Double-Wall Fuel Pipe With Pressure-Responsive Barrier Venting

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Solution Overview

Problem

Aircraft fuel systems, particularly those using liquid hydrogen, face challenges in managing pressure differences between inner and outer regions of double-wall pipes, which can lead to integrity issues and the need for complex venting systems.

Innovation Solution

The introduction of an openable barrier between the inner and outer regions of double-wall pipes, which opens when the pressure in the outer region exceeds that in the inner region, allows for pressure equalization and reduces the risk of pipe integrity loss without requiring external venting systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a double-wall pipe structure is used to maintain pressure differences between inner and outer regions, then thermal insulation performance is improved, but the risk of pipe integrity loss increases due to unmanaged pressure differences

Engineering Contradiction:
Improvethermal insulation performanceVSAvoidpipe integrity
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The barrier is segmented into multiple sections (first barrier section and second barrier section) that can open independently or collectively based on pressure differential, allowing controlled pressure equalization while maintaining thermal insulation during normal operation

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The barrier transitions from a static closed structure to a dynamic openable structure that responds to pressure differential conditions, opening to equalize pressure when needed and closing to maintain thermal insulation when pressure is balanced

Inventive Principle:
Principle #15Dynamics

2Reliability

If complex venting systems are added to manage pressure in the outer region, then pipe integrity is protected, but system weight and complexity increase

Engineering Contradiction:
Improvepipe integrityVSAvoidventing system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The barrier provides self-service pressure management by automatically opening in response to pressure differential without requiring external control systems, sensors, or power sources, thereby protecting pipe integrity while avoiding additional system complexity

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The pressure management function is extracted from a separate complex venting system and integrated directly into the barrier structure itself, eliminating the need for external venting components while maintaining pipe integrity protection

Inventive Principle:
Principle #2Taking out (Extraction)

3Temperature

If the barrier remains closed to maintain pressure differential, then thermal insulation is optimized, but pressure equalization capability is reduced

Engineering Contradiction:
Improvethermal insulationVSAvoidpressure equalization capability
Core Design Contradiction:
TemperatureVSAdaptability or versatility

Solution Approach 1:

The barrier dynamically adjusts its state between closed (for thermal insulation) and open (for pressure equalization) based on real-time pressure differential conditions, providing both thermal optimization and pressure adaptability

Inventive Principle:
Principle #15Dynamics

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

This solution effectively reduces the likelihood of pipe integrity loss and eliminates the need for complex venting systems, thereby reducing weight, cost, and complexity in aircraft fuel systems.

Implementation Method 1

the at least one barrier is configured to open when a pressure in the interspace is higher than a pressure in the inner region

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentEP4497985A1Double-wall pipe for an aircraft fuel system
Publication Date: 2025.01.29 AIRBUS OPERATIONS LTD
  • EP4497985A1 patent drawingFigure 1~2
  • EP4497985A1 patent drawingFigure 3~4C
  • EP4497985A1 patent drawing

AI summary

Disclosed is a double-wall pipe for an aircraft fuel system. The double-wall pipe comprises an inner wall defining a first open end, a second open end, and an inner region connecting the first open end to the second open end and via which a fuel is flowable through the double-wall pipe, in use. The double-wall pipe also comprises an outer wall disposed at least in part around the inner wall to define an interspace, between the inner wall and the outer wall, that is fluidically isolated from the inner region. The double-wall pipe further comprises at least one barrier that is openable to create a passage that fluidically connects the interspace to the inner region. The at least one barrier is configured to open when a pressure in the interspace is higher than a pressure in the inner region.