A method for controlling a refrigerator

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Solution Overview

Problem

Refrigerators face issues with high power consumption and temperature deviation due to repeated compressor operation and excessive cooling, leading to overcooling and reduced freshness of stored items.

Innovation Solution

A control method that adjusts the compressor and fan power based on temperature references, operating at initial cooling power when above a first temperature and delay power when below a second temperature, maintaining the storage room temperature within a set range to reduce power consumption and prevent overcooling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the compressor is repeatedly started and stopped to maintain set temperature, then the storage room temperature can be maintained within limit ranges, but power consumption increases due to repeated startup

Engineering Contradiction:
Improvestorage room temperatureVSAvoidpower consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by transitioning from a static on/off control mode to a dynamic variable-speed control mode. The compressor speed is continuously adjusted based on the temperature difference between the storage room and set temperature, allowing smooth modulation of cooling output without repeated startups and stops, thereby reducing power consumption while maintaining temperature control.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operational parameter of the compressor from binary (on/off) to continuous (variable speed). By controlling the rotational speed of the compressor motor according to temperature conditions, the system achieves gradual cooling adjustment rather than abrupt on/off cycles, eliminating startup power surges and reducing overall energy consumption.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the damper is fully opened to cool the storage room quickly, then cooling efficiency improves, but the storage room is overcooled and temperature stability deteriorates

Engineering Contradiction:
Improvecooling efficiencyVSAvoidtemperature stability
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The patent applies dynamics by making the damper opening degree variable rather than fixed at fully open. The damper position is dynamically adjusted based on real-time temperature feedback, allowing the system to optimize the balance between cooling efficiency and temperature stability, preventing overcooling while maintaining effective cooling when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback control by continuously monitoring the storage room temperature and adjusting the damper opening degree accordingly. When the temperature approaches the set point, the damper is partially closed to reduce cooling input, preventing overcooling. This closed-loop feedback mechanism maintains temperature stability while preserving cooling efficiency when temperature deviations occur.

Inventive Principle:
Principle #23Feedback

3Power

If the damper is fully opened to supply cool air from freezing compartment, then cooling power increases, but the freezing compartment load rapidly increases

Engineering Contradiction:
Improvecooling powerVSAvoidfreezing compartment load
Core Design Contradiction:
PowerVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the damper opening degree variable based on cooling needs. Instead of keeping the damper fully open, the system dynamically adjusts the opening to provide sufficient cooling power to the storage room while limiting the amount of cool air drawn from the freezing compartment, thereby preventing excessive load on the freezing compartment.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent applies partial action by opening the damper only to the extent necessary to meet the cooling demand of the storage room. Rather than fully opening the damper which would provide excessive cooling power and overburden the freezing compartment, the system uses partial opening to achieve optimal balance between cooling effectiveness and load distribution.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3392583B1A method for controlling a refrigerator
Publication Date: 2022.05.11 LG ELECTRONICS INC
  • EP3392583B1 patent drawingFigure 1
  • EP3392583B1 patent drawingFigure 2A
  • EP3392583B1 patent drawingFigure 2B

AI summary

A control method for a refrigerator, comprises sensing a temperature of a storage room; operating a cool air supply means at a cooling power when the sensed temperature of the storage room is equal to or above a first reference temperature; operating the cool air supply means at a delay power, which is less than the cooling power, when the sensed temperature of the storage room is equal to or below a second reference temperature, which is less than the first reference temperature while the cool air supply means is operating at the cooling power; and allowing a control unit to determine a cooling power or a delay power of the cool air supply means according to the temperature of the storage room while the cool air supply means is operating at the delay power, and operating the cool air supply means at the determined cooling power or delay power.