Scroll compressor and air conditioner having same

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Solution Overview

Problem

In bottom-compression type scroll compressors, oil is mixed with refrigerant and can stagnate, leading to decreased oil viscosity, oil shortages, and increased friction and wear, especially in low-temperature environments.

Innovation Solution

A liquid refrigerant discharge unit is installed to induce stagnated liquid refrigerant towards a refrigerant discharge tube, and a venturi tube is used to enhance the discharge of liquid refrigerant through a venturi effect, thereby preventing stagnation and maintaining oil viscosity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a bottom-compression type scroll compressor is used, then the compressor can achieve high pressure ratio and compact structure, but liquid refrigerant stagnates in the inner space causing oil viscosity decrease and friction loss

Engineering Contradiction:
Improvepressure ratioVSAvoidoil viscosity maintenance
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent extracts and removes the stagnated liquid refrigerant from the inner space of the compressor casing. By providing a liquid refrigerant discharge passage that extends to the lowermost position and using a refrigerant flow inducing passage to actively draw out accumulated liquid refrigerant, the system prevents oil viscosity degradation caused by liquid refrigerant mixing, thereby maintaining reliable lubrication while preserving the high pressure ratio capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a liquid refrigerant discharge passage and refrigerant flow inducing passage as intermediary structures. These passages act as mediators to actively manage the removal of liquid refrigerant from the inner space, preventing direct contact between liquid refrigerant and oil, thus maintaining oil viscosity without compromising the compressor's high pressure ratio performance

Inventive Principle:
Principle #24Intermediary (Mediator)

2Temperature

If the compressor operates in low-temperature environment, then cooling performance is improved, but liquid refrigerant stagnation increases causing friction and wear

Engineering Contradiction:
Improvecooling performanceVSAvoidfriction and wear
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent implements preliminary action by proactively providing a liquid refrigerant discharge passage and refrigerant flow inducing passage before liquid refrigerant accumulation becomes problematic. These structures are pre-configured to automatically draw out and remove liquid refrigerant at the lowermost position of the inner space, preventing friction and wear before they can occur during low-temperature operation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent extracts liquid refrigerant from the inner space using a dedicated discharge passage system. By continuously removing liquid refrigerant that would otherwise accumulate and mix with oil during low-temperature operation, the system prevents friction and wear while maintaining effective cooling performance

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If oil is mixed with refrigerant to facilitate return, then oil circulation is improved, but oil stagnates at upper side of motor unit and is discharged outside

Engineering Contradiction:
Improveoil circulationVSAvoidoil discharge
Core Design Contradiction:
Ease of operationVSLoss of substance

Solution Approach 1:

The patent segments the inner space into distinct functional zones: a liquid refrigerant discharge passage for removing liquid refrigerant, an oil storage space for collecting returned oil, and a refrigerant discharge passage for discharging compressed refrigerant. This segmentation prevents mixing between liquid refrigerant and oil, allowing oil to be properly stored and circulated while preventing oil loss through discharge

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces an oil storage space and flow path guide as intermediary structures. These components act as mediators to separate the paths of liquid refrigerant and oil, enabling oil to be properly collected and circulated without stagnating at the upper side of the motor unit or being discharged outside the compressor

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution effectively prevents excessive stagnation of liquid refrigerant, maintains oil viscosity, and reduces friction and wear, enhancing the efficiency and reliability of the air conditioning system.

Implementation Method 1

a venturi tube is used to enhance the discharge of liquid refrigerant through a venturi effect

Methodology Applied
Scientific EffectVenturi effect: Venturi Effect

Data Source

PatentEP4067657B1Scroll compressor and air conditioner having same
Publication Date: 2025.05.07 LG ELECTRONICS INC
  • EP4067657B1 patent drawingFigure 1
  • EP4067657B1 patent drawingFigure 2
  • EP4067657B1 patent drawingFigure 3

AI summary

Air conditioner and scroll compressor for an air conditioner including: a refrigerant discharge tube (116) through which refrigerant discharged to an inner space (110a) of a casing (110) is discharged into a refrigeration cycle; a venturi tube (191) disposed adjacent to the refrigerant discharge tube (116) in the inner space of the casing; and a liquid refrigerant discharge tube (192) having a first end connected to the venturi tube (191) and a second end opposite to the first end and communicating with the inner space of the casing at a lower side of the refrigerant discharge tube, whereby liquid refrigerant can be suppressed from excessively stagnating in the inner space of the casing.