Cold Shrink Cable Sealing for Oil Containment
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Solution Overview
Problem
Existing cable cover systems for oil-impregnated paper insulation cables face challenges in maintaining a reliable seal and containing oil, especially under high internal pressures or temperature changes, which can lead to oil leakage and compromised electrical integrity.
Innovation Solution
A cold shrink cover system comprising tubular oil barrier tubes, electrically conductive mesh, dual layer mastic tapes, and pressure retention tapes, along with a tubular cold shrink joint body and spacer, is used to form a robust seal around the cable connections, ensuring containment of oil and maintaining electrical integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If heat shrinkable sleeves are used to contain oil in PILC cables, then oil containment is achieved, but the system becomes vulnerable to oil leakage under high internal pressures or temperature changes
Solution Approach 1:
The sealing system is divided into multiple functional segments: an inner sealing layer with mastic material for primary oil containment, an outer protective layer for structural support, and intermediate bonding layers. This segmentation allows each layer to specialize in specific functions, improving overall reliability while managing complexity through modular design.
Solution Approach 2:
The invention uses composite material structures combining mastic sealing material with polymer matrixes, and further combines this with outer protective layers. This composite approach creates a sealing system that can withstand high internal pressures and temperature changes while maintaining oil containment reliability.
2Reliability
If multiple layers of sealing material are applied to ensure adequate seal, then oil containment improves, but manufacturing complexity and installation difficulty increase
Solution Approach 1:
Multiple sealing functions are merged into a single integrated covering assembly that includes the inner sealing layer, mastic material, bonding layers, and outer protective layer as a unified structure. This merging maintains comprehensive seal integrity while simplifying manufacturing and installation compared to applying separate sealing components.
Solution Approach 2:
The invention employs flexible thin film structures that can conform to the cable geometry and provide adequate sealing through their inherent flexibility and adaptability. These thin film-based sealing structures achieve reliable oil containment without requiring complex multi-component assembly procedures.
3Reliability
If mastic or sealant material is used at ends of the sleeve to ensure adequate seal, then oil containment is improved, but the risk of oil leakage and displacement increases under high pressure
Solution Approach 1:
The sealing structure uses composite materials combining mastic sealing compounds with polymer matrixes that provide both sealing capability and structural strength. This composite construction prevents oil leakage and displacement under high pressure conditions while maintaining effective oil containment.
Solution Approach 2:
The covering assembly employs curved and rounded structural features that distribute mechanical stresses uniformly, preventing stress concentration that could lead to oil leakage. The curved geometry of the sealing layers helps resist high internal pressures and prevents oil displacement.
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 system effectively retains oil within the cable, even under high pressure conditions, and provides a reliable seal that prevents oil leakage and displacement, ensuring the electrical integrity of the cable connections.
Implementation Method 1
A cold shrink cover system comprising tubular oil barrier tubes, electrically conductive mesh, dual layer mastic tapes, and pressure retention tapes, along with a tubular cold shrink joint body and spacer, is used to form a robust seal around the cable connections
Implementation Method 2
A mastic material surrounds the cable and engages the sheath end and the oil barrier tube end
Implementation Method 3
pressure retention tapes, along with a tubular cold shrink joint body and spacer, is used to form a robust seal around the cable connections, ensuring containment of oil
Data Source
Figure 1~3
Figure 4~6B
Figure 7~10
AI summary
A covered cable assembly includes a cable and a sealing assembly. The cable includes a metal sheath and a cable core. The metal sheath has a sheath terminal edge defining a sheath opening. The cable core extends through the metal sheath. The cable core includes an electrical conductor and an oil-impregnated paper insulation layer surrounding the electrical conductor. An extended cable core section of the cable core extends through the sheath opening and beyond the sheath terminal edge. The sealing assembly includes an oil barrier tube, a sealing mastic and a pressure retention tape. The oil barrier tube surrounds the extended cable core section. The sealing mastic surrounds the cable about the sheath terminal edge and overlaps portions of the metal sheath and the oil barrier tube adjacent the sheath terminal edge to effect an oil barrier seal between the metal sheath and the cable core at the sheath opening. The pressure retention tape surrounds the sealing mastic to limit displacement of the sealing mastic.