Hot Water Storage Tank Cold-Sink Structure for Heat-Loss Reduction

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Solution Overview

Problem

Hot water storage tanks experience significant heat losses due to multiple openings that create heat transport paths from the inside to the outside, particularly in vacuum-insulated tanks where additional openings are not feasible.

Innovation Solution

A hot water storage tank design featuring a cold sink at the bottom around the opening, with a peripheral ring shape to extend the insulation distance, combined with a vacuum insulation unit having an evacuated medium and a side wall around the opening to enhance sealing and reduce heat transfer, along with a heating flange device that integrates connections for the heating element, cold water inlet, hot water return, and temperature sensor through a single opening, eliminating the need for separate passages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple openings are provided in the storage tank for separate connections (heating element, cold water inlet, hot water outlet, temperature sensor), then the functional versatility and ease of installation are improved, but heat losses increase due to multiple heat transport paths from inside to outside

Engineering Contradiction:
Improvefunctional versatilityVSAvoidheat losses
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent combines multiple separate connections (heating element, cold water inlet, hot water outlet, temperature sensor) into a single integrated flange assembly. This merging approach maintains all required functional connections while reducing the number of openings in the vacuum insulation from multiple separate holes to one consolidated opening, thereby minimizing heat transport paths and reducing energy losses.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The flange assembly serves multiple functions simultaneously: it provides structural support, creates a sealed opening for the vacuum insulation, and accommodates all necessary connections (heating element, water inlet/outlet, temperature sensor) through integrated passages. This multi-functionality eliminates the need for separate openings for each connection type.

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

2Loss of energy

If a single opening is used with an integrated flange assembly, then heat losses are reduced by minimizing heat transport paths, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improveheat lossesVSAvoiddevice complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The design segments the flange assembly into modular components that can be manufactured separately and then assembled. The flange body, sealing elements, and connection passages are designed as distinct segments that simplify manufacturing while achieving the complex function of providing multiple connections through a single opening in the vacuum insulation.

Inventive Principle:
Principle #1Segmentation

3Loss of energy

If vacuum insulation is maintained without additional openings, then thermal insulation performance is improved, but the ease of installation and maintenance of heating components is reduced

Engineering Contradiction:
Improvethermal insulation performanceVSAvoidease of installation
Core Design Contradiction:
Loss of energyVSEase of operation

Solution Approach 1:

The flange assembly is pre-designed and pre-assembled with all necessary connections (heating element, water inlet/outlet, temperature sensor) integrated into a single unit before installation. This preliminary preparation allows the entire assembly to be installed through one opening in the vacuum insulation, maintaining thermal performance while simplifying the installation process.

Inventive Principle:
Principle #10Preliminary 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 design significantly reduces heat losses by minimizing heat transfer paths and maintaining vacuum insulation, while allowing for efficient installation and sealing of the heating flange device, ensuring secure sealing and reduced mixing of water layers.

Implementation Method 1

a vacuum insulation unit (16) having an evacuated medium

Methodology Applied
Scientific EffectVacuum insulation: Vacuum

Implementation Method 2

The hot water storage tank has an inner container (10) and an outer container (20) with a cavity (H) into which fine-pored granules are filled. The cavity is evacuated.

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 3

The insulation unit has a cold sink (302) at the bottom, which is arranged around the opening

Methodology Applied
Scientific EffectHeat sink: Heat Sink

Implementation Method 4

A gap is provided between the outer container and the inner container between an outer ring and an inner ring, which reduces heat transfer to the outside.

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP3315872B1Hot water storage tank and heating flange for a hot water storage tank
Publication Date: 2021.03.10 STIEBEL ELTRON GMBH & CO KG
  • EP3315872B1 patent drawingFigure 1
  • EP3315872B1 patent drawingFigure 2a~2b
  • EP3315872B1 patent drawingFigure 3

AI summary

The invention relates to a hot water storage tank (1) with a storage container (3) which has an opening (12) and an insulating unit (2) which surrounds the storage container (3) and has a base (301), the insulating unit ( 2) at the bottom (301) having a cold sink (302, 303, 304, 305, 306, 307) arranged around the opening (12). The invention also relates to a heating flange device (100) for this hot water tank and a hot water tank (1) with a heating flange device (100).