Embedded Sensor for Closed Cell Foam Thermal Insulation Quality

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Solution Overview

Problem

Conventional methods for determining the thermal insulation quality of closed cell foams are destructive, time-consuming, and unsuitable for monitoring in situ, especially in large-scale applications like district heating pipes, as they require sample extraction and cannot account for long-term changes or environmental factors.

Innovation Solution

A non-destructive method using sensors to measure characteristic parameters like thermal conductivity and carbon dioxide concentration within the foam, with a control and processing device comparing these values to reference values to assess insulation quality, allowing for continuous monitoring over time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional destructive methods are used to determine heat conductivity, then measurement can be performed, but the cell gases diffuse out and air diffuses in, undermining measurement quality

Engineering Contradiction:
Improveheat conductivity measurement accuracyVSAvoidsample integrity
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The sensor is introduced into the foam structure before the foam is fully formed or sealed, allowing the sensor to be surrounded by the closed cell foam. This preliminary positioning ensures that when the foam completes its closed cell structure, the sensor is already enclosed and protected from environmental exposure, eliminating the need for later destructive sampling while maintaining measurement integrity throughout the foam's service life.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If conventional destructive methods are used, then heat conductivity can be measured, but many samples must be prepared simultaneously, requiring much time and material

Engineering Contradiction:
Improveheat conductivity measurementVSAvoidsample preparation time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The sensor is introduced into the foam structure before the foam is fully formed or sealed, allowing the sensor to be surrounded by the closed cell foam. This preliminary positioning ensures that when the foam completes its closed cell structure, the sensor is already enclosed and protected from environmental exposure, eliminating the need for later destructive sampling while maintaining measurement integrity throughout the foam's service life.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The sensor system enables the foam to self-monitor its own thermal insulation properties. By having the sensor embedded within the foam structure, the foam itself provides the measurement capability without requiring external intervention or additional samples. This self-service approach eliminates the need for multiple sample preparations and allows continuous monitoring of the same foam structure over time.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If conventional destructive methods are used, then heat conductivity can be measured, but they cannot be applied to work pieces in operation

Engineering Contradiction:
Improveheat conductivity measurementVSAvoidin situ measurement capability
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The sensor is introduced into the foam structure before the foam is fully formed or sealed, allowing the sensor to be surrounded by the closed cell foam. This preliminary positioning ensures that when the foam completes its closed cell structure, the sensor is already enclosed and protected from environmental exposure, eliminating the need for later destructive sampling while maintaining measurement integrity throughout the foam's service life.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The embedded sensor enables continuous monitoring of the foam's thermal insulation properties throughout its entire service life. Rather than performing discrete destructive measurements that stop the monitoring capability, the sensor provides ongoing measurements without interrupting the foam's function or requiring removal of samples, thus maintaining continuous useful action for quality assessment.

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 approach provides a fast, reliable, and cost-effective means to assess and predict the insulation quality of closed cell foams, detecting changes and potential failures, such as gas ingress or damage, over the lifespan of the insulation, making it suitable for large-scale applications.

Implementation Method 1

measuring a characteristic parameter of the cell gas present in the closed cell foam, in particular the thermal conductivity or the carbon dioxide concentration

Methodology Applied
Scientific EffectThermal conductivity measurement: Conduction (thermal)

Implementation Method 2

measuring a characteristic parameter of the cell gas present in the closed cell foam, in particular the thermal conductivity or the carbon dioxide concentration

Methodology Applied
Scientific EffectCO2 concentration detection: Absorption Spectroscopy

Data Source

PatentEP4177604A1Method and system for determining the quality of a closed cell foam with respect to thermal insulation
Publication Date: 2023.05.10 BRUGG ROHR AG HLDG
  • EP4177604A1 patent drawingFigure 1~2
  • EP4177604A1 patent drawingFigure 3
  • EP4177604A1 patent drawingFigure 4

AI summary

The invention relates to a method for determining the quality of a closed cell foam (9) with respect to its thermal insulation, to a system for carrying out the method and to an insulated pipe with such a system. A characteristic parameter of cell gas present in the closed cell foam is measured, wherein the method comprises the steps of introducing a sensor (1) adapted to measure the characteristic parameter into the foam (9), triggering by means of a control and processing device a measurement of the characteristic parameter in the foam by the sensor (1), thereby obtaining a corresponding current measured value which is transmitted to the control and processing device (12), and determining the quality of the closed cell foam (9) by comparing by means of the control and processing device the current measured value or a replacement value derived from the current measured value with a corresponding reference value.