Folded Capillary Support Structure for Planar Heat Pipes

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Solution Overview

Problem

Conventional planar heat pipes face limitations in size and angle of inclination due to limited capillary action, rigidity issues, and the need for additional support structures, which restrict their ability to efficiently transfer heat over large areas and maintain even temperature distribution.

Innovation Solution

A planar heat transfer device with a folded capillary support structure that provides both capillary action and mechanical support, formed from a wire mesh to maintain the distance between walls and enhance capillary effect, allowing for efficient heat transport and distribution without additional spacers or support structures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If conventional planar heat pipes are used with traditional capillary structures, then heat transfer efficiency is maintained over small areas, but the device size is limited and cannot be scaled to large areas

Engineering Contradiction:
Improveheat transfer areaVSAvoidheat transfer reliability
Core Design Contradiction:
Area of stationary objectVSReliability

Solution Approach 1:

The patent combines the support structure and capillary structure into a single integrated folded capillary support structure. This merging eliminates the need for separate support structures and dimples, allowing the heat pipe to be scaled to large areas while maintaining reliable heat transfer through the unified structure that provides both mechanical support and capillary action.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The folded capillary support structure serves multiple functions simultaneously: it provides mechanical support to maintain the spacing between walls, enables capillary action for working fluid transport, and supports larger device areas. This multi-functionality allows the structure to scale to large areas while maintaining heat transfer reliability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Strength

If additional support structures and dimples are incorporated to maintain structural integrity, then rigidity is improved, but device complexity increases

Engineering Contradiction:
Improvestructural rigidityVSAvoidstructure complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The support structure and capillary structure are merged into a single folded capillary support structure. This integration eliminates the need for additional separate support structures and dimples, reducing device complexity while maintaining the necessary structural rigidity through the folded design.

Inventive Principle:
Principle #5Merging (Combining)

3Area of stationary object

If the heat pipe size is increased to cover larger areas, then heat distribution coverage is improved, but capillary action becomes insufficient

Engineering Contradiction:
Improveheat distribution areaVSAvoidcapillary action effectiveness
Core Design Contradiction:
Area of stationary objectVSEase of operation

Solution Approach 1:

The capillary support structure is folded in at least one direction, creating a three-dimensional configuration within the two-dimensional heat pipe plane. This folding increases the effective capillary rise height without increasing the horizontal footprint, enabling the heat pipe to cover larger areas while maintaining effective capillary action for working fluid transport.

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

4Temperature

If the spacing between walls is increased to ensure vapor space, then heat transfer efficiency is improved, but structural stability deteriorates

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidstructural stability
Core Design Contradiction:
TemperatureVSStability of the object's composition

Solution Approach 1:

The folded capillary support structure simultaneously provides the necessary spacing between walls for efficient heat transfer and the structural stability to maintain that spacing. The folded configuration creates a rigid structure that prevents wall collapse while maintaining the optimal vapor space distance.

Inventive Principle:
Principle #5Merging (Combining)

5Ease of manufacture

If conventional manufacturing methods are used, then manufacturing process is simple, but manufacturing precision is limited for large-area devices

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoiddimensional precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The invention changes the geometric parameters of the capillary support structure by folding it in at least one direction. This parameter change allows the structure to achieve the necessary rise height and mechanical strength for large-area heat pipes while maintaining compatibility with conventional layer-by-layer sintering manufacturing methods, thus improving manufacturing precision without completely changing the manufacturing process.

Inventive Principle:
Principle #35Parameter changes

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 device achieves effective heat distribution and removal over large areas, enabling larger sizes and varied angles of inclination, with improved rigidity and capillary action, preventing local overheating and ensuring efficient heat transport through the folded capillary structure.

Implementation Method 1

The capillary support structure extends, folded in at least one direction, between the first wall and the second wall to provide support and capillary action for condensed working fluid. This enables the transport of condensed working fluid through the capillary support structure from the second wall to the first wall.

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

During this transport, the liquid working fluid 450 successively evaporates along the first wall 410 (due to a heat source acting there). Near the second wall 420, the gaseous working fluid condenses

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

Near the second wall 420, the gaseous working fluid condenses and flows vertically downwards in the liquid phase. Thus, the entire cavity 400 forms a heat cycle for the working fluid.

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 4

A working fluid is located in the resulting cavity, which continuously condenses and evaporates during operation. This phase transition makes it possible to transfer large amounts of heat at a constant temperature level.

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP3812684B1Planar heat transfer device, use thereof and method for its manufacture
Publication Date: 2023.06.07 ALBAKRI SAMI ABDULRAHMAN A
  • EP3812684B1 patent drawingFigure 1
  • EP3812684B1 patent drawingFigure 2
  • EP3812684B1 patent drawingFigure 3A~3B

AI summary

A planar heat transfer device for heat distribution and removal from a planar heat source (50) is disclosed. The device comprises: a cavity (100) bounded by a first wall (110) for coupling to the planar heat source (50) and an opposing second wall (120), and containing a working fluid (150); and a capillary support structure (200) that extends folded in at least one direction (R) between the first wall (110) and the second wall (120) to provide support and capillary action for condensed working fluid (151), enabling the transport of condensed working fluid (151) through the capillary support structure (200) from the second wall (120) to the first wall (110).