Hydrogen gas detection for aircraft

Patent metadata

Field	Value
Publication number	US-12515810-B2
Application number	US-202318507498-A
Country	US
Kind code	B2
Filing date	Nov 13, 2023
Priority date	Nov 13, 2023
Publication date	Jan 6, 2026
Grant date	Jan 6, 2026

Abstract

System and associated methods relate to detecting and responding to hydrogen leakage in an aircraft. The system includes a hydrogen tank and a fuel pipeline surrounded by an enclosed chamber. The system further includes one or more vacuum pumps fluidly coupled to the enclosed chamber to create the control volume vacuum. The system further includes vacuum sensors mounted within the control volume vacuum, configured to sense a vacuum pressure value. The system further includes hydrogen detectors fluidly connected downstream of the one or more vacuum pumps, configured to sense the hydrogen concentration of the exhaust from the one or more vacuum pumps. The system further includes a controller and an emergency vacuum. The controller is configured to evaluate whether an emergency hydrogen leak condition exists based upon the vacuum pressure value and the hydrogen concentration. The controller can then open a valve to operate emergency vacuum if necessary.

First claim

The invention claimed is:

1 . A system for detecting hydrogen leakage in an aircraft, the aircraft including a hydrogen tank configured to store hydrogen fuel and a fuel pipeline fluidly connected between the hydrogen tank and a downstream engine, the system comprising:
an enclosed chamber, the enclosed chamber surrounding the hydrogen tank and the fuel pipeline; one or more vacuum pumps fluidly connected to an interior of the enclosed chamber to create a control volume vacuum within the enclosed chamber, the one or more vacuum pumps fluidly connected to the interior of enclosed chamber at a location downstream of the hydrogen tank; one or more vacuum sensors mounted within the control volume vacuum and configured to sense a vacuum pressure at one or more locations within the control volume vacuum; one or more hydrogen detectors fluidly connected to a vacuum pump exhaust pipeline downstream of the one or more vacuum pumps; an emergency vacuum, wherein a first end of the emergency vacuum is fluidly connected to the control volume vacuum, and a second end of the emergency vacuum is coupled to atmosphere external to the aircraft; an emergency vacuum release valve fluidly connected between the control volume vacuum and the second end of the emergency vacuum; a controller coupled to the emergency vacuum release valve, wherein:
the controller is coupled to the one or more vacuum sensors, wherein the one or more vacuum sensors are configured to transmit one or more vacuum pressure values to the controller; and
the controller is coupled to the one or more hydrogen detectors, wherein the one or more hydrogen detectors are configured to transmit one or more hydrogen concentration values to the controller;
wherein the controller is configured to calculate a change in vacuum pressure over time based upon the one or more vacuum pressure values; and wherein the controller is configured to send a signal to open the emergency vacuum release valve, thereby permitting flow from the control volume vacuum to atmosphere external to the aircraft via the emergency vacuum, in response to the change in vacuum pressure over time of at least one of the one or more vacuum sensors exceeding a predetermined rate of change threshold and in response to at least one of the one or more hydrogen concentration values exceeding a predetermined percentage of a lower explosive limit concentration value of hydrogen.

2 . The system of claim 1 , wherein the controller is configured to send a signal to open the emergency vacuum release valve, thereby permitting flow from the control volume vacuum to atmosphere external to the aircraft via the emergency vacuum, in response to at least one of the vacuum pressure values exceeding a predetermined vacuum threshold.

3 . The system of claim 1 , wherein the controller is configured to send a signal to open the emergency vacuum release valve in response to at least one of the one or more vacuum pressure values exceeding a predetermined vacuum threshold and in response to at least one of the one or more hydrogen concentration values exceeding a predetermined percentage of a lower explosive limit concentration value of hydrogen.

4 . The system of claim 1 , wherein the controller is configured to emit an air leakage emergency signal to a connected aircraft communication system in response to at least one of the one or more vacuum pressure values exceeding a predetermined vacuum threshold while the one or more hydrogen concentration values are below a predetermined percentage of a lower explosive limit concentration value of hydrogen.

5 . The system of claim 4 , wherein the air leakage emergency signal includes an indication that maintenance is required on the control volume vacuum.

6 . The system of claim 1 , wherein the controller is configured to emit a low-level alarm in response to the one or more hydrogen concentration values being within a first percentage range of a lower explosive limit concentration value of hydrogen and wherein the controller is configured to emit a high-level alarm in response to the one or more hydrogen concentration values being within a second percentage range of a lower explosive limit concentration value of hydrogen.

7 . The system of claim 1 , wherein the one or more hydrogen detectors are fluidly coupled to an aircraft air cycle system such that cabin air is routed to the one or more hydrogen detectors.

8 . The system of claim 1 , wherein the one or more hydrogen detectors are fluidly coupled to the downstream engine such that bleed air is routed to the one or more hydrogen detectors.

9 . The system of claim 1 , wherein the hydrogen tank contains liquid H 2 .

10 . A method for detecting hydrogen leakage in an aircraft, the aircraft including a hydrogen tank configured to store hydrogen fuel and a fuel pipeline fluidly connecting the hydrogen tank to a downstream engine, the method comprising:
evacuating an enclosed chamber that surrounds the hydrogen tank and surrounds the fuel pipeline via one or more vacuum pumps to create a control volume vacuum, wherein the one or more vacuum pumps are fluidly connected to the enclosed chamber at a location downstream of the hydrogen tank; sensing, via one or more vacuum sensors mounted within the control volume vacuum, one or more vacuum pressure values; sensing, via one or more hydrogen detectors fluidly connected downstream of the one or more vacuum pumps, one or more hydrogen concentration values; transmitting the one or more vacuum pressure values and the one or more hydrogen concentration values to a controller; evaluating, via the controller, whether an emergency condition is met in response to the one or more vacuum pressure values and/or the one or more hydrogen concentration values; emitting an air leakage emergency signal to a connected aircraft communication system in response to at least one of the one or more vacuum pressure values exceeding a predetermined vacuum threshold while the one or more hydrogen concentration values are below a predetermined percentage of a lower explosive limit concentration value of hydrogen.

11 . The method of claim 10 , wherein the emergency condition is met when at least one of the one or more vacuum pressure values exceeds a predetermined vacuum threshold and when at least one of the one or more hydrogen concentration values exceeds a predetermined percentage of a lower explosive limit concentration value of hydrogen.

12 . The method of claim 11 , further comprising:
transmitting a signal from the controller to the emergency vacuum release valve, wherein the emergency vacuum release valve is fluidly connected to an emergency vacuum, the emergency vacuum configured to eject hydrogen from the control volume to atmosphere external to the aircraft; opening the emergency vacuum release valve; and ejecting the hydrogen fuel from the control volume to atmosphere external to the aircraft via the emergency vacuum.

13 . The method of claim 10 , wherein the one or more hydrogen detectors are fluidly coupled to the downstream engine such that bleed air is routed to the one or more hydrogen detectors.

14 . The method of claim 10 , wherein the one or more hydrogen detectors are fluidly coupled to an aircraft air cycle system such that cabin air is routed to the one or more hydrogen detectors.

Assignees

• Kidde Tech Inc

Inventors

• Porterfield John W
• Chattaway Adam

Classifications

• G08B21/16

  Combustible gas alarms · CPC title

• G01N33/005

  H2 · CPC title

• B64D37/005

  Accessories not provided for in the groups B64D37/02 - B64D37/28 · CPC title

• G01M3/226

  for containers, e.g. radiators · CPC title

• B64D37/32 Primary

  Safety measures not otherwise provided for, e.g. preventing explosive conditions · CPC title