Hermetic Rack Enclosure Cooling and Fire Safety

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current electronic system enclosures in storage systems are vulnerable to shutdowns or degraded performance due to external cooling system failures, risk of fire propagation, and inadequate protection against electromagnetic disturbances.

Innovation Solution

A hermetic metallic casing with independent forced convection cooling systems, featuring dual fans and heat dissipation fins, that confines smoke and prevents oxygen supply during fires, while maintaining ventilation and protecting against electromagnetic interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If forced air convection cooling is used, then cooling efficiency is improved, but oxygen supply to fire is increased and fire spread risk is worsened

Engineering Contradiction:
Improvecooling efficiencyVSAvoidfire spread risk
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The cooling system is segmented into multiple independent zones with separate fans and ducts. Each enclosure has its own independent cooling system, so that cooling failure in one enclosure does not affect others. The segmentation also applies to the fire containment strategy, where each enclosure is isolated to prevent fire spread.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Hermetic seals and fire barriers are introduced as intermediary elements between the cooling airflow and the electronic systems. These intermediaries allow thermal energy to be managed while blocking the direct supply of oxygen to fires and containing smoke within enclosed spaces.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If redundant cooling systems are used, then system availability is improved, but device complexity and cost are worsened

Engineering Contradiction:
Improvesystem availabilityVSAvoidcooling system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system is divided into independent modular enclosures, each with its own cooling system. This segmentation provides redundancy at the module level without requiring complex system-wide redundancy. Each module can operate independently, maintaining overall system availability even if individual modules fail.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cooling system design changes from a centralized approach to a distributed modular approach. This parameter change in system architecture provides inherent redundancy while reducing overall complexity, as each simple modular unit can be independently maintained and replaced.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If hermetic casing is used, then fire containment is improved, but heat dissipation is worsened

Engineering Contradiction:
Improvefire containmentVSAvoidheat dissipation
Core Design Contradiction:
Object-affected harmful factorsVSTemperature

Solution Approach 1:

Heat is extracted from the enclosed hermetic space through dedicated thermal management pathways. Heat sinks and thermal conduction paths are integrated into the hermetic enclosure structure, allowing heat to be removed from the sealed environment without compromising the fire containment integrity of the hermetic seal.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Thermal interfaces and heat transfer mediators are introduced between the electronic systems and the external environment. These intermediaries enable efficient heat dissipation while maintaining the hermetic seal that provides fire containment, separating the thermal management function from the fire safety function.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Object-affected harmful factors

If standard enclosures are used, then electromagnetic interference protection is insufficient, but shielding effectiveness is worsened

Engineering Contradiction:
Improveelectromagnetic interference protectionVSAvoidenclosure complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The enclosure employs composite construction combining conductive materials for electromagnetic shielding with hermetic sealing components. The metallic or conductive coating layers provide Faraday cage effects for EMI protection, while integrated gaskets and seals maintain the hermetic barrier, achieving multiple protective functions through material composition rather than separate components.

Inventive Principle:
Principle #40Composite materials

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

Ensures robust and autonomous cooling, prevents fire spread, and shields electronic systems from electromagnetic disturbances, maintaining system availability and safety.

Implementation Method 1

The cooling system therefore uses forced convection capable of maintaining ventilation in the event of a failure of one of the two fans.

Methodology Applied
Scientific EffectForced convection: Forced Convection

Implementation Method 2

The power lost by the system is extracted by heat transfer by conduction before the cooling system removes it by transfer by convection.

Methodology Applied
Scientific EffectHeat transfer by conduction: Conduction (thermal)

Implementation Method 3

The power lost by the system is extracted by heat transfer by conduction before the cooling system removes it by transfer by convection.

Methodology Applied
Scientific EffectHeat transfer by convection: Convection

Implementation Method 4

The pipe wall is at least partially airtight. The airtight duct cools the electronic system without directly supplying it with oxygen. Furthermore, a fire cannot spread to other enclosures, and smoke is contained.

Methodology Applied
Scientific EffectPhysical containment: Physical Containment

Data Source

PatentEP2432308B1Protection device for electronic system mounted in a rack
Publication Date: 2020.03.11 ZODIAC AERO ELECTRIC
  • EP2432308B1 patent drawingFigure 1~3
  • EP2432308B1 patent drawingFigure 4~6

AI summary

The device has a metal case (2) to receive an electronic system. The case is mounted in a rack of a storage system i.e. cabinet. The case comprises openings (5, 7) that are formed on corresponding front and rear faces of the case. A stand-alone cooling system (8) has a pipe (9) that connects the openings, where the pipe is provided with an air-tight wall. The cooling system has fans associated with corresponding openings, and a heat dissipation fin arranged between the fans. The cooling system is connected with an external air extraction system.