Nested Tank Cold Storage for Building Energy Reliability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Building supply systems relying on renewable energy sources, such as PVT modules and heat pumps, face challenges in operational reliability during bad weather and high summer temperatures, leading to inefficiencies and increased carbon footprints due to auxiliary heating systems using fossil fuels.

Innovation Solution

A cold storage device comprising a tank-in-tank-in-tank system with multiple refrigerant containers, allowing for increased heat capacity and efficient energy storage and retrieval, which can be integrated into building supply systems to enhance reliability and reduce carbon emissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If PVT module systems are designed with large dimensions to ensure operational reliability during bad weather, then reliability is improved, but efficiency deteriorates due to frequent stagnation

Engineering Contradiction:
Improveoperational reliabilityVSAvoidefficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent implements a tank-in-tank-in-tank configuration where the first storage container (ice storage) is nested within the second storage container (central tank), which is itself nested within the third storage container (outer tank). This nested structure allows the system to store large amounts of ice in a compact footprint, ensuring operational reliability during bad weather without requiring excessively large PVT module dimensions that would cause stagnation.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If auxiliary heating systems using fossil fuels are implemented to cover peak load, then operational reliability is improved, but carbon footprint increases

Engineering Contradiction:
Improveoperational reliabilityVSAvoidcarbon footprint
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The system pre-cools water and stores ice in the first storage container during periods when renewable energy is available (sunny weather, nighttime cooling). This preliminary action creates a thermal buffer that can be drawn upon during peak demand or bad weather periods, eliminating the need for fossil fuel-based auxiliary heating and thereby reducing carbon footprint while maintaining operational reliability.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If electric heating elements are used frequently for peak load coverage, then operational reliability is improved, but operating costs increase due to high power consumption

Engineering Contradiction:
Improveoperational reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system uses the building's own cooling demand to create ice during off-peak hours, essentially serving itself. The ice storage system provides its own heating/cooling needs by melting stored ice during high-demand periods, eliminating or reducing the need for separate electric heating elements and thereby reducing power consumption and operating costs while maintaining operational reliability.

Inventive Principle:
Principle #25Self-service

4Quantity of substance

If conventional ice storage systems are used, then cooling storage is provided, but heat capacity is insufficient for multi-day to semi-seasonal storage

Engineering Contradiction:
Improveice storage capacityVSAvoidstorage duration
Core Design Contradiction:
Quantity of substanceVSDuration of action of stationary object

Solution Approach 1:

The nested tank configuration enables vastly increased heat capacity compared to conventional ice storage. The first storage container stores ice, the second central tank surrounds it with additional refrigerant, and the third outer tank provides further thermal mass. This multi-layer nested structure allows the system to store enough cooling energy for multi-day to semi-seasonal periods, addressing the insufficient heat capacity of conventional systems.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent transitions from two-dimensional conventional ice storage to a three-dimensional nested tank structure. By utilizing vertical and radial space through the tank-in-tank-in-tank configuration, the system dramatically increases storage capacity without proportionally increasing footprint, enabling multi-day to semi-seasonal storage duration.

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

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 cold storage device significantly enhances the operational reliability and energy efficiency of building supply systems by providing multi-day to semi-seasonal ice storage, reducing the need for fossil fuel-based auxiliary heating, and enabling sustainable electricity and heating systems.

Implementation Method 1

at least a first storage container (11) for storing cold energy in the form of ice

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

a second storage container (12) for a second refrigerant (K2), which is arranged around the first storage container (11)... a third storage container (13) for a third refrigerant (K3), which in turn is arranged around the second storage container (12)

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Data Source

PatentEP4560244A1Storage device and use of such a storage device as an energy storage device in a building supply system
Publication Date: 2025.05.28 PVT SOLAR AG
  • EP4560244A1 patent drawingFigure 1
  • EP4560244A1 patent drawingFigure 2
  • EP4560244A1 patent drawingFigure 3

AI summary

The present invention relates to a cold storage device (1) comprising at least: a first storage container (11) for holding a first refrigerant (K1); a second storage container (12) for a second refrigerant (K2), which is arranged around the first storage container (11) and completely holds the first storage container (11), and a third storage container (13) for a third refrigerant (K3), which in turn is arranged around the second storage container (12) and at least partially holds the second storage container (12); and to the use of such a cold storage device (1) as an energy store in a building supply system, comprising at least: a photothermal module (3), a heat pump (2), and a consumer.The cold storage device (1) according to the invention can advantageously serve as a powerful "battery" for sustainably generated energy, increasing the independence and range of such a building supply system. The cold storage device (1) is particularly suitable for converting existing buildings that were previously heated with fossil fuels.