Insulated Medium Pipe Foam Using HFO Cell Gas and Vapor Barriers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing thermally insulated pipe systems face issues with gas diffusion leading to increased thermal conductivity and potential damage due to water vapor accumulation, particularly in plastic medium pipes, where traditional barrier layers either suppress gas exchange completely or fail to provide adequate insulation.
Innovation Solution
Incorporating hydrofluoroolefins (HFOs) as cell gases in the thermal insulation foam, combined with selective polymer barrier layers, to reduce thermal conductivity and prevent water vapor diffusion while maintaining mechanical stability and producibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional barrier layers (metallic or polymer) are used to prevent gas diffusion, then gas exchange is suppressed, but water vapor diffusion is completely prevented causing water accumulation in thermal insulation
Solution Approach 1:
The patent applies different barrier properties to different regions of the system. The inner barrier layer uses polymer materials (EVOH, PA, PVDC) that are selectively permeable - they block gas diffusion (N2, O2, CO2) while allowing water vapor transmission. This local differentiation of barrier properties resolves the contradiction by preventing gas exchange without trapping water vapor.
Solution Approach 2:
The patent employs composite barrier structures combining multiple polymer layers with different permeation characteristics. The multilayer construction integrates materials like EVOH/PE, PA/PE, or PVDC/PE, where each layer contributes specific barrier properties. This composite approach achieves selective permeability - blocking gas while permitting water vapor transmission.
2Loss of energy
If metallic barrier layers are used to suppress gas exchange, then gas diffusion is completely prevented, but water vapor diffusion is also completely prevented
Solution Approach 1:
The patent changes the material parameter from metallic to polymer-based barrier layers. Polymer materials have different permeation characteristics compared to metals - they provide adequate gas barrier properties while maintaining water vapor transmission capability. This parameter change resolves the contradiction by achieving thermal insulation without water trapping.
3Reliability
If polymer barrier layers (EVOH, PA, PVDC) are used instead of metallic layers, then gas diffusion is reduced, but production complexity increases
Solution Approach 1:
The patent makes the polymer barrier layers multi-functional by selecting materials that simultaneously provide gas barrier properties and water vapor transmission. The same polymer layer (e.g., EVOH/PE, PA/PE, PVDC/PE) performs both functions, eliminating the need for separate gas barrier and vapor transmission layers, thus reducing overall system complexity.
Solution Approach 2:
The patent merges the gas barrier function and water vapor transmission function into a single integrated polymer barrier layer structure. Instead of using separate metallic gas barrier layers and porous vapor transmission layers, the polymer multilayer construction combines both functions in one system, simplifying the overall structure.
4Loss of energy
If known polymer barrier layer pipes are used, then gas diffusion is reduced, but insulation capability becomes inadequate
Solution Approach 1:
The patent uses thin film polymer barrier layers (EVOH, PA, PVDC) that provide effective gas barrier properties without adding significant thickness. These flexible thin film barriers maintain the thermal insulation capability while achieving adequate gas diffusion reduction, resolving the contradiction between insulation performance and gas barrier reliability.
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 use of HFOs in the cell gases of thermally insulated conduit pipes improves insulation properties, reduces combustibility, and prevents bubble formation, leading to enhanced mechanical stability and cost-effective production with improved safety and reduced investment costs.
Implementation Method 1
a first thermal insulation (3) arranged around the inner pipe (4)
Implementation Method 2
a barrier layer (9) arranged between the outer pipe (2) and the first thermal insulation (3)
Data Source
AI summary
The invention relates to a thermally insulated conduit pipe, comprising at least one medium pipe, at least one thermal insulation arranged around the medium pipe, and at least one outer jacket arranged around the thermal insulation, wherein the outer jacket possibly comprises a barrier made of plastic, and wherein the thermal insulation comprises a foam, the cell gas of which contains at least 10 vol % HFOs. Such conduit pipe has good insulating behavior, good environmental balance, and is easily producible.