Linear Compressor Refrigerator Noise Control via Evaporator Heat Exchange

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Solution Overview

Problem

Refrigerators with linear compressors generate loud operation noise during heavy heating loads due to high vibration frequencies, which resonate with the refrigerator body, especially when the compressor is located at the top and closer to the user.

Innovation Solution

A control method that monitors the evaporator temperature and reduces heat exchange by closing the air door and/or blower, decreasing the inlet and outlet pressures of the linear compressor, thereby reducing its vibration frequency and operation noise.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the linear compressor operates under heavy heating load conditions, then the cooling capacity is sufficient, but the operation noise increases due to high vibration frequencies resonating with the refrigerator body

Engineering Contradiction:
Improvecooling capacityVSAvoidoperation noise
Core Design Contradiction:
PowerVSObject-generated harmful factors

Solution Approach 1:

The patent implements periodic action by controlling the air door and blower to cycle between open and closed states. During heavy heating loads, the system periodically adjusts the heat exchange rate by closing the air door and stopping the blower, which modulates the evaporator temperature and compressor operating conditions to reduce vibration frequency and noise while maintaining cooling capacity

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent applies parameter changes by dynamically adjusting the evaporator temperature through control of the air door and blower. By changing the heat exchange rate parameter, the system modifies the compressor's inlet and outlet pressures, thereby changing the vibration frequency parameter to avoid resonance and reduce noise during heavy heating loads

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the evaporator heat exchange rate is high, then the cooling efficiency is improved, but the evaporator temperature increases causing higher compressor vibration frequency and noise

Engineering Contradiction:
Improvecooling efficiencyVSAvoidvibration frequency
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent implements dynamics by making the heat exchange rate adjustable rather than fixed. The air door and blower are dynamically controlled based on operating conditions, allowing the system to adapt the evaporator temperature and cooling efficiency in real-time, thereby reducing vibration frequency and noise when necessary while maintaining high cooling efficiency when needed

Inventive Principle:
Principle #15Dynamics

3Volume of stationary object

If the linear compressor is positioned at the top of the refrigerator to maximize freezing compartment volume, then the storage capacity is improved, but the noise is more noticeable as the compressor is closer to the user's ear

Engineering Contradiction:
Improvefreezing compartment volumeVSAvoidperceived noise
Core Design Contradiction:
Volume of stationary objectVSObject-generated harmful factors

Solution Approach 1:

The patent applies the taking out principle by extracting the noise problem from the fixed compressor position. Since the compressor must remain at the top for volume optimization, the system extracts the harmful vibration and noise effects through active control of the air door and blower, which reduces the compressor's vibration frequency and operational noise while maintaining the beneficial top-positioning for maximum storage capacity

Inventive Principle:
Principle #2Taking out (Extraction)

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 method effectively decreases the operation noise of the linear compressor by rapidly lowering the evaporator temperature and reducing vibration frequencies, preventing resonance with the refrigerator body.

Implementation Method 1

linear compressors are used to compress the coolant to make cooling

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

the temperature of the evaporator in the cooling loop of the linear compressor will be relatively high

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

the entire vibration frequency of the linear compressor decreases, and is not easy to resonate with the refrigerator body

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 4

with the increase of the heating load of the refrigerator, the vibration frequency when the linear compressor operates will also be relatively high, easy to resonate with the refrigerator body and will generate relatively loud noise

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP3372932B1Refrigerator adopting linear compressor and control method thereof
Publication Date: 2022.11.09 HAIER SMART HOME CO LTD
  • EP3372932B1 patent drawingFigure 1
  • EP3372932B1 patent drawingFigure 2
  • EP3372932B1 patent drawingFigure 3

AI summary

Disclosed is a refrigerator adopting a linear compressor and a control method thereof. The method includes: monitoring the temperature of an evaporator of the refrigerator; if the current temperature of the evaporator of the refrigerator is greater than or equal to a first preset temperature threshold, then invoking a noise reduction mode to actively reduce the heat exchange amount between the evaporator and a compartment of the refrigerator until the current temperature of the evaporator of the refrigerator is smaller than or equal to a second preset temperature threshold, and invoking a cooling mode to resume the normal heat exchange between the evaporator and the compartment of the refrigerator, wherein the first preset temperature threshold is higher than the second preset temperature threshold. In the present invention, when there is a heavy heating load, the air door of the evaporator and/or the blower is closed so that the heat exchange rate of the evaporator decreases, the temperature of the evaporator decreases rapidly, and the inlet and outlet pressures of the linear compressor also decrease accordingly. Finally, the entire vibration frequency of the linear compressor decreases, and is not easy to resonate with the refrigerator body, achieving the advantage of low operation noise.