Hydrogen concentration estimating method and system for fuel cell

Patent metadata

Field	Value
Publication number	US-10566637-B2
Application number	US-201816004483-A
Country	US
Kind code	B2
Filing date	Jun 11, 2018
Priority date	Dec 12, 2017
Publication date	Feb 18, 2020
Grant date	Feb 18, 2020

Abstract

A hydrogen concentration estimating method for a fuel cell includes: measuring a flow rate of air supplied to a fuel cell stack, and comparing the measured flow rate of the air with a predetermined flow rate; determining a model of an air processing system according to a comparison result; and estimating hydrogen concentration of a fuel processing system based on the determined model of the air processing system.

First claim

What is claimed is:

1. A hydrogen concentration estimating method for a fuel cell, the method comprising:
measuring a flow rate of air supplied to a fuel cell stack, and comparing the measured flow rate of the air with a predetermined flow rate;
determining the air processing system to be an open model when the measured flow rate of air exceeds the predetermined flow rate;
determining the air processing system to be a closed model when the measured flow rate of the air is equal to or less than the predetermined flow rate; and
estimating hydrogen concentration of a fuel processing system based on the determined model of the air processing system.

2. The method of claim 1 , wherein in comparing the measured flow rate of the air with the predetermined flow rate, the predetermined flow rate is set by a flow rate of air that occurs when air supply to the fuel cell stack is shut off.

3. The method of claim 1 , wherein when the air processing system is determined to be the open model, when estimating the hydrogen concentration of the fuel processing system, hydrogen partial pressure of the air processing system is zero.

4. The method of claim 1 , wherein when the air processing system is determined to be the open model, when estimating the hydrogen concentration of the fuel processing system, nitrogen partial pressure or oxygen partial pressure of the air processing system is based on gas pressure and water vapor partial pressure of the air processing system.

5. The method of claim 1 , wherein when the air processing system is determined to be the closed model, when estimating the hydrogen concentration of the fuel processing system, hydrogen partial pressure of the air processing system is increased by hydrogen that crosses over from the fuel processing system.

6. The method of claim 5 , wherein when estimating the hydrogen concentration, the hydrogen partial pressure of the air processing system is obtained using the following equations:

n

H
2

=

n

H
2

⁢
_init

+

∫

⁢

n
.

H
2

⁢
dt

P

H
2

=

n

H
2

⁢

RT

V
Ca

n H 2 : the number of moles of hydrogen in the air processing system, n H 2- init : the initial number of moles of hydrogen in the air processing system, {dot over (n)} H 2 : the number of moles of crossed-over hydrogen per unit time, P H 2 : the hydrogen partial pressure of the air processing system, R: gas constant, T: gas temperature, V Ca : volume in the air processing system.

7. The method of claim 1 , wherein when the air processing system is determined to be the closed model, while estimating the hydrogen concentration of the fuel processing system, oxygen partial pressure of the air processing system is decreased by oxygen that crosses over to the fuel processing system.

8. The method of claim 7 , wherein when estimating the hydrogen concentration, the oxygen partial pressure of the air processing system is obtained using the following equation:

P

O
2

=

P

O
2

⁢
_init

⁢

exp
⁡

(

-

t

T
1

)

P O 2 : the oxygen partial pressure of the air processing system, P O 2- init : initial oxygen partial pressure of the air processing system, t: duration time of the closed model of the air processing system, T1: time constant (constant).

9. The method of claim 1 , wherein when the air processing system is determined to be the closed model, when estimating the hydrogen concentration of the fuel processing system, nitrogen partial pressure of the air processing system is decreased by nitrogen that crosses over to the fuel processing system.

10. The method of claim 7 , wherein when estimating the hydrogen concentration, the nitrogen partial pressure of the air processing system is obtained using the following equations:

P

N
2

=

n

N
2

⁢

RT

V
Ca

n

N
2

=

n
Ca

-

n

H
2

-

n

O
2

,

n
Ca

=

P
Ca

⁢

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Lee Joon Yong
• Kwon Soon Woo

Classifications

• H01M8/04231

  Purging of the reactants · CPC title

• H01M8/04798

  of fuel cell reactants · CPC title

• H01M8/04447 Primary

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

• H01M8/04388

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

• H01M8/04753

  of fuel cell reactants · CPC title