Fuel cell system

Patent metadata

Field	Value
Publication number	US-10886547-B2
Application number	US-201916270885-A
Country	US
Kind code	B2
Filing date	Feb 8, 2019
Priority date	Feb 9, 2018
Publication date	Jan 5, 2021
Grant date	Jan 5, 2021

Abstract

A fuel cell system includes: a fuel cell including a fuel gas passage through which a fuel gas flows and an oxidant gas passage through which an oxidant gas flows, an inlet of the fuel gas passage being located closer to an outlet of the oxidant gas passage than to an inlet of the oxidant gas passage, an outlet of the fuel gas passage being located closer to the inlet of the oxidant gas passage than to the outlet of the oxidant gas passage; an oxidant gas supply unit supplying the oxidant gas to the fuel cell; and a supply amount controller configured to control the oxidant gas supply unit, the supply amount controller is configured to control the oxidant gas supply unit so that a stoichiometric ratio of the oxidant gas in a high-temperature high output power state is greater than that in a high-temperature low output power state.

First claim

What is claimed is:

1. A fuel cell system comprising:
a fuel cell including a fuel gas passage through which a fuel gas flows and an oxidant gas passage through which an oxidant gas flows, an inlet of the fuel gas passage being located closer to an outlet of the oxidant gas passage than to an inlet of the oxidant gas passage, an outlet of the fuel gas passage being located closer to the inlet of the oxidant gas passage than to the outlet of the oxidant gas passage;
an oxidant gas supply unit supplying the oxidant gas to the fuel cell; and
a supply amount controller configured to control the oxidant gas supply unit to control a supply amount of the oxidant gas to the fuel cell,
wherein the supply amount controller is configured to control the oxidant gas supply unit so that a stoichiometric ratio of the oxidant gas in a high-temperature high output power state is greater than a stoichiometric ratio of the oxidant gas in a high-temperature low output power state, the high-temperature high output power state being a state where a temperature of the fuel cell is higher than a predetermined temperature and a power generation amount of the fuel cell is greater than a predetermined power generation amount, the high-temperature low output power state being a state where the temperature of the fuel cell is higher than the predetermined temperature and the power generation amount of the fuel cell is equal to or less than the predetermined power generation amount.

2. The fuel cell system according to claim 1 , further comprising:
a fuel gas supply unit supplying the fuel gas to the fuel cell, wherein
the supply amount controller is configured to control the fuel gas supply unit to control a supply amount of the fuel gas to the fuel cell, and
the supply amount controller is configured to control the fuel gas supply unit so that a stoichiometric ratio of the fuel gas in the high-temperature high output power state is less than a stoichiometric ratio of the fuel gas in the high-temperature low output power state.

3. The fuel cell system according to claim 1 , wherein the supply amount controller is configured to control the oxidant gas supply unit so that the stoichiometric ratio of the oxidant gas in the high-temperature high output power state is greater than the stoichiometric ratio of the oxidant gas in the high-temperature low output power state and a stoichiometric ratio of the oxidant gas when the temperature of the fuel cell is equal to or less than the predetermined temperature.

4. The fuel cell system according to claim 2 , wherein the supply amount controller is configured to control the oxidant gas supply unit so that the stoichiometric ratio of the oxidant gas in the high-temperature high output power state is greater than the stoichiometric ratio of the oxidant gas in the high-temperature low output power state and a stoichiometric ratio of the oxidant gas when the temperature of the fuel cell is equal to or less than the predetermined temperature, and
the supply amount controller is configured to control the fuel gas supply unit so that the stoichiometric ratio of the fuel gas in the high-temperature high output power state is a value between the stoichiometric ratio of the fuel gas in the high-temperature low output power state and a stoichiometric ratio of the fuel gas when the temperature of the fuel cell is equal to or less than the predetermined temperature.

5. The fuel cell system according to claim 1 , wherein the predetermined temperature is 70° C. or greater.

6. The fuel cell system according to claim 1 , wherein the power generation amount of the fuel cell is considered to be greater than the predetermined power generation amount when a current density of the fuel cell is greater than a predetermined current density of 1.0 A/cm2 or greater.

7. The fuel cell system according to claim 1 , wherein the power generation amount of the fuel cell is considered to be greater than the predetermined power generation amount when a voltage of the fuel cell is less than a predetermined voltage of 0.75 V or less.

Assignees

• Toyota Motor Co Ltd

Inventors

• Shimomura Tetsuya
• Maeda Masashi
• Takeuchi Norimitsu

Classifications

• H01M8/04388

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

• H01M8/0258

  characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant · CPC title

• H01M2250/20

  Fuel cells in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M8/04089 Primary

  of gaseous reactants · CPC title

• H01M8/04425

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