Fuel cell system and method for operating the same, and electrochemical system and method for operating the same

Patent metadata

Field	Value
Publication number	US-2020099084-A1
Application number	US-201916533461-A
Country	US
Kind code	A1
Filing date	Aug 6, 2019
Priority date	Sep 21, 2018
Publication date	Mar 26, 2020
Grant date	—

Abstract

A fuel cell system includes a fuel cell stack constituted by cells, each of the cells includes a fuel electrode, an air electrode, and an electrolyte, and generate electric power through a reaction of a fuel gas and air, a casing that houses the fuel cell stack, a temperature detector that detects a first temperature, the first temperature is a temperature of the fuel cell stack or inside the casing, and a controller. The controller controls based on the first temperature so as to allow an operation at a first predetermined temperature. The controller controls such that the first temperature reaches a temperature higher than or equal to a second predetermined temperature for a predetermined time. The second predetermined temperature is a temperature at which 475° C. embrittlement that occurs on stainless steel is eliminated. The first predetermined temperature is lower than the second predetermined temperature.

First claim

What is claimed is:

1 . A fuel cell system comprising:
a fuel cell stack constituted by a plurality of cells, each of the cells including a fuel electrode, an air electrode, and an electrolyte, and generating electric power through a reaction of a fuel gas and air; a casing that houses the fuel cell stack; a temperature detector that detects a first temperature, the first temperature being a temperature of the fuel cell stack or a temperature inside the casing; and a controller that controls based on the first temperature so as to allow an operation at a first predetermined temperature, and controls such that the first temperature reaches a temperature higher than or equal to a second predetermined temperature for a predetermined time, wherein the second predetermined temperature is a temperature at which 475° C. embrittlement that occurs on stainless steel is eliminated, and the first predetermined temperature is lower than the second predetermined temperature.

2 . The fuel cell system according to claim 1 , further comprising:
a fuel feeder that feeds the fuel gas to the fuel electrode; and an air feeder that feeds an oxidant gas to the air electrode, wherein the controller controls at least one of an amount of the fuel gas fed by the fuel feeder and an amount of the oxidant gas fed by the air feeder such that the first temperature detected by the temperature detector reaches a temperature higher than or equal to the second predetermined temperature.

3 . The fuel cell system according to claim 1 , wherein the fuel cell stack, the casing that houses the fuel cell stack, and at least one of members disposed in the casing together with the fuel cell stack are formed of stainless steel.

4 . The fuel cell system according to claim 2 , comprising:
at least one of a combustor in which an anode off-gas discharged from the fuel electrode of the cells and a cathode off-gas discharged from the air electrode are burned and a combustion space having a combustion function, wherein the controller controls an amount of the fuel gas fed by the fuel feeder such that a temperature of the fuel cell stack reaches a temperature higher than or equal to the second predetermined temperature for the predetermined time.

5 . The fuel cell system according to claim 2 , wherein the controller controls an amount of the oxidant gas fed by the air feeder such that a temperature of the fuel cell stack reaches a temperature higher than or equal to the second predetermined temperature for the predetermined time.

6 . The fuel cell system according to claim 1 , wherein the second predetermined temperature is 590° C. or higher.

7 . The fuel cell system according to claim 1 , wherein the predetermined time is 1 minute to 60 minutes.

8 . The fuel cell system according to claim 2 , wherein the controller controls at least one of an amount of the fuel gas fed by the fuel feeder and an amount of the oxidant gas fed by the air feeder during power generation such that a temperature of the fuel cell stack periodically reaches, at particular intervals, a temperature higher than or equal to the second predetermined temperature for the predetermined time.

9 . The fuel cell system according to claim 1 , wherein the electrolyte in the cells constituting the fuel cell stack is a proton conductor.

10 . The fuel cell system according to claim 1 , wherein the electrolyte is formed of Ba x Zr y M z O 3−σ , where M is at least one element selected from the group consisting of Sc, In, Lu, Yb, Tm, Er, Y, Ho, Dy, and Gd and 0.9≤x≤1.0, 0.6≤y≤0.90, 0.1≤z≤0.4, and 2.70≤3−σ≤2.95 are satisfied.

11 . The fuel cell system according to claim 1 , wherein the fuel cell stack is constituted by cells including a metal support.

12 . A method for operating a fuel cell system including a fuel cell stack constituted by a plurality of cells, each of the cells including a fuel electrode, an air electrode, and an electrolyte, and generating electric power through a reaction of a fuel gas and air, a casing that houses the fuel cell stack, and a temperature detector that detects a first temperature, the first temperature being a temperature of the fuel cell stack or a temperature inside the casing,
the method comprising: controlling based on the first temperature so as to allow an operation at a first predetermined temperature; and controlling such that the first temperature reaches a temperature higher than or equal to a second predetermined temperature for a predetermined time, wherein the second predetermined temperature is a temperature at which 475° C. embrittlement that occurs on stainless steel is eliminated, and the first predetermined temperature is lower than the second predetermined temperature.

13 . An electrochemical system comprising:
an electrochemical stack constituted by a plurality of cells, each of the cells including a fuel electrode, an air electrode, and an electrolyte, and generating electric power through a reaction of a fuel gas and air; a casing that houses the electrochemical stack; a temperature detector that detects a first temperature, the first temperature being a temperature of the electrochemical stack or a temperature inside the casing; and a controller that controls based on the first temperature so as to allow an operation at a first predetermined temperature, and controls such that the first temperature reaches a temperature higher than or equal to a second predetermined temperature for a predetermined time, wherein the second predetermined temperature is a temperature at which 475° C. embrittlement that occurs on stainless steel is eliminated, and the first predetermined temperature is lower than the second predetermined temperature.

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Onuma Shigenori
• Kuroha Tomohiro

Classifications

• H01M8/04029

  Heat exchange using liquids · CPC title

• H01M8/04089

  of gaseous reactants · CPC title

• H01M8/04044

  Purification of heat exchange media · CPC title

• H01M8/222 Primary

  Fuel cells in which the fuel is based on compounds containing nitrogen, e.g. hydrazine, ammonia · CPC title

• H01M8/0432 Primary

  Temperature; Ambient temperature · CPC title