Fuel cell system and control method of fuel cell system

Patent metadata

Field	Value
Publication number	US-2018331376-A1
Application number	US-201815975315-A
Country	US
Kind code	A1
Filing date	May 9, 2018
Priority date	May 12, 2017
Publication date	Nov 15, 2018
Grant date	—

Abstract

There is provided a fuel cell system comprising a fuel cell including an electrolyte membrane, an anode and a cathode; and a controller configured to control a fuel gas supply part and an oxidizing gas supply part to supply amounts of a fuel gas and an oxidizing gas corresponding to a required power, to the fuel cell. During an intermittent operation that has the required power equal to or lower than a predetermined value and stops power generation in the fuel cell, the controller estimates a crossover amount that is an amount of the fuel gas moved from the anode to the cathode through the electrolyte membrane. The controller also calculates a supply amount of the oxidizing gas that is an amount of the oxidizing gas to be supplied to the fuel cell, based on the estimated crossover amount and controls the oxidizing gas supply part to supply the calculated supply amount of the oxidizing gas to the fuel cell. The supply amount of the oxidizing gas is calculated by an expression of; supply amount of oxidizing gas=crossover amount/2/oxygen concentration in oxidizing gas.

First claim

What is claimed is:

1 . A fuel cell system, comprising:
a fuel cell including an electrolyte membrane, an anode and a cathode; a fuel gas supply part configured to supply a fuel gas to the anode; an oxidizing gas supply part configured to supply an oxidizing gas to the cathode; and a controller configured to control the fuel gas supply part and the oxidizing gas supply part to supply amounts of the fuel gas and the oxidizing gas corresponding to a required power to the fuel cell, wherein during an intermittent operation that has the required power equal to or lower than a predetermined value and stops power generation in the fuel cell, the controller estimates a crossover amount that is an amount of the fuel gas moved from the anode to the cathode through the electrolyte membrane, the controller calculates a supply amount of the oxidizing gas that is an amount of the oxidizing gas to be supplied to the fuel cell, based on the estimated crossover amount, and the controller controls the oxidizing gas supply part to supply the calculated supply amount of the oxidizing gas to the fuel cell, wherein the supply amount of the oxidizing gas is calculated by an expression of
supply amount of oxidizing gas=crossover amount/2/oxygen concentration in oxidizing gas.

2 . The fuel cell system according to claim 1 , further comprising:
a pressure sensor configured to measure a pressure at the anode, wherein during the intermittent operation, the controller calculates an amount of pressure drop at the anode, based on a pressure value obtained from the pressure sensor, and estimates the crossover amount, based on the amount of pressure drop at the anode and a volume of the anode.

3 . The fuel cell system according to claim 2 ,
wherein the controller stores a relationship information between a pressure value at the anode and the crossover amount, during the intermittent operation, the controller determines an initial value of the crossover amount, based on the pressure value obtained from the pressure sensor, according to the relationship information between the pressure value at the anode and the crossover amount, and the controller calculates the supply amount of the oxidizing gas, based on a sum of the initial value of the crossover amount and the crossover amount that is estimated based on the amount of pressure drop at the anode and the volume of the anode.

4 . The fuel cell system according to claim 3 ,
wherein the controller stores a relationship information between a characteristic of the electrolyte membrane and a correction value of the crossover amount, and during the intermittent operation, the controller corrects the initial value of the crossover amount, based on the correction value of the crossover amount corresponding to the characteristic of the electrolyte membrane.

5 . The fuel cell system according to claim 1 , further comprising:
a voltage sensor configured to measure a voltage of the fuel cell, wherein the controller stores a target voltage of the fuel cell during the intermittent operation, and a relationship information between the voltage of the fuel cell and the supply amount of the oxidizing gas, during the intermittent operation, the controller calculates the supply amount of the oxidizing gas based on a voltage difference between a voltage value obtained from the voltage sensor and the target voltage, from the voltage difference, according to the relationship information between the voltage of the fuel cell and the supply amount of the oxidizing gas, and the controller controls the oxidizing gas supply part to supply the supply amount of the oxidizing gas calculated based on the voltage difference and the supply amount of the oxidizing gas calculated based on the crossover amount, to the fuel cell.

6 . A control method of a fuel cell system, comprising:
during an intermittent operation that has a required power, which is required for a fuel cell configured to generate electric power by a fuel gas supplied to an anode and an oxidizing gas supplied to a cathode, equal to or lower than a predetermined value and stops power generation in the fuel cell, estimating a crossover amount that is an amount of the fuel gas moved from the anode of the fuel cell to the cathode of the fuel cell through an electrolyte membrane, calculating a supply amount of the oxidizing gas that is an amount of the oxidizing gas to be supplied to the fuel cell, based on the estimated crossover amount, and supplying the calculated supply amount of the oxidizing gas to the fuel cell, wherein the supply amount of the oxidizing gas is calculated by an expression of:
supply amount of oxidizing gas=crossover amount/2/oxygen concentration in oxidizing gas.

7 . The control method of the fuel cell system according to claim 6 , further comprising:
during the intermittent operation, calculating an amount of pressure drop at the anode, based on a pressure value at the anode, and estimating the crossover amount, based on the amount of pressure drop at the anode and a volume of the anode.

8 . The control method of the fuel cell system according to claim 7 , further comprising:
during the intermittent operation, determining an initial value of the crossover amount, based on the pressure value at the anode, according to a relationship information between the pressure value at the anode and the crossover amount, and calculating the supply amount of the oxidizing gas, based on a sum of the initial value of the crossover amount and the crossover amount that is estimated based on the amount of pressure drop at the anode and the volume of the anode.

9 . The control method of the fuel cell system according to claim 8 , further comprising:
during the intermittent operation, correcting the initial value of the crossover amount, based on a correction value of the crossover amount corresponding to a characteristic of the electrolyte membrane.

10 . The control method of the fuel cell system according to claim 6 , further comprising:
during the intermittent operation, calculating the supply amount of the oxidizing gas based on a voltage difference between a voltage value of the fuel cell and a target voltage of the fuel cell during the intermittent operation, from the voltage difference, according to a relationship information between the voltage of the fuel cell and the supply amount of the oxidizing gas, and supplying the supply amount of the oxidizing gas calculated based on the voltage difference and the supply amount of the oxidizing gas calculated based on the crossover amount, to the fuel cell.

Assignees

• Toyota Motor Co Ltd

Inventors

• Miyamoto Yusuke
• Ishikawa Tomotaka
• Iio Atsuo

Classifications

• H01M8/04753

  of fuel cell reactants · CPC title

• H01M8/10

  Fuel cells with solid electrolytes · CPC title

• H01M8/04104 Primary

  Regulation of differential pressures · CPC title

• H01M8/04395

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

• H01M2008/1095

  Fuel cells with polymeric electrolytes · CPC title