Phase change display

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Solution Overview

Problem

Current refrigeration systems using safer fluorocarbon refrigerants face restrictions due to global warming concerns, leading to potential safety issues with flammable or toxic alternatives, where leaks in heat pump housings are not easily detectable, posing risks to maintenance personnel.

Innovation Solution

A display device is integrated into the heat pump housing with a heated viewing window coated with a light-absorbing wax-like material that dissolves and liquefies when exposed to the gaseous refrigerant, allowing visible indication of leaks through a collection system and associated lighting or alarm mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Difficulty of detecting and measuring

If electronic detection systems are used to detect refrigerant leaks, then leak detection capability is improved, but system complexity and cost increase

Engineering Contradiction:
Improveleak detection capabilityVSAvoidsystem complexity
Core Design Contradiction:
Difficulty of detecting and measuringVSDevice complexity

Solution Approach 1:

The coating acts as a passive intermediary that provides leak detection through visual color changes, eliminating the need for complex electronic sensors, power supplies, and control systems while maintaining effective leak detection capability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The coating performs the detection function autonomously through its inherent chemical or physical reaction with the refrigerant, requiring no external power source, control electronics, or active monitoring systems.

Inventive Principle:
Principle #25Self-service

2Difficulty of detecting and measuring

If a viewing window with color-changing coating is installed to detect leaks, then leak visibility is improved, but the device complexity increases due to additional components

Engineering Contradiction:
Improveleak visibilityVSAvoiddevice complexity
Core Design Contradiction:
Difficulty of detecting and measuringVSDevice complexity

Solution Approach 1:

The viewing window serves multiple functions: it provides visual inspection of the housing interior, detects refrigerant leaks through color changes, and indicates the type of refrigerant present. This multi-functionality reduces the need for separate detection devices.

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

Solution Approach 2:

The color-changing property of the coating provides intuitive visual indication of leak conditions, making the complex detection function simple and immediately recognizable to operators.

Inventive Principle:
Principle #32Color changes

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 external detection of refrigerant leaks in heat pump housings, enhancing safety by providing a visible indication of leaks and potential hazards, thus improving maintenance safety and compliance with environmental regulations.

Implementation Method 1

the coating becomes liquid when the gaseous working fluid is dissolved and runs off

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

the coating becomes liquid when the gaseous working fluid is dissolved and runs off

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP3940316A1Phase change display
Publication Date: 2022.01.19 VAILLANT GMBH(DE)
  • EP3940316A1 patent drawingFigure 1
  • EP3940316A1 patent drawingFigure 2
  • EP3940316A1 patent drawing

AI summary

Display device for a closed heat pump housing in which a heat pump process is operated with a flammable, carbon-containing working fluid, in which a heated viewing window is positively fitted in a recess on one of the outer walls of the heat pump housing, the viewing window is in contact with the gas interior of the housing, the viewing window is provided on the surface facing the interior of the housing with a light-absorbing solid coating, the gaseous working fluid is soluble in the solid coating, the coating becomes liquid and runs off when the gaseous working fluid dissolves, thereby revealing the interior of the housing.