Fuel cell system and control method of same

Patent metadata

Field	Value
Publication number	US-10297845-B2
Application number	US-201515515509-A
Country	US
Kind code	B2
Filing date	Aug 3, 2015
Priority date	Oct 2, 2014
Publication date	May 21, 2019
Grant date	May 21, 2019

Abstract

A first representative value is acquired representing an amount of liquid water in a hydrogen gas passage (30) when a fuel cell stack (10) is to be started up. Based on the first representative value, a first purge gas amount is calculated. A second representative value is acquired representing a concentration of hydrogen gas in a hydrogen gas passage when the fuel cell stack is to be started up. Based on the second representative value, a second purge gas amount is calculated. The greater of the first purge gas amount and the second purge gas amount is set as a startup purge gas amount. When the fuel cell stack is to be started up, hydrogen gas is fed to the fuel cell stack while the purge control valve 38 is temporally opened to purge the gas by the startup purge gas amount.

First claim

The invention claimed is:

1. A fuel cell system comprising:
a fuel cell stack configured to generate electric power by an electrochemical reaction between a fuel gas and an oxidant gas;
a fuel gas feed path connecting an inlet of a fuel gas passage formed inside the fuel cell stack and a fuel gas source with each other;
a fuel gas feeder arranged in the fuel gas feed path and configured to control a feed of fuel gas to the fuel cell stack;
a purge passage connected to an outlet of the fuel gas passage and separated from the fuel gas feed path;
a purge control valve arranged inside the purge passage; and
a controller configured to:
acquire a first representative value representing an amount of liquid water in the fuel gas passage when the fuel cell stack is to be started up;
calculate a first purge gas amount based on the acquired first representative value;
acquire a second representative value representing a concentration of fuel gas in the fuel gas passage when the fuel cell stack is to be started up;
calculate a second purge gas amount based on the acquired second representative value;
set the greater of the first purge gas amount and the second purge gas amount as a startup purge gas amount; and
when the fuel cell stack is to be started up, feed fuel gas to the fuel cell stack by the fuel gas feeder and, at the same time, open the purge control valve temporarily so as to purge the gas by the startup purge gas amount.

2. The fuel cell system according to claim 1 , wherein the first purge gas amount is a purge gas amount necessary for making an amount of liquid water in the fuel gas passage decrease to a predetermined target amount.

3. The fuel cell system according to claim 1 , wherein the second purge gas amount is a purge gas amount necessary for making a concentration of fuel gas in the fuel gas passage increase to a predetermined target concentration.

4. The fuel cell system according to claim 1 , wherein the first representative value is a relative humidity in the fuel gas passage when the fuel cell stack is to be started up.

5. The fuel cell system according to claim 1 , wherein the first representative value is an amount of change of a temperature of the fuel cell stack when the fuel cell stack is to be started up with respect to a temperature of the fuel cell stack when the fuel cell stack was stopped.

6. The fuel cell system according to claim 1 , wherein the second representative value is an elapsed time from when the fuel cell stack is stopped to when it is to be started up.

7. The fuel cell system according to claim 1 , wherein the second representative value is a fuel gas partial pressure in the fuel gas passage when the fuel cell stack is to be started up.

8. The fuel cell system according to claim 1 , wherein the controller is configured to start feed of oxidant gas to the fuel cell stack after the temporal opening of the purge control valve is finished, when the fuel cell stack is to be started up.

9. A control method of a fuel cell system, the fuel cell system comprising:
a fuel cell stack configured to generate electric power by an electrochemical reaction between a fuel gas and an oxidant gas;
a fuel gas feed path connecting an inlet of a fuel gas passage formed inside the fuel cell stack and a fuel gas source with each other;
a fuel gas feeder arranged in the fuel gas feed path and configured to control a feed of fuel gas to the fuel cell stack;
a purge passage connected to an outlet of the fuel gas passage and separated from the fuel gas feed path; and
a purge control valve arranged inside the purge passage,
the control method of a fuel cell system configured to:
acquire a first representative value representing an amount of liquid water in the fuel gas passage when the fuel cell stack is to be started up;
calculate a first purge gas amount based on the acquired first representative value;
acquire a second representative value representing a concentration of fuel gas in the fuel gas passage when the fuel cell stack is to be started up;
calculate a second purge gas amount based on the acquired second representative value;
set the greater of the first purge gas amount and the second purge gas amount as a startup purge gas amount; and
when the fuel cell stack is to be started up, feed fuel gas to the fuel cell stack by the fuel gas feeder and, at the same time, open the purge control valve temporarily so as to purge the gas by the startup purge gas amount.

10. A fuel cell system comprising:
a fuel cell stack configured to generate electric power by an electrochemical reaction between a fuel gas and an oxidant gas;
a fuel gas feed path connecting an inlet of a fuel gas passage formed inside the fuel cell stack and a fuel gas source with each other;
a fuel gas feeder arranged in the fuel gas feed path and configured to control a feed of fuel gas to the fuel cell stack;
a purge passage connected to an outlet of the fuel gas passage and separated from the fuel gas feed path;
a purge control valve arranged inside the purge passage; and
an electronic control unit configured to:
acquire a first representative value representing an amount of liquid water in the fuel gas passage when the fuel cell stack is to be started up;
calculate a first purge gas amount based on the acquired first representative value;
acquire a second representative value representing a concentration of fuel gas in the fuel gas passage when the fuel cell stack is to be started up;
calculate a second purge gas amount based on the acquired second representative value;
set the greater of the first purge gas amount and the second purge gas amount as a startup purge gas amount; and
when the fuel cell stack is to be started up, feed fuel gas to the fuel cell stack by the fuel gas feeder and, at the same time, open the purge control valve temporarily so as to purge the gas by the startup purge gas amount.

11. The fuel cell system according to claim 10 , wherein the first purge gas amount is a purge gas amount necessary for making an amount of liquid water in the fuel gas passage decrease to a predetermined target amount.

12. The fuel cell system according to claim 10 , wherein the second purge gas amount is a purge gas amount necessary for making a concentration of fuel gas in the fuel gas passage increase to a predetermined target concentration.

13. The fuel cell system according to claim 10 , wherein the first representative value is a relative humidity in the fuel gas passage when the fuel cell stack is to be started up.

14. The fuel cell system according to claim 10 , wherein the first representative value is an amount of change of a temperature of the fuel cell stack when the fuel cell stack is to be started up with respect to a temperature of the fuel cell stack when the fuel cell stack was stopped.

15. The fuel cell system according to claim 10 , wherein the second representative value is an elapsed time from when the fuel cell stack is stopped to when it is to be started up.

16. The fuel cell system according to claim 10 , wherein the second representative value is a fuel gas partial pressure in the fuel gas passage when the fuel cell stack is to be started up.

17. The fuel cell system according to claim 10 , wherein the electronic control unit is configured to start feed of oxidant gas to the fuel cell stack after the temporal opening of the purge control valve is finished, when the fuel cell stack is to be started up.

Assignees

• Toyota Motor Co Ltd

Inventors

• Yamaue Keita

Classifications

• H01M8/04365

  of other components of a fuel cell or fuel cell stacks · CPC title

• Y02T90/32

  Cross-Sectional Technologies · mapped topic

• H01M8/045

  of anode reactants at the inlet or inside the fuel cell · CPC title

• H01M8/04753

  of fuel cell reactants · CPC title

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title