Pressure Relief Venting With Fire Suppression for Arc Faults

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Solution Overview

Problem

Hot gases escaping from an electric apparatus during an arc fault can ignite outside the housing, posing a fire hazard, and existing pressure relief devices do not adequately address this risk.

Innovation Solution

An electric apparatus with a fire prevention system that releases a fire prevention substance, such as carbon dioxide or liquid nitrogen, upon detection of a pressure rise indicative of an arc fault, to minimize or eliminate the fire hazard.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If a pressure relief device is used to allow hot gases to flow out of the housing during a fault situation, then the pressure inside the housing is reduced, but fire hazard is created in the vicinity of the fluid port

Engineering Contradiction:
Improvepressure inside the housingVSAvoidfire hazard
Core Design Contradiction:
Stress or pressureVSObject-affected harmful factors

Solution Approach 1:

The fire prevention system is activated in advance to release fire prevention substance before or when the pressure relief device opens, creating a protective atmosphere that prevents combustion of the hot gases escaping through the fluid port

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

A fire prevention substance (such as nitrogen or carbon dioxide) is introduced as an intermediary between the hot gases and the external environment, preventing the hot gases from igniting by displacing oxygen and creating a non-combustible atmosphere around the fluid port

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If the housing is sealed to prevent fire hazard, then fire safety is improved, but pressure build-up during fault situations cannot be relieved

Engineering Contradiction:
Improvefire hazardVSAvoidpressure inside the housing
Core Design Contradiction:
Object-affected harmful factorsVSStress or pressure

Solution Approach 1:

The pressure relief device and fire prevention system are merged into a single integrated system where the pressure relief function and fire prevention function work together - the fire prevention substance is released through the same fluid port when pressure relief is needed, combining both functions in one mechanism

Inventive Principle:
Principle #5Merging (Combining)

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 fire prevention system effectively reduces the risk of fires by releasing a fire suppression substance when a pressure relief device transitions, ensuring the safety of the apparatus and its surroundings.

Implementation Method 1

the fire prevention system is adapted to release the fire prevention substance when a fault situation relating to the electric equipment located inside the housing is detected

Methodology Applied
Scientific EffectHeat absorption: Heat Sink

Implementation Method 2

A first predetermined pressure rise inside the housing 2 moves the pressure relief device 8 outwards relative to the housing 2

Methodology Applied
Scientific EffectGas displacement: Pressure Gradient

Data Source

PatentEP3903892B1Electric apparatus comprising pressure relief device
Publication Date: 2026.02.11 ABB (SCHWEIZ) AG
  • EP3903892B1 patent drawingFigure 1~2
  • EP3903892B1 patent drawingFigure 3~4

AI summary

An electric apparatus comprising a housing (2), an electric equipment (4) located inside the housing (2), a fluid port (6), a pressure relief device (8), and a detection system adapted to detect a fault situation relating to the electric equipment (4) based on at least one indicative event. A transition of the pressure relief device (8) from a first operating position to a second operating position is adapted to take place as a response to a first predetermined pressure rise inside the housing (2). The electric apparatus comprises a fire prevention system (10) comprising fire prevention substance, and being operatively connected to the detection system such that the fire prevention system (10) is adapted to release the fire prevention substance as a response to the fault situation detected by the detection system.