Method for operating fuel cell system

Patent metadata

Field	Value
Publication number	US-9825318-B2
Application number	US-201615221602-A
Country	US
Kind code	B2
Filing date	Jul 28, 2016
Priority date	Jan 26, 2011
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

A method for operating a fuel cell system includes detecting a pressure in a fuel supply path located downstream of a pressure reducing valve using a pressure sensor. Whether or not the pressure detected by the pressure sensor exceeds a predetermined threshold pressure is determined. The pressure in the fuel supply path located downstream of the pressure reducing is reduced when the pressure detected by the pressure sensor exceeds the predetermined threshold pressure.

First claim

What is claimed is:

1. A method for operating a fuel cell system that includes a fuel cell, a fuel-gas supplier, a fuel supply path connecting the fuel cell to the fuel-gas supplier, a shut-off valve to switch between a supply mode and a shut-off mode for fuel gas supplied toward the fuel supply path from the fuel-gas supplier, a pressure reducing valve provided in the fuel supply path between the shut-off valve and the fuel cell to reduce a downstream pressure relative to an upstream pressure, and a controller, the method comprising:
detecting a pressure in the fuel supply path located downstream of the pressure reducing valve using a pressure sensor;
determining, during an activation process of the fuel cell, whether or not the pressure detected by the pressure sensor exceeds a predetermined threshold pressure; and
reducing the pressure in the fuel supply path located downstream of the pressure reducing valve when the pressure detected by the pressure sensor during the activation process of the fuel cell exceeds the predetermined threshold pressure by controlling an open state and a closed state of a depressurizing device with the controller.

2. The method according to claim 1 , wherein
if the pressure detected by the pressure sensor exceeds the predetermined threshold pressure when the fuel cell is activated, the controller controls the depressurizing device to reduce the pressure in the fuel supply path located downstream of the pressure reducing valve to the predetermined threshold pressure or to a pressure lower than the predetermined threshold pressure, and subsequently opens the shut-off valve and actuates an auxiliary device so as to begin generation of electric power by the fuel cell.

3. The method according to claim 2 , wherein
the depressurizing device includes a low-pressure open valve provided in the fuel supply path located downstream of the pressure reducing valve, the low-pressure open valve being to switch the fuel supply path between a state in which the fuel supply path is in communication with a low-pressure area with a pressure lower than the predetermined threshold pressure and a state in which the fuel supply path is shut off from the low-pressure area, and
the controller opens the low-pressure open valve so as to reduce the pressure in the fuel supply path located downstream of the pressure reducing valve, and includes a pressure responsive valve provided in the fuel supply path located downstream of the pressure reducing valve, the pressure responsive valve being to switch from the closed state to the open state when the pressure in the fuel supply path located downstream of the pressure reducing valve exceeds an upper limit pressure set to be higher than the predetermined threshold pressure so as to allow the fuel supply path to communicate with the low-pressure area.

4. The method according to claim 2 , wherein
the predetermined threshold pressure is set based on a maximum normal pressure value of the auxiliary device.

5. The method according to claim 2 , further comprising:
opening the shut-off valve when the pressure in the fuel supply path located downstream of the pressure reducing valve decreases to the predetermined threshold pressure or lower; and
actuating the auxiliary device after opening the shut-off valve such that supply of the fuel gas to the fuel cell commences.

6. The method according to claim 1 , wherein
the fuel cell is not activated until the pressure in the fuel supply path located downstream of the pressure reducing valve decreases to the predetermined threshold pressure.

7. The method according to claim 1 , wherein
whether or not the pressure detected by the pressure sensor exceeds a predetermined threshold pressure is determined when an ignition switch is turned on.

8. The method according to claim 1 , wherein the depressurizing device includes a low-pressure open valve provided in the fuel supply path located downstream of the pressure reducing valve, and the step of reducing the pressure in the fuel supply path located downstream of the pressure reducing valve includes changing the low-pressure open valve from the closed state to the open state.

9. The method according to claim 1 , wherein the depressurizing device includes an electromagnetic valve or an injector that opens or closes in accordance with a control signal from the controller, and the step of reducing the pressure in the fuel supply path located downstream of the pressure reducing valve includes changing the electromagnetic valve or the injector from the closed state to the open state.

10. The method according to claim 1 , further comprising controlling the depressurizing device with a control signal to enter the closed state when the pressure in the fuel supply path located downstream of the pressure reducing valve reaches the predetermined threshold pressure or a pressure lower than the predetermined threshold pressure.

11. The method according to claim 1 , wherein the depressurizing device is controlled by the controller to be in the open state, and controlled by the controller to be in the closed state, after the controller determines that a starter switch has been turned on.

12. A method for operating a fuel cell system that includes a fuel cell, a fuel-gas supplier, a fuel supply path connecting the fuel cell to the fuel-gas supplier, a shut-off valve to switch between a supply mode and a shut-off mode for fuel gas supplied toward the fuel supply path from the fuel-gas supplier, a pressure reducing valve provided in the fuel supply path between the shut-off valve and the fuel cell to reduce a downstream pressure relative to an upstream pressure, a controller, and a depressurizing valve, the method comprising:
detecting a pressure in the fuel supply path located downstream of the pressure reducing valve using a pressure sensor;
determining, during an activation process of the fuel cell, whether or not the pressure detected by the pressure sensor exceeds a predetermined threshold pressure;
opening the depressurizing valve with the controller to reduce the pressure in the fuel supply path located downstream of the pressure reducing valve during the activation process of the fuel cell when the pressure detected by the pressure sensor exceeds the predetermined threshold pressure;
closing the depressurizing valve with the controller after opening the depressurizing valve when the pressure in the fuel supply path located downstream of the pressure reducing valve reaches the predetermined threshold pressure or to a pressure lower than the predetermined threshold pressure; and
actuating an auxiliary device after closing the depressurizing valve to begin generation of electric power by the fuel cell.

13. The method according to claim 12 , wherein the depressurizing valve is an electromagnetic valve or an injector that opens or closes in accordance with a control signal from the controller, and the step of reducing the pressure in the fuel supply path located downstream of the pressure reducing valve includes changing the electromagnetic valve or the injector from the closed state to the open state.

14. The method according to claim 12 , further comprising controlling the depressurizing device to enter the closed state with a control signal when the pressure in the fuel supply path located downstream of the pressure reducing valve reaches the predetermined threshold pressure or to a pressure lower than the predetermined threshold pressure.

15. The method according to claim 12 , further comprising determining that a starter switch is turned on,
wherein the steps of opening the depressurizing valve

Assignees

• Honda Motor Co Ltd

Inventors

• Kato Koichi
• Takaku Koichi

Classifications

• Y02T90/32

  Cross-Sectional Technologies · mapped topic

• H01M8/04388 Primary

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

• H01M8/04753

  of fuel cell reactants · CPC title

• H01M2250/20

  Fuel cells in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M8/04432 Primary

  Pressure differences, e.g. between anode and cathode · CPC title