Needle-Shaped Temperature Sensor Retrofit Through Thermal Insulation

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Solution Overview

Problem

Existing thermal storage systems often lack the ability to easily retrofit additional temperature sensors without dismantling thermal insulation, which is impractical due to the complex installation process and potential for varying measurement quality.

Innovation Solution

A method and temperature sensor design allowing for the direct insertion of needle-shaped sensors through thermal insulation, establishing a thermally conductive connection with the metal container surface, verified by electrical resistance measurement, and using a conductive adhesive for secure fixation and calibration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If temperature sensors are retrofitted by integrating guide tubes into thermal insulation, then temperature measurement capability is improved, but device complexity and installation difficulty increase significantly

Engineering Contradiction:
Improvetemperature measurement capabilityVSAvoidinstallation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts the temperature sensor directly from the insulation layer by inserting it through the insulation material without requiring guide tubes or complex mounting structures. The sensor is positioned to contact the container wall directly, simplifying the retrofit process while maintaining measurement capability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses thermal adhesive as an intermediary substance to bond the temperature sensor to the container wall through the insulation layer. This adhesive provides both mechanical fixation and thermal conduction, eliminating the need for complex guide tube structures while ensuring reliable temperature measurement.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If thermal insulation is removed to install additional temperature sensors, then sensor installation flexibility is improved, but heat loss increases and installation becomes more difficult

Engineering Contradiction:
Improvesensor installation flexibilityVSAvoidheat loss
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The patent segments the insulation layer by creating a localized insertion path rather than removing the entire insulation covering. This allows the sensor to be installed through a small aperture while the majority of the insulation remains intact, maintaining thermal efficiency while providing installation flexibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local modification to the insulation layer only where the sensor needs to pass through, rather than removing or compromising the overall insulation structure. The insulation maintains its protective and thermal properties everywhere except at the specific insertion point, minimizing energy loss.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If spring preload is used to press temperature sensors onto the water tank, then thermal contact is improved, but measurement reliability deteriorates due to temperature sensitivity of the spring

Engineering Contradiction:
Improvethermal contact qualityVSAvoidmeasurement reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent replaces the temperature-sensitive spring mechanical system with a thermal adhesive bonding system. The adhesive provides consistent thermal contact and mechanical fixation without being subject to temperature-induced dimensional changes, thereby improving measurement reliability while maintaining good thermal contact.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the fixation mechanism from a mechanical spring system (whose properties vary with temperature) to a chemical adhesive system (whose properties remain stable across the operating temperature range). This parameter change eliminates the reliability issue associated with spring temperature sensitivity.

Inventive Principle:
Principle #35Parameter changes

4Loss of information

If multiple temperature sensors are installed at different heights, then temperature profile measurement capability is improved, but installation complexity and cost increase

Engineering Contradiction:
Improvetemperature profile informationVSAvoidinstallation complexity
Core Design Contradiction:
Loss of informationVSDevice complexity

Solution Approach 1:

The patent enables each temperature sensor to independently penetrate the insulation and contact the container wall at its designated height without requiring complex guide structures or inter-sensor coordination. Each sensor is a self-contained unit that can be installed separately, simplifying the overall multi-sensor installation process while capturing the complete temperature profile.

Inventive Principle:
Principle #25Self-service

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

Enables simple and durable retrofitting of temperature sensors without removing insulation, ensuring accurate thermal contact and measurement quality, facilitating modernization of heating systems with precise control capabilities.

Implementation Method 1

Each temperature sensor (7) is inserted from outside the thermal insulation (5) directly through the insulation until its tip reaches a thermal contact area (10) with an outer surface (4) of the metal container (3)

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

the establishment or existence of a correct thermally conductive connection between the at least one temperature sensor (7) and the outer surface (4) of the metal container (3) is verified by measuring the electrical resistance between the temperature sensor (7) and the metal container (3)

Methodology Applied
Scientific EffectElectrical resistance: Electrical Resistance

Data Source

PatentEP4180785B1Method and temperature sensor for retrofitting a heat storage unit with additional temperature sensors
Publication Date: 2025.12.03 VAILLANT GMBH(DE)
  • EP4180785B1 patent drawingFigure 1~2
  • EP4180785B1 patent drawingFigure 3~4

AI summary

The invention relates to a method and a corresponding temperature sensor (7) for retrofitting a heat storage unit (2) of a heating system (1) arranged in a metal container (3), which is provided with thermal insulation (5), with additional temperature sensors (7) without removing the thermal insulation (5). A temperature sensor (7) with a needle-shaped sensor holder (8) is inserted from outside the thermal insulation (5) directly through the thermal insulation (5) to a thermal contact area (10) at its tip (9) with an outer surface (4) of the metal container (3). Preferably, the establishment or existence of a correct thermally conductive connection between the temperature sensor (7) and the outer surface (4) of the metal container (3) is verified by measuring the electrical resistance between the temperature sensor (7) and the metal container (3).The present invention allows for the simple retrofitting of existing heat storage units (2) with additional temperature sensors (7) without removing thermal insulation (5), so that heating systems (1) can be modernized and adapted to the highest standards without replacing their heat storage unit (2).