Cooling Element With Pulsating Heat Pipe Fins

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Solution Overview

Problem

Existing cooling elements with horizontal orientation suffer from insufficient cooling performance, particularly when used with power-semiconductor modules generating significant heat loads, as they are not efficient in fluid circulation and heat distribution.

Innovation Solution

Incorporating fins with flow channels that function as pulsating heat pipes, allowing fluid circulation independently of orientation, with fluid communication between channels to enhance heat transfer and distribution across the fins.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cooling elements are used in horizontal orientation with conventional fins, then the structure is simple and easy to manufacture, but the cooling performance is insufficient for high heat loads

Engineering Contradiction:
Improvecooling performanceVSAvoidstructure complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent introduces pulsating heat pipes as fluid-filled channels within the fin structure, utilizing phase change and capillary action to actively transport heat. This hydraulic/pneumatic system enables superior cooling performance by circulating working fluid through the fins, transforming passive thermal conduction into active heat pumping without external power

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The pulsating heat pipes utilize phase transitions of the working fluid (evaporation and condensation) to transfer heat. The fluid evaporates at the hot base plate, transports vapor through the fin channels, condenses releasing heat, and returns as liquid, creating a continuous heat pumping cycle that dramatically improves cooling capability

Inventive Principle:
Principle #36Phase transitions

2Temperature

If external pumps are added to improve fluid circulation, then cooling performance improves, but device complexity and power requirements increase

Engineering Contradiction:
Improvecooling performanceVSAvoiddevice complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The pulsating heat pipes are designed to be self-driven through internal capillary forces and phase change dynamics. The narrow capillary channels create surface tension effects that automatically pump the working fluid through the system without external assistance. The system serves itself by using the heat load to drive its own circulation

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces mechanical pumping systems with a thermodynamic-capillary system. Instead of using mechanical pumps driven by motors and power supplies, the invention uses phase change mechanisms and capillary pressure to achieve fluid circulation, eliminating complex mechanical components

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Temperature

If conventional fins are used without internal flow channels, then manufacturing is simpler, but heat distribution across the fins is insufficient

Engineering Contradiction:
Improveheat distributionVSAvoidmanufacturing complexity
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The fin structure is segmented into multiple discrete pulsating heat pipe channels, each acting as an independent heat transport pathway. This segmentation allows heat to be distributed throughout the fin array through multiple parallel fluid circulation loops, ensuring uniform heat distribution across all fins rather than relying on conduction alone

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The flow channels are nested within the fin structure itself, with the fluid passages embedded in the fin material or as integral parts of the fin assembly. This nesting integrates the heat transport function directly into the heat dissipation structure, combining form and function in a single component

Inventive Principle:
Principle #7Nested doll (Nesting)

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 cooling element achieves improved cooling performance and can be used in any orientation, efficiently dissipating heat without the need for external pumps, thereby addressing the limitations of traditional cooling elements.

Implementation Method 1

Incorporating fins with flow channels that function as pulsating heat pipes, allowing fluid circulation independently of orientation

Methodology Applied
Scientific EffectPulsating heat pipe: Heat Pipe

Implementation Method 2

A pulsating heat pipe involves a meandering flow channel 1 having a capillary dimension, in other words a cross-section small enough for capillary forces to dominate over gravity forces

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 3

a second surface (13) of the cooling element is provided with fins (14) for forwarding a heat load received from the electric component (12) to surroundings via the fins

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 4

An airflow 15 may be generated to pass between the fins 14 such that the fins dissipate heat into this airflow 15

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2876400B1Cooling element
Publication Date: 2016.10.05 ABB TECH OY
  • EP2876400B1 patent drawingFigure 1a~2
  • EP2876400B1 patent drawingFigure 3~5
  • EP2876400B1 patent drawingFigure 6~7

AI summary

The invention relates to a cooling element (40) comprising a first surface (11) for receiving an electric component (12), a second surface (13) which is provided with fins (14) for forwarding a heat load received from the electric component (12) via the first surface (11) to surroundings. In order to obtain a cooling element providing efficient cooling one or more of the fins (14) are provided with a flow channel (1) for passing a fluid within each respective fin.