LNG Tank Coupler for Thermal Insulation Integrity

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing tank designs for liquefied natural gas (LNG) transport face issues with deformation due to liquid oscillations and difficulties in welding secondary sealing barriers, primarily because of protruding corrugations on primary sealing barriers, which affect the integrity and efficiency of the thermal insulation and sealing.

Innovation Solution

The design features a secondary thermal insulation with juxtaposed blocks and secondary metal plates with corrugations that are housed in grooves, and primary metal plates with offset edges, using mechanical coupling members to maintain the blocks and plates, allowing for better elasticity and easier welding, while also incorporating a coupler system for secure attachment to the ship's hull.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If protruding corrugations are used on the primary sealing barrier, then the sealing barrier can be formed with undulations, but the sheet can deform under liquid oscillations and welding positioning becomes difficult

Engineering Contradiction:

Improvesealing integrityVSAvoidresistance to liquid oscillation deformation

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent inverts the conventional design by placing re-entrant corrugations on the primary sealing barrier instead of protruding corrugations. The re-entrant corrugations face the outside of the tank rather than the inside, allowing the corrugations to be housed in grooves of the primary insulation blocks. This inversion eliminates deformation under liquid oscillations while maintaining sealing integrity.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent introduces grooves in the primary insulation blocks as intermediary structures to house the corrugations of the primary sealing barrier. This intermediary groove structure provides a stable positioning mechanism that prevents deformation while maintaining the sealing function, resolving the conflict between sealing integrity and resistance to deformation.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If protruding corrugations are used on the primary sealing barrier, then the sealing barrier structure is simplified, but welding device positioning becomes difficult

Engineering Contradiction:

Improvesealing barrier structureVSAvoidwelding positioning

Core Design Contradiction:

Device complexityVSEase of manufacture

Solution Approach 1:

The grooves in the primary insulation blocks serve as intermediary structures that provide precise positioning for the welding devices. By housing the corrugations within these grooves, the welding devices can be accurately positioned on the flat surfaces of the insulation blocks, eliminating the positioning difficulties caused by protruding corrugations while maintaining structural simplicity.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Ease of manufacture

If re-entrant corrugations are used on the primary sealing barrier, then welding becomes easier, but the secondary sealing barrier requires Triplex composite sheet losing elasticity

Engineering Contradiction:

Improvewelding easeVSAvoidelasticity of secondary sealing barrier

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent applies the inversion principle to both primary and secondary sealing barriers by using re-entrant corrugations on both barriers instead of protruding corrugations. This allows both barriers to be made with standard corrugated sheets that maintain their elasticity, while still providing easy welding conditions. The secondary barrier no longer requires Triplex composite sheet because the re-entrant corrugation design eliminates the need for additional composite construction.

Inventive Principle:

Principle #13The other way round (Inversion)

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 tank's mechanical strength, reduces stress concentrations, simplifies welding, and maintains thermal insulation integrity by utilizing the elasticity of corrugated metal plates, ensuring a watertight and thermally efficient LNG tank.

Implementation Method 1

utilizing the elasticity of corrugated metal plates

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

thermally insulating layer covered with metal sheets

Methodology Applied

Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP2729729B1Thermally-insulating sealed tank

Publication Date: 2016.03.23 GAZTRANSPORT & TECHNIGAZ SA

Figure 1~1A
Figure 2~3
Figure 4~7

AI summary

The invention comprises a coupler for maintaining an element (1) in position in relation to a retaining structure (3), said element being subjected to detachment forces. The coupler comprises: a foot (15) including an outer casing (15a) containing an insulating plug (15d) and a resilient means (15b) which pushes the plug against the retaining structure; a head (16) including an outer casing (19) containing an insulating bushing (20) and a sleeve (21) which has two internally threaded ends and receives an end fitting (24) provided with a collar (24a) that bears on a plate (25) borne by the element, said casing being solidly connected to a platen (18) that is mechanically linked to the element (1); and a rod (14) threaded at both ends and screwed at one end into the bushing (20) of the head and at the other end into a nut (15c) of the foot.