Fuel cell system

Patent metadata

Field	Value
Publication number	US-2019148747-A1
Application number	US-201816156473-A
Country	US
Kind code	A1
Filing date	Oct 10, 2018
Priority date	Nov 13, 2017
Publication date	May 16, 2019
Grant date	—

Abstract

In a fuel cell system, a controller is configured to, to stop the fuel cell system, (a) execute an oxidizing gas consumption process by supplying a fuel gas to an anode and sweeping current from a fuel cell while a supply-side on-off valve and an exhaust-side on-off valve are closed to seal the remaining oxidizing gas in the cathode, and (b) stop sweeping the current at a time point at which the difference between pressure of the cathode that decreases in response to the sweeping of the current and an estimated pressure value of the cathode that decreases by consumption of the oxidizing gas remaining in the cathode in response to the sweeping of the current becomes larger than a predetermined determination threshold value to end the oxidizing gas consumption process.

First claim

What is claimed is:

1 . A fuel cell system comprising:
a fuel cell that generates power using a reaction between a fuel gas supplied to an anode and an oxidizing gas supplied to a cathode; an anode gas supply unit configured to supply the fuel gas to the anode; a cathode gas supply unit configured to supply the oxidizing gas to the cathode; a supply-side on-off valve configured to stop supplying the oxidizing gas to the cathode by the cathode gas supply unit; an exhaust-side on-off valve configured to shut off cathode off-gas exhausted from the cathode; and a controller configured to control the anode gas supply unit, the cathode gas supply unit, the supply-side on-off valve, and the exhaust-side on-off valve to control power generation of the fuel cell, wherein the controller is configured to, to stop the fuel cell system,
(a) execute an oxidizing gas consumption process by supplying the fuel gas to the anode and sweeping current from the fuel cell while the supply-side on-off valve and the exhaust-side on-off valve are closed to seal the remaining oxidizing gas in the cathode, and
(b) stop sweeping the current at a time point at which a difference between pressure of the cathode that decreases in response to the sweeping of the current and an estimated pressure value of the cathode that decreases by consumption of the oxidizing gas remaining in the cathode in response to the sweeping of the current becomes larger than a predetermined determination threshold value to end the oxidizing gas consumption process.

2 . The fuel cell system according to claim 1 , wherein the controller is configured to
store, as a voltage threshold value, an output voltage of the fuel cell corresponding to the time point at which the difference between the pressure of the cathode that decreases in response to the sweeping of the current and the estimated pressure value of the cathode becomes larger than the predetermined determination threshold value in advance, and detect the time point at which the difference between the pressure of the cathode and the estimated pressure value of the cathode becomes larger than the predetermined determination threshold value by detecting a time point at which the output voltage of the fuel cell becomes less than the voltage threshold value to stop sweeping the current.

Assignees

• Toyota Motor Co Ltd

Inventors

• Yamamori Keitaro
• Kakimi Yosuke

Classifications

• H01M8/0494

  of fuel cell stacks · CPC title

• H01M8/0441

  of cathode exhausts · CPC title

• H01M8/04753 Primary

  of fuel cell reactants · CPC title

• H01M8/04303 Primary

  applied during shut-down · CPC title

• H01M8/04761

  of fuel cell exhausts · CPC title