Vacuum-Enclosed Johnston Coupling for Compact Cryogenic Insulation
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Solution Overview
Problem
Existing Johnston couplings for vacuum-insulated cryogenic lines face challenges in thermal insulation and handling due to their length, leading to energy loss and potential fire hazards during the transport of supercooled media like LNG and liquid hydrogen.
Innovation Solution
A plug-in coupling design featuring an annular gap between the inner and outer pipe pieces, surrounded by insulating vacuum, which enhances thermal insulation and allows for a shorter construction, improving handling and space efficiency while maintaining effective sealing and centring mechanisms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the pipe-in-pipe length is increased to improve thermal insulation, then thermal insulation performance is improved, but the coupling length and handling difficulty increase
Solution Approach 1:
The patent introduces an additional vacuum enclosure dimension around the existing pipe-in-pipe structure. Instead of merely extending the length of the single vacuum space, it creates a multi-dimensional insulation approach with concentric vacuum layers, effectively adding thermal insulation capacity without proportionally increasing coupling length
Solution Approach 2:
The patent implements nested vacuum enclosures where an inner vacuum space is contained within an outer vacuum space. This nested structure maximizes thermal insulation within a compact geometry, providing enhanced insulation performance while maintaining a reasonable coupling length
2Loss of energy
If the pipe-in-pipe length is increased to improve thermal insulation, then thermal insulation performance is improved, but handling ease deteriorates
Solution Approach 1:
By adding a radial dimension to the insulation structure through concentric vacuum enclosures, the patent achieves superior thermal insulation without requiring excessive axial length, thereby maintaining manageable coupling dimensions for ease of handling and installation
Solution Approach 2:
The nested vacuum enclosure design provides high insulation performance within a compact form factor, making the coupling easier to handle, transport, and install compared to conventional designs that would require much longer pipe-in-pipe sections to achieve equivalent insulation
3Ease of operation
If the coupling length is reduced to improve handling, then handling ease is improved, but thermal insulation performance deteriorates
Solution Approach 1:
The nested vacuum enclosures create multiple thermal barriers within a short axial distance, enabling the coupling to maintain excellent thermal insulation performance while keeping the overall length reduced for improved handling and installation
4Loss of energy
If additional vacuum enclosures are added to improve thermal insulation, then thermal insulation performance is improved, but device complexity increases
Solution Approach 1:
The nested vacuum enclosure structure, while providing enhanced thermal insulation, follows a systematic concentric design that can be manufactured as integrated components. The inner and outer enclosures are arranged in a predictable geometric pattern that simplifies manufacturing and assembly processes compared to alternative complex insulation designs
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 proposed coupling achieves improved thermal insulation by lengthening the path of heat penetration, allowing for a shorter design that simplifies handling and reduces energy losses, while maintaining effective sealing and centring, thus addressing the limitations of conventional Johnston couplings.
Implementation Method 1
the two double-walled pipelines must be plugged one inside the other over a predetermined length... the outer surface is thermally insulated with respect to the inner media-conducting pipe in a highly effective manner
Implementation Method 2
between the inner and the outer pipe piece of the coupling socket, there is formed an annular gap which is open in the region of the second connecting flange and which is surrounded both at its inner circumference and at its outer circumference by an insulating vacuum
Implementation Method 3
The insulating vacuums which adjoin the inner circumference and outer circumference of the open annular gap improve the thermal insulation of the plug-in coupling. In simple terms, it is achieved by means of the proposed construction that the path that the heat penetrating from the outside into the plug-in coupling must cover before the heat reaches a media-conducting line is lengthened
Data Source
AI summary
A plug-in coupling for connecting a first to a second double-walled, vacuum-insulated cryogenic line includes a coupling plug and a coupling socket. The coupling plug has an inner and an outer pipe piece and a first connecting flange and is connected to the first cryogenic line. The coupling socket has an inner and an outer pipe piece and a second connecting flange and is connected to the second cryogenic line. In an assembled state of the plug-in coupling, the coupling plug has been plugged into an open annular gap in the coupling socket. The annular gap is surrounded both at its inner circumference and at its outer circumference by an insulating vacuum, whereby the thermal insulation of the plug-in coupling is improved. This construction makes possible a shorter design of the plug-in coupling, which, while achieving good thermal insulation, is space-saving and easy to handle.