Refrigerator Door Air Duct Layout for Low-Frost Ice Making

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Solution Overview

Problem

Existing refrigerator designs face issues with cool air loss, increased power consumption, and reduced energy efficiency due to the installation of cool air ducts on the side wall face of the refrigerating chamber, which leads to heat exchange with external air, frost generation, longer duct lengths, and inefficient cool air circulation.

Innovation Solution

A refrigerator design where cool air ducts are positioned within the refrigerating chamber door, allowing direct supply of cool air from the freezing chamber to the refrigerating chamber, with a sealing mechanism to prevent external air infiltration and a damper system to control air flow based on ice level and temperature, optimizing air circulation and reducing the need for a defrosting heater.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If cool air ducts are installed on the side wall face of the refrigerating chamber, then cool air can be supplied to the ice making chamber, but the insulation thickness is reduced causing heat exchange with external air and cool air loss

Engineering Contradiction:
Improvecool air supply to ice making chamberVSAvoidcool air loss due to heat exchange
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The cool air ducts are nested within the refrigerating chamber door structure, specifically positioned within the protrusion of the door. This nesting approach allows the ducts to be housed without compromising the external insulation layer, as the door's protrusion provides internal space for duct installation while maintaining the original wall thickness and insulation integrity.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The duct installation moves from a lateral wall position to a vertical door position, utilizing the third dimension (door depth/protrusion) to accommodate ducts. This dimensional shift allows cool air supply functionality while preserving the insulation thickness of the main chamber walls.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Loss of energy

If cool air ducts are protruded to the inner side of the inner case to maintain wall thickness, then insulation is preserved, but the valid volume of the refrigerating chamber is reduced

Engineering Contradiction:
Improveinsulation thickness maintenanceVSAvoidvalid volume of refrigerating chamber
Core Design Contradiction:
Loss of energyVSVolume of stationary object

Solution Approach 1:

The refrigerating chamber door is segmented into functional zones: the protrusion area houses the ducts, while the main chamber interior retains full volume. This segmentation isolates the duct installation space to the door structure itself, preventing intrusion into the chamber's valid storage volume.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Ducts are nested within the door's protrusion structure, utilizing the door's own spatial features rather than encroaching on chamber volume. The protrusion acts as a dedicated duct housing that does not reduce the chamber's usable space.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Object-affected harmful factors

If heaters are installed between cool air ducts and outer case to prevent frost, then frost generation is reduced, but power consumption increases and cool air temperature rises

Engineering Contradiction:
Improvefrost generation on ductsVSAvoidpower consumption of heaters
Core Design Contradiction:
Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The heaters are extracted from the system by eliminating the thermal bridge between ducts and outer case. The protrusion design isolates ducts from the outer wall, removing the frost risk and eliminating the need for heating elements entirely.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The design converts the potential harm of cold duct surfaces into a benefit by using the protrusion structure to naturally insulate ducts from external air, eliminating frost formation without active heating.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

4Productivity

If cool air ducts are installed on the side wall face, then air flow path is established, but the duct length increases causing more cool air loss and delayed supply

Engineering Contradiction:
Improvecool air circulationVSAvoidduct length
Core Design Contradiction:
ProductivityVSLength of moving object

Solution Approach 1:

Instead of extending ducts laterally across the chamber wall, the air flow path is inverted to use the vertical door structure. Cool air flows downward through the door's protrusion, shortening the duct length and reducing thermal loss while maintaining effective air circulation.

Inventive Principle:
Principle #13The other way round (Inversion)

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 design reduces cool air loss, minimizes frost generation, decreases power consumption, and enhances energy efficiency by maintaining insulation thickness, prolonging cool air stay in the ice making chamber, and effectively utilizing cool air for both ice making and refrigeration.

Implementation Method 1

at least one evaporator configured to cool air used in regulating operating temperatures in the refrigerating compartment and the freezing compartment

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

a damper system to control air flow based on ice level and temperature, optimizing air circulation

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

a sealing mechanism to prevent external air infiltration and maintain insulation thickness

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 4

an ice compartment positioned at the refrigerating compartment door and configured to receive cool air from the freezing compartment

Methodology Applied
Scientific EffectFreezing: Freezing

Data Source

PatentEP2419685B1Refrigerator related technology
Publication Date: 2018.08.08 LG ELECTRONICS INC
  • EP2419685B1 patent drawingFigure 1
  • EP2419685B1 patent drawingFigure 2
  • EP2419685B1 patent drawingFigure 3~4

AI summary

A refrigerator and its operation method are disclosed. Cool air ducts guide cool air from a freezing compartment to an ice compartment that is positioned at a refrigerating compartment door. At least a portion of the cool air ducts are located at a barrier that separates the freezing compartment and the refrigerating compartment.