Indoor Unit Valve Partitioning to Contain Refrigerant Leaks

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Solution Overview

Problem

Existing air conditioning systems face challenges in preventing refrigerant leakage and ensuring safety, particularly when flammable refrigerants are used.

Innovation Solution

The air conditioner incorporates a shutoff valve device with first and second shutoff valves disposed in attic or underfloor spaces, respectively. This configuration ensures that any refrigerant leakage flows into a partitioned space rather than the air conditioning target space, enhancing safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If shutoff valves are installed in the air conditioning target space, then refrigerant leakage can be controlled, but safety is compromised due to potential contamination of the living space

Engineering Contradiction:
Improverefrigerant leakage controlVSAvoidsafety
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent divides the space into two distinct zones: the air conditioning target space (living space) and the attic/underfloor space (non-living space). By installing shutoff valves in the non-living space and routing refrigerant pipes through dedicated openings, the system segments the refrigerant containment area from the living area. This segmentation ensures that even if leakage occurs, it is confined to the non-living space, resolving the contradiction between leakage control capability and safety.

Inventive Principle:
Principle #1Segmentation

2Object-affected harmful factors

If shutoff valves are disposed in attic or underfloor spaces, then safety is improved by preventing refrigerant inflow to the target space, but device complexity increases

Engineering Contradiction:
ImprovesafetyVSAvoidinstallation complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent combines multiple functions into the shutoff valve device: the valve body, the opening through which pipes pass, and the heat insulating material are integrated into a single unit installed in the attic or underfloor space. This merging reduces the number of separate components and simplifies installation, thereby reducing device complexity while maintaining the safety benefit of locating valves outside the living space.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The heat insulating material serves as an intermediary element that performs multiple functions: it seals the gap between the opening and refrigerant pipes to prevent refrigerant leakage, and it provides thermal insulation. This intermediary component simplifies the overall structure by combining sealing and insulation functions in a single element, reducing installation complexity while maintaining safety.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If heat insulating material is used to close gaps, then refrigerant leakage is prevented, but manufacturing cost increases

Engineering Contradiction:
Improveleakage preventionVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The heat insulating material is designed to perform multiple functions simultaneously: it provides thermal insulation for the refrigerant pipes, seals the gap between the opening and pipes to prevent refrigerant leakage, and acts as a cushioning element. By making this single component multi-functional, the patent eliminates the need for separate sealing materials and insulation layers, thereby reducing manufacturing cost while maintaining reliable leakage prevention.

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

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

The solution effectively suppresses the inflow of refrigerant into the air conditioning target space, even if leakage occurs, thereby ensuring high safety standards, especially when using flammable refrigerants.

Implementation Method 1

a heat insulating material configured to close a gap between the opening and the liquid refrigerant pipe and a gap between the opening and the gas refrigerant pipe

Methodology Applied
Scientific EffectPhysical Containment: Physical Containment

Data Source

PatentEP4056924B1Air conditioners and use of an air conditioner
Publication Date: 2025.04.30 DAIKIN INDUSTRIES LTD
  • EP4056924B1 patent drawingFigure 1
  • EP4056924B1 patent drawingFigure 2
  • EP4056924B1 patent drawingFigure 3

AI summary

Provided are an air conditioning indoor unit capable of suppressing an increase in local installation work when a shutoff valve is provided in an air conditioner, and an air conditioner including the air conditioning indoor unit. An air conditioning indoor unit (30) blows the air having exchanged heat in a utilization heat exchanger (32) to an air conditioning target space. The air conditioning indoor unit includes a liquid refrigerant pipe (37a) and a gas refrigerant pipe (37b) connected to the utilization heat exchanger, a casing (40), a first shutoff valve (52) and a second shutoff valve (54), and a partition wall (60). The casing accommodates the utilization heat exchanger. An opening (481, 482) communicating with the air conditioning target space is formed in the casing. The first shutoff valve and the second shutoff valve are disposed in a first space (S1) in the casing. The first shutoff valve is disposed in the liquid refrigerant pipe. The second shutoff valve is disposed in the gas refrigerant pipe. The partition wall separates the first space and a second space (S2). The second space is a space in the casing and communicates with the air conditioning target space via the opening.