Aircraft Hydrogen Supply Venting for Leak Containment

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Solution Overview

Problem

Existing hydrogen supply systems in aircraft are not adequately safe against hydrogen leaks, which can lead to secondary leaks and potential incidents.

Innovation Solution

A hydrogen supply system with double-walled pipelines, inert gas isolation, pressure sensors, shut-off valves, and a ventilation system to evacuate hydrogen in case of leaks, combined with an inert gas injection system to reduce hydrogen concentration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hydrogen is conveyed through double-walled pipelines with inert gas isolation, then hydrogen leak safety is improved, but device complexity increases

Engineering Contradiction:
Improvehydrogen leak safetyVSAvoiddouble-walled pipeline structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a double-walled pipeline structure where the inner conduit is nested within the outer conduit, creating an inner zone between them. This nested configuration allows inert gas to be introduced into the inner zone to isolate hydrogen leaks from the external environment, thereby improving safety while managing the complexity through a systematic layered design.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent introduces an inert gas (such as nitrogen or argon) into the inner zone between the inner and outer conduits. This inert atmosphere serves as a protective barrier that prevents hydrogen from contacting oxygen in the external environment, eliminating the risk of combustion even when hydrogen leaks occur within the double-walled structure.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

2Reliability

If a ventilation system is added to evacuate hydrogen in case of leaks, then safety against secondary leaks is improved, but device complexity increases

Engineering Contradiction:
Improvesafety against secondary leaksVSAvoidventilation system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces a ventilation system that acts as an intermediary between the inner zone and the external environment. This system includes ventilation conduits with controllable valves that can evacuate hydrogen from the inner zone to the external environment when leaks are detected, preventing dangerous hydrogen accumulation and secondary leaks.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements a feedback mechanism where sensors detect hydrogen concentration or pressure changes in the inner zone, and this information triggers the ventilation system to activate. The control unit receives signals from the sensors and automatically opens the ventilation valves to evacuate hydrogen, creating a closed-loop safety system that responds dynamically to leak conditions.

Inventive Principle:
Principle #23Feedback

3Reliability

If an inert gas injection system is implemented, then hydrogen concentration is reduced, but device complexity increases

Engineering Contradiction:
Improvehydrogen concentration reductionVSAvoidinert gas injection system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements an inert gas injection system that introduces inert gas (such as nitrogen or argon) into the inner zone to dilute and displace hydrogen. This creates a safer atmosphere by reducing hydrogen concentration below flammable limits, preventing combustion even when hydrogen leaks occur in the inner zone.

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

Solution Approach 2:

The patent changes the compositional parameter of the gas mixture in the inner zone by injecting inert gas. This alters the hydrogen concentration from potentially flammable levels to safe, non-flammable levels, fundamentally changing the safety characteristics of the environment within the double-walled pipeline structure.

Inventive Principle:
Principle #35Parameter changes

4Reliability

If multiple shut-off valves are positioned to isolate sections, then leak containment is improved, but device complexity increases

Engineering Contradiction:
Improveleak containmentVSAvoidmultiple shut-off valves
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the hydrogen supply system into multiple isolated sections, each equipped with shut-off valves at its boundaries. This segmentation allows a leak in one section to be contained without affecting other sections, as the control unit can close the appropriate valves to isolate the affected area while maintaining hydrogen supply to unaffected sections.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts and removes the ability of hydrogen to propagate throughout the entire system by positioning shut-off valves that can close off specific sections. When a leak is detected, the control unit activates these valves to extract the leaking section from the active hydrogen supply network, preventing the leak from spreading to other parts of the system.

Inventive Principle:
Principle #2Taking out (Extraction)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system effectively contains and reduces hydrogen leaks, minimizing the risk of secondary leaks and enhancing aircraft safety by isolating and venting hydrogen to ambient air.

Implementation Method 1

at least one system for injecting an inert gas into the inner zone comprising at least: an inert gas reservoir, an injection conduit connecting the inert gas reservoir and the inner zone

Methodology Applied
Scientific EffectInert gas injection:

Implementation Method 2

a diffuser connected to the inert gas reservoir, positioned within the container and substantially coaxial with the cylindrical tubular body

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 3

at least one ventilation system configured to evacuate a gas present in the inner zone to the outer zone of the secondary structure

Methodology Applied
Scientific EffectGas evacuation:

Implementation Method 4

each hydrogen pipeline includes at least one pressure sensor configured to measure pressure in the inner zone, an increase in pressure in the inner zone corresponding to a probable leak of hydrogen or oxygen

Methodology Applied
Scientific EffectPressure measurement:

Implementation Method 5

a hydrogen sensor configured to detect the presence of hydrogen in the inner zone

Methodology Applied
Scientific EffectHydrogen detection:

Implementation Method 6

a heat exchanger configured to heat the hydrogen as it changes from a liquid to a gaseous state

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 7

a high-pressure pump to pressurize the hydrogen

Methodology Applied
Scientific EffectPressurization: Pressurisation

Data Source

PatentEP4455021B1Aircraft comprising at least one hydrogen supply device provided with at least one gas discharge system in case of a leak
Publication Date: 2025.10.29 AIRBUS OPERATIONS (SAS)
  • EP4455021B1 patent drawingFigure 1~3
  • EP4455021B1 patent drawingFigure 4~5
  • EP4455021B1 patent drawingFigure 6~7

AI summary

The invention relates to an aircraft comprising at least one secondary structure separating an internal zone and an external zone, and at least one hydrogen supply device (26) connecting a hydrogen tank (24) and an engine (20), and including at least one section (42) equipped with shut-off valves (34, 34') for isolation in case of a leak. The section (42) comprises at least one external enclosure, at least one internal element located within the external enclosure and channeling the hydrogen, and at least one internal zone (Zi) located between the internal element and the external enclosure. The hydrogen supply device (26) includes at least one ventilation system (46) configured to vent gases present in the internal zone (Zi) to the external zone of the secondary structure. In case of a leak, the ventilation system (46) vents the hydrogen present in the internal zone (Zi) to reduce its concentration.