Fuel cell system and control method for fuel cell system

Patent metadata

Field	Value
Publication number	US-2016190618-A1
Application number	US-201414911543-A
Country	US
Kind code	A1
Filing date	Jul 16, 2014
Priority date	Aug 12, 2013
Publication date	Jun 30, 2016
Grant date	—

Abstract

A fuel cell system includes a compressor for supplying the cathode gas to the fuel cell, an anode gas discharge system for discharging anode off-gas discharged from the fuel cell into a cathode gas flow passage, a pulsating operation control unit for causing a pressure of the anode gas to pulsate based on an operating state of the fuel cell, a purge control unit for purging the anode off-gas into the cathode gas flow passage based on an impurity concentration of an anode of the fuel cell and a pressure of the anode, and a compressor control unit for controlling the compressor based on a purge flow rate controlled by the purge control unit, and the purge control unit for setting the pressure of the anode to a predetermined value determined according to a pulsating state of the anode gas.

First claim

1 .- 9 . (canceled)

10 . A fuel cell system for generating power by supplying anode gas and cathode gas to a fuel cell, comprising:
a compressor for supplying the cathode gas to the fuel cell; an anode gas discharge system for discharging anode off-gas discharged from the fuel cell into a cathode gas flow passage; a pulsating operation control unit configured to cause a pressure of the anode gas to pulsate based on an operating state of the fuel cell; a purge control unit configured to purge the anode off-gas into the cathode gas flow passage based on an impurity concentration of an anode of the fuel cell and calculating a purge flow rate based on the impurity concentration of the anode of the fuel cell and a pressure of the anode; and a compressor control unit configured to control the compressor based on the purge flow rate calculated by the purge control unit, the purge control unit configured to set the pressure of the anode to a predetermined value determined according to a pulsating state of the anode gas to suppress beat noise of the compressor due to the pulsation of the anode gas.

11 . The fuel cell system according to claim 10 , wherein the predetermined value is an upper limit target pressure when the pressure of the anode gas is caused to pulsate.

12 . The fuel cell system according to claim 10 , wherein the predetermined value is a lower limit target pressure when the pressure of the anode gas is caused to pulsate.

13 . The fuel cell system according to claim 10 , wherein the predetermined value is an average pressure between an upper limit target pressure and a lower limit target pressure when the pressure of the anode gas is caused to pulsate.

14 . The fuel cell system according to claim 10 , wherein the purge control unit sets the pressure of the anode to an actual pressure of the anode gas instead of the predetermined value if the actual pressure of the anode gas becomes higher than the predetermined value.

15 . The fuel cell system according to claim 10 , wherein the pulsating operation control unit calculates an upper limit target pressure and a lower limit target pressure when the pressure of the anode gas is caused to pulsate based on a load of the fuel cell, and sets the upper and lower limit target pressures higher when the load of the fuel cell is high than when the load of the fuel cell is low.

16 . The fuel cell system according to claim 10 , comprising:
a first target supply flow rate calculation unit configured to calculate a first target supply flow rate of the compressor based on the purge flow rate; and a second target supply flow rate calculation unit configured to calculate a second target supply flow rate of the compressor based on a load of the fuel cell, wherein the compressor control unit controls the compressor based on the larger one of the first and second target supply flow rates.

17 . The fuel cell system according to claim 10 , wherein:
the anode gas discharge system includes a purge valve for regulating a flow rate of the anode off-gas discharged into the cathode gas flow passage; the purge control unit calculates an opening of the purge valve based on the impurity concentration of the anode of the fuel cell, and purges the anode off gas into the cathode gas flow passage based on the opening of the purge valve and the pressure of the anode.

18 . A control method for a fuel cell system which is provided with a fuel cell supplied with anode gas and cathode gas, a compressor for supplying the cathode gas to the fuel cell, and an anode gas discharge system for discharging anode off-gas discharged from the fuel cell into a cathode gas flow passage, comprising:
a pulsating operation control step of causing a pressure of the anode gas to pulsate based on an operating state of the fuel cell; a purge control step of purging the anode off-gas into the cathode gas flow passage based on an impurity concentration of an anode of the fuel cell and calculating a purge flow rate based on the impurity concentration of the anode of the fuel cell and a pressure of the anode; and a compressor control step of controlling the compressor based on the purge flow rate calculated by the purge control step, the pressure of the anode being set to a predetermined value determined according to a pulsating state of the anode gas in the purge control step to suppress beat noise of the compressor due to the pulsation of the anode gas.

Assignees

• Nissan Motor

Inventors

• Asai Yoshitomo
• Tomita Yousuke

Classifications

• H01M2250/20

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

• H01M8/04388

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

• H01M8/04231

  Purging of the reactants · CPC title

• H01M8/04776 Primary

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

• H01M8/04753

  of fuel cell reactants · CPC title