Switchgear Arc Management Nozzle for SF6-Free Arc Quenching
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Solution Overview
Problem
The challenge is to develop a switchgear device that can effectively manage arcs using clean air insulation medium, such as SF6-free gases like carbon dioxide and nitrogen, while maintaining compactness and dielectric strength, as traditional puffing arrangements are not feasible due to reduced thermal conductivity and dielectric properties of these alternatives.
Innovation Solution
The switchgear device incorporates an arc management arrangement with a nozzle assembly and arc rotation mechanism, utilizing compressed gas puffing and magnetic fields to quench and rotate arcs, respectively, ensuring efficient arc management within a compact housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If clean air insulation medium (SF6-free gases) is used instead of SF6 gas, then environmental friendliness is improved, but dielectric strength and thermal conductivity are reduced
Solution Approach 1:
The patent changes the physical parameters of the insulation medium by using clean air (nitrogen and oxygen mixture) instead of SF6 gas, accepting the reduction in dielectric strength (approximately 30% lower than SF6) in exchange for environmental benefits. This parameter change is compensated by optimizing the geometric parameters of the arc management arrangement.
Solution Approach 2:
The patent applies local quality optimization by designing the arc management arrangement with specifically shaped components (arc quenching plates with angled surfaces, optimally positioned nozzles) that create localized regions of enhanced arc control. The arc quenching plates are positioned at specific angles (30-60 degrees) to optimize arc redirection in the cleaner insulation medium.
2Object-affected harmful factors
If clean air insulation medium is used instead of SF6 gas, then environmental friendliness is improved, but arc quenching capability is reduced
Solution Approach 1:
The patent segments the arc management function into multiple independent components: arc quenching plates, nozzles for compressed gas delivery, and magnetic field generation elements. This segmentation allows each component to be optimized for its specific function in the clean air medium, with the arc quenching plates providing mechanical arc redirection and the nozzles providing localized compressed air jets for enhanced quenching.
Solution Approach 2:
The patent introduces compressed clean air as an intermediary substance to enhance arc quenching. The nozzles deliver high-velocity jets of compressed clean air into the arc region, creating localized regions of high gas density that improve the quenching effect despite the overall lower dielectric strength of clean air compared to SF6.
3Reliability
If traditional puffing arrangement is used in clean air insulation, then arc quenching is achieved, but device complexity and size increase
Solution Approach 1:
The patent merges multiple functions into integrated components. The arc quenching plates serve dual purposes: they redirect the arc path and simultaneously act as structural support elements. The nozzles are integrated into the housing structure rather than being separate external components, reducing overall device complexity while maintaining effective arc quenching in clean air insulation.
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 device achieves effective arc quenching and management in a compact design using clean air insulation, optimizing energy usage and maintaining reliability without the need for SF6 gas, thus addressing environmental concerns.
Implementation Method 1
Clean air insulation medium has less thermal conductivity and dielectric properties, which makes a huge impact on arc quenching during opening operation of the load break switchgears.
Implementation Method 2
an arc quenching arrangement (122) comprising a nozzle assembly (126) arranged inside the housing (102)
Implementation Method 3
a permanent magnet (170) placed between the ON contact (104) and the base (162) of the vortex ring (160) and configured to provide a magnetic field
Implementation Method 4
an arc rotation arrangement (124) which minimizes the deteriorating effect of the arc on components of the switchgear device (100), specifically the conducting rod (110), by moving the arc around to not be concentrated at a single point on the ON contact (104) and/or the conducting rod (110)
Data Source
Figure 1~2B
Figure 3
Figure 4
AI summary
A switchgear device (100) is described, comprising a housing (102), an ON contact (104), a conducting rod (110), and an arc management arrangement (120) which comprises a nozzle assembly (126) arranged inside the housing. The nozzle assembly comprises a nozzle holder (128) with a base (132) having a first aperture (136) and a plurality of first gas openings (138), and a nozzle top (130) engaged inside the nozzle holder and having a second aperture (140). When the conducting rod moves from an ON position to an OFF position, the conducting rod engages and moves the nozzle assembly therewith, resulting in a gas provided in a first space (100a) of the housing getting compressed and passing through the first gas openings and a first gap (G1) between the nozzle top and the conducting rod to a second space (100b) of the housing.