Air conditioning system

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Solution Overview

Problem

Air conditioning systems face performance and stability issues due to excessive liquid refrigerant injection, which can lead to compressor damage and inefficiencies, particularly in cooling and heating operations.

Innovation Solution

The system incorporates a control unit to manage the ratio of liquid refrigerant injected into the compressor by using an injection heat exchanger and expansion valves, ensuring the refrigerant is injected in a two-phase or superheated vapor state, preventing liquid compression and enhancing performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If liquid refrigerant is injected into the compressor to improve cooling performance, then the cooling efficiency is improved, but the risk of liquid compression and compressor damage increases

Engineering Contradiction:
Improvecooling efficiencyVSAvoidcompressor safety
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The injection heat exchanger pre-cools the liquid refrigerant before it enters the compressor by performing heat exchange with the refrigerant from the condenser. This preliminary action ensures the refrigerant is in an appropriate state (controlled liquid ratio) before compression, improving cooling efficiency while preventing liquid compression damage to the compressor

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The control unit continuously monitors the operating state and adjusts the opening degree of the injection valve to maintain the liquid refrigerant ratio below a predetermined value. This feedback control ensures optimal cooling performance while preventing excessive liquid refrigerant from entering the compressor, thus protecting against compressor damage

Inventive Principle:
Principle #23Feedback

2Productivity

If the opening degree of the injection valve is increased to improve cooling performance, then the refrigerant injection amount increases, but the liquid refrigerant ratio becomes excessive leading to compressor damage

Engineering Contradiction:
Improvecooling performanceVSAvoidliquid compression
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The control unit continuously monitors the operating state and adjusts the opening degree of the injection valve to maintain the liquid refrigerant ratio below a predetermined value. This feedback control ensures optimal cooling performance while preventing excessive liquid refrigerant from entering the compressor, thus protecting against compressor damage

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts the opening degree parameter of the injection valve based on operating conditions to optimize the liquid refrigerant ratio. By changing this parameter within optimal ranges, the system achieves improved cooling performance while avoiding the harmful effects of excessive liquid compression

Inventive Principle:
Principle #35Parameter changes

3Reliability

If an injection heat exchanger is installed to control refrigerant state, then the reliability is improved, but the device complexity increases

Engineering Contradiction:
Improvesystem stabilityVSAvoidheat exchanger structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The injection heat exchanger is integrated with the base pan of the outdoor unit, merging the heat exchanger function with the existing structural component. This integration approach improves system reliability by ensuring proper refrigerant state control while minimizing the increase in device complexity through effective use of existing space and structures

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The injection heat exchanger serves multiple functions: it cools the liquid refrigerant before compression, utilizes the base pan structure for mounting, and integrates with the existing refrigerant circulation system. This multi-functionality approach justifies the added complexity by providing multiple benefits within a single integrated component

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 approach improves cooling and heating performance, particularly in low temperature regions, while preventing compressor damage and increasing system reliability by maintaining a controlled liquid refrigerant ratio below a predetermined value.

Implementation Method 1

an injection heat exchanger for performing heat exchange between the refrigerant passed through the injection valve and the refrigerant introduced into the second expansion device

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

a first expansion device for throttling the refrigerant passed through the condenser; a second expansion device for throttling the refrigerant passed through the first expansion device

Methodology Applied
Scientific EffectThrottling: Pressure Drop

Implementation Method 3

a compressor for compressing refrigerant

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 4

a condenser and for condensing the refrigerant discharged from the compressor

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 5

an evaporator and for evaporating the refrigerant passed through the second expansion device

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP2083230B1Air conditioning system
Publication Date: 2020.04.15 LG ELECTRONICS INC
  • EP2083230B1 patent drawingFigure 1
  • EP2083230B1 patent drawingFigure 2
  • EP2083230B1 patent drawingFigure 3

AI summary

An air conditioning system 100 can improve the cooling/heating performance of the system because the injection of refrigerant into a compressor 110 is achieved. The air conditioning system can further improve the cooling/heating performance in a low temperature region by injecting the refrigerant as a two-phase refrigerant or a superheated vapor state into the compressor. The air conditioning system can prevent damage of the compressor and further improve reliability by controlling such that the ratio of a liquid refrigerant in the refrigerant injected into the compressor may be less than a set value.