Heat Exchanger Tube Material Layout to Prevent Air Conditioner Corrosion

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Solution Overview

Problem

Air conditioners using copper refrigerant tubes are heavy and expensive due to copper's high cost and weight, and the use of different metals for refrigerant tubes and heat dissipating fins leads to corrosion issues.

Innovation Solution

The use of aluminum and copper combination tubes for refrigerant tubes and heat dissipating fins, where both components are made of the same metal to prevent corrosion and reduce weight, with distributors and injectors designed to enhance refrigerant distribution and flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If copper refrigerant tubes are used, then reliability and thermal expansion characteristic are improved, but weight and cost increase

Engineering Contradiction:
ImprovereliabilityVSAvoidweight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The refrigerant tube is divided into two segments: a copper tube portion (first tube) and an aluminum tube portion (second tube). The copper segment provides reliability and thermal expansion resistance where needed, while the aluminum segment reduces overall weight and cost. This segmentation allows the system to achieve both high reliability and reduced weight by placing each material where it is most beneficial.

Inventive Principle:
Principle #1Segmentation

2Reliability

If copper refrigerant tubes are used, then reliability is improved, but cost increases

Engineering Contradiction:
ImprovereliabilityVSAvoidcost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The refrigerant tube is segmented into copper and aluminum portions, allowing the expensive copper material to be used only where reliability is critical, while aluminum is used for the remaining portions to reduce cost. This selective material usage maintains reliability while significantly lowering manufacturing costs.

Inventive Principle:
Principle #1Segmentation

3Weight of moving object

If different metals are used for refrigerant tubes and heat dissipating fins, then weight is reduced, but corrosion resistance deteriorates

Engineering Contradiction:
ImproveweightVSAvoidcorrosion resistance
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The invention applies different material qualities to different locations: the copper tube portion is used where corrosion resistance and thermal expansion stability are most critical, while aluminum tubes are used where weight reduction is prioritized. The coupling tube design ensures that dissimilar metals do not directly contact, preventing galvanic corrosion while maintaining the weight benefits of aluminum.

Inventive Principle:
Principle #3Local quality

4Weight of moving object

If aluminum refrigerant tubes are used, then weight and cost are reduced, but thermal expansion characteristic deteriorates

Engineering Contradiction:
ImproveweightVSAvoidthermal expansion characteristic
Core Design Contradiction:
Weight of moving objectVSStability of the object's composition

Solution Approach 1:

The refrigerant tube is segmented into copper and aluminum portions, with the copper segment specifically positioned to handle thermal expansion challenges. The copper portion provides stable thermal expansion characteristics where temperature variations are most severe, while aluminum portions provide weight reduction in less critical areas.

Inventive Principle:
Principle #1Segmentation

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 solution reduces the weight and cost of air conditioners, increases their lifespan by preventing corrosion, and improves thermal conductivity, leading to reduced power consumption and easier installation.

Implementation Method 1

refrigerant tubes and heat dissipating fins may be subject to corrosion when formed of different metals. The coupling tube includes a first metal part contacting the aluminum tube and a second metal part contacting the copper tube, preventing direct contact between dissimilar metals

Methodology Applied
Scientific EffectGalvanic corrosion prevention:

Implementation Method 2

heat dissipating fins coupled to the refrigerant tubes for facilitating heat exchange between refrigerant in the tubes and external air

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

the refrigerant is evaporated in the indoor heat exchanger

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 4

the refrigerant is evaporated in the indoor heat exchanger and is guided back to the compressor

Methodology Applied
Scientific EffectHeat absorption during phase change: Latent Heat

Implementation Method 5

the refrigerant discharged from the compressor is condensed by the outdoor heat exchanger

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 6

the refrigerant discharged from the compressor is condensed by the outdoor heat exchanger

Methodology Applied
Scientific EffectHeat release during phase change: Latent Heat

Implementation Method 7

the refrigerant discharged from the compressor is condensed by the outdoor heat exchanger and is expanded (decompressed) by the expansion device

Methodology Applied
Scientific EffectPressure reduction: Depressurisation

Data Source

PatentEP2594869B1Air conditioner
Publication Date: 2020.09.30 LG ELECTRONICS INC
  • EP2594869B1 patent drawingFigure 1
  • EP2594869B1 patent drawingFigure 2
  • EP2594869B1 patent drawingFigure 3

AI summary

An air conditioner is provided. The air conditioner may include a compressor (10), a condenser (30), an expansion device (40) and an evaporator (70). The condenser or the evaporator may include a heat exchange tube formed of an aluminum material and allowing refrigerant to flow therein, and a fin connected to the heat exchange tube, the fin being formed of the same metal material as that of the heat exchange tube so as to prevent potential corrosion of the heat exchange tube.