Method for controlling fuel cell system

Patent metadata

Field	Value
Publication number	US-2018339603-A1
Application number	US-201715829358-A
Country	US
Kind code	A1
Filing date	Dec 1, 2017
Priority date	May 25, 2017
Publication date	Nov 29, 2018
Grant date	—

Abstract

A method for controlling a fuel cell system includes steps of: (a) determining whether hydrogen (H2) is detected in an interior space of a stack enclosure in which a fuel cell stack is accommodated; (b) stopping power generation that is performed using the stack when it is determined in step (a) that the hydrogen is detected; (c) opening a purge valve to discharge gases circulating in an anode through the purge valve, and opening a condensate discharge valve to discharge condensate contained in a water trap through the condensate discharge valve; and (d) determining whether the hydrogen discharged through at least one of the purge valve and the condensate discharge valve in step (c) flows back to the interior space based on H2 concentration in the interior space.

First claim

What is claimed is:

1 . A method for controlling a fuel cell system, the method comprising steps of:
(a) determining whether hydrogen (H 2 ) is detected in an interior space of a stack enclosure in which a fuel cell stack is accommodated; (b) stopping power generation that is performed using the stack when it is determined in step (a) that the hydrogen is detected; (c) opening a purge valve to discharge gases circulating in an anode through the purge valve, and opening a condensate discharge valve to discharge condensate contained in a water trap through the condensate discharge valve; and (d) determining whether the hydrogen discharged through at least one of the purge valve and the condensate discharge valve in step (c) flows back to the interior space based on H 2 concentration measured in the interior space.

2 . The method according to claim 1 , wherein step (a) is performed by determining whether the hydrogen is detected a predetermined number of times or more.

3 . The method according to claim 1 , wherein step (b) is performed by stopping supply of the hydrogen to the anode and stopping supply of air to a cathode.

4 . The method according to claim 1 , wherein step (c) is performed by intermittently opening the purge valve a predetermined number of times, and intermittently opening the condensate discharge valve a predetermined number of times.

5 . The method according to claim 4 , wherein step (d) is performed by determining whether the H 2 concentration is lower than a predetermined dangerous concentration.

6 . The method according to claim 5 , further comprising step (e) of stopping the fuel cell system when it is determined in step (d) that the measured H 2 concentration is higher than or equal to the predetermined dangerous concentration.

7 . The method according to claim 6 , wherein step (e) is performed by warning that the measured H 2 concentration is higher than or equal to the predetermined dangerous concentration, using at least one of display devices provided in the fuel cell system.

8 . The method according to claim 5 , further comprising step (f) of determining whether the measured H 2 concentration exceeds a predetermined safety concentration when it is determined in step (d) that the measured H 2 concentration is lower than the predetermined dangerous concentration,
wherein the predetermined safety concentration is lower than the predetermined dangerous concentration by a predetermined ratio.

9 . The method according to claim 8 , further comprising step (g) of determining whether the measured H 2 concentration exceeds a predetermined boundary concentration while limitedly driving an air compressor within a predetermined reference driving time to allow the hydrogen to be discharged from the interior space due to a negative pressure provided by the air pressure when it is determined in step (f) that the measured H 2 concentration exceeds the predetermined safety concentration,
wherein the predetermined boundary concentration is higher than the predetermined safety concentration by a predetermined ratio, and is lower than the predetermined dangerous concentration by a predetermined ratio.

10 . The method according to claim 9 , further comprising step (h) of determining whether an actual power generation stop time taken from the beginning of step (b) to the present time is less than a predetermined reference power generation stop time when it is determined in step (f) that the measured H 2 concentration is lower than or equal to the predetermined safety concentration or when it is determined in step (g) that the measured H 2 concentration is lower than or equal to the predetermined boundary concentration,
wherein step (f) is performed again when it is determined in step (h) that the actual power generation stop time is less than the reference power generation stop time.

11 . The method according to claim 10 , further comprising step (i) of restarting the power generation that is performed using the stack when it is determined in step (h) that the actual power generation stop time is greater than or equal to the reference power generation stop time.

12 . The method according to claim 11 , further comprising step (j) of recording an actual driving time for which the air compressor is driven during the actual power generation stop time, after step (i).

13 . The method according to claim 12 , further comprising step (k) of storing the actual driving time recorded in step (j) as a reference driving time.

14 . The method according to claim 9 , further comprising step (l) of stopping the fuel cell system when it is determined in step (g) that the measured H 2 concentration exceeds the predetermined boundary concentration.

15 . The method according to claim 14 , further comprising step (m) of individually recording an actual power generation stop time taken from the beginning of step (b) to the present time, and an actual driving time for which the air compressor is driven during the actual power generation stop time, after step (l).

16 . The method according to claim 15 , further comprising steps of:
(n) determining whether the actual power generation stop time recorded in step (m) is less than a predetermined reference power generation stop time; and (o) storing the actual power generation stop time as the reference power generation stop time, and storing the actual driving time as a reference driving time, when it is determined in step (n) that the actual power generation stop time is less than the reference power generation stop time.

17 . The method according to claim 16 , further comprising step (p) of storing the actual driving time as the reference driving time when it is determined in step (n) that the actual power generation stop time is greater than or equal to the reference power generation stop time.

18 . The method according to claim 2 , wherein the determining whether the hydrogen is detected is performed for a predetermined detection time using a hydrogen sensor provided in the stack enclosure.

19 . The method according to claim 4 , wherein:
opening time and opening degree of the purge valve is determined according to the H 2 concentration measured in the anode, and opening time and opening degree of the condensate discharge valve is determined according to a level of the condensate in the water trap.

20 . The method according to claim 5 , wherein the predetermined dangerous concentration is set to be lower than an ignitable concentration with respect to a hydrogen ignition probability.

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Shim Jae Young
• Yang Sung Ho
• Jang Jae Hun
• Park Hyo Jin
• Jeon Kang Sik
• Jin Young Pin

Classifications

• G05D7/0682

  using a plurality of flow sources · CPC title

• H01M8/04455

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

• H01M8/04447

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

• H01M2250/20

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

• H01M8/04679 Primary

  of fuel cell stacks · CPC title