PCM Pellet Encapsulation via Flexible Permeable Coating
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The expansion of phase change materials (PCMs) and air within their pores during thermal cycles poses a significant challenge for encapsulation, leading to pressure buildup and potential rupture of the encapsulation capsule, which is not effectively addressed by existing technologies.
Innovation Solution
A method involving coating PCM pellets with a flexible, selectively permeable material to allow air diffusion while preventing molten PCM passage, followed by heating to create an internal void and subsequent metal coating to form a rigid capsule, thereby managing expansion and reducing manufacturing complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If PCM is encapsulated in a rigid capsule, then structural strength is improved, but pressure buildup from expansion during thermal cycles causes capsule rupture
Solution Approach 1:
The patent applies a flexible polymer coating layer around the PCM pellet that can expand and contract during thermal cycles. This flexible shell allows the PCM to expand when heated and contract when cooled without generating excessive pressure that would rupture a rigid capsule, while still providing containment and structural support.
Solution Approach 2:
The patent creates an internal void space within the PCM pellet before encapsulation. This pre-formed void acts as a cushion that accommodates the expansion of PCM during heating, preventing pressure buildup that would otherwise lead to capsule rupture. The void is created by removing material or introducing a compressible substance during the pellet formation process.
2Use of energy by moving object
If PCM is encapsulated with air-tight sealing, then thermal energy storage efficiency is improved, but expansion of trapped air during heating causes pressure buildup and potential rupture
Solution Approach 1:
The patent employs a porous polymer coating material that allows air and other gases to diffuse through its structure. This porous structure enables the egress of expanding air during heating while maintaining the encapsulation's ability to retain thermal energy, thus resolving the contradiction between airtight sealing and air expansion management.
3Reliability
If complex encapsulation processes are used to prevent rupture, then capsule reliability is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent performs preliminary actions during the pellet formation process, including creating the internal void space and applying the flexible polymer coating in a single integrated step. This preliminary preparation of the PCM pellet with built-in expansion accommodation features simplifies the subsequent encapsulation process and reduces manufacturing complexity while maintaining capsule reliability.
Solution Approach 2:
The patent uses composite material structures, combining the PCM core with a flexible polymer coating layer and incorporating internal void spaces. This composite approach achieves reliable rupture resistance through the synergistic combination of materials and structural features, rather than requiring complex multi-step processes or additional components.
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 approach effectively encapsulates PCMs, reducing the risk of capsule rupture and simplifying the manufacturing process, enabling cost-effective thermal energy storage solutions for solar and industrial applications.
Implementation Method 1
air contained within the pores of the solid pellet diffuses out through the pores of the flexible material
Implementation Method 2
The PCM expands as it is heated as does the flexible material
Implementation Method 3
As the molten PCM cools it solidifies from the outside-in so that the pellet maintains much of its increased size
Implementation Method 4
air that was dissolved in the molten PCM migrates from the solidifying PCM to the remaining molten PCM in the center of the pellet
Data Source
AI summary
In one embodiment, a phase change material is encapsulated by forming a phase change material pellet, coating the pellet with flexible material, heating the coated pellet to melt the phase change material, wherein the phase change materials expands and air within the pellet diffuses out through the flexible material, and cooling the coated pellet to solidify the phase change material.