Fuel cell system and fuel cell system control method

Patent metadata

Field	Value
Publication number	US-2020266460-A1
Application number	US-201716648052-A
Country	US
Kind code	A1
Filing date	Sep 29, 2017
Priority date	Sep 29, 2017
Publication date	Aug 20, 2020
Grant date	—

Abstract

A fuel cell system is provided and the fuel cell system includes: a fuel cell; a fuel processing unit configured to process a raw fuel to produce a fuel gas for the fuel cell; an oxidant gas heating unit configured to heat an oxidant gas for the fuel cell; a combustor configured to combust the raw fuel to produce a combustion gas for use in heating the fuel processing unit and the oxidant gas heating unit; a supply control unit configured to, during a warm-up of the fuel cell, control supply of the raw fuel to the fuel processing unit and the combustor; and a power generation control unit configured to control a power generation state during the warm-up of the fuel cell. When the fuel cell has reached a power generation available temperature, the power generation control unit is configured to cause the fuel cell to perform power generation, and the supply control unit is configured to supply the raw fuel to both the fuel processing unit and the combustor.

First claim

1 .- 11 . (canceled)

12 . A fuel cell system comprising:
a fuel cell; a fuel processing unit configured to process a raw fuel to produce a fuel gas for the fuel cell; an oxidant gas heating unit configured to heat an oxidant gas for the fuel cell; a combustor configured to combust the raw fuel to produce a combustion gas for use in heating the fuel processing unit and the oxidant gas heating unit; a supply control unit configured to, during a warm-up of the fuel cell, control supply of the raw fuel to the fuel processing unit and the combustor; and a power generation control unit configured to control a power generation state during the warm-up of the fuel cell, wherein when the fuel cell has reached a power generation available temperature, the power generation control unit is configured to cause the fuel cell to perform power generation, and the supply control unit is configured to supply the raw fuel of a flow rate, being greater than a supply flow rate of the raw fuel in a rated operation after the warm-up, to the fuel processing unit and the combustor in a divided manner.

13 . A fuel cell system comprising:
a fuel cell;
a fuel processing unit disposed in an anode gas passage of the fuel cell and configured to process a raw fuel for the fuel cell;
an oxidant gas heating unit disposed in a cathode gas passage of the fuel cell and configured to heat an oxidant gas for the fuel cell;
a combustor configured to combust the raw fuel and disposed to be capable of heating the fuel processing unit and the oxidant gas heating unit by a combustion gas of the raw fuel;
a supply control unit configured to, during a warm-up of the fuel cell, control supply of the raw fuel to the fuel processing unit and the combustor; and
a power generation control unit configured to control a power generation state during the warm-up of the fuel cell,
wherein the power generation control unit is configured to cause the fuel cell to perform power generation when the fuel cell has reached a power generation available temperature, and
wherein:
the supply control unit includes a warm-up target flow rate setting unit configured to set a warm-up target flow rate according to a temperature of the fuel cell as a target flow rate of the raw fuel during the warm-up of the fuel cell; and
the supply control unit is configured to, when the fuel cell has reached the power generation available temperature, supply the raw fuel of the warm-up target flow rate to the fuel processing unit and the combustor in a divided manner, the warm-up target flow rate being greater than a supply flow rate of the raw fuel in a rated operation after the warm-up.

14 . The fuel cell system according to claim 13 , wherein:
the warm-up target flow rate setting unit includes a target combustion gas temperature setting unit configured to set a target combustion gas temperature being a target temperature of the combustion gas; a relational equation indicating a relationship between the warm-up target flow rate, a heat energy of the combustion gas, a waste heat recovery amount of an anode gas flowing in the fuel processing unit, and a power generation amount of the fuel cell is set; and the warm-up target flow rate setting unit sets the warm-up target flow rate using the relational equation based on the target combustion gas temperature.

15 . The fuel cell system according to claim 13 , wherein:
the warm-up target flow rate setting unit includes a target combustion gas temperature setting unit configured to set a target temperature of the combustion gas, and a combustion gas temperature detection unit configured to detect a temperature of the combustion gas; and the warm-up target flow rate setting unit sets the warm-up target flow rate based on the target temperature of the combustion gas and the detected temperature of the combustion gas.

16 . The fuel cell system according to claim 14 , wherein:
the warm-up target flow rate setting unit further includes a fuel cell temperature detection unit configured to detect a temperature of the fuel cell; and the warm-up target flow rate setting unit is configured to set the target temperature of the combustion gas based on the temperature of the fuel cell.

17 . The fuel cell system according to claim 12 , wherein the supply control unit is configured to, in response to an increase of a temperature difference between input and output of the fuel cell, increase in the warm-up target flow rate a ratio of the raw fuel to be supplied to the fuel processing unit.

18 . The fuel cell system according to claim 12 , wherein:
the supply control unit is configured to be capable of switching between a first supply mode in which a ratio of the raw fuel to be supplied to the fuel processing unit is relatively high in the warm-up target flow rate, and a second supply mode in which a ratio of the raw fuel to be supplied to the combustor is relatively high in the warm-up target flow rate; and the supply control unit is configured to select the second supply mode when a temperature difference between input and output of the fuel cell is equal to or less than a predetermined value, and select the first supply mode when the temperature difference is greater than the predetermined value.

19 . The fuel cell system according to claim 12 , wherein a flow rate of the raw fuel that is supplied to the fuel processing unit during the warm-up is equal to or less than a target flow rate of the raw fuel that is set at a normal time after the warm-up.

20 . The fuel cell system according to claim 12 , wherein the power generation control unit is configured to cause the fuel cell to perform the power generation at a lower limit voltage according to a temperature of the fuel cell.

21 . A fuel cell system control method for controlling a fuel cell system configured to perform power generation by supplying a fuel gas produced by processing of a raw fuel to a fuel cell, the fuel cell system control method comprising:
at a start of the fuel cell system, determining whether or not the fuel cell is in a state of being capable of the power generation; when the fuel cell is in the state of being capable of the power generation, processing the raw fuel, causing the fuel cell to perform the power generation, and heating the fuel cell by heat energy produced by the power generation; combusting the raw fuel and heating the fuel cell using as a heat source a combustion gas produced by combustion of the raw fuel; and dividing the raw fuel of a flow rate, being greater than a supply flow rate of the raw fuel required for a rated operation of the fuel cell, for the processing of the raw fuel and the combustion of the raw fuel.

Assignees

• Nissan Motor

Inventors

• Noda Tetsushi
• Yaguchi Tatsuya
• Chikugo Hayato

Classifications

• H01M8/0618

  Reforming processes, e.g. autothermal, partial oxidation or steam reforming · CPC title

• H01M8/04776

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

• H01M8/04753

  of fuel cell reactants · CPC title

• H01M8/04373

  of auxiliary devices, e.g. reformers, compressors, burners · CPC title

• H01M8/04328

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