Long-term heat storage device and method for long-term heat storage of solar energy and other types of energy with changing availability

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Solution Overview

Problem

Current long-term heat storage systems for solar and fluctuating energy sources face challenges in maintaining energy continuity due to high heat losses, limited temperature range, and high production costs, making them unsuitable for reliable 24/7 energy supply.

Innovation Solution

A long-term heat storage system utilizing a thermally insulated fixed bed of rock fill made from volcanic materials like basalt, diabase, granite, and gneiss, with a micronized powder insulation to minimize heat losses and optimize storage capacity, allowing temperatures up to 1000°C and efficient energy transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional insulation materials (mineral wool) are used in long-term heat storage systems, then the system structure is simple and easy to manufacture, but heat losses are high and storage duration is limited

Engineering Contradiction:
Improveheat lossesVSAvoidinsulation structure complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent applies composite insulation structure combining multiple materials: a reflective insulation layer (aluminum foil), a vacuum layer, and a outer protective layer. This composite approach reduces heat losses through reflection and vacuum insulation while maintaining structural integrity for long-term storage

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent employs porous insulation materials with specific pore structures to trap air and reduce thermal conduction. The porous structure creates multiple interfaces that scatter heat transfer paths, significantly reducing heat losses while maintaining material stability at high temperatures

Inventive Principle:
Principle #31Porous materials

2Quantity of substance

If heat storage temperature is increased to improve exergy and storage capacity, then energy density increases, but heat losses increase and material stability becomes challenging

Engineering Contradiction:
Improvestorage capacityVSAvoidheat losses
Core Design Contradiction:
Quantity of substanceVSLoss of energy

Solution Approach 1:

The patent optimizes the temperature range parameters for heat storage, operating within 200-950°C to balance storage capacity and heat losses. The system adjusts operational parameters dynamically to maintain optimal temperature differentials that maximize exergy while minimizing thermal losses to the environment

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent transitions from conventional low-temperature storage to high-temperature storage regime, fundamentally changing the thermal dimension of operation. This dimensional shift in temperature range enables significantly higher storage capacities and exergy values, transforming the system's energy density characteristics

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Reliability

If solar energy concentration is increased to achieve high temperatures, then exergy and exergetic efficiency improve, but system complexity and cost increase

Engineering Contradiction:
Improveenergy continuityVSAvoidconcentration system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces a heat transfer medium as an intermediary between the solar concentrator and the heat storage mass. This mediator efficiently transfers concentrated solar energy to the storage system, decoupling the concentration mechanism from the storage mechanism and simplifying overall system design while maintaining high exergy

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent extracts and separates the heat storage function from the solar concentration function, allowing independent optimization of each subsystem. The heat storage system can operate independently once charged, providing reliability even when solar input fluctuates, while the concentration system can be simplified to only perform its primary function

Inventive Principle:
Principle #2Taking out (Extraction)

4Duration of action of stationary object

If storage duration is extended to cover winter months, then energy continuity is improved, but heat losses accumulate and insulation requirements increase

Engineering Contradiction:
Improvestorage durationVSAvoidcumulative heat losses
Core Design Contradiction:
Duration of action of stationary objectVSLoss of energy

Solution Approach 1:

The patent implements preliminary charging of the heat storage system during summer months when solar energy is abundant, storing thermal energy in advance for winter consumption. This preliminary action allows the system to be self-sufficient during winter without active input, extending storage duration while minimizing cumulative losses through optimized insulation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs enhanced insulation layers and thermal protection measures beforehand to cushion against heat losses during extended storage. The insulation system is designed to maintain thermal integrity over months, preventing cumulative losses from compromising stored energy before winter consumption

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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 system achieves low heat losses over extended periods, enabling efficient storage and retrieval of thermal energy for continuous energy supply, reducing costs and enhancing energy reliability.

Implementation Method 1

The long-term heat storage system comprises a heat storage mass with an insulating layer surrounding it... The new type of insulation is designed to ensure long-term storage of thermal energy in a particularly cost-effective manner, while keeping heat losses to a minimum.

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

The energy collected from the sun or other energy sources with fluctuating availability is stored in a long-term thermal storage system... The new concept requires the efficient transfer of solar energy or other energy sources with fluctuating availability to a heat transfer medium. The thermal energy is then transported to the long-term thermal storage system and the thermal storage mass.

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP2847442B1Long-term heat storage device and method for long-term heat storage of solar energy and other types of energy with changing availability
Publication Date: 2019.07.10 IPROCONSULT GMBH
  • EP2847442B1 patent drawingFigure 1
  • EP2847442B1 patent drawingFigure 1A
  • EP2847442B1 patent drawingFigure 1B

AI summary

The invention relates to a long-term heat storage device for long-term storage of solar energy and other types of energy, in the heat storage material of which a rock bulk material (1), in particular of volcanic origin, such as diabase, basalt, granite and gneiss, is used. The rock bulk material preferably forms a polydisperse bulk material, in particular as the void volume of the rock bulk material (granulate) having a first particle size or particle size distribution takes up a granulate having a second particle size or particle size distribution. The rock bulk material (1) can be enclosed, preferably all around or predominantly, by a bulk powder fill (5, 16), in particular an ash fill, in particular with a shell of shaped rocks (2, 6, 17) interposed. The rock bulk material (1) can be enclosed, all around or predominantly, at least laterally, by a shell of shaped rocks (2, 6, 17) which is in particular cylindrical, in particular by a masonry wall (2).