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US 7,678,477 B2Granted
Method of operating a fuel cell stack
AssigneeGM Global Technology Operations LLC
InventorPaul Taichiang Yu
Life of this patent
Estimating the term…
Abstract
A method of operating a fuel cell stack including disconnecting the primary electrical device and purging gas in the cathode reactant gas flow field by flowing air into the cathode reactant gas flow field. Thereafter, the gas in the cathode reactant flow field is purged again by flowing hydrogen into the cathode reactant gas flow field. Gas in the anode reactant gas flow field is purged by flowing air into the anode reactant gas flow field. Thereafter, the anode reactant gas flow field is filled with hydrogen and both the anode and the cathode are stored with hydrogen.
Claims20
A method comprising:
- operating a fuel cell stack comprising flowing hydrogen into an anode reactant gas flow field and flowing air comprising oxygen and nitrogen into a cathode reactant gas flow field of the fuel cell stack and producing electricity with the fuel cell stack to operate a primary electrical device in an external circuit connected to the fuel cell stack;
- shutting down the fuel cell stack comprising:
- disconnecting the primary electrical device from the fuel cell stack;
- purging gas in the cathode reactant gas flow field by flowing air comprising oxygen and nitrogen into the cathode reactant gas flow field;
- thereafter, purging gas from the cathode reactant gas flow field by flowing hydrogen into the cathode reactant gas flow field;
- purging gas from the anode reactant gas flow field by flowing air comprising oxygen and nitrogen into the anode reactant gas flow field;
- thereafter, filling the anode reactant gas flow field with hydrogen.
4 more elements
A method comprising:
- operating a fuel cell stack having a cathode side and an anode side, the operating comprising flowing hydrogen into the anode side and flowing air comprising oxygen and nitrogen into the cathode side and producing electricity with the fuel cell stack and operating a primary electrical device in an external circuit with the electricity;
- shutting down the fuel cell stack comprising:
- purging the cathode side with dry air to remove liquid water and steam therefrom;
- purging the dry air from the cathode side by flowing hydrogen into the cathode side;
- purging the anode side by flowing air comprising oxygen and nitrogen into the anode side, and so that the purging of the anode side and the cathode side makes the anode side and cathode side substantially free of water;
- filling the anode side with hydrogen, therefore, both the cathode side and the anode side are filled with hydrogen.
3 more elements
Dependencies are inferred from the claim text.