Arrangement for a cathode recirculation in a fuel cell and method for cathode recirculation

Patent metadata

Field	Value
Publication number	US-2018301720-A1
Application number	US-201615769300-A
Country	US
Kind code	A1
Filing date	Oct 19, 2016
Priority date	Oct 22, 2015
Publication date	Oct 18, 2018
Grant date	—

Abstract

The invention relates to an arrangement for a cathode recirculation of a fuel cell ( 10 ) of a fuel cell system ( 1 ) with a cathode supply ( 30 ) for the fuel cell ( 10 ), having a cathode supply path ( 31 ) and a cathode waste gas path ( 32 ), and a flushing loop ( 50 ) of a stack housing ( 16 ) of the fuel cell ( 10 ) is mechanically connected in terms of fluid to the cathode supply ( 30 ), wherein a recirculation fluid ( 7 ) can be circulated in the cathode supply ( 30 ) and in the flushing loop ( 50 ) by means of a recirculation fluid pressure generator ( 33, 53 ) in the cathode supply ( 30 ) and/or in the flushing loop ( 50 ).
The invention also relates to a method for cathode recirculation of a fuel cell ( 10 ) of a fuel cell system ( 1 ) if a vehicle, in particular of an electric vehicle, wherein a recirculation fluid ( 7 ) is conveyed through a cathode supply path ( 31 ), through the cathode chambers of the fuel cell ( 10 ), and through a cathode waste gas path (32), and the recirculation fluid ( 7 ) is also conveyed through a flushing loop ( 50 ) for a stack housing ( 16 ) of the fuel cell ( 10 ) as well as the stack housing ( 16 ).

First claim

1 . A fuel cell system, comprising:
a cathode supply having a cathode supply path and a cathode waste gas path; a stack housing including a flushing loop fluidically connected to the cathode supply; and a recirculation fluid pressure generator located in the cathode supply or in the flushing loop; wherein a recirculation fluid can be circulated in the cathode supply and in the flushing loop by the recirculation fluid pressure generator.

2 . The fuel cell system according to claim 1 ,
wherein the flushing loop has a first side fluidically coupled with the cathode supply path and has a second side opposite the first side fluidically coupled with the cathode waste gas path; and wherein the flushing loop is fluidically connected to the cathode supply path and to the cathode waste gas path.

3 . The fuel cell system according to claim 1 , wherein the recirculation fluid pressure generator is a cathode condenser located in the cathode supply path or a housing ventilator located in the flushing loop.

4 . The fuel cell system according to claim 1 , wherein the cathode waste gas path includes downstream of a fluid-mechanical connection of the flushing loop to the cathode waste gas path.

5 . A method, comprising:
conveying a recirculation fluid through a cathode supply path, through cathode chambers of a fuel cell, and through a cathode waste gas path, conveying the recirculation fluid through a flushing loop of a stack housing of the fuel cell; and conveying the recirculation fluid through the stack housing.

6 . The method according to claim 5 , wherein the recirculation fluid is conveyed by a recirculation fluid pressure generator.

7 . (canceled)

8 . The method according to claim 5 , further comprising:
using the recirculation fluid pressure generator to circulate the recirculation fluid through the cathode supply path, the cathode chambers, the cathode waste gas path, the flushing loop, and the stack housing until essentially no oxygen remains in the recirculation fluid.

9 . A method of flushing a stack housing of a fuel cell system of an automobile, comprising:
using a housing ventilator to flush a flushing fluid through a flushing route and through the stack housing; flusing the flushing fluid through a downstream segment of a cathode waste gas path; and discharging the flushing fluid from the downstream segment of the cathode waste gas path into an environment surrounding the automobile.

10 . (canceled)

11 . The fuel cell system according to claim 2 wherein the flushing loop is fluidically connected to the cathode supply path upstream of a cathode condenser.

12 . The fuel cell system according to claim 2 wherein the flushing loop is fluidically connected to an air filter.

13 . The fuel cell system according to claim 2 wherein the flushing loop is fluidically connected to the cathode waste gas path downstream of a cathode turbine.

14 . The fuel cell system according to claim 2 wherein the flushing loop is fluidically connected to the cathode waste gas path upstream of a hydrogen sensor.

15 . The fuel cell system according to claim 4 wherein the regulator is a stop valve.

16 . The method according to claim 6 wherein the reciruclation fluid pressure generator is a cathode condenser located in the cathode supply path.

17 . The method according to claim 16 wherein the recirculation fluid pressure generator includes a housing ventilator in an inactive state.

18 . The method according to claim 6 wherein the recirculation fluid pressure generator is a housing ventilator in the flushing loop.

19 . The method according to claim 18 wherein the recirculation fluid pressure generator includes a cathode condenser in an inactive state.

20 . The method of claim 9 wherein the automobile is an electric vehicle.

Assignees

• Volkswagen Ag
• Audi Ag

Inventors

• Grundei Daniel
• Kirchhoff Maren Ramona

Classifications

• H01M8/2475

  Enclosures, casings or containers of fuel cell stacks · CPC title

• H01M8/04225

  during start-up · CPC title

• H01M8/04097

  with recycling of the reactants (H01M8/04119, H01M8/04104 take precedence) · CPC title

• H01M8/04111

  using a compressor turbine assembly · CPC title

• H01M8/04228

  during shut-down · CPC title