Method for Purging a Fuel Cell and Device for Carrying Out Said Method

Patent metadata

Field	Value
Publication number	US-2016344047-A1
Application number	US-201615227048-A
Country	US
Kind code	A1
Filing date	Aug 3, 2016
Priority date	Apr 17, 2014
Publication date	Nov 24, 2016
Grant date	—

Abstract

A method is provided for purging a fuel cell. The method is characterized by suctioning the purge gas through the fuel cell by use of low pressure.

First claim

What is claimed is:

1 . A method for purging a fuel cell, the method comprising the acts of:
suctioning purging gas through the fuel cell, wherein the suctioning of the purging gas through the fuel cell occurs via a negative pressure.

2 . The method according to claim 1 , wherein, during the suctioning of the purging gas through the fuel cell, a delivery device for cathode gas is operated in a normal delivery direction.

3 . The method according to claim 2 , further comprising the act of:
delivering out the purging gas suctioned through the fuel cell via a fuel-cell exhaust-gas outlet.

4 . The method according to claim 1 , further comprising the act of:
delivering out the purging gas suctioned through the fuel cell via a fuel-cell exhaust-gas outlet.

5 . The method according to claim 4 , wherein the purging gas suctioned through the fuel cell is delivered into the fuel-cell exhaust-gas outlet via a first bypass line.

6 . The method according to claim 1 , wherein the purging gas is suctioned in via a cathode-gas supply of the fuel cell.

7 . The method according to claim 1 , wherein:
the purging gas is first filtered by a cathode-gas air filter of the fuel cell, and the filtered purging gas is then suctioned through the fuel cell.

8 . The method according to claim 1 , wherein:
during suctioning of the purging gas upstream of the fuel cell, the purging gas is suctioned in via a cathode-gas air filter without flowing through a delivery device, and during the suctioning of the purging gas, the delivery device is connected via at least one line to a fuel-cell exhaust gas line such that the purging gas is suctioned in through the fuel cell.

9 . The method according to claim 1 , wherein the purging gas suctioned through the fuel cell is delivered out via a purging-gas outlet provided in a cathode-gas supply of the fuel cell.

10 . The method according to claim 1 , wherein the purging gas is suctioned in via a purging-gas supply provided in a cathode-gas supply of the fuel cell or is suctioned in via a separate purging-gas supply.

11 . The method according to claim 1 , wherein the negative pressure is generated by operating a delivery device of the fuel cell in a reverse direction.

12 . The method according to claim 1 , wherein the purging gas is suctioned in via a fuel-cell exhaust-gas line via a fuel-cell exhaust-gas outlet.

13 . The method according to claim 1 , wherein
after deactivation of the fuel cell, a delivery direction is initially maintained for one to ten seconds.

14 . The method according to claim 1 , wherein water is condensed out of the fuel cell exhaust air and/or out of the purging gas before suctioning the purging gas through the fuel cell via the negative pressure.

15 . A device, comprising:
a fuel cell having a cathode-gas supply and a fuel-cell exhaust-gas line; a delivery device arranged in the cathode-gas supply, wherein the delivery device is configured to generate negative pressure in the fuel cell to suction the purging gas through the fuel cell.

16 . The device according to claim 15 , wherein the delivery device supplies cathode gas to the fuel cell and is operated in a normal delivery direction during the suctioning of the purging gas through the fuel cell.

17 . The device according to claim 15 , further comprising:
a purging-gas supply; and a purging-gas outlet, wherein the purging-gas supply and/or the purging-gas outlet are arranged in the cathode-gas supply between the delivery device and the fuel cell.

18 . The device according to claim 15 , further comprising:
a first bypass line and/or a second bypass line, wherein the first bypass line connects the fuel-cell exhaust gas line and the cathode-gas supply downstream of the delivery device, and the second bypass line connects the cathode-gas supply downstream of the delivery device to the cathode-gas supply upstream of the delivery device.

19 . The device according to claim 15 , further comprising:
a plurality of multi-way valves arranged in the cathode-gas supply and/or in the fuel-cell exhaust-gas line, wherein the multi-way valves are configured such that, during normal operation of the fuel cell, cathode gas is conducted to the fuel cell and fuel-cell exhaust gas is discharged from the fuel cell, and during suctioning of the purging gas through the fuel cell, purging gas is conducted from a cathode air filter into the fuel cell and the purging gas is supplied, downstream of the fuel cell, to the delivery device. 20 , The device according to claim 15 , further comprising a condenser arranged in the fuel-cell exhaust-gas line.

Assignees

• Bayerische Motoren Werke Ag

Inventors

• Schmid Johannes
• Frisch Norbert

Classifications

• H01M8/04164

  by condensers, gas-liquid separators or filters · CPC title

• H01M8/04843

  of fuel cell exhausts · CPC title

• H01M8/04955

  Shut-off or shut-down of fuel cells · CPC title

• H01M8/04253 Primary

  Means for solving freezing problems · CPC title

• H01M8/04111

  using a compressor turbine assembly · CPC title