Fuel cell system and method of shutting down the same

Patent metadata

Field	Value
Publication number	US-10411280-B2
Application number	US-201715603451-A
Country	US
Kind code	B2
Filing date	May 24, 2017
Priority date	May 30, 2016
Publication date	Sep 10, 2019
Grant date	Sep 10, 2019

Abstract

A method of shutting down a fuel cell system includes a fuel cell includes generating power via an electrochemical reaction between a fuel gas and an oxidant gas. A shutdown command is output to the fuel cell to stop generating power. The fuel cell is controlled to continue generating power during an oxygen consumption process to consume oxygen in the oxidant gas remaining in a cathode system of the fuel cell even when the shutdown command is output to the fuel cell. At least one of voltage, current, and power output from the fuel cell is detected during the oxygen consumption process. Whether an abnormality occurs during the oxygen consumption process is determined based on at least one of the voltage, the current, and the power. The fuel cell is controlled to stop generating power during the oxygen consumption process when it is determined that abnormality occurs.

First claim

What is claimed is:

1. A method of shutting down a fuel cell system including a fuel cell, comprising:
generating power via an electrochemical reaction between a fuel gas and an oxidant gas;
outputting a shutdown command to the fuel cell to stop generating power;
controlling the fuel cell to supply the fuel gas and to continue generating power during an oxygen consumption process to consume oxygen in the oxidant gas circulating in a cathode system of the fuel cell even when the shutdown command is output to the fuel cell;
detecting at least one of voltage, current, and power output from the fuel cell during the oxygen consumption process;
determining whether an abnormality occurs during the oxygen consumption process based on at least one of the voltage, the current, and the power; and
controlling the fuel cell to stop generating power during the oxygen consumption process when it is determined that abnormality occurs.

2. A fuel cell system comprising:
a fuel cell to generate power via an electrochemical reaction between a fuel gas and an oxidant gas;
at least one detector to detect at least one of voltage, current, and power output from the fuel cell during an oxygen consumption process; and
circuitry configured to
output a shutdown command to the fuel cell to stop generating power;
control the fuel cell to supply the fuel gas and to continue generating power during the oxygen consumption process to consume oxygen in the oxidant gas circulating in a cathode system of the fuel cell even when the circuitry outputs the shutdown command to the fuel cell;
determine whether an abnormality occurs during the oxygen consumption process based on at least one of the voltage, the current, and the power; and
control the fuel cell to stop generating power during the oxygen consumption process when the circuitry determines that abnormality occurs.

3. A method of shutting down a fuel cell system including a fuel cell, comprising:
generating power via an electrochemical reaction between a fuel gas and an oxidant gas;
outputting a shutdown command to the fuel cell to stop generating power;
controlling the fuel cell to continue generating power during an oxygen consumption process to consume oxygen in the oxidant gas remaining in a cathode system of the fuel cell even when the shutdown command is output to the fuel cell;
detecting at least one of voltage, current, and power output from the fuel cell during the oxygen consumption process;
determining whether an abnormality occurs during the oxygen consumption process based on at least one of the voltage, the current, and the power;
controlling the fuel cell to stop generating power during the oxygen consumption process when it is determined that abnormality occurs;
setting a target value for the current or the power,
wherein it is determined that the abnormality occurs during the oxygen consumption process when the current or the power detected has not been decreased to the target value within a determination time after the target value is set.

4. The method according to claim 1 , further comprising:
setting a threshold value for the current or the power,
wherein it is determined that the abnormality occurs during the oxygen consumption process when the current or the power detected has been increased to the threshold value.

5. The method according to claim 1 , further comprising:
setting a target value for the voltage,
wherein it is determined that the abnormality occurs during the oxygen consumption process when the voltage detected has not been decreased to the target value within a voltage determination time after the target value is set.

6. The method according to claim 1 , further comprising:
setting a threshold value for the voltage,
wherein it is determined that the abnormality occurs during the oxygen consumption process when the voltage has been increased to the voltage threshold value.

7. The method according to claim 1 ,
wherein when the fuel cell is controlled to stop generating power, fuel gas sealing control for introducing and sealing the fuel gas to and within the fuel cell is not performed.

8. The method according to claim 1 ,
wherein the oxygen consumption processing is stopped by outputting a valve open command to an on-off valve for stopping flow of the oxidant gas into the cathode system of the fuel cell.

9. The method according to claim 3 , further comprising:
setting a control voltage value for the fuel cell in the oxygen consumption processing such that the control voltage value decreases stepwise.

10. The method according to claim 9 ,
wherein when the current or the power detected has been decreased to the target value within the determination time, a new control voltage value lower than the control voltage value is set.

11. The method according to claim 5 , further comprising:
setting a control current value for the fuel cell in the oxygen consumption processing such that the control current value decreases stepwise.

12. The method according to claim 11 ,
wherein when the voltage detected has been decreased to the target voltage value within the voltage determination time, a new control current value lower than the control current value is set.

Assignees

• Honda Motor Co Ltd

Inventors

• Ojima Kuniaki
• Taruya Kenji

Classifications

• H01M8/04619

  of fuel cell stacks · CPC title

• H01M8/04753

  of fuel cell reactants · CPC title

• H01M8/04559

  of fuel cell stacks · CPC title

• H01M8/04589

  of fuel cell stacks · CPC title

• H01M8/04679

  of fuel cell stacks · CPC title