Circuit Breaker Liquid Arc-Extinction Medium
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional circuit breakers using compressed SF6 gas face limitations in increasing arc interruption performance without increasing cost or size, requiring complex pressure build-up mechanisms and high-pressure storage vessels due to the low critical temperature of SF6.
Innovation Solution
A circuit breaker design that uses a liquid arc-extinction medium, such as an organofluorine compound, which evaporates to generate high blow pressure for arc extinction, eliminating the need for external pressurization and allowing for a simpler and more economical construction. The design incorporates a floating piston and auxiliary compartment to manage pressure and control the ejection of the medium, ensuring efficient arc extinction and cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If compressed SF6 gas is used as arc extinction medium, then arc interruption performance can be achieved, but the critical temperature limitation requires complex pressure build-up mechanisms and high-pressure storage vessels
Solution Approach 1:
The patent changes the physical state parameter of the arc extinction medium from gaseous SF6 to liquid organofluorine compound. This parameter change eliminates the need for complex pressure build-up mechanisms because the liquid can be stored at atmospheric or near-atmospheric pressure, and the phase change to gas during arc extinction provides the necessary expansion and cooling effects naturally.
Solution Approach 2:
The patent utilizes the phase transition from liquid to gas of the organofluorine compound during arc extinction. The liquid medium is stored in a simple reservoir and automatically vaporizes when exposed to arc heat, providing both the extinction medium and the necessary pressure through phase change, eliminating complex mechanical pressure build-up systems.
2Volume of moving object
If liquid SF6 is used to reduce circuit breaker size, then compactness is achieved, but extremely high storage pressures are required due to low critical temperature
Solution Approach 1:
The patent changes the chemical composition parameter from SF6 to organofluorine compounds with higher critical temperatures. This allows the liquid medium to be stored at much lower pressures while maintaining the desired compact size, as the higher critical temperature enables liquid storage at near-atmospheric conditions.
Solution Approach 2:
The patent employs a simple, disposable-like liquid reservoir design that does not require high-pressure containment structures. The liquid organofluorine compound is stored in a simple tank that can be refilled or replaced, eliminating the need for expensive, complex high-pressure storage vessels required by SF6 systems.
3Reliability
If high blow pressure is generated using complex ejection devices, then arc extinction performance is improved, but device complexity and cost increase
Solution Approach 1:
The patent implements a self-service system where the liquid organofluorine compound automatically vaporizes and generates the necessary blow pressure through its own phase change when exposed to arc heat. No external ejection devices, pumps, or complex mechanisms are required - the medium serves itself by converting liquid to gas and naturally expanding to extinguish the arc.
Solution Approach 2:
The patent replaces mechanical ejection systems (pumps, valves, pressure build-up mechanisms) with a thermal-phased based system. The arc heat itself triggers the phase change and pressure generation, substituting complex mechanical ejection devices with a simple thermal response mechanism.
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 solution provides improved arc interruption performance, reduced size, and lower costs by leveraging the high boiling point of organofluorine compounds, which absorb arc energy for vaporization and cooling, enhancing the circuit breaker's operational efficiency and safety.
Implementation Method 1
the arc-extinction medium is ejected which instantly evaporates in the injection zone, the blow pressure present in the injection zone readily increases
Implementation Method 2
part of the arc energy is absorbed for vaporisation of the extinction liquid leading to improved cooling of the arc
Implementation Method 3
when the liquid is used for exhaust gas cooling, it readily evaporates after ejection and thus very efficiently cools the exhaust gases
Data Source
Figure 1
Figure 2~3
Figure 4a~4c
AI summary
The present invention relates to a circuit breaker comprising an ejection device (8, 9; 80, 90) comprising a compartment (14a), in which an arc-extinction medium (18; 18a, 18b) for improving circuit breaker operation is contained, and having an ejection orifice (17) through which the arc-extinction medium (18; 18a, 18b) is to be ejected, wherein the ejection orifice (17) opens out into an injection zone (5, 6, 71) of the circuit breaker (1) in which the pressure is lower than in an arcing zone (32) when an arc is present, and wherein the arc-extinction medium (18; 18a, 18b) and/or exhaust-cooling medium (18; 18a, 18b) is at least partially present in liquid form, when it is contained in the ejection device (8, 9; 80, 90).