Existing-Pipe Air Conditioner Retrofit for Parallel Cooling and Heating

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Solution Overview

Problem

The existing air conditioner systems require new communication pipes during reinstallation to enable parallel cooling and heating operations, leading to increased costs and complexity.

Innovation Solution

The system includes a refrigerant circuit with operation switching units connected through preinstalled indoor and outdoor communication pipes, along with a gas-liquid separation unit, allowing for parallel operation switching without the need for new pipes, using difluoromethane as a refrigerant to enhance pressure tolerance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a cooling/heating switching unit is added to enable parallel cooling and heating operations, then the operational versatility is improved, but the device complexity and reinstallation cost increase due to requiring new communication pipes

Engineering Contradiction:
Improveparallel cooling and heating operation capabilityVSAvoidreinstallation complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system divides the communication piping into multiple independent paths: existing communication pipes continue to connect the outdoor unit to individual indoor units, while newly added communication pipes connect the cooling/heating switching unit to the indoor units. This segmentation allows the new functionality to be added without disrupting the existing pipe infrastructure, reducing reinstallation complexity while maintaining operational versatility

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cooling/heating switching unit acts as an intermediary device that receives refrigerant from the outdoor unit through existing communication pipes and distributes it to indoor units through new communication pipes. This intermediary approach enables parallel cooling and heating operations by providing an additional routing path without requiring complete redesign of the existing piping system

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If new communication pipes are installed to connect the cooling/heating switching unit to indoor units, then the parallel operation capability is achieved, but the reinstallation cost and time increase

Engineering Contradiction:
Improveparallel cooling and heating operation capabilityVSAvoidreinstallation time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent designs the system so that the cooling/heating switching unit can be integrated into the existing infrastructure with minimal modifications. The communication pipes are routed through readily accessible locations near the outdoor unit, and the switching unit is positioned to facilitate easy connection to existing indoor unit piping, thereby reducing the time required for reinstallation while achieving parallel operation capability

Inventive Principle:
Principle #10Preliminary action

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 flexible and cost-effective reinstallation by utilizing existing pipes, reducing the need for new installations and lowering overall costs, while maintaining efficient refrigeration cycles for both cooling and heating operations.

Implementation Method 1

a refrigerant circuit (20) that includes an outdoor unit (2) and a plurality of indoor units (3) and is able to perform a refrigeration cycle in which a cooling operation and a heating operation are performed in parallel with each other

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

The air conditioner includes a plurality of operation switching units (5), each of which is connected to an associated one of the indoor units (3) through two indoor communication pipes (13, 14) and changes directions of refrigerants flowing through the indoor communication pipes (13, 14)

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

a gas-liquid separation unit (4) with which the operation switching units (5) are connected in parallel with each other through three intermediate communication pipes (15, 16, 17) comprised of two gas pipes and one liquid pipe

Methodology Applied
Scientific EffectGas-liquid separation: Cyclone Separation

Data Source

PatentEP2924360B1Air conditioner and air conditioner construction method
Publication Date: 2018.01.03 DAIKIN INDUSTRIES LTD
  • EP2924360B1 patent drawingFigure 1
  • EP2924360B1 patent drawingFigure 2A~2B
  • EP2924360B1 patent drawingFigure 3

AI summary

Operation switching units (5), each changing directions of a refrigerant flowing through its associated indoor unit (3) in response to a switch from a cooling operation to a heating operation, or vice versa, are each connected with the associated indoor unit (3) through indoor communication pipes (13, 14); a gas-liquid separation unit (4) is connected with an outdoor unit (2) through outdoor communication pipes (11, 12); and the operation switching units (5) are connected with the gas-liquid separation unit (4) through two intermediate communication pipes (15, 16) preinstalled and one intermediate communication pipe (17) newly installed. This provides a simple and cost-effective means for upgrading a preinstalled air conditioner making a switch from cooling to heating, and vice versa, into an air conditioner (1) that can perform a cooling operation and a heating operation in parallel with each other.