Double-Wall Hydrogen Pipe Connection With Buffer-Space Leak Detection

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Solution Overview

Problem

Existing hydrogen pipelines in aircraft, which transport hydrogen in liquid form at -270°C, face challenges in maintaining a perfect seal and detecting leaks effectively, especially at connection areas between sections, due to insufficient pressure retention mechanisms.

Innovation Solution

The pipeline design includes a connection system with annular seals and a buffer space, utilizing a stop mechanism and spacers to maintain seal integrity and a leak detection system that measures pressure and gas characteristics in the buffer space to detect potential leaks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If grooves are used to immobilize annular seals in the connection system, then seal positioning is simplified, but the seals cannot maintain their position against pressure differences between the buffer space and the ducts

Engineering Contradiction:
Improveseal positioningVSAvoidseal retention
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The connection system employs a composite structure combining grooves for initial seal positioning with additional retention mechanisms (such as retention rings or clamps) that provide mechanical constraint against pressure differential forces. This multi-mechanism approach ensures both ease of installation and reliable seal retention under operating conditions.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The design incorporates pre-compression of the annular seals through the connection system's mechanical structure, creating a cushioning effect that counteracts pressure differential forces before they can cause seal displacement. This pre-applied mechanical constraint ensures seals remain positioned despite pressure variations between the buffer space and connected ducts.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Device complexity

If the connection system uses simple grooves for seal retention, then the structure remains simple, but it fails to prevent seal displacement under pressure differential

Engineering Contradiction:
Improveconnection system structureVSAvoidseal position stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The connection system is segmented into distinct functional zones: grooves for seal positioning, retention mechanisms for seal constraint, and pressure equalization pathways. This segmentation allows each element to perform its specific function optimally while maintaining overall system simplicity through modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Retention rings or clamps act as intermediary elements between the grooves and the pressure differential forces. These intermediaries transfer and distribute the mechanical constraint forces evenly across the seal structure, preventing displacement while adding minimal complexity to the overall connection system.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Length of moving object

If multiple sections are connected end to end to achieve the required hydrogen transport distance, then the pipeline can reach distant turbojets or fuel cells, but leak detection and seal integrity become more difficult to ensure

Engineering Contradiction:
Improvepipeline lengthVSAvoidconnection seal integrity
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

The connection system incorporates pressure sensors and leak detection mechanisms that continuously monitor the buffer space pressure and provide feedback on seal integrity. This real-time monitoring allows for immediate detection of pressure changes that may indicate seal failure or hydrogen leakage, enabling proactive maintenance across the extended pipeline network.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The design includes preliminary leak detection capabilities built into each connection point before the pipeline is fully operational. Pressure sensors and detection systems are pre-installed and calibrated to detect potential seal issues at connection points, allowing for preventive maintenance before actual leaks occur in the extended pipeline system.

Inventive Principle:
Principle #10Preliminary action

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 configuration enhances the safety and reliability of hydrogen pipelines by effectively preventing hydrogen leaks and maintaining seal integrity across the entire length, including connection areas, through precise pressure management and leak detection.

Implementation Method 1

at least one pressure sensor configured to measure the pressure in the intervening space

Methodology Applied
Scientific EffectPressure measurement:

Implementation Method 2

at least one leak detection system configured to determine a characteristic of the first atmosphere

Methodology Applied
Scientific EffectGas detection:

Data Source

PatentEP4155597B1Hydrogen pipe with double wall comprising at least one system for detecting leaks in at least one connection system, aircraft comprising at least one such pipe
Publication Date: 2024.11.06 AIRBUS OPERATIONS (SAS)
  • EP4155597B1 patent drawingFigure 1~4
  • EP4155597B1 patent drawingFigure 5~7

AI summary

The invention relates to a pipeline comprising: - at least first and second sections (16.1, 16.2), each having external and internal conduits (26, 28), - at least one connection system (22) linking the first and second sections (16.1, 16.2) and comprising: ∘ at least one downstream ring (42) connected to at least one of the external and internal conduits (26, 28) of the first section (16.1), ∘ at least one upstream ring (40) connected to at least one of the external and internal conduits (26, 28) of the second section (16.2), ∘ connecting elements linking the upstream and downstream rings (40, 42), ∘ first and second annular joints, interposed between the upstream and downstream rings (40, 42), configured to delimit, with the upstream and downstream rings (40, 42), a buffer space containing a atmosphere, the pipeline including at least one leak detection system configured to determine at least one characteristic of the atmosphere of the buffer space.