Bridging Elements for LNG Tank Insulation Stress
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Solution Overview
Problem
Existing thermally insulating tanks for liquefied natural gas storage experience mechanical stress on secondary sealing membranes due to thermal and mechanical stresses, leading to inefficient insulation and potential leakage, as the spacing of insulating panels causes friction and uneven stress distribution.
Innovation Solution
A sealed and thermally insulating tank design featuring a secondary sealing membrane with corrugated metal sheets welded to each other and bridging elements that connect adjacent insulating panels, preventing mutual spacing and reducing stress on the secondary sealing membrane.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the insulating panels of the secondary thermal insulation barrier are spaced apart to accommodate thermal and mechanical stresses, then the tank can withstand thermal contraction and hull deformation, but the secondary sealing membrane experiences significant mechanical stress and friction against the insulating panels
Solution Approach 1:
A bridging element is introduced as an intermediary component between the insulating panels and the secondary sealing membrane. The bridging element has a first portion that contacts the insulating panels and a second portion that contacts the secondary sealing membrane, distributing the mechanical stresses and preventing direct friction between the sealing membrane and the moving insulating panels.
Solution Approach 2:
The connection system is segmented into distinct functional portions: the bridging element is divided into a first portion for contacting insulating panels and a second portion for contacting the secondary sealing membrane. This segmentation allows each portion to be optimized for its specific function and reduces stress concentration on the sealing membrane.
2Stability of the object's composition
If the secondary sealing membrane is welded to metal plates fixed to the insulating panels, then the sealing membrane is anchored to the thermal barrier, but the spacing of insulating panels generates friction and uneven stress distribution on the sealing membrane
Solution Approach 1:
The bridging element is designed with flexibility to deform under thermal and mechanical stresses. This dynamic capability allows the bridging element to accommodate panel movement and stress variations while maintaining continuous support for the secondary sealing membrane, ensuring both anchoring stability and uniform stress distribution.
3Adaptability or versatility
If the insulating panels are allowed to move apart during thermal contraction, then the tank accommodates thermal stress, but the secondary sealing membrane experiences friction and mechanical stress
Solution Approach 1:
The bridging element serves as a mediator that decouples the movement of insulating panels from the secondary sealing membrane. It allows the panels to move during thermal contraction while maintaining continuous support for the sealing membrane, eliminating direct friction between the panels and the membrane.
Data Source
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AI summary
The invention concerns a sealed and thermally insulating vessel for storing a fluid, comprising a secondary thermal insulation barrier (1) and a secondary sealing membrane (4); the secondary sealing membrane (4) comprising a plurality of corrugated metal sheets (24) sealingly welded to each other and each comprising at least two perpendicular corrugations (25, 26); the secondary thermal insulation barrier (1) comprising a plurality of juxtaposed insulating panels (2), each insulating panel (2) having an inner face (10), opposite the bearing wall, (10) provided with metal plates (17, 18) to which the corrugated metal sheets (24) are welded; each insulating panel (2) being associated with the adjacent insulating panels (2) via a plurality of bridging elements (22).