Fuel cell system and control method for fuel cell system

Patent metadata

Field	Value
Publication number	US-2019173107-A1
Application number	US-201816110840-A
Country	US
Kind code	A1
Filing date	Aug 23, 2018
Priority date	Aug 20, 2010
Publication date	Jun 6, 2019
Grant date	—

Abstract

A fuel cell system includes: a fuel cell stack; a fuel gas supply/exhaust unit; an oxidant gas supply/exhaust unit; and a control unit. The control unit determines whether there is a phenomenon in the fuel cell stack resulting from local power generation concentration within a plane of a membrane electrode assembly due to a water distribution. When it is determined that there is the phenomenon, the control unit controls at least one of the fuel gas supply/exhaust unit and the oxidant gas supply/exhaust unit.

First claim

What is claimed is:

1 - 20 . (canceled)

21 . A fuel cell system comprising:
a fuel cell having a membrane electrode assembly, the membrane electrode assembly having an anode and a cathode which are respectively bonded to both surfaces of an electrolyte membrane formed of a solid polymer; a fuel gas flow passage flowing fuel gas along a surface of the anode; an oxidant gas flow passage flowing oxidant gas along a surface of the cathode; a fuel gas supply/exhaust unit configured to supply fuel gas to the anode and configured to exhaust anode off-gas exhausted from the anode, via the fuel gas flow passage; and an oxidant gas supply/exhaust unit configured to supply oxidant gas to the cathode and configured to exhaust cathode off-gas exhausted from the cathode, via the oxidant gas flow passage; a power generation concentration determining unit configured to determine whether there is a phenomenon in the fuel cell resulting from local power generation concentration, where the amount of power generation per unit area locally exceeds an allowable value, within a plane of the membrane electrode assembly due to a water distribution, the water distribution including a water content distribution within a plane of the electrolyte membrane, a residual water distribution in the fuel gas flow passage and a residual water distribution in the oxidant gas flow passage, the power generation concentration determining unit being configured to estimate the water distribution on the basis of an operating condition of the fuel cell, and the power generation concentration determining unit being configured to determine on the basis of the estimated water distribution whether a cause of the power generation concentration is a locally insufficient water content in the electrolyte membrane, a locally excessive amount of residual water in the fuel gas flow passage or a locally excessive amount of residual water in the oxidant gas flow passage; and a control unit configured to control at least one of the fuel gas supply/exhaust unit and the oxidant gas supply/exhaust unit so as to eliminate the phenomenon when the power generation concentration determining unit determines that there is the phenomenon, the control unit being configured to control at least one of the fuel gas supply/exhaust unit and the oxidant gas supply unit on the basis of the determined cause of the power generation concentration, and the control unit being configured to control the fuel gas supply/exhaust unit so as to increase a flow rate of the fuel gas supplied to the anode when it is determined that the cause of the power generation concentration is a locally insufficient water content in the electrolyte membrane.

22 . The fuel cell system according to claim 21 , wherein when it is determined that the cause of the power generation concentration is a locally insufficient water content in the electrolyte membrane, the control unit is configured to control the oxidant gas supply/exhaust unit so as to reduce a flow rate of the oxidant gas supplied to the cathode.

23 . The fuel cell system according to claim 21 , wherein when it is determined that the cause of the power generation concentration is a local insufficient water content in the electrolyte membrane, the control unit is configured to control the oxidant gas supply/exhaust unit so as to increase a back pressure of the cathode off-gas.

24 . The fuel cell system according to claim 21 , wherein when it is determined that the cause of the power generation concentration is a locally excessive amount of residual water in the fuel gas flow passage, the control unit is configured to control the fuel gas supply/exhaust unit so as to increase a flow rate of the fuel gas supplied to the anode.

25 . The fuel cell system according to claim 21 , wherein when it is determined that the cause of the power generation concentration is a locally excessive amount of residual water in the oxidant gas flow passage, the control unit is configured to control the oxidant gas supply/exhaust unit so as to increase a flow rate of the oxidant gas supplied to the cathode.

26 . The fuel cell system according to claim 21 , wherein when it is determined that the cause of the power generation concentration is a locally excessive amount of residual water in the oxidant gas flow passage, the control unit is configured to control the oxidant gas supply/exhaust unit so as to reduce a back pressure of the cathode off-gas.

Assignees

• Toyota Motor Co Ltd

Inventors

• Matsusue Masaaki

Classifications

• H01M8/04365

  of other components of a fuel cell or fuel cell stacks · CPC title

• H01M8/0435

  of cathode exhausts · CPC title

• H01M8/045

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

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title

• H01M8/04529

  of the electrolyte · CPC title