Heat transport system

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Solution Overview

Problem

Conventional chiller systems face challenges in reducing installation space and maintenance time due to large water pipe diameters and risk of refrigerant leakage, which can lead to environmental and safety issues, especially when using refrigerants with low global warming potential and zero ozone layer destruction coefficient.

Innovation Solution

A heat transport system incorporating a refrigerant circuit with a refrigerant booster, outdoor air heat exchanger, medium heat exchanger, and refrigerant flow path switching device, using HFC-32 and/or HFO refrigerants, and a medium circuit with a medium booster, indoor air heat exchanger, and first medium flow path switching device, utilizing carbon dioxide as the heat transfer medium to reduce pipe diameter and minimize leakage risks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If a water circuit with large diameter pipes is installed indoors for heat exchange, then heat exchange efficiency is improved, but installation space requirement increases and installation/maintenance time increases

Engineering Contradiction:
Improveheat exchange efficiencyVSAvoidinstallation space
Core Design Contradiction:
TemperatureVSArea of stationary object

Solution Approach 1:

The patent extracts the large-diameter water pipes from the indoor space and relocates them to the outdoor unit. The indoor unit only contains the heat exchanger and control components, while the water circulation system is moved outdoors, thereby reducing indoor installation space while maintaining heat exchange efficiency.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system is divided into separate functional modules: an outdoor unit containing the water circuit and heat exchanger, and an indoor unit containing only the air handling components. This segmentation allows the large-diameter pipes to be located outdoors while keeping the indoor installation compact.

Inventive Principle:
Principle #1Segmentation

2Temperature

If refrigerant is circulated indoors for direct heat exchange with indoor air, then heat exchange efficiency is improved, but safety risk increases due to potential refrigerant leakage and combustion hazard

Engineering Contradiction:
Improveheat exchange efficiencyVSAvoidsafety
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent extracts the refrigerant circulation system from the indoor space and relocates it entirely to the outdoor unit. The indoor unit handles only air circulation and heat exchange with water, eliminating any possibility of refrigerant leakage indoors while maintaining effective heat exchange through the water-mediated thermal transfer.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Water serves as an intermediary heat transfer medium between the outdoor refrigerant system and the indoor air. The refrigerant exchanges heat with water outdoors, and the water then circulates to exchange heat with indoor air, thereby mediating the heat transfer process and eliminating direct refrigerant presence indoors.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-affected harmful factors

If combustible refrigerants are used to achieve low global warming potential and zero ozone layer destruction, then environmental performance is improved, but safety risk increases due to combustion hazard upon leakage

Engineering Contradiction:
Improveenvironmental loadVSAvoidsafety
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent extracts the combustible refrigerant system from the indoor environment and confines it entirely to the outdoor unit. This allows the use of environmentally friendly but potentially combustible refrigerants like HFO-1234yf or HFO-1234ze without exposing the indoor space to safety risks, as any potential leakage would occur outdoors away from occupied spaces.

Inventive Principle:
Principle #2Taking out (Extraction)

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 system effectively reduces pipe diameter, installation space, and maintenance effort while ensuring safety by eliminating the risk of refrigerant leakage and minimizing environmental impact through the use of low-global-warming-potential refrigerants and carbon dioxide as the heat transfer medium.

Implementation Method 1

a refrigerant booster (21) which boosts the refrigerant

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

an outdoor air heat exchanger (23) which exchanges heat between the refrigerant and the outdoor air

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

a medium heat exchanger (25) which exchanges heat between the refrigerant and the heat transfer medium

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 4

the outdoor air heat exchanger functions as an evaporator of the refrigerant

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 5

the medium heat exchanger functions as a radiatior of the refrigerant

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 6

a medium booster (31) which boosts the heat transfer medium

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 7

a plurality of indoor air heat exchangers (52a, 52b, and 52c) which exchange heat between the heat transfer medium and the indoor air

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP4019862B1Heat transport system
Publication Date: 2024.05.01 DAIKIN INDUSTRIES LTD
  • EP4019862B1 patent drawingFigure 1
  • EP4019862B1 patent drawingFigure 2
  • EP4019862B1 patent drawingFigure 3

AI summary

A heat transport system includes a refrigerant circuit and a medium circuit. The refrigerant circuit includes a refrigerant booster, an outdoor air heat exchanger, a medium heat exchanger, and a refrigerant flow path switching device, and a fluid containing HFC-32 and/or HFO refrigerant is sealed in the refrigerant circuit as a refrigerant. The medium circuit includes a medium booster, a medium heat exchanger, a first medium flow path switching device, and a plurality of indoor air heat exchangers, and carbon dioxide is sealed in the medium circuit as a heat transfer medium.