Indoor Unit Pipe Insulation Channel for Refrigerant Leak Detection

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing air conditioning apparatuses face difficulties in detecting refrigerant leaks that occur outside the casing of the indoor unit, as the leaks are not easily guided back inside for detection.

Innovation Solution

The air conditioning apparatus includes a communication passage formed by a space between the dew condensation prevention members and the refrigerant pipes, which guides leaked refrigerant inside the casing, where a refrigerant leakage sensor can detect it, eliminating the need for sensors outside the casing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a gas sensor is installed only inside the casing to detect refrigerant leaks, then the device complexity is reduced, but the ability to detect leaks outside the casing deteriorates

Engineering Contradiction:
Improvesensor installation complexityVSAvoidleak detection capability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent introduces a communication passage as an intermediary channel that connects the external environment to the internal sensor location. This passage allows leaked refrigerant to travel from outside the casing to the gas sensor inside, enabling detection without placing sensors externally. The communication passage thus mediates between the sensor's fixed internal position and the variable external leak locations.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If the pipe connection end portion is fully covered by dew condensation prevention members, then dew condensation prevention is improved, but refrigerant leak detection capability deteriorates

Engineering Contradiction:
Improvedew condensationVSAvoidrefrigerant leak detection
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The dew condensation prevention member is segmented into multiple sections: a first section that covers the pipe connection end portion to prevent dew condensation, and a second section that includes or forms the communication passage for refrigerant detection. This segmentation allows the single component to simultaneously perform both dew condensation prevention and leak detection functions without interfering with each other.

Inventive Principle:
Principle #1Segmentation

3Strength

If metal materials are used for communication passages, then structural strength is improved, but dew condensation occurrence increases

Engineering Contradiction:
Improvecommunication passage strengthVSAvoiddew condensation
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The patent employs composite material construction where the dew condensation prevention member is made of foam material (providing insulation and strength) while incorporating a communication passage. The foam material's low thermal conductivity prevents dew condensation on the communication passage surface, while the overall structure maintains sufficient mechanical strength. This composite approach resolves the contradiction between using metal (strong but condenses) and non-metal materials.

Inventive Principle:
Principle #40Composite materials

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 configuration allows for effective detection of refrigerant leaks that occur outside the casing, enhancing leak detection efficiency without increasing the number of sensors, and prevents dew condensation issues through the use of non-metal materials and stable fastening mechanisms.

Implementation Method 1

the leaked refrigerant is easily guided to the inside of the casing due to the communication passage causing the space of the part covered by the first dew condensation prevention member or the second dew condensation prevention member at the pipe-connection end portion to be in communication with the internal space of the casing

Methodology Applied
Scientific EffectDiffusion: Diffusion

Implementation Method 2

a first dew condensation prevention member covering the pipe-connection end portion from the radially outer side, the first dew condensation prevention member having a first communication passage forming portion forming the first communication passage

Methodology Applied
Scientific EffectThermal Insulation: Thermal Insulation

Data Source

PatentEP3936785B1Air-conditioning device
Publication Date: 2023.11.15 DAIKIN INDUSTRIES LTD
  • EP3936785B1 patent drawingFigure 1
  • EP3936785B1 patent drawingFigure 2
  • EP3936785B1 patent drawingFigure 3

AI summary

An object is to provide an air conditioning apparatus in which, even when a refrigerant leaks outside a casing, the leaked refrigerant is easily guided to the inside of the casing. In an indoor unit (3) of an air conditioning apparatus (1) that includes a casing (30) having an opening (64a), an indoor heat exchanger (51) disposed in the casing (30), a liquid-side connection pipe (53) or a gas-side connection pipe (54) extending from the indoor heat exchanger (51) to the outside of the casing (30) through the opening (64a), and an indoor-side dew condensation prevention member (71) that covers the periphery of the liquid-side connection pipe (53) or the gas-side connection pipe (54), an end portion of the liquid-side connection pipe (53) or the gas-side connection pipe (54) is used in a state of being covered from the periphery thereof by a connection-side dew condensation prevention member (72) or is covered from the periphery thereof by the indoor-side dew condensation prevention member (71), and there is formed a communication passage (91) that causes a space of a part covered by the dew condensation prevention member at the end portion of the liquid-side connection pipe (53) or the gas-side connection pipe (54) to be in communication with the internal space of the casing (30).