Refrigerator Compressor Frequency Control for Lower Cooling Power

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Solution Overview

Problem

Existing refrigerator control methods fail to optimize power consumption by inefficiently managing the operation of compressor capacities and cooling frequencies between the refrigerator and freezer compartments, leading to increased energy usage.

Innovation Solution

A control method that involves driving the inverter-type refrigerator compartment compressor to cool the refrigerator compartment to a set temperature, then starting the inverter-type freezer compartment compressor before finishing the refrigerator compartment operation, maintaining its frequency, and subsequently varying the frequency of the refrigerator compartment compressor to reduce capacity and extend cooling time, while the freezer compartment compressor operates at full capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the refrigerator compartment compressor and freezer compartment compressor operate simultaneously at full capacity, then the cooling speed is fast, but the power consumption increases

Engineering Contradiction:
Improvecooling speedVSAvoidpower consumption
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by varying the operating frequency of the refrigerator compartment compressor based on the operational state of the freezer compartment compressor. When the freezer compartment compressor is running, the refrigerator compartment compressor operates at a reduced frequency (first frequency), and when the freezer compartment compressor stops, the refrigerator compartment compressor increases to a higher frequency (second frequency). This dynamic adjustment optimizes the balance between cooling speed and power consumption.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operating parameters (frequency) of the refrigerator compartment compressor according to different operational phases. The controller adjusts the frequency parameter dynamically: operating at a lower frequency during freezer cooling to reduce power consumption, and at a higher frequency when the freezer compressor stops to maintain cooling efficiency. This parameter change strategy resolves the contradiction between speed and energy usage.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the refrigerator compartment compressor operates at high frequency continuously, then the cooling efficiency is high, but the power consumption increases

Engineering Contradiction:
Improvecooling efficiencyVSAvoidpower consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent implements periodic action by alternating between two frequency modes based on the freezer compartment compressor's operation. The refrigerator compartment compressor operates at a lower frequency (first frequency) during periods when the freezer compressor is active, and switches to a higher frequency (second frequency) when the freezer compressor stops. This periodic frequency adjustment maintains cooling efficiency while reducing overall power consumption.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically adjusts the refrigerator compartment compressor frequency in response to the freezer compartment compressor's operational state. This dynamic control ensures that the refrigerator compartment receives adequate cooling during freezer operation (when cold air is being generated) while maximizing energy efficiency, and increases cooling capacity only when necessary (when the freezer compressor stops).

Inventive Principle:
Principle #15Dynamics

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 method reduces power consumption by shortening the time to reach target temperatures in both compartments, allowing for efficient operation and reduced energy usage, especially through the frequency-varying operation which extends the cooling time of the refrigerator compartment.

Implementation Method 1

the refrigerator is formed to cool an inside of the storage space using cooling air generated through heat exchange with a refrigerant circulated in a refrigeration cycle

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

The refrigeration cycle for cooling the refrigerator compartment and the freezer compartment may include a compressor, a condenser and an evaporator

Methodology Applied
Scientific EffectRefrigeration cycle:

Implementation Method 3

driving again the refrigerator compartment compressor after the freezer compartment driving operation is finished, the refrigerator compartment compressor being operated in a state in which a frequency thereof is varied to reduce a capacity when the driving thereof starts

Methodology Applied
Scientific EffectFrequency variation:

Data Source

PatentEP3144609B1Control method for refrigerator
Publication Date: 2018.04.25 LG ELECTRONICS INC
  • EP3144609B1 patent drawingFigure 1
  • EP3144609B1 patent drawingFigure 2
  • EP3144609B1 patent drawingFigure 3

AI summary

Provided is a control method for a refrigerator, including an refrigerator compartment driving operation [S110] of cooling a refrigerator compartment by driving of an inverter type refrigerator compartment compressor; a freezer compartment-first-driving operation [S130] of starting driving of an inverter type freezer compartment compressor when the refrigerator compartment reaches a set temperature (D1) before an operation of the refrigerator compartment is finished; a freezer compartment driving operation [S160] of maintaining the driving of the freezer compartment compressor after the refrigerator compartment driving operation is finished and cooling the freezer compartment to a target temperature (D3); and a frequency-varying operation [S180] of cooling the refrigerator compartment to a target temperature (D2) by driving again the refrigerator compartment compressor after the freezer compartment driving operation is finished, the refrigerator compartment compressor being operated in a state in which a frequency thereof is varied to reduce a capacity when the driving thereof starts.