Circuit Breaker Swirling Gas Diffuser Arc Extinction

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Solution Overview

Problem

Existing circuit breakers face challenges in effectively extinguishing arcs due to hot zones formed by the interaction of quenching gas with contacts, leading to reduced performance and potentially shorter device lifespan.

Innovation Solution

Incorporation of a mechanical swirling device downstream of the nozzle within the diffuser to impart a swirl flow on the quenching gas, creating a centrifugal force that reduces hot zones by directing the gas away from the contacts, thereby enhancing arc extinction efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If quenching gas is released towards the arc for cooling down and extinguishing the arc, then arc extinction performance is improved, but hot zones are formed due to contact barrier deteriorating gas flow

Engineering Contradiction:
Improvearc extinction performanceVSAvoidhot zones temperature
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The patent introduces a swirling device that adds a rotational dimension to the linear quenching gas flow. The gas flow is transformed from a simple axial direction into a three-dimensional swirling pattern, allowing the quenching gas to reach the arc region from multiple angles and paths, thereby eliminating dead zones and hot spots that form with linear flow alone.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The swirling device acts as an intermediary element between the quenching gas source and the arc region. It modifies the gas flow characteristics by imparting rotation, which then enables the quenching gas to effectively penetrate and cool the arc zone without being blocked by the contact barrier, thus mediating the interaction between gas flow and arc extinction.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If contacts are positioned to define an arcing region, then current breaking function is achieved, but flow of quenching gas is deteriorated by contact barrier

Engineering Contradiction:
Improvecurrent breaking functionVSAvoidquenching gas flow efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The swirling device transforms the unidirectional gas flow into a multi-dimensional swirling flow pattern. This rotational component allows the quenching gas to navigate around the contact barrier and reach the arcing region more effectively, maintaining high flow efficiency while preserving the necessary current breaking function.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent changes the flow parameters of the quenching gas by imparting rotational motion. This modification in flow parameters (adding angular velocity and creating centrifugal effects) enables the gas to overcome the contact barrier obstruction and maintain efficient flow into the arcing region, thus resolving the contradiction between current breaking function and gas flow efficiency.

Inventive Principle:
Principle #35Parameter changes

3Temperature

If mechanical swirling device is added to impart swirl flow, then hot zones are reduced, but device complexity increases

Engineering Contradiction:
Improvehot zones temperatureVSAvoidcircuit breaker structure
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The swirling device is designed to be self-driven by the kinetic energy of the quenching gas flow itself. The gas flow naturally interacts with the swirling elements to generate rotation without requiring external power sources or complex control mechanisms. This self-service approach reduces device complexity while achieving the temperature reduction benefit.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent uses the pneumatic energy of the quenching gas flow to drive the swirling mechanism. By utilizing the existing gas pressure and velocity to create rotation through properly designed flow passages and swirling elements, the system avoids adding complex mechanical drive systems, thereby minimizing the increase in device complexity while effectively reducing hot zones.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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 mechanical swirling device effectively reduces hot zones and improves thermal interruption performance, leading to more efficient arc extinction and extended device lifespan.

Implementation Method 1

Incorporation of a mechanical swirling device downstream of the nozzle within the diffuser to impart a swirl flow on the quenching gas, creating a centrifugal force that reduces hot zones by directing the gas away from the contacts

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

an arc-extinguishing system operates by releasing a quenching gas towards the arc for cooling down and finally extinguishing the arc

Methodology Applied
Scientific EffectConvection cooling: Convection

Data Source

PatentEP3503151B1Circuit breaker and method of performing a current breaking operation
Publication Date: 2022.04.13 HITACHI ENERGY SWITZERLAND AG
  • EP3503151B1 patent drawingFigure 1
  • EP3503151B1 patent drawingFigure 2A~2B
  • EP3503151B1 patent drawingFigure 3A~3B

AI summary

A circuit breaker (1) includes: first and second contacts (10, 20) moveable relative to each other along an axis (2) of the circuit breaker (1) between an open and closed configuration and defining an arcing region (3) in which an arc is formed during current breaking operation; a nozzle (30) directing a flow of quenching gas onto the arcing region (3) during current breaking operation, a diffusor (40) downstream of the nozzle (30) for further transporting the quenching gas within the arcing region (3) and/or downstream of the arcing region (3), and a mechanical swirling device (50) arranged downstream of the nozzle (30) and at least partially in the diffusor (40) for imparting a swirl onto the quenching gas flowing along the diffusor (40), the mechanical swirling device (50) having an axial overlap with the second contact (20) in the open configuration of the circuit breaker (1).