Graphite PCM Panel Orifices for High-Load Thermal Storage

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Solution Overview

Problem

Existing thermal energy storage methods, such as sensible heat storage in water and thermochemical storage, are limited by pressure constraints and require controlled pressure vessels, while latent thermal energy storage in compressed expanded graphite matrices are inefficient due to suboptimal impregnation of phase-change materials.

Innovation Solution

An expanded and compressed graphite panel (GNE panel) with impregnation orifices perpendicular to its compression plane facilitates the impregnation of phase-change material, reducing delamination and leakage, and is integrated into a heat storage and exchange device with retaining plates and rods for enhanced thermal conductivity and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the GNE panel is impregnated with phase-change material through conventional methods, then thermal energy storage capacity is improved, but the amount of phase-change material that can be impregnated is limited

Engineering Contradiction:
Improveamount of phase-change materialVSAvoidimpregnation efficiency
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The GNE panel utilizes its inherently porous structure created during the expansion and compression process to enable effective impregnation with phase-change material. The porosity allows the liquid phase-change material to penetrate deeply into the graphite matrix, significantly increasing the impregnation capacity compared to conventional non-porous materials.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The GNE panel is pre-formed with a specific porous structure through expansion and compression before the impregnation process. This preliminary structuring creates optimal pathways and surface area for subsequent phase-change material impregnation, ensuring maximum absorption capacity is achieved before the actual thermal storage operation begins.

Inventive Principle:
Principle #10Preliminary action

2Quantity of substance

If the GNE panel is impregnated with phase-change material, then thermal energy storage capacity is improved, but leakage of phase-change material occurs during operation

Engineering Contradiction:
Improveamount of phase-change materialVSAvoidleakage prevention
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The GNE panel's compressed graphite structure acts as a flexible confining matrix that holds the impregnated phase-change material securely. The compressed structure provides mechanical containment while allowing thermal energy exchange, preventing leakage during operational thermal cycles without requiring additional rigid containment vessels.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The GNE panel creates a composite structure where the graphite matrix and phase-change material work together as an integrated system. The graphite provides structural integrity and thermal conductivity, while the impregnated phase-change material provides thermal energy storage, forming a unified composite that prevents separation and leakage.

Inventive Principle:
Principle #40Composite materials

3Quantity of substance

If the GNE panel is impregnated with phase-change material, then thermal energy storage capacity is improved, but delamination of the GNE panel occurs

Engineering Contradiction:
Improveamount of phase-change materialVSAvoidstructural integrity
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The porous structure of the GNE panel is designed to accommodate the phase-change material within its internal voids rather than on external surfaces. This internal impregnation approach prevents surface-level delamination by distributing the phase-change material throughout the bulk structure, maintaining external structural integrity.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The phase-change material is nested within the porous structure of the GNE panel, with the graphite matrix forming an outer shell that contains the inner phase-change material. This nested configuration ensures the phase-change material remains confined within the stable graphite structure, preventing delamination during thermal cycling.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 GNE panel effectively stores and exchanges thermal energy by allowing high impregnation of phase-change material, improving thermal conductivity and reducing leakage, while maintaining structural integrity and efficiency in thermal energy transfer.

Implementation Method 1

The GNE panel being impregnated with a phase change material... during a liquid phase impregnation of the phase change material

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

The storage of latent thermal energy within a heat storage material is also known... The phase transition of the heat storage material can occur through a change between solid-solid, liquid-liquid, or solid-liquid states

Methodology Applied
Scientific EffectLatent heat storage: Latent Heat

Implementation Method 3

the impregnation holes facilitate the evacuation of gases and the entry of the phase change material in liquid phase during impregnation

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 4

a first flat heat exchanger having a first heat exchange surface in contact with a first main surface of the GNE panel

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP4682219A1Compressed expanded graphite panel for storing thermal energy and thermal exchange storage device comprising such a panel
Publication Date: 2026.01.21 INSULA FRANCE
  • EP4682219A1 patent drawingFigure 1~3a
  • EP4682219A1 patent drawingFigure 3b~5
  • EP4682219A1 patent drawingFigure 6~7

AI summary

One aspect of the invention relates to an expanded and compressed graphite panel 1, referred to as the GNE panel, for thermal energy storage, the GNE panel 1 being impregnated with a phase-change material, the GNE panel 1 being notable in that it comprises a plurality of impregnation orifices 2 for the entry of the phase-change material during a liquid-phase impregnation of the phase-change material, each impregnation orifice 2 having a longitudinal axis X perpendicular to a compression plane P of the GNE panel 1.