Gas-Insulated Substation Junction Sealing Without Dismantling
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Solution Overview
Problem
Existing methods for sealing gas leaks in gas-insulated substations are inefficient, difficult to implement under pressure, and often require dismantling, leading to operational disruptions and incomplete sealing due to residual gas bubbles.
Innovation Solution
A method involving the use of a liquid sealing product with a kinematic viscosity of 3000 mm²/s or higher, injected under controlled pressure increases, to completely replace residual gas in the inter-seal volume through a leakage recovery duct, ensuring bubble-free sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a strip of fabric is wound over the flanged junction to form a tourniquet for external sealing, then the sealing method is simple to implement, but the flanged junction cannot be accessed or dismantled later and the sealing is not durable under pressure
Solution Approach 1:
A liquid resin is introduced as an intermediary substance that flows into the inter-seal volume through the leakage recovery duct. The resin acts as a mediator between the sealing requirement and the mechanical seal interface, filling gaps and creating a durable seal without requiring external tourniquets that block access.
Solution Approach 2:
The sealing function is segmented into two parts: the primary mechanical seals and the secondary liquid resin seal. The liquid resin is injected separately through the leakage recovery duct to fill remaining gaps, allowing the mechanical seals to maintain their function while adding supplemental sealing where needed.
2Reliability
If an enclosure is created around the flange junction with hermetic shuttering for external sealing, then gas leakage can be contained, but the shuttering is heavy and cumbersome and difficult to maintain over time
Solution Approach 1:
The sealing function is extracted from the external enclosure structure and relocated to the internal inter-seal volume. Instead of containing gas with heavy shuttering, the liquid resin is injected directly into the inter-seal volume to seal leaks from within, eliminating the need for complex external enclosures.
Solution Approach 2:
The liquid resin is injected under pressure through the leakage recovery duct to ensure complete filling of the inter-seal volume. The hydraulic injection process forces the resin into all gaps and voids, creating an effective seal without requiring mechanical enclosures or shuttering structures.
3Reliability
If the assembly is dismantled to revise bearing surfaces and change mechanical seals, then complete sealing can be achieved, but operational continuity is interrupted and downtime occurs
Solution Approach 1:
The liquid resin is injected into the inter-seal volume before any dismantling occurs. This preliminary sealing action addresses leaks while the system is still assembled and operational, allowing the mechanical seals to be replaced or revised later without compromising the immediate sealing requirement.
Solution Approach 2:
The sealing process is made continuous by injecting liquid resin through the existing leakage recovery duct while the system remains assembled and operational. This maintains gas containment and operational continuity, eliminating the need to dismantle assemblies to achieve sealing.
4Ease of operation
If sealing product is injected between the flanges to fill gaps and stop leakage, then sealing can be achieved without dismantling, but residual gas bubbles may remain causing incomplete sealing
Solution Approach 1:
The physical parameters of the liquid resin are specifically selected to ensure complete filling. The resin has appropriate viscosity to flow into all gaps but remains liquid enough to be forced into voids under injection pressure, and its fluidity allows it to displace gas bubbles completely rather than trapping them.
Solution Approach 2:
The liquid resin is injected under controlled pressure through the leakage recovery duct to force complete filling of the inter-seal volume. The pressurized injection process drives the resin into all gaps and voids while expelling residual gas bubbles, ensuring complete sealing without trapping air pockets.
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 method provides a durable, bubble-free seal that maintains operational continuity and extends assembly life without dismantling, using cost-effective tools and materials.
Implementation Method 1
during injection, the sealing product is in the form of a liquid whose kinematic viscosity, measured at 40° C. under 1 atm, is greater than or equal to 3000 mm2/s
Implementation Method 2
the injection is carried out under pressure by a plurality of successive increases in injection pressure until any residual gas is expelled from the inter-seal volume
Implementation Method 3
a strip of fabric, for example of resin-impregnated glass fabric, is wound over the flanged junction... to form a tourniquet
Data Source
AI summary
A method for sealing a junction with a contact surface and counter-contact surface of an element of a compartment of a gas-insulated substation includes an injection of a sealing product into an inter-seal volume formed between the contact surface and counter-contact surface by using a leakage recovery duct opening into the inter-seal volume. During injection, the sealing product is in the form of a liquid whose kinematic viscosity, measured at 40° C. under 1 atm, is greater than or equal to 3000 mm2/s. Injection is carried out under pressure by a plurality of successive increases in injection pressure until any residual gas is expelled from the inter-seal volume by pressurized leakage of this residual gas via at least one of the two mechanical seals.