Thermal Storage With Thermosensitive Polymer Gel for Heating and Cooling

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing heat storage materials have low heat storage density, leading to larger thermal storage tanks and apparatuses, and cannot be used in cooling apparatuses.

Innovation Solution

A heat storage apparatus using a thermosensitive polymer gel with reversible hydrophilic-hydrophobic transition at a lower critical solution temperature, allowing the solvent to remain in a liquid state during transitions, thereby enhancing heat storage density and enabling the apparatus to store cooling energy without increasing size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If inorganic hydrated salt is used as heat storage material, then heat storage density is improved, but corrosion of metal and deleterious properties occur

Engineering Contradiction:
Improveheat storage densityVSAvoidcorrosion and deleterious effects
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by using organic compounds (carboxylic acids, esters, amides, nitriles, or their hydrates) instead of inorganic hydrated salts. This parameter change maintains high heat storage density while eliminating corrosion and deleterious effects, as the organic compounds are chemically compatible with metal components.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite material systems where organic heat storage compounds are combined with appropriate container materials and heat exchange media. This composite approach allows the system to leverage the high heat storage density of organic compounds while using corrosion-resistant materials for structural components, thereby resolving the contradiction between heat storage performance and material compatibility.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If organic heat storage materials like paraffin, fatty acids, or sugar alcohol are used, then corrosion and deleterious effects are eliminated, but heat storage density becomes small

Engineering Contradiction:
Improvecorrosion resistanceVSAvoidheat storage density
Core Design Contradiction:
Object-affected harmful factorsVSQuantity of substance

Solution Approach 1:

The patent optimizes the molecular structure and composition parameters of organic heat storage materials by selecting from specific chemical classes (carboxylic acids, esters, amides, nitriles, or their hydrates) with appropriate molecular weights and functional groups. This parameter optimization increases the heat of fusion and heat storage density while maintaining the inherent corrosion resistance of organic compounds.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes phase transition phenomena (melting and freezing) of the selected organic compounds to achieve high heat storage density. By carefully selecting organic materials with suitable melting points and high heats of fusion, the system captures and releases large amounts of thermal energy during phase changes, thereby increasing heat storage density while maintaining corrosion resistance.

Inventive Principle:
Principle #36Phase transitions

3Quantity of substance

If heat storage materials with low melting point (100°C or less) are used to store low-temperature exhaust heat, then heat storage density is improved, but the materials cannot be used in cooling apparatuses

Engineering Contradiction:
Improveheat storage densityVSAvoidapplicability to cooling apparatuses
Core Design Contradiction:
Quantity of substanceVSAdaptability or versatility

Solution Approach 1:

The patent designs the heat storage system with universal applicability by using organic compounds that can function in both heating and cooling modes. The system can store low-temperature exhaust heat during heating operations and provide cooling during peak demand periods, thereby achieving multi-functionality and increasing adaptability while maintaining high heat storage density through appropriate material selection.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 heat storage apparatus achieves high heat storage density and can be used in cooling apparatuses without enlarging its size, eliminating the need for additional components like condensers or water transfer passages.

Implementation Method 1

the heat storage material makes reversible hydrophilic-hydrophobic transition at a lower critical solution temperature

Methodology Applied
Scientific EffectHydrophilic-hydrophobic transition:

Implementation Method 2

reversible hydrophilic-hydrophobic transition at a lower critical solution temperature

Methodology Applied
Scientific EffectLower critical solution temperature:

Implementation Method 3

heat storage material makes reversible hydrophilic-hydrophobic transition at a lower critical solution temperature

Methodology Applied
Scientific EffectPhase transition: Phase Change

Implementation Method 4

a heat exchanger that causes heat exchange to be performed between a heating fluid and a heat storage material to heat the heat storage material and store heat in the heat storage material

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP4039769B1Thermal storage device
Publication Date: 2025.07.09 MITSUBISHI ELECTRIC CORP
  • EP4039769B1 patent drawingFigure 1~2
  • EP4039769B1 patent drawingFigure 3
  • EP4039769B1 patent drawing

AI summary

A heat storage apparatus includes: a container sealed, with a heat storage material encased in the container, the above material including a thermosensitive polymer gel including a thermosensitive polymer and a solvent selected from the group consisting of water, organic solvents, and compounds of water or organic solvents; and a heat exchanger that is housed in the container to transfer heat between the above material and a heating/cooling fluid to heat or cool the material, and store heating energy or cooling energy in the material, and that transfers heat between the material and a heat utilization fluid to receive heat from the material and to transfer heat from the material. The material makes a reversible hydrophilic-hydrophobic transition at a lower critical solution temperature, and the solvent included in the thermosensitive polymer gel is kept in a liquid state in hydrophilic-hydrophobic transition.