamber;
measuring a resulting voltage;
evaluating whether at least a threshold value for the resulting voltage has been reached immediately after the start of the introduction of hydrogen into the anode chamber; and
determining the starting state as a function of whether the threshold value has been reached, and
wherein a low threshold value is assigned to an H 2 /H 2 starting state, in which hydrogen is present in both the anode chamber and the cathode chamber, and a high threshold value is assigned to an air/air starting state, in which air is present in both the anode chamber and the cathode chamber.

2. The method according to claim 1 , wherein a temporal voltage build-up is detected and, with respect to a temporal gradient dU/dt of the temporal voltage build-up, after the initial introduction of hydrogen into the anode chamber, evaluated in order to determine the starting state as a function of whether at least one threshold value for the temporal gradient has been reached.

3. The method according to claim 2 , wherein a flat gradient is assigned to the H 2 /H 2 starting state and a steep gradient is assigned to the air/air starting state.

4. The method according to claim 2 wherein there is a gas-tight blocking of the anode and cathode chambers.

5. The method according to claim 1 , wherein, in the absence of gas-tight blocking of the anode and cathode chambers, a period between the initial introduction of hydrogen into the anode chamber and a start of an air supply is detected in order to determine the starting state as a function of whether a threshold value for the period has been reached.

6. The method according to claim 1 , wherein the fuel-cell system has a plurality of membrane-electrode assemblies arranged in a stack, and the threshold value is determined as a function of a stack voltage.

7. The method according to claim 1 , wherein a measurement of a hydrogen concentration is carried out in the cathode exhaust gas, and a temporal profile is evaluated with respect to a concentration gradient of the hydrogen concentration in the cathode exhaust gas.

8. The method according to claim 1 , wherein a frequency of individual starting states is detected and supplied to a diagnostic system.

9. The method according to claim 8 , wherein a prediction of reversible damage takes place on the basis of the data acquired by the diagnostic system.

10. A method for determining a starting state of a fuel-cell system having cathode and anode chambers separated by a membrane-electrode assembly, comprising:
initially introducing hydrogen into the anode chamber;
measuring a resulting voltage;
evaluating whether at least a threshold value for the resulting voltage has been reached immediately after the start of the introduction of hydrogen into the anode chamber; and
determining the starting state as a function of whether the threshold value has been reached, and
wherein a temporal voltage build-up is detected and, with respect to a temporal gradient dU/dt of the temporal voltage build-up, after the initial introduction of hydrogen into the anode chamber, evaluated in order to determine the starting state as a function of whether at least one threshold value for the temporal gradient has been reached;
wherein a flat gradient is assigned to an H 2 /H 2 starting state, in which hydrogen is present in both the anode chamber and the cathode chamber, and a steep gradient is assigned to an air/air starting state, in which air is present in both the anode chamber and the cathode chamber.

11. The method according to claim 10 wherein there is a gas-tight blocking of the anode and cathode chambers.

12. The method according to claim 10 , wherein, in the absence of gas-tight blocking of the anode and cathode chambers, a period between the initial introduction of hydrogen into the anode chamber and a start of an air supply is detected in order to determine the starting state as a function of whether a threshold value for the period has been reached.

13. The method according to claim 10 , wherein the fuel-cell system has a plurality of membrane-electrode assemblies arranged in a stack, and the threshold value is determined as a function of a stack voltage.

14. The method according to claim 10 , wherein a measurement of a hydrogen concentration is carried out in the cathode exhaust gas, and a temporal profile is evaluated with respect to a concentration gradient of the hydrogen concentration in the cathode exhaust gas.

15. The method according to claim 10 , wherein a frequency of individual starting states is detected and supplied to a diagnostic system.

16. A method for determining a starting state of a fuel-cell system having cathode and anode chambers separated by a membrane-electrode assembly, comprising:
initially introducing hydrogen into the anode chamber;
measuring a resulting voltage;
evaluating whether at least a threshold value for the resulting voltage has been reached immediately after the start of the introduction of hydrogen into the anode chamber; and
determining the starting state as a function of whether the threshold value has been reached, and
wherein a measurement of a hydrogen concentration is carried out in the cathode exhaust gas, and a temporal profile is evaluated with respect to a concentration gradient of the hydrogen concentration in the cathode exhaust gas.

17. The method according to claim 16 , wherein, in the absence of gas-tight blocking of the anode and cathode chambers, a period between the initial introduction of hydrogen into the anode chamber and a start of an air supply is detected in order to determine the starting state as a function of whether a threshold value for the period has been reached.

18. The method according to claim 16 , wherein the fuel-cell system has a plurality of membrane-electrode assemblies arranged in a stack, and the threshold value is determined as a function of a stack voltage.

19. The method according to claim 16 , wherein a frequency of individual starting states is detected and supplied to a diagnostic system.

Assignees

• Audi Ag
• Volkswagen Ag

Inventors

• Kirchhoff Maren Ramona
• Schröder Christian

Classifications

• Y02E60/50

  Fuel cells · CPC title

• H01M8/0447

  of cathode exhausts · CPC title

• H01M8/04225 Primary

  during start-up · CPC title

• H01M8/1004

  characterised by membrane-electrode assemblies [MEA] (H01M8/12 takes precedence) · CPC title

• H01M8/04559

  of fuel cell stacks · CPC title