Method for detecting leaks in an air conditioning system

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional air conditioning systems using natural refrigerants face challenges in detecting leaks effectively, especially small leaks, due to the flammability, explosiveness, and toxicity of these refrigerants, requiring a robust and reliable detection method to ensure safety in enclosed spaces like small rooms.

Innovation Solution

A method involving temperature sensors to record and calculate differential temperatures across the refrigerant evaporator, detecting leaks by monitoring changes in outlet and evaporator differential temperatures, which triggers automatic system shutdown and isolation of the refrigerant circuit from the air-conditioned space, without needing pressure or gas sensors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If robust leak detection systems are implemented, then safety is improved, but device complexity increases

Engineering Contradiction:
Improveleak detection reliabilityVSAvoiddetection system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The leak detection system utilizes the evaporator's existing temperature sensors and operational data to self-diagnose leaks. The control unit analyzes temperature differentials that naturally occur during evaporator operation, eliminating the need for separate, complex detection hardware. The system serves itself by monitoring its own operational parameters.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The temperature sensors already present in the evaporator for climate control purposes are also used for leak detection. This multi-functional approach allows the same components to serve dual purposes: regulating temperature and detecting leaks, thereby avoiding additional complexity while maintaining high detection reliability.

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

2Device complexity

If temperature-based leak detection is used, then device complexity is reduced, but measurement precision for small leaks may deteriorate

Engineering Contradiction:
Improvedetection system complexityVSAvoidsmall leak detection precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

Instead of measuring refrigerant concentration directly in one dimension, the system measures temperature differential across the evaporator in another dimension. This indirect measurement approach using temperature changes provides sensitive detection of small leaks without requiring complex gas sensing equipment, effectively translating a difficult measurement into a more manageable thermal measurement.

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

This method allows for reliable detection of leaks, including small and creeping leaks, ensuring safe operation by automatically shutting off the system and isolating the refrigerant circuit from the occupied space, effectively protecting people from refrigerant exposure.

Implementation Method 1

a refrigerant evaporator (15) which can exchange heat with a room (18) to be air-conditioned

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

a refrigerant evaporator (15) which can exchange heat with a room (18) to be air-conditioned

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

a refrigerant condenser (12) which can exchange heat with an environment (14)

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP3428554B1Method for detecting leaks in an air conditioning system
Publication Date: 2019.07.24 TRUMA GERATETECHNIK GMBH & CO KG
  • EP3428554B1 patent drawingFigure 1
  • EP3428554B1 patent drawingFigure 2~3

AI summary

A method for leak detection in an air conditioning system (10) is described, in which the room temperature of the room to be air-conditioned (18) is measured upstream of the refrigerant evaporator (15) at an air inlet side (41), the refrigerant inlet temperature at the refrigerant inlet (16) of a refrigerant evaporator (15), and the refrigerant outlet temperature at a refrigerant outlet (17) of the refrigerant evaporator (15) are recorded. Based on this, an outlet differential temperature is calculated as the difference between the room temperature and the refrigerant outlet temperature, and an evaporator differential temperature is calculated as the difference between the refrigerant outlet temperature and the refrigerant inlet temperature. A leak is detected if the outlet differential temperature falls below a defined value and/or if the evaporator differential temperature exceeds a defined value.