Snow-Layer Thermal Storage for Continuous Cold Energy Accumulation

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Solution Overview

Problem

Existing power-to-cold energy storage systems face inefficiencies due to cyclic ice generation and removal processes, which lead to thermal losses and wear, and are limited by low volumetric refrigeration capacity and the need for large turbo compressors.

Innovation Solution

A temporary energy storage system that uses a thermal storage tank with a chiller and a snow generator to create snow particles in a cooled airstream, which settle on water to form a snow layer, allowing for efficient storage of latent heat in a spatially disconnected manner.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If ice is generated on heat exchanger surfaces, then energy storage is achieved, but thermal losses increase and wear occurs due to cyclic generation and removal

Engineering Contradiction:
Improveenergy storage capacityVSAvoidthermal losses
Core Design Contradiction:
Quantity of substanceVSLoss of energy

Solution Approach 1:

The invention extracts the harmful cyclic ice removal process from the system by directly generating ice slurry in the storage tank without forming ice layers on heat exchanger surfaces. The ice is generated in-situ where it is needed, eliminating the need for periodic removal and associated thermal losses.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces an intermediary mechanism (direct ice generation in storage tank) between the cooling system and energy storage, allowing ice to be formed directly in the storage medium without adhering to heat exchanger surfaces, thus preventing thermal loss cycles.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Quantity of substance

If ice layers are removed from heat exchangers, then ice slurry is formed, but additional mechanical energy is required

Engineering Contradiction:
Improveice slurry formationVSAvoidmechanical energy consumption
Core Design Contradiction:
Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The invention removes the need for mechanical ice removal processes by directly generating ice slurry in the storage tank. No mechanical energy is required for ice layer removal since ice is formed directly in the desired location and form.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system performs self-service by automatically generating ice slurry in the storage tank through direct cooling, eliminating the need for external mechanical intervention to create the ice slurry mixture.

Inventive Principle:
Principle #25Self-service

3Quantity of substance

If ice generation is performed cyclically, then energy storage is achieved, but refrigeration capacity fluctuates

Engineering Contradiction:
Improveenergy storageVSAvoidrefrigeration capacity stability
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The invention enables continuous ice slurry generation in the storage tank rather than cyclic operation. The cooling system continuously produces and stores ice slurry, maintaining stable refrigeration capacity without the fluctuations inherent in cyclic generation and removal processes.

Inventive Principle:
Principle #20Continuity of useful action

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 system operates at constant refrigeration capacity, reduces thermal losses, and increases storage density, enabling scalable energy storage in the MW range while maintaining simplicity and robustness.

Implementation Method 1

a chiller (16) comprising a heat exchanger configured for generating cooled air in the thermal storage tank (12)

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

generating snow particles suspended in the cooled air... by injecting water into the stream of cooled air

Methodology Applied
Scientific EffectFreezing: Freezing

Implementation Method 3

such that the snow particles settle on the water stored in the thermal storage tank (12) for forming a snow layer on the water

Methodology Applied
Scientific EffectSedimentation: Sedimentation

Implementation Method 4

storing power through the refrigeration of carrier liquids can be efficient and compact, such as by converting water to ice and temporarily storing the resulting ice or ice-water slurry with high energy density due to the high latent heat of ice

Methodology Applied
Scientific EffectLatent heat storage: Latent Heat

Data Source

PatentEP3967955B1Temporary energy storage system for cold energy
Publication Date: 2025.02.19 HOCHSCHULE FUR ANGEWANDTE WISSENSCHAFTEN MUNCHEN
  • EP3967955B1 patent drawingFigure 1
  • EP3967955B1 patent drawingFigure 2
  • EP3967955B1 patent drawingFigure 3

AI summary

A temporary energy storage system (10), the system (10) comprising a thermal storage tank (12) for storing water (14); a chiller (16) for generating cooled air (18) in the thermal storage tank (12); and a snow generator (22) for generating snow particles (24) suspended in the cooled air (18), such that the snow particles (24) settle on the water (14) stored in the thermal storage tank (12) for forming a snow layer (26) on the water (14).