Method and apparatus for controlling a combined heat and power fuel cell system

• US 20060003199A1
• Filed: 09/06/2005
• Published: 01/05/2006
• Est. Priority Date: 05/31/2001
• Status: Active Grant

• Current Assignee: Arne W. Ballantine, Dustan L. Skidmore, John W. Parks, Ryan Hallum
• Original Assignee: Arne W. Ballantine, Dustan L. Skidmore, John W. Parks, Ryan Hallum
• Inventors: Skidmore, Dustan L., Ballantine, Arne W., Parks, John W., Hallum, Ryan
• Granted Patent: US 7,332,236 B2
• Time in Patent Office: Days
• US Class Current: 429/434
• CPC Class Codes: H01M 8/04007 related to heat exchange
• CPC Class Codes: H01M 8/04089 of gaseous reactants
• CPC Class Codes: H01M 8/0432 Temperature; Ambient temperature
• CPC Class Codes: H01M 8/04373 of auxiliary devices, e.g. reformers, compressors, burners
• CPC Class Codes: H01M 8/04559 of fuel cell stacks
• CPC Class Codes: H01M 8/04589 of fuel cell stacks
• CPC Class Codes: H01M 8/04604 Power, energy, capacity or load
• CPC Class Codes: H01M 8/04701 Temperature
• CPC Class Codes: H01M 8/04731 of other components of a fuel cell or fuel cell stacks
• CPC Class Codes: H01M 8/04738 of auxiliary devices, e.g. reformer, compressor, burner
• CPC Class Codes: H01M 8/04753 of fuel cell reactants
• CPC Class Codes: H01M 8/04768 of the coolant
• CPC Class Codes: H01M 8/04776 at auxiliary devices, e.g. reformer, compressor, burner
• CPC Class Codes: H01M 8/0612 from carbon-containing material
• CPC Class Codes: Y02E 20/14 Combined heat and power generation [CHP]
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A cogeneration fuel cell system and associated methods of operation are provided that accommodate a demand for heat as well as a demand for electric power. The system is operated among various modes to balance heat and power demand signals. In general, a fuel cell system is coupled to a power sink and a heat sink, and a controller is adapted to respond to data signals from the power sink and the heat sink. As examples, such data signals from the heat sink may include a temperature indication or a heat demand signal (such as from a thermostat), and such data signals from the power sink may include a voltage or current measurement, an electrical power demand signal, or an electrical load.

Claims

1. A method of operating a fuel cell system, comprising:

providing a fuel flow and an oxidant flow to a fuel cell stack to produce electricity;

providing the electricity to an electrical load;

transferring heat from the fuel cell stack to a heat sink by circulating a first coolant through a first coolant circuit, wherein the first coolant circuit is adapted to remove heat from the fuel cell stack and is further adapted to transfer heat to the heat sink;

measuring a thermal parameter of the heat sink;

generating a heat demand signal when the thermal parameter of the heat sink is below a predetermined level; and

shorting at least one fuel cell in the fuel cell stack in response to the heat demand signal.

2. The method of claim 1, wherein the heat sink comprises a water tank, and wherein the thermal parameter is a temperature of water in the water tank.

3. The method of claim 2, wherein the heat sink comprises air contained in a building, and wherein the thermal parameter comprises a temperature of the air contained in the building.

4. The method of claim 3, wherein the heat sink comprises a generator portion of an adsorption cooling system and wherein the thermal parameter is a temperature of the generator portion.

5. A method comprising:

providing a reactant flow to a fuel cell stack to produce electricity; and

selectively shorting at least one fuel cell of the fuel cell stack to increase a thermal output from the fuel cell stack.

6. The method of claim 5, further comprising:

transferring heat from the fuel cell stack to a heat sink;

measuring a thermal parameter of the heat sink;

generating a heat demand signal to control shorting of said at least one fuel cell stack in response to the thermal parameter of the heat sink.

7. The method of claim 6, wherein the heat sink comprises air contained in a building, and wherein the thermal parameter comprises a temperature of the air contained in the building.

8. The method of claim 6, wherein the heat sink comprises a generator portion of an adsorption cooling system and wherein the thermal parameter is a temperature of the generator portion.