# US 9,437,886 B2 · Fuel cell system and method for stopping power generation in fuel cell system

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- Number: US 9,437,886 B2
- Document ID: US9437886B2
- Status: Granted
- Kind: B2
- Application number: 13/440,673
- Filed: 2012-04-05
- Published: 2012-10-11
- Granted: 2016-09-06
- Earliest claimed: 2011-04-08
- Assignees: Honda Motor Co., Ltd.
- Applicants: Kazunori Fukuma; Nobutaka Nakajima
- Inventors: Kazunori Fukuma; Nobutaka Nakajima
- Web page: https://patentgrep.com/patent/US9437886B2

## CPC

- H01M 8/04201: {Reactant storage and supply, e.g. means for feeding, pipes}
- H01M 8/0258: characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant
- H01M 8/0267: having heating or cooling means, e.g. heaters or coolant flow channels
- H01M 8/04089: of gaseous reactants
- H01M 8/04126: {Humidifying}
- H01M 8/04223: during start-up or shut-down; Depolarisation or activation, e.g. purging; Means for short-circuiting defective fuel cells
- H01M 8/04228: during shut-down
- H01M 8/04303: applied during shut-down
- H01M 8/2483: characterised by internal manifolds
- H01M 8/04111: using a compressor turbine assembly
- H01M 2008/1095: {Fuel cells with polymeric electrolytes}
- Y02E 60/50: Fuel cells
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

An oxygen-containing gas supply device of a fuel cell system is equipped with an oxygen-containing gas supply flow passage that communicates with an oxygen-containing gas inlet of a fuel cell. An oxygen-containing gas discharge flow passage communicates with an oxygen-containing gas outlet of the fuel cell. A compressor is disposed in the oxygen-containing gas supply flow passage and a supply flow passage sealing valve is disposed downstream from the compressor in the oxygen-containing gas supply flow passage. A discharge flow passage sealing valve is disposed in the oxygen-containing gas discharge flow passage, and a discharge fluid circulation flow passage that communicates with the oxygen-containing gas discharge flow passage is disposed at a location upstream from the discharge flow passage sealing valve, while also communicating with the oxygen-containing gas supply flow passage at a location upstream from the compressor.

## Claims

### Claim 1

A fuel cell system comprising:
a fuel cell that generates electric power through an electrochemical reaction between an oxygen-containing gas, which is supplied to a cathode, and a fuel gas, which is supplied to an anode;
an oxygen-containing gas supply device for supplying the oxygen-containing gas to the fuel cell; and
a fuel gas supply device for supplying the fuel gas to the fuel cell,
wherein the oxygen-containing gas supply device comprises:
an oxygen-containing gas supply flow passage that communicates with an oxygen-containing gas inlet of the fuel cell;
an oxygen-containing gas discharge flow passage that communicates with an oxygen-containing gas outlet of the fuel cell;
a compressor disposed in the oxygen-containing gas supply flow passage;
a supply flow passage sealing valve disposed in the oxygen-containing gas supply flow passage at a location downstream from the compressor;
a discharge flow passage sealing valve disposed in the oxygen-containing gas discharge flow passage; and
a discharge fluid circulation flow passage connected to the oxygen-containing gas discharge flow passage at a location upstream from the discharge flow passage sealing valve, while also connecting to the oxygen-containing gas supply flow passage at a location upstream from the compressor,
wherein the discharge fluid circulation flow passage is configured to allow the oxygen-containing gas to flow from the oxygen-containing gas discharge flow passage to the oxygen-containing gas supply flow passage.

### Claim 2 (depends on 1)

The fuel cell system according to claim 1, wherein a circulation flow passage valve is disposed in the discharge fluid circulation flow passage.

### Claim 3 (depends on 1)

The fuel cell system according to claim 1, wherein a humidifier is arranged to straddle between the oxygen-containing gas supply flow passage and the oxygen-containing gas discharge flow passage.

### Claim 4 (depends on 3)

The fuel cell system according to claim 3, wherein the supply flow passage sealing valve is disposed in the oxygen-containing gas supply flow passage at a location upstream from the humidifier, whereas the discharge flow passage sealing valve is disposed in the oxygen-containing gas discharge flow passage at a location downstream from the humidifier.

### Claim 5 (depends on 1)

The fuel cell system according to claim 1, wherein the discharge flow passage sealing valve is capable of adjusting a degree of opening at least between a completely open state, and a minutely open state for maintaining a required flow rate to thereby raise the pressure on a side of the cathode above ordinary pressure and to thereby consume all of an oxygen component, and
further comprising:
a circulation flow passage valve disposed in the discharge fluid circulation flow passage; and
a control device for controlling the discharge flow passage sealing valve to be placed in the minutely open state when the circulation flow passage valve is opened.

### Claim 6 (depends on 1)

The fuel cell system according to claim 1, wherein the fuel gas supply device comprises a fuel gas supply flow passage that communicates with a fuel gas inlet of the fuel cell; and
one end of a branch passage communicates with the oxygen-containing gas supply flow passage at a location downstream from the supply flow passage sealing valve, and another end of the branch passage communicates with the fuel gas supply flow passage.

### Claim 7 (depends on 1)

The fuel cell system according to claim 1, wherein an expander turbine is disposed in the oxygen-containing gas discharge flow passage at a location downstream from the discharge flow passage sealing valve; and
the expander turbine is connected to and is capable of transmitting power to the compressor.