Subsea Heat Pipe Cooling for Semiconductor Modules

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Solution Overview

Problem

Subsea electronic equipment cooling systems face challenges with limited cooling efficiency due to natural convection and high inductive losses, particularly in subsea converters where stray inductance disrupts current flow.

Innovation Solution

The integration of heat pipes within thermally conductive blocks in subsea cooling systems to transfer heat away from semiconductor modules, reducing the thickness of heat sinks and minimizing stray inductance, while using dielectric fluids for passive cooling and seawater for heat exchanger systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If natural convection is used for passive cooling of semiconductor modules, then the cooling system is simple and reliable, but the cooling efficiency is limited

Engineering Contradiction:
Improvecooling system reliabilityVSAvoidcooling efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent introduces heat pipes as an intermediary component between the semiconductor modules and the dielectric fluid. The heat pipes actively transfer heat from the semiconductor modules to the surrounding dielectric fluid, enhancing the cooling efficiency while maintaining the passive overall system architecture. This resolves the contradiction by adding a heat transfer mediator that improves productivity without compromising reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the reliance on natural convection alone with a hybrid approach that incorporates phase-change heat transfer in heat pipes. The heat pipes use phase change (evaporation and condensation) to actively pump heat away from semiconductor modules, substituting the passive natural convection mechanism with a more efficient thermal transport mechanism while keeping the system pump-free.

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

2Temperature

If heat sink thickness is increased to improve cooling performance, then heat dissipation is enhanced, but stray inductance increases disrupting current flow

Engineering Contradiction:
Improveheat dissipation performanceVSAvoidstray inductance
Core Design Contradiction:
TemperatureVSObject-generated harmful factors

Solution Approach 1:

The patent introduces heat pipes as intermediary heat transfer components that are embedded in reduced-thickness heat sinks. These heat pipes act as thermal conduits that efficiently transport heat from the semiconductor modules to the dielectric fluid, enabling effective heat dissipation without requiring thick heat sinks. This resolves the contradiction by providing a thermal mediation mechanism that enhances cooling performance while maintaining low inductance through thin heat sink design.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent utilizes phase change (liquid to vapor and back) within the heat pipes to achieve high-efficiency heat transfer. The phase transition process in the heat pipes provides intense heat absorption at the evaporation section and heat release at the condensation section, enabling superior heat dissipation performance in a compact, thin heat sink structure, thus avoiding the need for thick heat sinks that would increase stray inductance.

Inventive Principle:
Principle #36Phase transitions

3Productivity

If active cooling with pumps is used, then cooling efficiency is improved, but system complexity and reliability requirements increase

Engineering Contradiction:
Improvecooling efficiencyVSAvoidcooling system complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent uses heat pipes as passive intermediary devices that perform active heat pumping without requiring external power or control systems. The heat pipes internally generate the driving force for heat transfer through phase change, eliminating the need for mechanical pumps while achieving high cooling efficiency. This resolves the contradiction by providing a passive intermediary mechanism that delivers active cooling performance without adding system complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The heat pipes are self-contained devices that automatically regulate heat transfer based on temperature differences without external control. They self-generate the driving force for heat pumping through phase change, requiring no external power supply, control systems, or maintenance. This self-service capability enables high cooling efficiency while keeping the system simple and reliable, resolving the contradiction between productivity and device complexity.

Inventive Principle:
Principle #25Self-service

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 approach enhances cooling efficiency by reducing inductive losses and maintaining mechanical stability under high ambient pressure, allowing for effective heat transfer and reduced thickness of heat sinks, thus improving the overall performance of subsea power conversion units.

Implementation Method 1

a heat pipe, the heat pipe being at least partly embedded in the thermally conductive block so as to transfer heat away from the thermally conductive block

Methodology Applied
Scientific EffectHeat pipe: Heat Pipe

Implementation Method 2

The heat pipes may thus be used to transfer heat away from semiconductor modules

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 3

The heat pipes may thus be used to transfer heat away from semiconductor modules

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 4

The oil in the converter tank (and in any oil-to-sea-water heat exchanger) may thus be moved by natural convection only

Methodology Applied
Scientific EffectNatural convection: Free Convection

Implementation Method 5

a thermally conductive block, the thermally conductive block being provided in the tank and in thermal contact with the semiconductor module so as to enable heat to be transferred from the semiconductor module to the thermally conductive block

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 6

passed into an external heat exchanger which is cooled by sea water

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP2900046B1Arrangement and method for subsea cooling of electronics equipment
Publication Date: 2019.08.14 ABB (SCHWEIZ) AG
  • EP2900046B1 patent drawingFigure 1
  • EP2900046B1 patent drawingFigure 2(a)~2(b)
  • EP2900046B1 patent drawingFigure 3(a)~3(b)

AI summary

There is presented an arrangement for subsea cooling of a semiconductor module. The arrangement comprises a tank, the tank being filled with a dielectric fluid. The arrangement comprises a semiconductor module, the semiconductor module being provided in the tank. The arrangement comprises a thermally conductive block, the thermally conductive block being provided in the tank and in thermal contact with the semiconductor module so as to enable heat to be transferred from the semiconductor module to the thermally conductive block. The arrangement comprises a heat pipe, the heat pipe being at least partly embedded in the thermally conductive block so as to transfer heat away from the thermally conductive block.