FUEL CELL SYSTEM

• US 20130040219A1
• Filed: 04/27/2010
• Published: 02/14/2013
• Est. Priority Date: 04/27/2010
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Naganuma, Yoshiaki, Tanaka, Hiromi, Yumita, Osamu, Mizuno, Nobukazu, Sakajo, Yuichi
• Granted Patent: US 8,765,316 B2
• Time in Patent Office: Days
• US Class Current: 429/429
• CPC Class Codes: B60H 1/0073 Control systems or circuits characterised by particular algorithms or computational models, e.g. fuzzy logic or dynamic models
• CPC Class Codes: H01M 2250/20 Fuel cells in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 2250/405 Cogeneration of heat or hot water
• CPC Class Codes: H01M 8/04014 Heat exchange using gaseous fluids; Heat exchange by combustion of reactants
• CPC Class Codes: H01M 8/04067 Heat exchange or temperature measuring elements, thermal insulation, e.g. heat pipes, heat pumps, fins
• CPC Class Codes: H01M 8/04268 Heating of fuel cells during the start-up of the fuel cells
• CPC Class Codes: H01M 8/04559 of fuel cell stacks
• CPC Class Codes: H01M 8/04589 of fuel cell stacks
• CPC Class Codes: H01M 8/04731 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 8/0494 of fuel cell stacks
• CPC Class Codes: H01M 8/04992 characterised by the implementation of mathematical or computational algorithms, e.g. feedback control loops, fuzzy logic, neural networks or artificial intelligence
• CPC Class Codes: Y02B 90/10 Applications of fuel cells in buildings
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02T 90/40 Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A fuel cell system includes a fuel cell, an operation controller and an air-conditioning mechanism. In response to a heating request for the air-conditioning mechanism during ordinary operation where the fuel cell is operated at an operating point on a current-voltage characteristic curve of the fuel cell, the operation controller compares a heat value-based required current value that is a current value of an operating point that is located on the current-voltage characteristic curve and satisfies a required heat value for the fuel cell with an output-based required current value that is a current value of an operating point that is located on the current-voltage characteristic curve and satisfies a required output for the fuel cell. When the output-based required current value is equal to or greater than the heat value-based required current value, the operation controller causes the fuel cell to be operated at an operating point on the current-voltage characteristic curve. When the output-based required current value is smaller than the heat value-based required current value, the operation controller controls the operating point of the fuel cell to an operating point of lower power generation efficiency than that of the operating point on the current-voltage characteristic curve.

Claims

1. A fuel cell system, comprising:

a fuel cell;

an operation controller configured to control operation of the fuel cell; and

an air-conditioning mechanism configured to execute heating by using exhaust heat of the fuel cell, wherein

in response to a heating request for the air-conditioning mechanism during ordinary operation where the fuel cell is operated at an operating point on a current-voltage characteristic curve of the fuel cell, the operation controller compares a heat value-based required current value with an output-based required current value, wherein the heat value-based required current value is a current value of an operating point that is located on the current-voltage characteristic curve and satisfies a required heat value for the fuel cell, wherein the output-based required current value is a current value of an operating point that is located on the current-voltage characteristic curve and satisfies a required output for the fuel cell,

when the output-based required current value is equal to or greater than the heat value-based required current value, the operation controller causes the fuel cell to be operated at an operating point on the current-voltage characteristic curve, and

when the output-based required current value is smaller than the heat value-based required current value, the operation controller performs operation-for-heating control that controls operating point of the fuel cell to an operating point of lower power generation efficiency than that of the operating point on the current-voltage characteristic curve of the fuel cell.

2. The fuel cell system according to claim 1, further comprising:

an oxidizing gas supplier configured to supply an oxidizing gas used for power generation of the fuel cell to the fuel cell;

an oxidizing gas supply line configured to connect the oxidizing gas supplier with the fuel cell;

a cathode off-gas exhaust line configured to discharge cathode off-gas from the fuel cell;

a bypass line configured to connect the oxidizing gas supply line with the cathode off-gas exhaust line; and

a flow control valve configured to regulate a flow rate ratio of a flow rate of the oxidizing gas flowing through the oxidizing gas supply line to the fuel cell to a flow rate of the oxidizing gas flowing through the oxidizing gas supply line to the bypass line out of the oxidizing gas supplied from the oxidizing gas supplier, wherein

the operation controller performs the operation-for-heating control that fixes a supply amount of the oxidizing gas by the oxidizing gas supplier to a supply amount to satisfy the output-based required current value and adjusts the flow control valve to shift the operating point of the fuel cell to a required operating point that is an operating point satisfying both the required heat value and the required output.

3. The fuel cell system according to claim 2, further comprising:

an ammeter configured to measure a current value of the fuel cell, wherein

at a start of the operation-for-heating control, the operation controller adjusts the flow control valve to supply a lower flow rate of the oxidizing gas, which is lower than a flow rate of the oxidizing gas to satisfy a current value of the required operating point out of the oxidizing gas supplied by the oxidizing gas supplier, to the fuel cell,

when the current value of the fuel cell measured by the ammeter is greater than the current value of the required operating point, the operation controller then adjusts the flow control valve to decrease the flow rate of the oxidizing gas supplied to the fuel cell, and

when the current value of the fuel cell measured by the ammeter is smaller than the current value of the required operating point, the operation controller then adjusts the flow control valve to increase the flow rate of the oxidizing gas supplied to the fuel cell.

4. The fuel cell system according to claim 1, further comprising:

a fuel cell temperature acquirer configured to acquire temperature of the fuel cell; and

a heating space temperature acquirer configured to acquire heating space temperature that is temperature of a space as heating target by the air-conditioning mechanism, wherein

at a start of the fuel cell, the operation controller performs start-time warm-up operation control that is control to lower the power generation efficiency of the fuel cell than that in the operation-for-heating control,

the operation controller has a first operation-for-heating mode that, in response to a heating request for the air-conditioning mechanism during the start-time warm-up operation control, terminates the start-time warm-up operation control, when the heating space temperature reaches a temperature to satisfy the heating request after the temperature of the fuel cell reaches a predetermined warm-up end temperature,

after termination of the start-time warm-up operation control, the operation controller compares the heat value-based required current value with the output-based required current value,

when the output-based required current value is equal to or greater than the heat value-based required current value, the operation controller controls the fuel cell to be operated at an operating point on the current-voltage characteristic curve, and

when the output-based required current value is smaller than the heat value-based required current value, the operation controller performs the operation-for-heating control.

5. The fuel cell system according to claim 4, further comprising:

a user interface, wherein

in addition to the first operation-for-heating mode, the operation controller has a second operation-for-heating mode that, in response to the heating request for the air-conditioning mechanism during the start-time warm-up operation control, terminates the start-time warm-up operation control when the temperature of the fuel cell reaches the warm-up end temperature, and

the user interface enables a user to select the operation-for-heating mode performed by the operation controller between the first operation-for-heating mode and the second operation-for-heating mode.