Method for determining the starting state of a fuel cell system

Patent metadata

Field	Value
Publication number	US-2021036347-A1
Application number	US-201916964526-A
Country	US
Kind code	A1
Filing date	Jan 23, 2019
Priority date	Jan 24, 2018
Publication date	Feb 4, 2021
Grant date	—

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

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.

2 . The method according to claim 1 , wherein a low threshold value is assigned to an H 2 /H 2 starting state, a high threshold value is assigned to an air/air starting state, and at least one further threshold value is assigned to an intermediate starting state.

3 . 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.

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

5 . The method according to claim 3 wherein there is a gas-tight blocking of the anode and cathode chambers.

6 . 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.

7 . 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.

8 . 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.

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

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

Assignees

• Audi Ag
• Volkswagen Ag

Inventors

• Kirchhoff Maren Ramona
• Schröder Christian

Classifications

• H01M8/04225 Primary

  during start-up · CPC title

• H01M8/04559

  of fuel cell stacks · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M8/1004

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

• H01M8/04089

  of gaseous reactants · CPC title