Smart-Grid Refrigerator Cooling Control for Peak-Rate Power Saving

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Solution Overview

Problem

Refrigerators operate their compressors periodically regardless of variable power rates, leading to high electricity costs during peak hours, causing financial burdens for consumers and businesses.

Innovation Solution

A refrigerator with a power-rate information receiving system that sets over-cooling and power-saving periods based on smart grid data, using over-cooled air to minimize electricity usage during high-power-rate times by selectively directing cold air between storage chambers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the compressor operates periodically to maintain storage chamber temperatures, then the refrigerator function is ensured, but electricity costs increase during peak power rate hours

Engineering Contradiction:
Improverefrigerator functionVSAvoidelectricity cost
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system performs preliminary over-cooling of storage chambers before peak power rate periods begin. The controller receives power rate information and activates the compressor at high power rates to cool the storage chambers in advance, storing cold energy that will be used during peak rate periods when the compressor operates at low or zero power rates.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system dynamically adjusts compressor operation based on real-time power rate information. The controller switches between high power rate operation (for over-cooling) and low power rate operation (for maintenance), optimizing the balance between refrigerator reliability and electricity cost based on varying power rate conditions.

Inventive Principle:
Principle #15Dynamics

2Temperature

If the compressor operates continuously to maintain optimal temperatures in all storage chambers, then temperature control is improved, but electricity consumption increases during peak hours

Engineering Contradiction:
Improvestorage chamber temperature controlVSAvoidelectricity consumption
Core Design Contradiction:
TemperatureVSUse of energy by stationary object

Solution Approach 1:

The system pre-cools storage chambers before peak power rate periods using the compressor, storing excess cold energy. During peak hours, this stored cold energy maintains temperatures without requiring continuous compressor operation, thus reducing electricity consumption while preserving temperature control.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The cold air damper acts as an intermediary to redistribute cold air from over-cooled storage chambers to other chambers that need cooling. This allows the system to maintain temperature control across all chambers without running the compressor at full capacity during peak rate periods.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Use of energy by moving object

If the compressor is stopped during peak power rate hours to save electricity costs, then electricity cost decreases, but temperature maintenance in storage chambers becomes difficult

Engineering Contradiction:
Improveelectricity costVSAvoidtemperature maintenance
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The system performs preliminary over-cooling of storage chambers before peak power rate periods. This stored cold energy serves as a thermal buffer that maintains temperatures during peak hours when the compressor is stopped or operates minimally, ensuring reliability without incurring high electricity costs.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The cold air damper redistributes cold air from over-cooled storage chambers to chambers that require temperature maintenance. This passive heat transfer mechanism maintains temperatures without requiring active compressor operation during peak rate periods.

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

This approach reduces electricity consumption and costs by optimizing compressor operation according to variable power rates, maintaining refrigerator functions with minimal electricity use during peak hours.

Implementation Method 1

a cold air damper for moving cold air of the over-cooled storage chamber to the other storage chamber

Methodology Applied
Scientific EffectCold air transfer: Convection

Data Source

PatentEP2526357B1Refrigerator and control method thereof
Publication Date: 2018.05.30 LG ELECTRONICS INC
  • EP2526357B1 patent drawingFigure 1
  • EP2526357B1 patent drawingFigure 2
  • EP2526357B1 patent drawingFigure 3

AI summary

A refrigerator and a control method of the refrigerator are discussed. According to an embodiment, a control method of a refrigerator connected to an electric power management network comprises steps of receiving power-rate information via the electric power management network; setting an over-cooling period and a power-saving period based on the received power-rate information; controlling at east one storage chamber to be over-cooled by over-cooling cold air during the over-cooling period; and controlling the other storage chamber to be over-cooled by the over-cooled cold air during the power-saving period. According to the present invention, the functions of the refrigerator are provided with minimal use of electricity and/or with reduced electricity charges.