Procedure for purging a fuel cell system with inert gas made from organic fuel
AssigneeUTC Fuel Cells, LLC
InventorsAlfred P. Meyer, Vincent M. Callaghan
Life of this patent
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Abstract
A procedure for purging a fuel cell system at start-up or shutdown comprises directing the organic fuel, along with air, into a burner to produce a gas that is essentially inert to the fuel cell, such as a gas of nitrogen, carbon dioxide and water vapor. That inert gas is passed through either or both the fuel cell and fuel processing system components, such as a reformer and shift converter, to purge those components of undesirable gases. In the case of shutdown, after the cell has been disconnected from the primary load, the inert gas produced in the burner is passed either in series or in parallel through the fuel cell and fuel processing system.
Claims11
In a procedure for shutting down a fuel cell system that is delivering power to a primary load, the system comprising a fuel cell having an anode electrode, a cathode electrode, and an electrolyte disposed therebetween, said cell also including an anode flow field for carrying a hydrogen containing fuel through the cell over the anode electrode and a cathode flow field for carrying an oxygen containing gas through the cell over the cathode electrode, the fuel cell system also including a source of organic fuel, a fuel processing system to convert the organic fuel to hydrogen, and a burner, the fuel processing system comprising a plurality of fuel processing components including a reformer upstream of and in series with a shift converter, the steps of:
- a. disconnecting the primary load from the cell and halting the processing of organic fuel within the fuel processing system to produce hydrogen;
- b. after step (a), directing air and organic fuel from the source into the burner in a ratio selected to result in burner combustion products consisting of inert gases;
- and
- c. passing at least a portion of the burner combustion products of step (b) through at least the reformer of the fuel processing system at least until the reformer has been purged of residual hydrogen and carbon monoxide.
Dependencies are inferred from the claim text.