Method and system for estimating hydrogen concentration of fuel cell

Patent metadata

Field	Value
Publication number	US-2019288310-A1
Application number	US-201816055391-A
Country	US
Kind code	A1
Filing date	Aug 6, 2018
Priority date	Mar 14, 2018
Publication date	Sep 19, 2019
Grant date	—

Abstract

A method for estimating a hydrogen concentration of a fuel cell includes estimating an initial amount of gas included at an anode side of a fuel cell, calculating a crossed over amount of gas between the anode side and a cathode side of the fuel cell and an amount of gas purged from the anode side to the outside from time when an initial amount of gas is predicted to a present time, and estimating a current hydrogen concentration at the anode side based on the predicted initial amount of gas, the calculated amount of crossed over gas, and the amount of purged gas.

First claim

What is claimed is:

1 . A method for estimating a hydrogen concentration in a fuel cell, the method comprising:
predicting, by an initial amount prediction part, an initial amount of gas contained at an anode side of the fuel cell; calculating, by a crossover calculator and a purge calculator, an amount of gas crossed over between the anode side and a cathode side of the fuel cell and an amount of gas purged from the anode side to the outside from a prediction time of the initial amount of gas to a current time, respectively; and estimating, by a concentration estimator, a current hydrogen concentration at the anode side based on the predicted initial amount of gas, the calculated amount of crossed over gas, and the amount of purged gas.

2 . The method of claim 1 , wherein the predicting of the initial amount of gas includes predicting the initial amount of gas at the anode side of the fuel cell based on a previously estimated concentration of the gas or using stop time data of the fuel cell or current state data of the fuel cell when the fuel cell is re-started.

3 . The method of claim 1 , wherein the calculating of the amount of crossed over gas and the amount of purged gas includes integrating a gas diffusion rate over time due to a gas partial pressure difference between the anode side and the cathode side to calculate the amount of crossed over gas.

4 . The method of claim 3 , wherein the gas diffusion rate is inversely proportional to a thickness of the electrolyte membrane of the fuel cell stack and is proportional to the gas partial pressure difference between the anode side and the cathode side.

5 . The method of claim 4 , wherein the gas diffusion rate is proportional to the gas diffusion coefficient, and the gas diffusion coefficient is varied according to a water content and a temperature of the electrolyte membrane disposed between the anode side and the cathode side of the fuel cell.

6 . The method of claim 1 , wherein the calculating of the amount of crossed over gas and the amount of purged gas includes calculating a purge rate of each gas by multiplying a total gas purge rate by a mole fraction of each gas and calculating the amount of purged gas by integrating the purge rate of each gas over time.

7 . The method of claim 6 , wherein the total gas purge rate is proportional to a pressure difference between a gas pressure at the anode side and a gas pressure at the outside.

8 . The method of claim 1 , wherein:
the predicting of the initial amount of gas includes predicting an initial amount of nitrogen and an initial amount of vapor at the anode side, respectively, the calculating of the amount of crossed over gas and the amount of purged gas includes calculating an amount of crossed over nitrogen and an amount of crossed over vapor, and an amount of purged nitrogen and an amount of purged vapor at the anode side, respectively, and the estimating of the current hydrogen concentration at the anode side includes calculating a current amount of nitrogen at the anode side based on the initial amount of nitrogen, the amount of crossed over nitrogen, and the amount of purged nitrogen, calculating a current amount of vapor at the anode side based on a predicted initial amount of vapor, the amount of crossed over vapor, and the amount of purged vapor, and estimating a current hydrogen concentration at the anode side using the current amount of nitrogen, the current amount of vapor, and a total gas amount at the anode side.

9 . A system for estimating a hydrogen concentration in a fuel cell, the system comprising:
an initial amount prediction part configured to predict an initial amount of gas contained at an anode side of the fuel cell; a crossover calculator configured to calculate an amount of gas crossed over between the anode side and a cathode side of the fuel cell and an amount of gas purged from the anode side to the outside from a prediction time of the initial amount of gas to a current time; a purge calculator configured to calculate an amount of gas purged from the anode side to the outside from an initial amount prediction time to a current time; and a concentration estimator configured to estimate a current hydrogen concentration at the anode side based on the predicted initial amount of gas, the calculated amount of crossed over gas, and the amount of purged gas.

10 . The system of claim 9 , wherein the initial amount prediction part predicts the initial amount of gas based on a previously estimated concentration of the gas or predicts an initial concentration of gas using stop time data of the fuel cell or current state data of the fuel cell when the fuel cell is re-started.

11 . The system of claim 9 , wherein the crossover calculator integrates a gas diffusion rate over time due to a gas partial pressure difference between the anode side and the cathode side to calculate the amount of crossed over gas.

12 . The system of claim 9 , wherein the purge calculator calculates a purge rate of each gas by multiplying a total gas purge rate by a mole fraction of each gas and calculating the amount of purged gas by integrating the purge rate of each gas over time.

13 . The system of claim 9 , wherein:
the initial amount prediction part predicts an initial amount of nitrogen and an initial amount of vapor at the anode side, the crossover calculator calculates an amount of crossed over nitrogen and an amount of crossed over vapor at the anode side, the purge calculator calculates an amount of purged nitrogen and an amount of purged vapor at the anode side, and the concentration estimator calculates a current amount of nitrogen at the anode side based on the initial amount of nitrogen, the amount of crossed over nitrogen, and the amount of purged nitrogen, calculates a current amount of vapor at the anode side based on an initial amount of vapor, the amount of crossed over vapor, and the amount of purged vapor, and estimates a current hydrogen concentration at the anode side using the current amount of nitrogen, the current amount of vapor, and a total gas amount at the anode side.

14 . A method for estimating a hydrogen concentration of a fuel cell, the method comprising estimating, by a controller, a current hydrogen concentration at an anode side using an initial amount of gas contained at the anode side of the fuel cell, an amount of gas crossed over between the anode side and a cathode side of the fuel cell from an initial amount prediction time to a current time, and an amount of gas purged from the anode side to the outside.

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Kwon Soon Woo
• Jang In Woo
• Lee Joon Yong

Classifications

• H01M8/04462

  of anode exhausts · CPC title

• H01M8/04402 Primary

  of anode exhausts · CPC title

• H01M8/04447 Primary

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

• H01M8/04432

  Pressure differences, e.g. between anode and cathode · CPC title

• H01M2250/20

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