Compressor Injection Heat Exchanger for Air Conditioner Cooling

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Solution Overview

Problem

Prior air conditioner technologies experience a reduction in cooling ability due to the bypass of high-temperature and high-pressure refrigerant during cooling operations, leading to a decrease in evaporation flow rate and efficiency.

Innovation Solution

An air conditioner design that includes an injection module with an injection heat exchanger and expansion valves to inject refrigerant that has undergone heat exchange in the indoor heat exchanger into the compressor during cooling operations, enhancing efficiency by increasing the refrigerant's enthalpy and preventing refrigerant flow back to the indoor heat exchanger during heating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a portion of high-temperature and high-pressure liquid-phase refrigerant is bypassed during cooling operation, then the coefficient of performance is enhanced, but the cooling ability deteriorates due to reduction in evaporation flow rate

Engineering Contradiction:
Improvecoefficient of performanceVSAvoidcooling ability
Core Design Contradiction:
Use of energy by moving objectVSProductivity

Solution Approach 1:

The patent introduces an injection heat exchanger as an intermediary device between the indoor heat exchanger and the compressor. This heat exchanger serves as a mediator to transfer heat from the bypassed refrigerant to the main refrigerant flow, allowing the bypassed refrigerant to contribute to cooling rather than merely being injected into the compressor. The intermediary device resolves the contradiction by enabling the bypassed refrigerant to enhance cooling performance while maintaining appropriate evaporation flow rate.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the traditional mechanical injection method (directly injecting bypassed refrigerant into the compressor) with a thermal substitution approach. Instead of mechanically forcing the bypassed refrigerant into the compressor, the system uses heat exchange in the injection heat exchanger to pre-cool the main refrigerant flow, substituting mechanical injection with thermal interaction to achieve both performance enhancement and cooling ability maintenance.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Productivity

If refrigerant is injected into the compressor during cooling operation, then efficiency increases, but refrigerant flow rate to indoor unit decreases

Engineering Contradiction:
ImproveefficiencyVSAvoidrefrigerant flow rate
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The injection heat exchanger acts as an intermediary that captures heat from the bypassed refrigerant and transfers it to the main refrigerant flow before the latter enters the indoor heat exchanger. This intermediary mechanism allows the system to maintain high refrigerant flow rate to the indoor unit while still utilizing the bypassed refrigerant's thermal energy, thereby maintaining both efficiency and refrigerant quantity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If refrigerant flow path is changed for heating operation, then heating performance is improved, but system complexity increases

Engineering Contradiction:
Improveheating performanceVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The injection heat exchanger is designed with multi-functionality to serve both cooling and heating operations. During cooling, it acts as a heat exchanger for bypassed refrigerant; during heating, it facilitates refrigerant flow redirection. This universal design allows the system to improve heating performance without proportionally increasing system complexity, as the same component performs multiple functions across different operating modes.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 design increases cooling efficiency by injecting heat-exchanged refrigerant into the compressor, maintaining refrigerant flow and enhancing the cooling ability, while also optimizing heating operations by diverting refrigerant through different paths.

Implementation Method 1

the injection module performs heat exchange between the portion of the refrigerant discharged from the indoor heat exchanger and refrigerant, which moves from the outdoor heat exchanger to the indoor heat exchanger, during the cooling operation

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

a first injection expansion valve for expanding refrigerant, which moves between the injection heat exchanger and the compressor

Methodology Applied
Scientific EffectExpansion: Pressure Drop

Implementation Method 3

a compressor for compressing refrigerant

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 4

an outdoor heat exchanger installed in an outdoor space for performing heat exchange between the refrigerant and outdoor air

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 5

an indoor heat exchanger installed in an indoor space for performing heat exchange between the refrigerant and indoor air

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP3193103B1Air conditioner
Publication Date: 2018.10.03 LG ELECTRONICS INC
  • EP3193103B1 patent drawingFigure 1
  • EP3193103B1 patent drawingFigure 2
  • EP3193103B1 patent drawingFigure 3

AI summary

Disclosed is an air conditioner including a compressor for compressing refrigerant, an outdoor heat exchanger installed in an outdoor space for performing heat exchange between the refrigerant and outdoor air, an indoor heat exchanger installed in an indoor space for performing heat exchange between the refrigerant and indoor air, a switching valve for guiding the refrigerant, discharged from the compressor, to the outdoor heat exchanger during a cooling operation and to the indoor heat exchanger during a heating operation, and an injection module for injecting a portion of the refrigerant, discharged from the indoor heat exchanger, to the compressor, and the injection module performs heat exchange between a portion of the refrigerant discharged from the indoor heat exchanger and the refrigerant, which moves from the outdoor heat exchanger to the indoor heat exchanger, during the cooling operation, and injects the refrigerant into the compressor, thus increasing efficiency.