Fuel cell system and method for warming up fuel cell system

Patent metadata

Field	Value
Publication number	US-11205785-B2
Application number	US-201716638223-A
Country	US
Kind code	B2
Filing date	Aug 14, 2017
Priority date	Aug 14, 2017
Publication date	Dec 21, 2021
Grant date	Dec 21, 2021

Abstract

A fuel cell system includes a fuel cell configured to be supplied with fuel and air to generate electricity, a reformer configured to reform the fuel to be supplied to the fuel cell, a heat source device configured to heat an off-gas discharged from the fuel cell to produce a heating gas and configured to heat the reformer, a fuel cell heating device configured to heat the air to be supplied to the fuel cell using the heating gas, a fuel cell temperature acquisition unit configured to acquire a temperature of the fuel cell, and a reformer temperature acquisition unit configured to acquire a temperature of the reformer. The fuel cell system includes a controller configured to, in a warm-up operation to perform a warm-up of the reformer and a warm-up of the fuel cell, control at least one of the heat source device and the fuel cell heating device based on the temperature of the reformer and the temperature of the fuel cell to adjust at least one of a heating amount of the off-gas and a heating amount of the air by the heating gas.

First claim

The invention claimed is:

1. A fuel cell system comprising:
a fuel cell configured to be supplied with fuel and air to generate electricity;
a reformer configured to reform the fuel to be supplied to the fuel cell;
a heat source device configured to heat an off-gas discharged from the fuel cell to produce a heating gas and configured to heat the reformer;
a fuel cell heating device configured to heat the air to be supplied to the fuel cell using the heating gas;
a fuel cell temperature acquisition unit configured to acquire a temperature of the fuel cell;
a reformer temperature acquisition unit configured to acquire a temperature of the reformer; and
a controller configured to, in a warm-up operation to perform a warm-up of the reformer and a warm-up of the fuel cell, control at least one of the heat source device or the fuel cell heating device based on the temperature of the reformer and the temperature of the fuel cell to adjust at least one of a heating amount of the off-gas or a heating amount of the air by the heating gas,
wherein the controller is configured to reduce the heating amount of the air by the heating gas to control a warm-up progress balance according to progress states of the warm-up of the reformer and the warm-up of the fuel cell when a warm-up degree of the fuel cell based on the temperature of the fuel cell is greater than a warm-up degree of the reformer based on the temperature of the reformer, the warm-up degree of the fuel cell being a ratio of the temperature of the fuel cell acquired by the fuel cell temperature acquisition unit to a warm-up target temperature of the fuel cell, and the warm-up degree of the reformer being a ratio of the temperature of the reformer acquired by the reformer temperature acquisition unit to a warm-up target temperature of the reformer.

2. The fuel cell system according to claim 1 , wherein:
the fuel cell heating device includes an air heat exchanger provided to an air supply passage configured to supply the air to the fuel cell, the air heat exchanger configured to perform heat exchange of the air in the air supply passage with the heating gas, a bypass passage provided to the air supply passage to bypass the air heat exchanger, and a bypass valve provided in the bypass passage; and
the controller is configured to control an opening degree of the bypass valve to adjust an air flow rate to be supplied to the air heat exchanger.

3. The fuel cell system according to claim 1 , wherein:
the heat source device includes a discharged gas combustor configured to produce a combustion gas as the heating gas by burning the off-gas, and a fuel supply amount adjustment unit configured to adjust an amount of the fuel to be supplied to the discharged gas combustor; and
the controller is configured to control the fuel supply amount adjustment unit to adjust a fuel supply amount to the discharged gas combustor.

4. The fuel cell system according to claim 3 , further comprising:
a raw fuel tank storing raw fuel;
a combustor fuel supply passage configured to supply the fuel from the raw fuel tank to the discharged gas combustor; and
a combustion gas supply passage configured to supply the combustion gas produced in the discharged gas combustor to the fuel cell heating device,
wherein:
the heat source device includes an injector provided in the combustor fuel supply passage; and
the controller is configured to control the injector to adjust the fuel supply amount to the discharged gas combustor.

5. The fuel cell system according to claim 1 , wherein:
the fuel cell heating device includes an air heat exchanger configured to heat the air by performing a heat exchange with the heating gas, a bypass passage configured to supply a part of the air to the fuel cell, the part of the air bypassing the air heat exchanger through the bypass passage, and a bypass valve in the bypass passage;
a target bypass valve opening degree of the bypass valve is calculated to increase an opening degree of the bypass valve as a temperature deviation between the temperature of the fuel cell and the warm-up target temperature of the fuel cell decreases; and
the controller is configured to limit an increase of the heating amount of the off-gas when the temperature deviation becomes a predetermined value or less, the predetermined value being a value where the opening degree of the bypass valve is fully open.

6. A fuel cell system comprising:
a fuel cell configured to be supplied with fuel and air to generate electricity;
a reformer configured to reform the fuel to be supplied to the fuel cell;
a heat source device configured to heat an off-gas discharged from the fuel cell to produce a heating gas and configured to heat the reformer;
a fuel cell heating device configured to heat the air to be supplied to the fuel cell using the heating gas;
a fuel cell temperature acquisition unit configured to acquire a temperature of the fuel cell;
a reformer temperature acquisition unit configured to acquire a temperature of the reformer; and
a controller configured to, in a warm-up operation to perform a warm-up of the reformer and a warm-up of the fuel cell, control at least one of the heat source device or the fuel cell heating device based on the temperature of the reformer and the temperature of the fuel cell to adjust at least one of a heating amount of the off-gas or a heating amount of the air by the heating gas,
wherein the controller is configured to increase the heating amount of the off-gas to control a warm-up progress balance according to progress states of the warm-up of the reformer and the warm-up of the fuel cell when a warm-up degree of the reformer based on the temperature of the reformer is greater than a warm-up degree of the fuel cell based on the temperature of the fuel cell, the warm-up degree of the fuel cell being a ratio of the temperature of the fuel cell acquired by the fuel cell temperature acquisition unit to a warm-up target temperature of the fuel cell, and the warm-up degree of the reformer being a ratio of the temperature of the reformer acquired by the reformer temperature acquisition unit to a warm-up target temperature of the reformer.

7. A method for warming up a fuel cell system, the method comprising:
producing a heating gas by heating an off-gas discharged from a fuel cell configured to be supplied with fuel and air to generate electricity, and heating a reformer configured to reform the fuel to be supplied to the fuel cell;
acquiring a temperature of the fuel cell and a temperature of the reformer; and
heating the fuel cell using the heating gas,
wherein:
at least one of a heating amount of the off-gas or a heating amount of the air by the heating gas is adjusted based on the temperature of the fuel cell and the temperature of the reformer; and
the heating amount of the air by the heating gas is reduced and a warm-up progress balance according to progress states of warm-up of the reformer and warm-up of the fuel cell is thereby controlled when a warm-up degree of the fuel cell based on the temperature of the fuel cell is greater than a warm-up degree of the reformer based on the temperature of the reformer, the warm-up degree of the fuel cell being a ratio of the temperature of the fuel cell acquired to a warm-up target temperature of the fuel cell, and the warm-up degree of the reformer being a ratio of the temperature of the reformer acquired to a warm-up target temperature of the reformer.

8. A method for warming up a fuel cell system, the method comprising:
producing a heating gas by heating an off-gas discharged from a fuel cell configured to be supplied with fuel and air to generate electricity, and heating a reformer configured to reform the fuel to be supplied to the

Assignees

• Nissan Motor

Inventors

• Chikugo Hayato
• Miyazaki Shinichi
• Yaguchi Tatsuya
• Sato Masashi

Classifications

• H01M8/04335

  of cathode reactants at the inlet or inside the fuel cell · CPC title

• H01M8/04022 Primary

  Heating by combustion · CPC title

• H01M8/04738

  of auxiliary devices, e.g. reformer, compressor, burner · CPC title

• H01M8/04268

  Heating of fuel cells during the start-up of the fuel cells · CPC title

• H01M8/0435

  of cathode exhausts · CPC title