Membrane Bonding Structure for Octagonal LNG Tank
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Solution Overview
Problem
The existing membrane type LNG storage tanks face difficulties in uniformly connecting membrane sheets over all regions due to the octagonal shape, leading to structural performance deterioration and increased manufacturing costs due to different corrugation intervals on inclined and flat surfaces.
Innovation Solution
A membrane bonding structure with bonding panels on the hypotenuse portions of the storage tank, allowing for the same corrugation interval on inclined surfaces as on flat surfaces, using metallic bonding panels for welding and incorporating connection membranes to absorb thermal stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If membrane sheets are connected on inclined surfaces of an octagonal storage tank, then the tank can maintain its structural shape, but the corrugation intervals become non-uniform leading to structural performance deterioration
Solution Approach 1:
The patent divides the storage tank surface into distinct regions: inclined surfaces and flat surfaces. By segmenting the membrane structure into separate first membranes (for inclined surfaces) and second membranes (for flat surfaces), each can be optimized independently with uniform corrugation intervals within their respective regions, avoiding the need for non-uniform intervals across the entire tank surface.
Solution Approach 2:
The patent applies different membrane configurations to different regions of the tank. The first membranes on inclined surfaces have corrugations perpendicular to the sloshing load direction, while the second membranes on flat surfaces have corrugations in a different orientation. This local differentiation allows each region to maintain uniform corrugation intervals appropriate to its specific geometry and functional requirements.
2Shape
If different corrugation intervals are used on inclined and flat surfaces, then the membrane can adapt to the octagonal shape, but the device complexity and manufacturing costs increase
Solution Approach 1:
The patent segments the membrane system into multiple independent membrane units (first membranes and second membranes) that can be manufactured separately with standard uniform corrugation intervals. This segmentation allows each membrane type to be produced using the same manufacturing process, reducing complexity despite the overall system's geometric complexity.
Solution Approach 2:
The patent uses the same basic membrane design and corrugation pattern for both first and second membranes, differing only in their orientation and placement. This universal approach allows a single membrane manufacturing process and design template to serve multiple locations on the tank, reducing the variety of unique components needed while still adapting to the octagonal shape.
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 solution maintains uniform corrugation intervals, improves structural performance, reduces component complexity, and lowers manufacturing costs by eliminating the need for different types of membranes, while effectively managing thermal stress in cryogenic conditions.
Implementation Method 1
incorporating connection membranes to absorb thermal stress
Implementation Method 2
a primary insulation layer disposed on the secondary sealing layer
Data Source
Figure 1~2
Figure 3
Figure 4~5a
AI summary
Disclosed is a membrane bonding structure for bonding a membrane for forming a sealed wall between first and second surfaces of a storage tank for storing liquefied gas. The membrane bonding structure may comprise: a planar portion panel (20) installed on the first and second surfaces so as to thermally insulate the storage tank; a bonding panel (30) installed on the boundary portion between the first and second surfaces together with the planar portion panel; a first membrane (42) attached to the planar portion panel on the first surface and to the bonding panel so as to seal the storage tank; and a second membrane (44) attached to the planar portion panel on the second surface and to the bonding panel so as to seal the storage tank. The first membrane and the second membrane may be attached to the bonding panel so as to make no direct connection.