Thermosiphon Data Center Cooling Eliminates Mechanical Pumps

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Solution Overview

Problem

Existing cooling systems for electronic equipment in data centers often face inefficiencies and high costs due to inadequate heat removal, leading to potential device failure and increased power consumption, especially in areas with difficult cooling access.

Innovation Solution

A thermosiphon system is implemented, utilizing multiple evaporator modules in thermal contact with heat-generating devices, where a working fluid changes phases to circulate heat without mechanical pumps, with a condenser module mounted externally to efficiently expel heat.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If forced convection cooling is used with fans and ductwork, then cooling airflow can be provided over electronic devices, but power consumption increases and devices in difficult-to-cool areas may still overheat

Engineering Contradiction:
Improvedevice temperatureVSAvoidcooling system power consumption
Core Design Contradiction:
TemperatureVSUse of energy by moving object

Solution Approach 1:

The patent replaces mechanical fans and pumps with a thermosiphon system that uses natural convection and phase change of working fluid. The fluid circulates through evaporator modules in thermal contact with electronic devices, absorbing heat and transporting it to condenser modules without mechanical propulsion, thereby eliminating the power consumption associated with forced convection cooling equipment.

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

Solution Approach 2:

The thermosiphon system utilizes phase transitions of the working fluid (evaporation at evaporator modules, condensation at condenser modules) to transfer heat. The fluid absorbs latent heat during evaporation from hot electronic components and releases latent heat during condensation at the condenser, providing efficient cooling without requiring mechanical energy input.

Inventive Principle:
Principle #36Phase transitions

2Reliability

If multiple evaporator modules are added to cool all devices, then cooling coverage improves, but system complexity and floor space increase

Engineering Contradiction:
Improvecooling coverageVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The cooling system is divided into multiple modular evaporator units, each equipped with its own thermosiphon loop containing working fluid. Each evaporator module can independently cool specific electronic devices or components, allowing selective cooling of high-heat-generating areas without requiring a complex centralized system to cover the entire rack.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The thermosiphon working fluid serves multiple functions: it acts as a heat transfer medium in evaporator modules, a transport medium through connecting conduits, and a condensing medium in condenser modules. This multi-functional approach reduces the number of separate cooling systems needed, simplifying overall system complexity while maintaining comprehensive cooling coverage.

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

3Use of energy by moving object

If thermosiphon system is used to reduce power consumption, then energy efficiency improves, but heat expulsion effectiveness may be reduced

Engineering Contradiction:
Improvecooling system power consumptionVSAvoidheat expulsion effectiveness
Core Design Contradiction:
Use of energy by moving objectVSPower

Solution Approach 1:

The condenser modules utilize phase change (condensation) of the working fluid to efficiently reject heat. When the vapor-phase working fluid enters the condenser, it condenses back to liquid phase, releasing latent heat to the surrounding environment or cooling medium. This phase transition process provides high heat expulsion effectiveness without requiring mechanical compression, maintaining energy efficiency while ensuring adequate heat rejection.

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 system reduces cooling system power requirements, maintains tight temperature ranges, requires less maintenance, and minimizes floor space, while providing efficient heat expulsion and reliability compared to other cooling methods.

Implementation Method 1

A liquid phase of a working fluid is circulated through the evaporator modules, into which heat from the heat-generating devices is transferred. As the heat is transferred to the working fluid, the liquid phase changes to a vapor phase or a mixed vapor-liquid phase

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

solid surface components of the evaporator modules and heat-generating devices, respectively, may be placed into physical contact (through a thermal interface material or otherwise) to create a thermal interface through which heat flows from the heat-generating devices to the working fluid

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 3

The vapor, or mixed, phase circulates to a condenser module of the thermosiphon system, where it is changed back to the liquid phase by a cooling fluid that is circulated through the condenser module

Methodology Applied
Scientific EffectCondensation: Condensation

Implementation Method 4

the liquid form of the fluid is then returned via gravity to the evaporator

Methodology Applied
Scientific EffectGravity: Gravitation

Data Source

PatentEP3736661B1Cooling electronic devices in a data center
Publication Date: 2024.04.03 GOOGLE LLC
  • EP3736661B1 patent drawingFigure 1
  • EP3736661B1 patent drawingFigure 2
  • EP3736661B1 patent drawingFigure 3

AI summary

A server rack thermosiphon system (500) includes a plurality of evaporators (550), each evaporator including a thermal interface for one or more heat-generating server rack devices (521); at least one condenser (515) mounted internal to a server rack (505), the condenser including a fluid-cooled heat transfer module; a liquid conduit that fluidly couples each of the evaporators to the condenser to deliver a liquid phase (507) of a working fluid from the condenser to the evaporators; and a vapor conduit that fluidly couples each of the evaporators to the condenser to deliver a mixed phase (503) of the working fluid from the evaporators to the condenser.