Defrosting device and refrigerator having same

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Solution Overview

Problem

Existing defrosting devices for evaporators in refrigeration cycles face challenges such as high power consumption, heater overheating, and reduced lifespan due to concentrated high-temperature heat, as well as issues with working fluid circulation and sealing.

Innovation Solution

A defrosting device with a heating unit and heat pipe configuration where the heating unit has a plate-shaped ceramic heater attached to the outer surface of a heater case, featuring a vacant space with separated inlets and outlets, and extended fins for enhanced heat transfer and circulation, preventing overheating and improving maintenance accessibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If working fluid is filled only into a bottom portion of the heater, then evaporation speed increases due to rapid heating, but the heater may overheat

Engineering Contradiction:
Improveevaporation speedVSAvoidheater overheating
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The heater is configured as a plate-shaped heater with a large surface area, transitioning from a conventional three-dimensional heating element to a two-dimensional plate structure. This dimensional change increases the heat transfer surface area in contact with the working fluid, enabling more efficient heat distribution and preventing localized overheating while maintaining rapid evaporation speed.

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

2Temperature

If the heater is accommodated into the heat pipe, then high-temperature heat is concentrated on an inside of the heat pipe, but this reduces the lifespan of the heater as well as causing sealing problems

Engineering Contradiction:
Improveheat concentrationVSAvoidheater lifespan
Core Design Contradiction:
TemperatureVSDuration of action of stationary object

Solution Approach 1:

The heating system is segmented into two separate components: the plate-shaped heater and the heat pipe. The heater is positioned adjacent to the heat pipe rather than being accommodated inside it, allowing the heater to generate heat that is then transferred to the working fluid in the heat pipe. This segmentation prevents the heater from being exposed to high-temperature concentrations inside the heat pipe, thereby extending its lifespan and avoiding sealing problems.

Inventive Principle:
Principle #1Segmentation

3Productivity

If a heater is vertically disposed in the top-down direction of the evaporator, then heating efficiency is improved, but manufacturing cost and maintenance difficulty increase

Engineering Contradiction:
Improveheating efficiencyVSAvoidmanufacturing cost
Core Design Contradiction:
ProductivityVSEase of manufacture

Solution Approach 1:

The invention uses a plate-shaped heater that can be manufactured using standard ceramic heating element fabrication processes, essentially copying proven manufacturing techniques from other applications. This approach avoids the need for custom vertical heater designs, reducing manufacturing costs while maintaining effective heating performance through the plate's large surface area contact with the working fluid.

Inventive Principle:
Principle #26Copying

4Volume of moving object

If the heater is accommodated into the heat pipe, then compact structure is achieved, but sealing problems occur

Engineering Contradiction:
Improvedevice compactnessVSAvoidsealing problem
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The heater is extracted from the heat pipe structure and positioned as a separate component adjacent to the heat pipe. This extraction eliminates the sealing interface between the heater and heat pipe, thereby preventing sealing problems while maintaining a compact overall structure through the close proximity arrangement of the heater and heat pipe components.

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 solution reduces power consumption, enhances heat transfer efficiency, prolongs heater lifespan, and ensures efficient working fluid circulation, effectively addressing the challenges of existing defrosting technologies.

Implementation Method 1

a heater attached to an outer surface of the heater case to heat working fluid within the heater case

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

a heat pipe, both end portions of which are connected to an inlet and an outlet of the heating unit, respectively, and at least part of which is disposed adjacent to a cooling tube to dissipate heat to the cooling tube of the evaporator due to high-temperature working fluid heated and transferred by the heating unit

Methodology Applied
Scientific EffectHeat pipe: Heat Pipe

Data Source

PatentEP3367025B1Defrosting device and refrigerator having same
Publication Date: 2020.03.11 LG ELECTRONICS INC
  • EP3367025B1 patent drawingFigure 1
  • EP3367025B1 patent drawingFigure 2
  • EP3367025B1 patent drawingFigure 3

AI summary

The present disclosure discloses a defrosting device, including a heating unit provided in an evaporator; and a heat pipe, both end portions of which are connected to an inlet and an outlet of the heating unit, respectively, and at least part of which is disposed adjacent to a cooling tube to dissipate heat to the cooling tube of the evaporator due to high-temperature working fluid heated and transferred by the heating unit, wherein the heating unit includes a heater case provided with a vacant space therein, and provided with the inlet and the outlet at positions separated from each other, respectively, along a length direction; and a heater attached to an outer surface of the heater case to heat working fluid within the heater case.