Fuel cell system and method for recirculating water in a fuel cell system

Patent metadata

Field	Value
Publication number	US-2017141417-A1
Application number	US-201615353385-A
Country	US
Kind code	A1
Filing date	Nov 16, 2016
Priority date	Nov 17, 2015
Publication date	May 18, 2017
Grant date	—

Abstract

A fuel cell system ( 1 ) in which a water separator ( 110 ) for separating liquid water from an exhaust gas ( 6, 4 ) of a fuel cell ( 10 ) of the fuel cell system ( 1 ) is fluid-mechanically coupled into an exhaust gas path ( 32, 22 ) of the fuel cell system. A water recirculator ( 120 ) is fluid-mechanically coupled into the fuel cell system ( 1 ), with the aid of which at least a portion of the water of the water separator ( 110 ) is once again providable to the fuel cell ( 10 ). Moreover, a method for recirculating water in a fuel cell system ( 1 ), in which liquid water of a fuel cell supply ( 30, 20 ) of the fuel cell system ( 1 ) is withdrawn at a removal site at/in the fuel cell supply ( 30, 20 ). The water upstream from the removal site is provided to the same fuel cell supply ( 30, 20 ) and/or to some other fuel cell supply ( 20, 30 ) of the fuel cell system ( 1 ).

First claim

What is claimed is:

1 . A fuel cell system comprising:
a fuel cell; a water separator for separating liquid water from an exhaust gas of the fuel cell, the water separator being fluid-mechanically coupled into an exhaust gas path of the fuel cell system; and a water recirculator fluid-mechanically coupled into the fuel cell system, at least a portion of the water of the water separator being once again providable to the fuel cell with aid of the water recirculator.

2 . The fuel cell system as recited in claim 1 wherein, starting from the water separator or from a water collector fluid-mechanically connected downstream from the water separator, water is providable to an operating medium of the fuel cell system, to the exhaust gas, or to a humidifier of a fuel cell supply of the fuel cell system with aid of the water recirculator.

3 . The fuel cell system as recited in claim 1 wherein the water separator is fluid-mechanically coupled into a cathode exhaust gas path of a cathode supply of the fuel cell system, and water is providable to a cathode operating medium of the fuel cell system, to a cathode exhaust gas of the fuel cell system, or to an anode supply of the fuel cell system with aid of the water recirculator.

4 . The fuel cell system as recited in claim 1 wherein a recirculation of the water through the water recirculator is achievable via natural circulation, a temperature gradient, a capillary force, a suction effect, a Coanda effect, or an exhaust gas turbocharger.

5 . The fuel cell system as recited in claim 1 wherein the humidifier includes an internal water recirculator, the water separator and the water recirculator being accommodated essentially within the humidifier.

6 . The fuel cell system as recited in claim 5 further comprising a cathode supply including a water recirculator at least partially external with respect to the humidifier, the water separator being provided outside or inside the humidifier, downstream in the cathode exhaust gas path, and a feed for the external water recirculator for introducing the water into a cathode exhaust gas path and being provided upstream in the cathode exhaust gas path, outside or inside the humidifier.

7 . A method for recirculating water in a fuel cell system, the method comprising:
withdrawing liquid water of a fuel cell supply of the fuel cell system at a removal site at or in the fuel cell supply; and providing the water upstream from the removal site to the fuel cell supply or to another fuel cell supply of the fuel cell system.

8 . The method as recited in claim 7 wherein the liquid water is withdrawn from an exhaust gas of the fuel cell system, from a water separator of the fuel cell system, or from a water collector of the fuel cell system; or the water is provided to an operating medium of the fuel cell system, to an exhaust gas of the fuel cell system, or to a humidifier of the fuel cell supply.

9 . The method as recited in claim 7 wherein the liquid water originates from a water separator in a cathode exhaust gas path of a cathode supply of the fuel cell system, and the water is provided to a humidifier of the cathode supply.

10 . The method as recited in claim 9 wherein the water is provided to a cathode exhaust gas upstream from the humidifier, at the humidifier, or in the humidifier.

11 . A vehicle comprising the fuel cell system as recited in claim 1 .

12 . The vehicle as recited in claim 11 wherein the vehicle is an electric vehicle.

13 . A vehicle performing the method steps for recirculating water as recited in claim 7 .

14 . The vehicle as recited in claim 13 wherein the vehicle is an electric vehicle.

Assignees

• Volkswagen Ag

Inventors

• Lucas Christian
• Staeck Rune

Classifications

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M8/04156

  with product water removal · CPC title

• H01M2250/20

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

• H01M8/04291 Primary

  Arrangements for managing water in solid electrolyte fuel cell systems (H01M8/04119 takes precedence) · CPC title

• H01M8/04141 Primary

  by water containing exhaust gases · CPC title