CO2-Barrier Enclosure Coating for Gas-Insulated Switchgear

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Solution Overview

Problem

Gas insulated electric apparatuses using CO2 as insulation gas experience higher leakage rates, leading to frequent refilling needs and increased service efforts, which is not addressed by existing technologies.

Innovation Solution

Incorporating a CO2-barrier arrangement, such as a SiOx compound coating or glass film layer, on the enclosure wall and sealings to reduce CO2 permeability, maintaining the insulating properties of epoxy-based composite materials while minimizing gas leakage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If CO2 is used as insulation gas, then environmental performance is improved, but gas leakage increases leading to frequent refilling needs

Engineering Contradiction:
Improveenvironmental performanceVSAvoidgas retention stability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

A CO2-barrier arrangement in the form of a coating layer (e.g., SiOx compound or glass film) is applied to the inner surface of the enclosure wall and sealings. This thin film structure specifically blocks CO2 permeation while maintaining the flexibility and integrity of the enclosure, thereby reducing gas leakage without compromising the overall system design

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The CO2-barrier arrangement combines different materials with complementary properties: the enclosure wall material (providing structural strength and insulation) is combined with a CO2-barrier coating layer (providing selective gas permeability resistance). This composite structure addresses both the mechanical requirements and the CO2 retention requirements simultaneously

Inventive Principle:
Principle #40Composite materials

2Reliability

If CO2-barrier arrangement is added to reduce leakage, then gas retention is improved, but device complexity increases

Engineering Contradiction:
Improvegas retention stabilityVSAvoidenclosure structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The CO2-barrier arrangement is merged with the existing enclosure wall structure and sealings. Instead of adding a separate, independent barrier system, the CO2-blocking function is integrated into the existing components through coating layers, thereby reducing gas leakage without significantly increasing overall device complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The CO2-barrier is implemented as a thin film coating rather than a thick or bulky structure. This approach provides effective CO2 blocking while maintaining a compact design that does not substantially increase the complexity or dimensions of the enclosure system

Inventive Principle:
Principle #30Flexible shells and thin films

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 CO2-barrier arrangement significantly reduces gas leakage, enhancing operational robustness and reducing the frequency of service occasions, ensuring reliable functionality over extended periods.

Implementation Method 1

The CO2-barrier arrangement is adapted to reduce the permeability of CO2 through an enclosure wall of the enclosure

Methodology Applied
Scientific EffectPermeation: Permeation

Data Source

PatentEP3416178B1Gas insulated electric apparatus with means to prevent gas leakage
Publication Date: 2026.03.25 HITACHI ENERGY SWITZERLAND AG
  • EP3416178B1 patent drawingFigure 1
  • EP3416178B1 patent drawingFigure 2
  • EP3416178B1 patent drawingFigure 3

AI summary

The present invention relates to a gas insulated electric apparatus (1) comprising an enclosure (7) and an electric high voltage appliance (9) located inside the enclosure. The enclosure (7) contains an insulation gas (8) comprising at least 70 % by volume of CO2. The insulation gas has an elevated and pre-determined operating gas pressure level. The enclosure (7) comprises a CO2-barrier arrangement (15) adapted to reduce the permeability of CO2 through the enclosure wall.