Factory-Assembled Refrigerant Pipe Unit to Reduce Installation Time

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Solution Overview

Problem

Conventional air conditioner installations require extensive on-site piping and heat insulation work, which is time-consuming and labor-intensive, often performed in confined spaces, necessitating a unitization of the refrigerant circuit to reduce installation time and improve safety.

Innovation Solution

A pipe unit is fabricated in a factory by integrating a liquid pipe and a gas pipe with a heat insulator, forming a single piece, allowing for partial unitization of the refrigerant circuit and simplifying fabrication, with brazing and heat insulation processes restricted to the factory to prevent on-site accidents and improve accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If piping work is performed on site after building framework is finished, then installation flexibility is maintained, but installation time becomes excessively long and requires many skilled workers

Engineering Contradiction:
Improveinstallation speedVSAvoidinstallation duration
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The pipe body with liquid pipe and gas pipe are fabricated and assembled in advance at the factory before installation. This preliminary fabrication allows the piping work to be prepared off-site, reducing on-site installation time and the need for skilled workers during the actual installation phase.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The refrigerant circuit is divided into modular components: the pipe body (containing liquid and gas pipes), heat insulators, and coupling parts. These segmented modules are manufactured separately and assembled on-site, enabling parallel preparation and reducing overall installation time while maintaining flexibility.

Inventive Principle:
Principle #1Segmentation

2Manufacturing precision

If heat insulation work is performed on site, then adaptability to building conditions is maintained, but heat insulation accuracy decreases and moisture condensation occurs

Engineering Contradiction:
Improveheat insulation accuracyVSAvoidmoisture condensation
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

Heat insulators are pre-installed on the pipe body at the factory under controlled conditions, ensuring proper fit and coverage before the pipes are installed in the building. This preliminary heat insulation prevents moisture condensation by ensuring complete coverage without gaps or defects that would occur with on-site installation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

Different heat insulation materials and thicknesses are applied to specific portions of the pipe body based on local thermal requirements. The liquid pipe and gas pipe receive appropriate heat insulation tailored to their specific thermal needs, optimizing insulation accuracy and preventing condensation at critical locations.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If brazing work is performed on site, then installation flexibility is maintained, but fire hazards and safety risks increase

Engineering Contradiction:
Improveinstallation flexibilityVSAvoidfire hazard
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

All brazing operations are completed at the factory before the pipe body is shipped for installation. This transfers the fire hazard from the construction site to the factory environment where proper safety controls and ventilation are already in place, eliminating on-site fire risks while maintaining installation flexibility through modular assembly.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The hazardous brazing process is extracted from the on-site installation sequence and performed separately at the factory. This separates the fire-prone manufacturing operation from the safe installation operation, allowing the pipe body to be assembled on-site using non-hazardous connection methods.

Inventive Principle:
Principle #2Taking out (Extraction)

4Ease of manufacture

If liquid pipe and gas pipe are fixed together as single piece, then fabrication is simplified and factory production is enabled, but device complexity increases

Engineering Contradiction:
Improvefabrication simplicityVSAvoidpipe unit integration
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The liquid pipe and gas pipe are merged into a single integrated pipe body structure, simplifying manufacturing by treating them as one unit during fabrication. This merging enables factory production while the modular design maintains ease of on-site assembly through standardized coupling interfaces.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2933571B1Method for fabricating a pipe unit
Publication Date: 2023.10.04 DAIKIN INDUSTRIES LTD
  • EP2933571B1 patent drawingFigure 1
  • EP2933571B1 patent drawingFigure 2~3
  • EP2933571B1 patent drawingFigure 4~5

AI summary

A pipe unit (50) is provided for a refrigerant circuit which performs a vapor compression refrigeration cycle by circulating a refrigerant. The pipe unit (50) includes a pipe body (53) having a liquid pipe (51) through which a liquid refrigerant for the refrigerant circuit (40) flows and a gas pipe (52) through which a gaseous refrigerant for the refrigerant circuit (40) flows; and a heat insulator (54) covering each of the liquid pipe (51) and the gas pipe (52) separately. The liquid pipe (51) and the gas pipe (52), each of which is covered with the heat insulator (54), are fixed together to form a single piece. Such partial unitization of the refrigerant circuit allows for reduction in the number of days required for installation of an air conditioner.