HFO-HFC Gas Mixture for Arc Resistance in Electrical Apparatus
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current medium and high voltage electrical apparatuses rely on sulfur hexafluoride (SF6) for insulation and arc extinguishing, which has a high global warming potential and long atmospheric residence time, necessitating the search for alternatives that maintain dielectric strength while reducing environmental impact.
Innovation Solution
A gas mixture comprising hydrofluoroolefins and hydrofluorocarbons, such as HFO-1234ze and HFC-227ea, with a dilution gas like carbon dioxide, offering low global warming potential and effective arc insulation and extinguishing properties, replacing SF6 in electrical apparatuses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sulfur hexafluoride (SF6) is used for electrical insulation and arc extinguishing, then dielectric strength and arc extinguishing performance are improved, but global warming potential increases significantly
Solution Approach 1:
The patent changes the chemical composition parameters by replacing SF6 with a mixture of hydrofluoroolefin (HFO-1234ze) and hydrofluorocarbon (HFC-227ea) in specific proportions (80-98% HFO and 2-20% HFC by volume), thereby reducing global warming potential from 22800 to below 100 while maintaining dielectric strength through optimized mixture composition
Solution Approach 2:
The patent creates a composite gas mixture combining hydrofluoroolefin and hydrofluorocarbon components, where HFO-1234ze provides low GWP (less than 150) and HFC-227ea enhances dielectric strength and internal arc resistance, achieving a synergistic effect that resolves the contradiction between environmental friendliness and electrical performance
2Object-affected harmful factors
If simple gases like air or nitrogen are used instead of SF6, then global warming potential is reduced, but dielectric strength decreases significantly
Solution Approach 1:
The patent optimizes the concentration parameters of HFO and HFC components in the gas mixture, specifically using 80-98% HFO-1234ze and 2-20% HFC-227ea by volume, which achieves dielectric strength comparable to SF6 while maintaining low global warming potential, overcoming the limitations of simple gases like air or nitrogen
3Object-affected harmful factors
If mixtures of SF6 and other gases are used to limit environmental impact, then global warming potential is reduced, but dielectric strength and internal arc resistance are compromised
Solution Approach 1:
The patent precisely controls the composition parameters by using 80-98% HFO-1234ze and 2-20% HFC-227ea by volume, where HFC-227ea specifically enhances internal arc resistance despite its higher individual GWP, achieving a balance where the mixture's overall GWP remains below 100 while maintaining adequate internal arc resistance for electrical apparatus
Solution Approach 2:
The patent replaces the long-lived SF6 molecule (3200 years atmospheric residence time) with shorter-lived HFO and HFC molecules that degrade more quickly in the atmosphere, reducing long-term environmental impact while maintaining functional performance through optimized mixture composition
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 mixture achieves a global warming potential reduction of up to 99% compared to SF6, maintaining dielectric strength and internal arc resistance, while being non-toxic and non-explosive, thus providing a more environmentally friendly solution for electrical insulation and arc extinguishing.
Implementation Method 1
the gas most often used is sulfur hexafluoride (SF6): this gas exhibits a relatively high dielectric strength
Implementation Method 2
SF6 has a relatively high dielectric strength, a good thermal conductivity and relatively low dielectric losses
Implementation Method 3
the extinguishing of electrical arcs are ensured by a gas mixture comprising at least one hydrofluorocarbon and one hydrofluoroolefin
Implementation Method 4
The mixture achieves a global warming potential reduction of up to 99% compared to SF6, maintaining dielectric strength and internal arc resistance
Data Source
AI summary
The invention relates to the use of a mixture of a hydrofluoroolefin and a hydrofluorocarbon, optionally combined with another fluorinated gas, as an electrical insulation medium and/or an electric arc extinguishing medium in a medium-voltage electrical apparatus. The invention also relates to a medium- or high-voltage electrical apparatus in which such a mixture provides electrical insulation and/or electric arc extinguishing.