Simplification of the electrical system of fuel cells by means of depletion of the cathode supply

Patent metadata

Field	Value
Publication number	US-2016204455-A1
Application number	US-201414911328-A
Country	US
Kind code	A1
Filing date	Jun 30, 2014
Priority date	Aug 14, 2013
Publication date	Jul 14, 2016
Grant date	—

Abstract

The invention relates to a fuel cell system ( 1 ), comprising at least one fuel cell ( 2 ), wherein the fuel cell ( 2 ) comprises an anode chamber ( 3 ) and a cathode chamber ( 4 ) separated from the anode chamber ( 3 ), and wherein the fuel cell system ( 1 ) also comprises a cathode gas source ( 5 ), a gas supply line ( 6 ), which is connected to the cathode gas source ( 5 ), for feeding cathode gas into the cathode chamber ( 4 ), and an exhaust air line ( 7 ), which is connected to the cathode chamber ( 4 ), for the conducting exhaust air out of the cathode chamber ( 4 ). According to the invention, the gas supply line ( 6 ) and the exhaust air line ( 7 ) are connected by means of at least one gas flow regulation element ( 8, 9 ), which opens the gas supply line ( 6 ) in the direction of the exhaust air line ( 7 ) and/or the exhaust air line ( 7 ) in the direction of the gas supply line ( 6 ) in dependence on an operating status of the fuel cell ( 2 ).

First claim

1 . A fuel cell system ( 1 ), comprising at least one fuel cell ( 2 ), wherein the fuel cell ( 2 ) comprises an anode chamber ( 3 ) and a cathode chamber ( 4 ) separated from the anode chamber ( 3 ), and wherein the fuel cell system ( 1 ) also comprises a cathode gas source ( 5 ), a gas supply line ( 6 ), which is connected to the cathode gas source ( 5 ), for feeding cathode gas into the cathode chamber ( 4 ), and an exhaust air line ( 7 ), which is connected to the cathode chamber ( 4 ) for conducting exhaust air out of the cathode chamber ( 4 ),
characterized in that the gas supply line ( 6 ) and the exhaust air line ( 7 ) are connected by at least one gas-flow regulation element ( 8 , 9 ), which opens the gas supply line ( 6 ) in the direction of the exhaust air line ( 7 ) and/or the exhaust air line ( 7 ) in the direction of the gas supply line ( 6 ) in dependence on an operating status of the fuel cell ( 2 ).

2 . The fuel cell system ( 1 ) according to claim 1 ,
characterized in that at least two gas-flow regulation elements ( 8 , 9 ) connect the exhaust air line ( 7 ) and the gas supply line ( 6 ), wherein the exhaust air can be conducted in the direction of the gas supply line ( 6 ) by the one gas-flow regulation element ( 8 ) in dependence on the operating status of the fuel cell ( 2 ), and wherein the cathode gas can be conducted in the direction of the exhaust air line ( 7 ) by the other gas-flow regulation element ( 9 ) in dependence on the operating status of the fuel cell ( 2 ).

3 . The fuel cell system ( 1 ) according to claim 1 ,
characterized in that a mass flow of the cathode gas can be regulated by a compressor ( 10 ) connected to the gas supply line ( 6 ).

4 . The fuel cell system ( 1 ) according to claim 1 ,
characterized in that at least one air mass flow sensor ( 11 ) is disposed in the gas supply line ( 6 ) for determining the oxygen content of the cathode gas via the mass flow thereof.

5 . The fuel cell system ( 1 ) according to claim 1 ,
characterized in that a lambda sensor ( 12 ) is disposed in the gas supply line ( 6 ), wherein the lambda sensor ( 12 ) is disposed between the gas-flow regulation element ( 8 ), which connects the exhaust air line ( 7 ) to the gas supply line ( 6 ), and the fuel cell ( 2 ).

6 . A method for operating a fuel cell ( 2 ) by a fuel cell system ( 1 ) according to claim 1 , wherein the fuel cell ( 2 ) comprises an anode chamber ( 3 ) and a cathode chamber ( 4 ) separated from the anode chamber ( 3 ), and wherein the fuel cell system ( 1 ) also comprises a cathode gas source ( 5 ), a gas supply line ( 6 ), which is connected to the cathode gas source ( 5 ), for feeding cathode gas into the cathode chamber ( 4 ), and an exhaust air line ( 7 ), which is connected to the cathode chamber ( 4 ), for conducting exhaust air out of the cathode chamber ( 4 ), and wherein the gas supply line ( 6 ) and the exhaust air line ( 7 ) are connected by at least one gas-flow regulation element ( 8 , 9 ), which opens the gas supply line ( 6 ) in the direction of the exhaust air line ( 7 ) and/or the exhaust air line ( 7 ) in the direction of the gas supply line ( 6 ) in dependence on an operating status of the fuel cell ( 2 ), comprising the following procedural steps:
a) startup of the fuel cell ( 2 ), b) restricting the voltage applied to the fuel cell ( 2 ) by depleting the cathode gas by feeding exhaust air into the gas supply line ( 6 ) by the gas-flow regulation element ( 8 ) and/or by conducting the cathode gas into the exhaust air line ( 7 ) by the gas-flow regulation element ( 9 ) and/or by reducing the mass flow of the cathode gas by reducing the rotational speed of a compressor ( 10 ) which is connected to the gas supply line ( 6 ), c) engaging primary contactors ( 13 ) which connect the fuel cell ( 2 ) to a HV on-board electrical system ( 14 ), d) lifting the restriction of the voltage applied to the fuel cell ( 2 ).

7 . The method according to claim 6 , characterized in that, when feeding exhaust air into the gas supply line ( 6 ), the oxygen content of the cathode gas is measured by at least one lambda sensor ( 12 ) prior to feeding the cathode gas into the cathode chamber ( 4 ).

8 . The method according to claim 6 , wherein startup of the fuel cell ( 2 ) occurs during freezing conditions.

9 . A method for operating a fuel cell ( 2 ) by a fuel cell system ( 1 ) according to claim 1 , wherein the fuel cell ( 2 ) comprises an anode chamber ( 3 ) and a cathode chamber ( 4 ) separated from the anode chamber ( 3 ), and wherein the fuel cell system ( 1 ) also comprises a cathode gas source ( 5 ), a gas supply line ( 6 ), which is connected to the cathode gas source ( 5 ), for feeding cathode gas into the cathode chamber ( 4 ), and an exhaust air line ( 7 ), which is connected to the cathode chamber ( 4 ), for conducting exhaust air out of the cathode chamber ( 4 ), and wherein the gas supply line ( 6 ) and the exhaust air line ( 7 ) are connected by at least one gas-flow regulation element ( 8 , 9 ), which opens the gas supply line ( 6 ) in the direction of the exhaust air line ( 7 ) and/or the exhaust air line ( 7 ) in the direction of the gas supply line ( 6 ) in dependence on an operating status of the fuel cell ( 2 ), comprising the following procedural steps:
a) startup of the fuel cell ( 2 ), b) restricting the voltage applied to the fuel cell ( 2 ) by depleting the cathode gas by feeding exhaust air into the gas supply line ( 6 ) by the gas-flow regulation element ( 8 ), c) engaging primary contactors ( 13 ) which connect the fuel cell ( 2 ) to a HV on-board electrical system ( 14 ), d) lifting the restriction of the voltage applied to the fuel cell ( 2 ).

10 . A method for operating a fuel cell ( 2 ) by a fuel cell system ( 1 ) according to claim 1 , wherein the fuel cell ( 2 ) comprises an anode chamber ( 3 ) and a cathode chamber ( 4 ) separated from the anode chamber ( 3 ), and wherein the fuel cell system ( 1 ) also comprises a cathode gas source ( 5 ), a gas supply line ( 6 ), which is connected to the cathode gas source ( 5 ), for feeding cathode gas into the cathode chamber ( 4 ), and an exhaust air line ( 7 ), which is connected to the cathode chamber ( 4 ), for conducting exhaust air out of the cathode chamber ( 4 ), and wherein the gas supply line ( 6 ) and the exhaust air line ( 7 ) are connected by at least one gas-flow regulation element ( 8 , 9 ), which opens the gas supply line ( 6 ) in the direction of the exhaust air line ( 7 ) and/or the exhaust air line ( 7 ) in the direction of the gas supply line ( 6 ) in dependence on an operating status of the fuel cell ( 2 ), comprising the following procedural steps:
a) startup of the fuel cell ( 2 ), b) restricting the voltage applied to the fuel cell ( 2 ) by conducting the cathode gas into the exhaust air line ( 7 ) by the gas-flow regulation element ( 9 ), c) engaging primary contactors ( 13 ) which connect the fuel cell ( 2 ) to a HV on-board electrical system ( 14 ), d) lifting the restriction of the voltage applied to the fuel cell ( 2 ).

11 . A method for operating a fuel cell ( 2 ) by a fuel cell system ( 1 ) according to claim 1 , wherein the fuel cell ( 2 ) comprises an anode chamber ( 3 ) and a cathode chamber ( 4 ) separated from the anode chamber ( 3 ), and wherein the fuel cell system ( 1 ) also comprises a cathode gas source ( 5 ), a gas supply line ( 6 ), which is connected to the cathode gas source ( 5 ), for feeding cathode gas into the cathode chamber ( 4 ), and an exhaust air line ( 7 ), which is connected to the cathode chamber ( 4 ), for conducting exhaust air out of the cathode chamber ( 4 ), and wherein the gas supply line ( 6 ) and the exhaust

Assignees

• Bosch Gmbh Robert

Inventors

• Kemmer Helerson

Classifications

• H01M8/04253

  Means for solving freezing problems · CPC title

• H01M8/04225 Primary

  during start-up · CPC title

• H01M8/0488

  of fuel cell stacks · CPC title

• H01M8/04395

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

• H01M2250/20

  Fuel cells in motive systems, e.g. vehicle, ship, plane · CPC title