Multi-Cavity Loop Heat Pipe for Compact Multi-Source Cooling

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Solution Overview

Problem

Existing loop heat pipes for electronic devices with multiple heat sources require significant space and high manufacturing costs, limiting their effectiveness and affordability in improving heat dissipation efficiency.

Innovation Solution

A loop heat pipe design with separate evaporation cavities and capillary structures that form an anti-backflow mechanism, allowing heat dissipation from multiple sources while minimizing space and reducing manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a loop heat pipe is designed to dissipate heat from multiple heat sources, then heat dissipation efficiency is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improveheat dissipation efficiencyVSAvoidstructure complexity
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The loop heat pipe is divided into multiple independent evaporation cavities (first evaporation cavity, second evaporation cavity, etc.), each capable of dissipating heat from separate heat sources. The housing is segmented into corresponding housing components, and the capillary structure is divided into multiple parts (first capillary structure, second capillary structure, etc.) that distribute throughout different cavities. This segmentation enables multi-source heat dissipation while maintaining manageable complexity through modular design.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The loop heat pipe structure is designed to serve multiple functions simultaneously: the same capillary structures serve both as liquid transport channels and as vapor blocking elements; the partition walls serve both as structural separators and as thermal isolation barriers; the housing components serve both as structural supports and as sealing elements. This multi-functionality reduces the need for additional specialized components, thereby reducing overall device complexity.

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

2Power

If a loop heat pipe is designed to dissipate heat from multiple heat sources, then heat dissipation efficiency is improved, but manufacturing cost increases

Engineering Contradiction:
Improveheat dissipation efficiencyVSAvoidmanufacturing cost
Core Design Contradiction:
PowerVSEase of manufacture

Solution Approach 1:

Multiple functional elements are merged into single components: the partition walls between evaporation cavities are integrated into the housing structure rather than being separate parts; the capillary structures are formed as continuous or semi-continuous elements that serve multiple cavities; the vapor outlets and liquid replenishment ports are integrated into the housing components. This merging reduces the total number of parts, simplifies manufacturing processes, and lowers assembly costs.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent employs parameter changes in the capillary structure design, including varying capillary pore sizes, different capillary material compositions, and adjusted capillary structure thicknesses in different regions. These parameter optimizations enable effective heat dissipation from multiple sources while using cost-effective materials and manufacturing techniques, balancing performance with manufacturing cost.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If capillary structures are added to block liquid replenishment ports, then anti-backflow performance is improved, but device complexity increases

Engineering Contradiction:
Improveanti-backflow performanceVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The vapor blocking function is extracted from the liquid replenishment port structure and implemented through separate capillary structures (first capillary structure, second capillary structure, etc.) that are positioned to block vapor outlets. This extraction allows the liquid replenishment ports to remain open for their primary function while the capillary structures provide the necessary vapor blocking capability through their capillary action and physical positioning.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The capillary structures serve as intermediary elements between the evaporation cavities and the vapor outlets. These capillary structures mediate the interaction between liquid and vapor phases by blocking vapor outlets while allowing liquid to flow through the capillary channels, thereby preventing vapor backflow without requiring complex mechanical valves or additional active components.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 design effectively dissipates heat from multiple sources, prevents vapor backflow, and reduces manufacturing costs, enhancing heat dissipation performance and reducing overall costs for electronic devices.

Implementation Method 1

the second capillary structure will absorb the condensed liquid and transport it to the first capillary structure that is in contact with it

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

the liquid contained in the evaporation cavities is heated and evaporates into vapor

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

the liquid contained in the evaporation cavities is heated and evaporates into vapor

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 4

The vapor flows to a cold end through the pipeline unit and condenses into liquid

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 5

Two adjacent evaporation cavities are separated by the first partition part, so that the heat between the adjacent evaporation cavities does not interfere with each other

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP4474748B1Loop heat pipe, housing assembly and electronic device
Publication Date: 2026.03.11 BEIJING XIAOMI MOBILE SOFTWARE CO LTD
  • EP4474748B1 patent drawingFigure 1
  • EP4474748B1 patent drawingFigure 2
  • EP4474748B1 patent drawingFigure 3

AI summary

The present disclosure discloses a loop heat pipe (200), a housing assembly (10a) and an electronic device (10). The loop heat pipe (200) includes a housing component (210), a first capillary structure (220) and a second capillary structure (230). The housing component (210) is provided with a pipeline unit (211), a first partition part (213) and at least two evaporation cavities (212). The evaporation cavity (212) includes a vapor outlet (202) communicated with one end of the pipeline unit (211) and a liquid replenishment port (203) communicated with the other end of a liquid replenishment passage (201). At least part of the first capillary structure (220) is disposed in the liquid replenishment passage (201) and the evaporation cavities (212). The second capillary structure (230) includes first bodies (231) that correspond to the evaporation cavities (212) on a one-to-one basis and block the liquid replenishment ports (203).