Controlling fuel cell fuel purge in response to recycle fuel blower operating conditions

• US 20060003204A1
• Filed: 07/01/2004
• Published: 01/05/2006
• Est. Priority Date: 07/01/2004
• Status: Abandoned Application

• Current Assignee: UTC Fuel Cells, LLC
• Original Assignee: UTC Fuel Cells, LLC
• Inventors: Narasimhamurthy, Praveen, Callahan, Christopher W., McCready, Christopher P.
• Application Number:
  US10/884,025
• Publication Number:
  US 20060003204A1
• Time in Patent Office: Days
• US Class Current: 429/415
• CPC Class Codes: H01M 8/04007 related to heat exchange
• CPC Class Codes: H01M 8/04097 with recycling of the reactants H01M8/04119, H01M8/04104 take precedence
• CPC Class Codes: H01M 8/04231 Purging of the reactants
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A fuel cell power plant fuel purge valve (26) is controlled in response to a parameter (40, 40a) of a fuel recycle blower which is indicative (20) of the recycle fuel impelled thereby, either alone or together with load current (33), pressure rise of the blower (50, 51), and temperature of the fuel recycle gas (44), to provide a pulse width modulation-control signal (28) controlling the purge valve.

Claims

1. A fuel cell power plant comprising:

a stack of fuel cells, each having anode fuel flow fields, each fuel flow field having an inlet and an outlet;

a controller;

a source providing hydrogen to the inlets of said fuel flow fields in response to said controller;

a recycle blower connected to the outlets of said fuel flow fields and providing recycle fuel to the inlets of said fuel flow fields;

a purge valve connected between the outlets of said fuel flow fields and exhaust, said exhaust selected from a burner or a vented ambient, said valve operated in response to said controller;

means for sensing a recycle blower parameter, indicative of the work required by said recycle blower as a function of the density of gas being impelled by said blower, and providing a parameter signal indicative thereof;

said controller responsive to said parameter signal for controlling the operation of said purge valve.

2. A fuel cell power plant according to claim 1 wherein said parameter is recycle blower speed.

3. A fuel cell power plant according to claim 1 wherein said parameter is recycle blower current.

4. A fuel cell power plant according to claim 1 wherein said controller, in controlling said purge valve, is also responsive to pressure rise across said blower, current through a load being powered by said fuel cell stack, and temperature of the fuel recycle gas for providing said parameter signal controlling said purge valve.

5. Apparatus for controlling a fuel purge valve in a fuel cell power plant, comprising:

means for sensing at least one parameter of a fuel recycle blower, selected from current and speed of said recycle blower, indicative of the density of gas being impelled thereby; and

means for controlling said fuel purge valve as a function of said parameter.

6. A method of controlling a fuel purge valve in a fuel cell power plant, comprising:

sensing at least one parameter of a fuel recycle blower, selected from current and speed of said recycle blower, indicative of the density of gas being impelled thereby; and

controlling said fuel purge valve as a function of said parameter.

7. A method according to claim 6 wherein said sensing step comprises:

sensing (I) current supplied to a load by said fuel cell power plant and (ii) speed of said recycle blower.

8. A method according to claim 6 wherein said sensing step comprises:

sensing pressure rise across said blower, current through a load being powered by said fuel cell stack, and temperature of the fuel recycle gas for providing said parameter signal controlling said purge valve.