Control method and control system of hydrogen concentration for fuel cell

Patent metadata

Field	Value
Publication number	US-10879547-B2
Application number	US-201816055454-A
Country	US
Kind code	B2
Filing date	Aug 6, 2018
Priority date	Mar 14, 2018
Publication date	Dec 29, 2020
Grant date	Dec 29, 2020

Abstract

A method of controlling hydrogen concentration of a fuel cell includes calculating hydrogen or nitrogen concentration of gas stored in a fuel tank; estimating hydrogen or nitrogen concentration at an anode of the fuel cell based on the calculated hydrogen or nitrogen concentration of the gas; and controlling a hydrogen supply unit based on the estimated hydrogen or nitrogen concentration at the anode such that the hydrogen or nitrogen concentration at the anode follows desired hydrogen concentration or desired nitrogen concentration.

First claim

What is claimed is:

1. A method of controlling hydrogen concentration of a fuel cell, the method comprising:
calculating, by a gas concentration estimator, hydrogen or nitrogen concentration of gas stored in a fuel tank;
estimating, by the gas concentration estimator, hydrogen or nitrogen concentration at an anode of the fuel cell based on the calculated hydrogen or nitrogen concentration of the gas;
controlling, by a controller, a hydrogen supply unit based on the estimated hydrogen or nitrogen concentration at the anode such that the hydrogen or nitrogen concentration at the anode follows desired hydrogen concentration or desired nitrogen concentration;
accumulatively measuring a number of times of filling the fuel tank with fuel before the calculation of hydrogen or nitrogen concentration of gas stored in the fuel tank,
wherein when the measured accumulated number of times of filling is less than a predetermined number of times, the hydrogen or nitrogen concentration of the gas stored in the fuel tank is calculated.

2. The method of claim 1 , further comprising accumulatively measuring the amount of fuel filled in the fuel tank before the calculation of hydrogen or nitrogen concentration of gas stored in the fuel tank,
wherein when the measured amount of accumulated fuel is less than a predetermined amount of fuel, the hydrogen or nitrogen concentration of the gas stored in the fuel tank is calculated.

3. The method of claim 1 , wherein, in the calculation of hydrogen or nitrogen concentration of gas stored in the fuel tank, the concentration of hydrogen or nitrogen is calculated under the assumption that hydrogen and nitrogen are included in the fuel tank and only pure hydrogen is injected into the fuel tank when the fuel tank is filled with fuel.

4. The method of claim 3 , wherein in the calculation of hydrogen or nitrogen concentration of gas stored in the fuel tank, the hydrogen concentration after fuel-filling is a calculated, using the hydrogen concentration before fuel-filling, filling ratio before fuel-filling, and filling ratio after fuel-filling.

5. The method of claim 1 , wherein in the estimating of hydrogen or nitrogen concentration at the anode of the fuel cell, the ratio of the hydrogen amount in an entire gas amount obtained by summing the nitrogen amount, hydrogen amount, and vapor amount at the anode is estimated.

6. The method of claim 5 , wherein the entire gas amount at the anode is estimated using pressure, volume, and temperature of the entire gas at the anode.

7. The method of claim 5 , wherein the nitrogen amount at the anode is estimated by adding a nitrogen amount filled in a fuel tank in a manufacturing process to a crossover amount of nitrogen, a purge amount of nitrogen, and the nitrogen amount supplied from the fuel tank that are integrated for time.

8. The method of claim 7 , wherein the nitrogen amount from the fuel tank integrated for time is estimated using the calculated hydrogen or nitrogen concentration of the gas stored in the fuel tank.

9. The method of claim 5 , wherein the vapor amount of the anode is estimated by adding vapor amount when the fuel cell is restarted to the crossover amount of vapor and the purge amount of vapor that are integrated for time.

10. The method of claim 5 , wherein the hydrogen amount at the anode is estimated by subtracting the nitrogen amount and the vapor amount from the entire gas amount at the anode.

11. The method of claim 1 , wherein in the controlling of a hydrogen supply unit, the gas pressure at the anode is controlled or purge for discharging the gas at the anode to the outside is controlled, in order to change the hydrogen concentration at the anode.

12. A system for controlling hydrogen concentration of a fuel cell, the system comprising:
a fuel tank that stores hydrogen to be supplied to the fuel cell;
a hydrogen supply unit that supplies the hydrogen in the fuel tank to the fuel cell;
a gas concentration estimator that calculates hydrogen or nitrogen concentration of the gas stored in the fuel tank and estimates hydrogen or nitrogen concentration at the anode of the fuel cell based on the calculated hydrogen or nitrogen concentration of the gas; and
a controller that controls the hydrogen supply unit based on the hydrogen or nitrogen concentration at the anode estimated by the gas concentration estimator such that the hydrogen or nitrogen concentration at the anode follows desired hydrogen concentration or desired nitrogen concentration,
wherein the gas concentration estimator accumulatively measures a number of times of filling the fuel tank with fuel before the calculation of hydrogen or nitrogen concentration of gas stored in the fuel tank,
wherein when the measured accumulated number of times of filling is less than a predetermined number of times, the hydrogen or nitrogen concentration of the gas stored in the fuel tank is calculated.

13. The system of claim 12 , wherein the hydrogen supply unit includes a fuel ejector and a fuel supply valve that are disposed between a recirculation line for supplying the hydrogen passing through the fuel cell back to the fuel cell and a fuel supply line for supplying the hydrogen in the fuel tank to the fuel cell, and
the controller controls gas pressure at the anode by controlling the fuel ejector and the fuel supply valve in order to change the hydrogen concentration at the anode.

14. The system of claim 12 , wherein the hydrogen supply unit includes a purge valve that is disposed in the recirculation line for supplying the gas passing through the fuel cell back to the fuel cell and discharges gas at the anode to the outside, and
the controller controls purge for discharging the gas at the anode to the outside by controlling the purge valve in order to change the hydrogen concentration at the anode.

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Kwon Soon Woo
• Ban Hyeon Seok
• Lee Joon Yong

Classifications

• H01M8/04992

  characterised by the implementation of mathematical or computational algorithms, e.g. feedback control loops, fuzzy logic, neural networks or artificial intelligence · CPC title

• H01M8/04798 Primary

  of fuel cell reactants · CPC title

• H01M8/04753

  of fuel cell reactants · CPC title

• H01M8/0444

  Concentration; Density (H01M8/04492 takes precedence) · CPC title

• H01M8/04231

  Purging of the reactants · CPC title