Phase Change Material Thermal Storage for Portable Device Heat Management

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Solution Overview

Problem

Conventional heat transfer techniques in computing devices often limit the availability of high power states due to excessive heat generation, leading to potential device damage and user experience issues such as noise and temperature concerns, especially in portable configurations where proximity to the device increases the impact of heat and fan noise.

Innovation Solution

A heat transfer device incorporating a phase change material with a melting temperature between low and high power states' temperatures, combined with heat pipes arranged to provide uniform cooling across various orientations, buffers against high power state heat generation, allowing extended use without increasing fan noise or power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conventional heat transfer techniques are used in portable computing devices, then heat can be dissipated, but the device generates excessive noise and heat that adversely affects user experience due to proximity

Engineering Contradiction:
Improveuser experience impact from heat and noiseVSAvoidheat and fan noise
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The phase change material undergoes phase transition in advance during low power states to pre-cool itself, storing cooling capacity before high power states occur. This preliminary action allows the material to absorb excess heat during high power states without requiring active fan cooling, thereby reducing noise and improving user experience.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent utilizes phase change material that transitions between solid and liquid states at a specific melting temperature. During low power states, the material is in liquid state and absorbs heat. During high power states, the material undergoes phase transition from liquid to solid, absorbing large amounts of latent heat and preventing temperature rise that would otherwise require noisy fan cooling.

Inventive Principle:
Principle #36Phase transitions

2Productivity

If high power states are used to improve device performance, then productivity increases, but excessive heat generation causes device damage and requires supplemental cooling

Engineering Contradiction:
Improvedevice performanceVSAvoidheat generation
Core Design Contradiction:
ProductivityVSTemperature

Solution Approach 1:

The phase change material is positioned in thermal communication with the heat-generating component and undergoes phase transition at a melting temperature between low and high power state temperatures. During high power states, the material absorbs excess heat through phase transition from liquid to solid, preventing temperature rise that would otherwise require supplemental cooling and enabling sustained high performance.

Inventive Principle:
Principle #36Phase transitions

Solution Approach 2:

The phase change material acts as an intermediary thermal buffer between the heat-generating component and the environment. It absorbs and stores thermal energy during high power states, mediating the heat transfer process and preventing direct heat accumulation that would require supplemental cooling systems.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Temperature

If cooling fan speed is increased to dissipate heat during high power states, then temperature control improves, but noise and power consumption increase

Engineering Contradiction:
Improvetemperature controlVSAvoidfan noise
Core Design Contradiction:
TemperatureVSObject-generated harmful factors

Solution Approach 1:

The phase change material pre-cools itself during low power states by absorbing heat when in liquid state, storing cooling capacity in advance. This preliminary cooling action eliminates the need for high fan speeds during subsequent high power states, maintaining temperature control while reducing fan noise and power consumption.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The material undergoes phase transition from liquid to solid during high power states, absorbing large amounts of latent heat. This phase change provides passive cooling that replaces active fan cooling, maintaining effective temperature control without the noise and additional power consumption associated with high-speed fan operation.

Inventive Principle:
Principle #36Phase transitions

4Object-generated harmful factors

If passive cooling devices are used to reduce heat, then noise is reduced, but cooling ability expires after a predetermined amount of heat is absorbed

Engineering Contradiction:
Improvenoise reductionVSAvoidcooling duration
Core Design Contradiction:
Object-generated harmful factorsVSDuration of action of moving object

Solution Approach 1:

The system continuously cycles between low and high power states, with the phase change material continuously absorbing and releasing heat through phase transitions. During low power states, the material cools itself by absorbing heat in liquid state. During high power states, it absorbs excess heat during phase transition. This continuous cycling ensures the cooling ability is constantly replenished, eliminating the expiration issue of conventional passive cooling devices.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The phase change material utilizes reversible phase transitions between solid and liquid states to continuously absorb and release heat. During low power states, the material is in liquid state and absorbs heat. During high power states, it transitions to solid state absorbing latent heat. This reversible phase change process continuously regenerates cooling capacity, allowing extended operation without cooling ability expiration.

Inventive Principle:
Principle #36Phase transitions

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 solution enables extended use of high power states without supplemental cooling, reducing noise and power consumption, while maintaining uniform temperature and improving user experience by leveraging phase change materials and heat pipes for efficient heat management.

Implementation Method 1

a phase change material configured to have a melting temperature that is below a temperature at which a cooling fan of the device is set to operate to cool the heat-generating device

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

phase change material configured to have a melting temperature

Methodology Applied
Scientific EffectLatent heat: Latent Heat

Implementation Method 3

a plurality of heat pipes configured to transfer heat using thermal conductivity and phase transition from the heat-generating device

Methodology Applied
Scientific EffectThermal conductivity: Conduction (thermal)

Implementation Method 4

transfer heat using thermal conductivity and phase transition

Methodology Applied
Scientific EffectPhase transition: Phase Change

Implementation Method 5

A plurality of heat pipes configured to transfer heat

Methodology Applied
Scientific EffectHeat pipe: Heat Pipe

Data Source

PatentEP2807530B1Heat transfer device with phase change material
Publication Date: 2019.08.28 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP2807530B1 patent drawingFigure 1
  • EP2807530B1 patent drawingFigure 2
  • EP2807530B1 patent drawingFigure 3

AI summary

A heat transfer device is described. In one or more implementations, a heat transfer device includes a heat sink and a thermal storage enclosure disposed proximal to at least a portion of the heat sink. The thermal storage enclosure configured to be disposed proximal to a heat-generating component of a device. The thermal storage enclosure includes a phase change material configured to have a melting temperature that is below a temperature at which a cooling fan of the device is set to operate to cool the heat- generating device.