Fuel cell system and control method for fuel cell system

Patent metadata

Field	Value
Publication number	US-10411279-B2
Application number	US-201515328150-A
Country	US
Kind code	B2
Filing date	Jun 16, 2015
Priority date	Jul 24, 2014
Publication date	Sep 10, 2019
Grant date	Sep 10, 2019

Abstract

A fuel cell system includes a gas supply passage configured to supply one of the anode gas and the cathode gas to the fuel cell, a refrigerant supply apparatus that supplies refrigerant for cooling the fuel cell to the fuel cell, a heat exchanger that exchanges heat between the refrigerant increased in temperature by the fuel cell and the gas supplied to the gas supply passage. The fuel cell includes a component that circulates the one of the anode gas and the cathode gas discharged from the fuel cell to the fuel cell, and a warm-up control unit that controls a flow rate of the refrigerant to a predetermined flow rate for warming up the fuel cell when the fuel cell is warmed up. The fuel cell system includes a gas temperature increase control unit increases the flow rate of the refrigerant to be supplied to the heat exchanger on the basis of a temperature of the gas circulated by the component or a parameter related to the temperature when the flow rate of the refrigerant is controlled by the warm-up control unit.

First claim

The invention claimed is:

1. A fuel cell system for supplying anode gas and cathode gas to a fuel cell and causing the fuel cell to generate power according to a load, comprising:
a gas supply passage configured to supply one of the anode gas and the cathode gas to the fuel cell;
a refrigerant supply apparatus configured to supply refrigerant for cooling the fuel cell to the fuel cell;
a heat exchanger configured to exchange heat between the refrigerant increased in temperature by the fuel cell and the gas supplied to the gas supply passage;
a component provided in the gas supply passage and configured to circulate the one of the anode gas and the cathode gas discharged from the fuel cell to the fuel cell;
a warm-up control unit configured to control a flow rate of the refrigerant to a predetermined flow rate for warming up the fuel cell when the fuel cell is warmed up; and
a gas temperature increase control unit configured to increase the flow rate of the refrigerant to be supplied to the heat exchanger on the basis of a temperature of circulation gas circulated by the component or a parameter related to the temperature of the circulation gas and a temperature of supplied gas before joining with the circulation gas when the flow rate of the refrigerant is controlled by the warm-up control unit.

2. The fuel cell system according to claim 1 , wherein:
the gas temperature increase control unit increases the flow rate of the refrigerant when a temperature of circulating gas circulated from the fuel cell to the component is not lower than a freezing point temperature and a temperature of discharged gas discharged from the component to the fuel cell is not higher than the freezing point temperature.

3. The fuel cell system according to claim 1 , wherein:
the gas temperature increase control unit increases the flow rate of the refrigerant to be higher than the flow rate controlled by the warm-up control unit when a temperature of circulating gas circulated from the fuel cell to the component exceeds a predetermined threshold value beyond which an amount of steam in the circulating gas increases.

4. The fuel cell system according to claim 3 , wherein:
the gas temperature increase control unit increases the flow rate of the refrigerant as a temperature difference increases, the temperature difference being a difference between a temperature of discharged gas discharged from the component to the fuel cell and a temperature of circulating gas.

5. The fuel cell system according to claim 3 , wherein:
the gas temperature increase control unit increases the flow rate of the refrigerant as a supply flow rate of the gas to be supplied to the fuel cell increases.

6. The fuel cell system according to claim 3 , wherein:
the gas temperature increase control unit decreases an increase amount of the flow rate of the refrigerant as an electrolyte membrane of the fuel cell becomes drier.

7. The fuel cell system according to claim 1 , wherein:
the gas temperature increase control unit limits an increase of the flow rate of the refrigerant to be supplied to the heat exchanger on the basis of a temperature of discharged gas discharged from the component to the fuel cell.

8. The fuel cell system according to claim 7 , further comprising:
a calculation unit configured to calculate the temperature of the discharged gas on the basis of a temperature of supplied gas supplied from the heat exchanger to the component and a temperature of circulating gas circulated from the fuel cell to the component, wherein:
the gas temperature increase control unit switches the flow rate of the refrigerant to be supplied to the heat exchanger to the flow rate controlled by the warm-up control unit when the temperature of the discharged gas increases to a limit threshold value determined on the basis of a freezing point temperature after the flow rate of the refrigerant is increased.

9. The fuel cell system according to claim 1 , wherein:
the parameter related to the temperature includes a temperature of the refrigerant.

10. A control method for a fuel cell system for supplying anode gas and cathode gas to a fuel cell and causing the fuel cell to generate power according to a load, the fuel cell system including a gas supply passage configured to supply one of the anode gas and the cathode gas to the fuel cell, a refrigerant supply apparatus configured to supply refrigerant for cooling the fuel cell to the fuel cell, a heat exchanger configured to exchange heat between the refrigerant increased in temperature by the fuel cell and the gas supplied to the gas supply passage, and a component provided in the gas supply passage and configured to circulate gas discharged from the fuel cell to the fuel cell, the control method comprising:
a warm-up control step of controlling a flow rate of the refrigerant to a predetermined flow rate for warming up the fuel cell when the fuel cell is warmed up; and
a gas temperature increase control step of increasing the flow rate of the refrigerant to be supplied to the heat exchanger on the basis of a temperature of circulation gas circulated by the component or a parameter related to the temperature of the circulation gas and a temperature of supplied gas before joining the circulation gas when the flow rate of the refrigerant is controlled by the warm-up control step.

11. A fuel cell system for supplying anode gas and cathode gas to a fuel cell and causing the fuel cell to generate power according to a load, comprising:
a gas supply passage configured to supply one of the anode gas and the cathode gas to the fuel cell;
a refrigerant supply configured to supply refrigerant for cooling the fuel cell to the fuel cell;
a heat exchanger configured to exchange heat between the refrigerant increased in temperature by the fuel cell and the gas supplied to the gas supply passage;
a component provided in the gas supply passage and configured to circulate the one of the anode gas and the cathode gas discharged from the fuel cell to the fuel cell;
a controller configured to execute:
a warm-up control step of controlling a flow rate of the refrigerant to a predetermined flow rate for warming up the fuel cell when the fuel cell is warmed up; and
a gas temperature increase control step of increasing the flow rate of the refrigerant to be supplied to the heat exchanger on the basis of a temperature of circulation gas circulated by the component or a parameter related to the temperature of the circulation gas and a temperature of supplied gas before joining the circulation gas when the flow rate of the refrigerant is controlled by the warm-up control step.

12. The fuel cell system according to claim 11 , wherein:
in the gas temperature increase control step, the controller is configured to increase the flow rate of the refrigerant when a temperature of circulating gas circulated from the fuel cell to the component is not lower than a freezing point temperature and a temperature of discharged gas discharged from the component to the fuel cell is not higher than the freezing point temperature.

13. The fuel cell system according to claim 11 , wherein:
in the gas temperature increase control step, the controller is configured to increase the flow rate of the refrigerant to be higher than the flow rate in the warm-up control step when a temperature of circulating gas circulated from the fuel cell to the component exceeds a predetermined threshold value beyond which an amount of steam in the circulating gas increases.

14. The fuel cell system according to claim 13 , wherein:
in the gas temperature increase control step, the controller is conf

Assignees

• Nissan Motor

Inventors

• Hoshi Kiyoshi

Classifications

• H01M8/04731

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

• H01M8/04343

  of anode exhausts · CPC title

• H01M8/04302

  applied during start-up · CPC title

• H01M8/04268

  Heating of fuel cells during the start-up of the fuel cells · CPC title

• H01M8/04253

  Means for solving freezing problems · CPC title