Air Conditioner Oil Level Control Using Dual-Height Collection Tubes

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Solution Overview

Problem

Air conditioners face challenges in maintaining a stable oil level within the compressor, which can affect performance and efficiency, as existing systems lack effective mechanisms to adjust and regulate oil levels accurately.

Innovation Solution

The air conditioner incorporates an oil sensor, adjustable electronic expansion valve, and a control unit that manage oil collection and discharge through separate collection tubes to maintain a predetermined oil level by adjusting the opening degree of the oil valve based on detected oil levels and patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single collection tube is used to return oil from the oil separator to the compressor, then the device complexity is reduced, but the oil level within the compressor cannot be maintained at a predetermined level

Engineering Contradiction:
Improvecollection tube structureVSAvoidoil level stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The single collection tube is segmented into a first collection tube and a second collection tube with different heights. The first collection tube returns oil when the level is sufficient, while the second collection tube activates when the oil level drops, ensuring continuous oil level maintenance through divided functional segments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically switches between the first and second collection tubes based on the oil level detected by the oil sensor. The control unit adjusts which tube is active, creating a dynamic response mechanism that adapts to changing oil levels to maintain stability.

Inventive Principle:
Principle #15Dynamics

2Quantity of substance

If the oil valve opening degree is increased to reduce oil level in the compressor, then the oil level decreases, but the compressor performance may degrade due to insufficient oil

Engineering Contradiction:
Improveoil level in compressorVSAvoidcompressor performance
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The oil sensor continuously monitors the oil level in the compressor and provides feedback to the control unit. Based on this feedback, the control unit dynamically adjusts the oil valve opening degree to regulate oil flow, ensuring the oil level remains within the optimal range that maintains compressor performance.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes the opening degree parameter of the oil valve based on detected oil levels. When oil level is high, the valve opening increases to reduce oil; when oil level is low, the valve opening decreases to conserve oil, dynamically adjusting this parameter to maintain optimal conditions.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If an oil sensor and control system are added to monitor and adjust oil levels, then the oil level stability is improved, but the device complexity increases

Engineering Contradiction:
Improveoil level maintenanceVSAvoidcontrol system structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The oil sensor and control unit create a self-regulating system that automatically monitors and adjusts oil levels without external intervention. The system serves itself by detecting oil level changes and autonomously controlling the oil valve to maintain optimal oil levels, eliminating the need for manual monitoring or complex external control mechanisms.

Inventive Principle:
Principle #25Self-service

4Measurement precision

If the second collection tube is positioned at a different height than the first collection tube, then the oil level control precision is improved, but the manufacturing complexity increases

Engineering Contradiction:
Improveoil level detection accuracyVSAvoidtube installation complexity
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

Different portions of the collection tube system are assigned different heights and functions. The first collection tube is positioned for normal oil level collection, while the second collection tube is positioned at a different height to detect and respond to low oil levels, creating local quality variations that enable precise oil level control at specific locations within the system.

Inventive Principle:
Principle #3Local quality

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 ensures a stable oil level within the compressor, minimizing performance degradation and optimizing the air conditioner's operation by dynamically adjusting the oil level to maintain efficiency and extend compressor lifespan.

Implementation Method 1

an oil sensor disposed in the compressor to detect oil stored in the compressor

Methodology Applied
Scientific EffectOil level detection:

Implementation Method 2

The oil valve comprises an electronic expansion valve of which an opening degree is adjustable

Methodology Applied
Scientific EffectValve flow control: Valve

Implementation Method 3

an oil separator to separate the oil from the refrigerant discharged from the compressor

Methodology Applied
Scientific EffectGravitational separation: Gravitation

Data Source

PatentEP2889556B1Air conditioner
Publication Date: 2020.09.30 LG ELECTRONICS INC
  • EP2889556B1 patent drawingFigure 1
  • EP2889556B1 patent drawingFigure 2
  • EP2889556B1 patent drawingFigure 3

AI summary

Provided is an air conditioner. The air conditioner includes a compressor compressing a refrigerant, an oil sensor disposed in the compressor to detect oil stored in the compressor, an oil separator to separate the oil from the refrigerant discharged from the compressor, a first collection tube to collect the oil separated by the oil separator into the compressor, a second collection tube disposed at a height different from that of the first collection tube, an oil valve disposed in the second collection tube, and a control unit to control the oil valve on the basis of information detected by the oil sensor.