Cryogenic Pipe-in-Pipe Insulation Without Vacuum or Bellows
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Solution Overview
Problem
Current subsea cryogenic pipeline technologies for LNG face challenges with high costs, maintenance issues, and reliability concerns due to the use of expensive alloys like INVAR and expansion bellows, as well as the need for vacuum insulation, which complicates manufacturing and operation.
Innovation Solution
The implementation of a silica aerogel-insulated pipe-in-pipe system with non-metallic or metallic bulkheads and spacers to manage thermal contraction and expansion, using ambient pressure and 9% nickel steel, eliminating the need for expensive alloys and vacuum systems, and incorporating fiber-optic sensors for real-time monitoring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If vacuum insulation is used in cryogenic pipelines, then thermal insulation performance is improved, but device complexity and maintenance cost increase
Solution Approach 1:
The patent applies porous insulation materials (aerogel, foam glass, perlite) filled in the annular space between inner and outer pipes. These materials provide effective thermal insulation at ambient pressure, eliminating the need for vacuum systems while maintaining cryogenic temperature stability and reducing system complexity.
2Stability of the object's composition
If INVAR alloy is used to accommodate thermal contraction, then thermal expansion/contraction is controlled, but manufacturing cost increases
Solution Approach 1:
The patent applies local quality by using ordinary carbon steel for the pipeline body while providing thermal contraction accommodation only where needed through the annular space design and insulation material selection. This avoids the need for expensive INVAR alloy throughout the entire pipeline while still achieving thermal stability.
Solution Approach 2:
The patent employs composite material strategies by combining ordinary steel pipeline with specialized insulation materials (aerogel, foam glass) and concrete weight coating. This composite approach achieves thermal contraction management and mechanical stability without requiring expensive INVAR alloy, reducing manufacturing costs while maintaining performance.
3Stability of the object's composition
If expansion bellows are installed in pipeline segments, then thermal expansion capability is improved, but reliability and durability worsen
Solution Approach 1:
The patent extracts the problematic expansion bellows component from the pipeline system entirely. Instead, it uses the annular space between concentric pipes filled with insulation materials to accommodate thermal expansion and contraction, eliminating the reliability issues associated with bellows while maintaining thermal expansion capability.
4Temperature
If low pressure environment is maintained in pipeline assembly, then thermal insulation is improved, but energy consumption and operation cost increase
Solution Approach 1:
The patent uses porous insulation materials (aerogel, foam glass, perlite) that provide effective thermal insulation at ambient pressure. These materials trap heat through their porous structure without requiring vacuum or low-pressure environments, eliminating energy consumption for pressure maintenance while maintaining excellent thermal insulation performance.
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 reduces pipeline costs, enhances reliability, and minimizes maintenance requirements while maintaining effective thermal insulation and mechanical stability, allowing for efficient long-distance subsea LNG transportation.
Implementation Method 1
The annular space is partially filled with a high efficiency microporous or nanoporous insulating material
Implementation Method 2
The sensor system includes a plurality of sensors distributed along a length of the outer pipeline and in communication with an optical source and detector
Data Source
AI summary
A cryogenic material transfer system incorporates a pipe-in-pipe configuration with a nanoporous or microporous insulating layer filling the annulus between the inner and outer pipe. The insulating layer is of sufficient flexibility to absorb and expansion or contraction of the inner pipe due to the flow of cryogenic material therethrough. For longer transfer systems a bulkhead is provided between adjacent pipe joints. Intermediately of the pipe joints an additional bulkhead may be employed to provide additional sealing or water stops and for providing provide additional load transfer. A fiber optic sensor system is installed in the annuals between the inner and outer pipe.