Self-Closing Cryogenic Coupling With Vacuum-Insulated Sealing

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Solution Overview

Problem

Coupling devices for cryogenic fluids, particularly liquid hydrogen, face challenges such as air trapping in dead volumes, inefficiency, and inadequate thermal insulation, which can lead to safety issues and inefficient transfer.

Innovation Solution

A detachable, self-closing coupling device with a sealing ring and valve mechanisms that transition from a closed to an open configuration through relative longitudinal movement, ensuring sealing and thermal insulation via a vacuum space and multilayer thermal insulation, minimizing dead volumes and allowing safe and efficient fluid transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a detachable coupling device is used for cryogenic fluid transfer, then ease of operation is improved, but air trapping in dead volumes occurs causing safety issues

Engineering Contradiction:
Improveease of couplingVSAvoidair trapping
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The valve mechanisms are designed to automatically close when the coupling ends are separated, performing the sealing action in advance before separation occurs. This preliminary closing action prevents air from entering the dead volumes during the coupling and decoupling operations, eliminating the air trapping hazard while maintaining ease of operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention extracts and eliminates the dead volume problem by designing a coupling mechanism where the valve seats are positioned such that no trapped volume remains between the valve mechanisms when coupled. The sealing surfaces are configured to meet flush, removing the harmful dead space where air could be trapped.

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of manufacture

If conventional fittings are used for liquefied natural gas applications, then ease of manufacture is improved, but thermal insulation is inadequate for hydrogen

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidthermal insulation
Core Design Contradiction:
Ease of manufactureVSTemperature

Solution Approach 1:

The coupling device employs a nested structure where an inner tube is positioned within an outer tube, creating a vacuum space between them for thermal insulation. This nested configuration allows the simple, easy-to-manufacture tubular structure to simultaneously provide the required thermal insulation performance for hydrogen applications.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The vacuum space between the inner and outer tubes creates an inert environment that provides thermal insulation. This vacuum barrier prevents heat transfer, maintaining the cryogenic temperatures required for hydrogen storage and transfer while keeping the overall structure simple and manufacturable.

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

3Ease of operation

If valve mechanisms are positioned at the ends of transport lines, then ease of operation is improved, but dead volumes are created causing air trapping

Engineering Contradiction:
Improvevalve accessibilityVSAvoiddead volume
Core Design Contradiction:
Ease of operationVSVolume of stationary object

Solution Approach 1:

The valve mechanisms are designed to close automatically as the coupling ends approach each other during the coupling process. This preliminary closing action occurs before the coupling is fully completed, ensuring that no air can enter the valve areas and eliminating dead volumes while maintaining easy valve operation when needed.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention merges the valve mechanisms with the coupling ends themselves, integrating the sealing and valve functions into a single unified structure. This integration eliminates separate dead volumes by making the valve seating surfaces part of the coupling interface, reducing the overall volume where air could be trapped.

Inventive Principle:
Principle #5Merging (Combining)

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 device provides a safe, efficient, and thermally insulated connection for cryogenic fluids by minimizing air trapping and ensuring reliable sealing and fluid communication, facilitating easy connection and disconnection while maintaining thermal efficiency.

Implementation Method 1

an outer tube (10, 11) arranged around each transport pipe (2, 3) and defining a vacuum space for thermal insulation of the transport pipe

Methodology Applied
Scientific EffectVacuum insulation: Vacuum

Implementation Method 2

defining a vacuum space for thermal insulation of the transport pipe

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP4180704B1Coupling device and method
Publication Date: 2024.04.17 LAIR LIQUIDE SA POUR LETUDE & LEXPLOITATION DES PROCEDES GEORGES CLAUDE
  • EP4180704B1 patent drawingFigure 1~3
  • EP4180704B1 patent drawingFigure 4~6

AI summary

Detachable self-closing coupling device for fluid transport comprising two fluid transport lines (2, 3) extending in a longitudinal direction and each comprising, at a connecting end, a valve mechanism (4, 6, 8, 5, 7, 9) the device (1) further comprising an external tube (10, 11) disposed around each transport line (2, 3), in the coupled position the two connecting ends are configured to be movable relatively longitudinally between a first configuration in which the valve mechanisms are closed and a second configuration in which the valve mechanisms are open the transition from the first configuration to the second configuration being effected by a relative longitudinal approach of the two valve mechanisms (4, 6, 8, 5, 7, 9),The connecting end of a first (3) of the two pipes comprises a sealing ring (12) integral with the outer tube (11), and comprising a set of sealing gasket(s) (14, 15) configured to ensure sealing against the outside, the sealing ring (12) being movable in translation along the longitudinal direction relative to the outer tube (11) between two distinct positions during the transition from the first configuration to the second configuration.