Indoor Air Conditioner Unit With Parallel Heat Exchangers for Uniform Heating

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Solution Overview

Problem

Air conditioners with multi-directional air supply units operating in supercritical refrigeration cycles face temperature variations of supply air depending on location due to uneven refrigerant temperature distribution across the heat exchanger, leading to inconsistent heating performance.

Innovation Solution

The design incorporates parallel-connected refrigerant flow paths with opposite flow directions at each end of the heat exchange region, ensuring high-temperature refrigerant flows at both ends during heating, reducing temperature differences between air outlets and enhancing uniformity of air supply temperature.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If the refrigerant flow path traverses back and forth once between one end and the other end of the heat exchanger, then the refrigerant flow path length is reduced, but the temperature distribution of refrigerant becomes uneven across the heat exchanger

Engineering Contradiction:
Improverefrigerant flow path lengthVSAvoidrefrigerant temperature distribution uniformity
Core Design Contradiction:
Length of moving objectVSTemperature

Solution Approach 1:

The heat exchanger is divided into multiple independent heat exchange sections (first heat exchange section and second heat exchange section) with refrigerant flow paths arranged in parallel. Each section handles a portion of the refrigerant flow, allowing temperature distribution to be balanced across sections while keeping individual path lengths short.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different heat exchange sections are configured with opposite refrigerant flow directions relative to the heat exchanger perimeter. This creates local temperature distribution optimization where high-temperature refrigerant flows at both ends of the heat exchanger during heating operation, ensuring uniform air temperature at different outlets.

Inventive Principle:
Principle #3Local quality

2Volume of moving object

If the heat exchanger is formed by bending to surround the fan, then the air supply structure is compact, but the refrigerant flow path length increases when traversing back and forth multiple times

Engineering Contradiction:
Improveindoor unit compactnessVSAvoidrefrigerant flow path length
Core Design Contradiction:
Volume of moving objectVSLength of moving object

Solution Approach 1:

The refrigerant flow path is segmented into parallel sections that traverse the heat exchanger once in opposite directions. This segmentation allows the bent heat exchanger configuration to maintain compactness while avoiding the need for multiple back-and-forth traversals that would excessively lengthen the refrigerant path.

Inventive Principle:
Principle #1Segmentation

3Device complexity

If refrigerant flows through the heat exchanger in a single direction, then the flow path is simple, but large temperature differences occur between inner and outer sides of the heat exchanger

Engineering Contradiction:
Improverefrigerant flow path configurationVSAvoidtemperature difference between heat exchanger sides
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The refrigerant flow direction in the second heat exchange section is inverted relative to the first heat exchange section. While the first section has refrigerant flowing from one end to the other, the second section has refrigerant flowing from the other end to the first end, creating opposite flow directions that balance temperature distribution across the heat exchanger perimeter.

Inventive Principle:
Principle #13The other way round (Inversion)

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 reduces temperature variations of supply air across different outlets, improving comfort by maintaining consistent air temperatures and increasing the efficiency of the air conditioning system.

Implementation Method 1

the heat exchanger is a cross-fin-and-tube heat exchanger... air radially blown out of the fan passes through the heat exchanger surrounding the fan

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

air radially blown out of the fan passes through the heat exchanger surrounding the fan. Then, the air temperature-conditioned during passage through the heat exchanger is supplied through the air outlets to the room

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2068091B1Indoor unit of air conditioner
Publication Date: 2024.09.18 DAIKIN INDUSTRIES LTD
  • EP2068091B1 patent drawingFigure 1
  • EP2068091B1 patent drawingFigure 2
  • EP2068091B1 patent drawingFigure 3~4

AI summary

An indoor unit for a multi-directional air supply air conditioner capable of performing at least a heating operation includes: an indoor fan (39) for sucking air in an axial direction thereof and radially blowing out the air; and a heat exchange part (38), connected in a refrigerant circuit (80) and disposed to surround the indoor fan (39), for exchanging heat between the air blown out of the indoor fan (39) and refrigerant in the refrigerant circuit (80). The heat exchange part (38) includes a plurality of heat exchangers (48) separated from each other along the direction of the perimeter thereof and connected in parallel with each other in the refrigerant circuit (80).