Crosslinked Energy Cable Insulation With In-Core Methane Adsorption

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Solution Overview

Problem

The existing degassing process for removing methane by-products from energy cables with crosslinked insulating layers is time-consuming and costly, and existing microporous materials for methane adsorption are not suitable for use at ambient pressure and temperature, posing challenges for cable manufacturing efficiency and safety.

Innovation Solution

Incorporating a microporous material with a bimodal pore volume distribution, featuring peaks at 0.55-0.65 nm and 0.75-0.85 nm, to irreversibly adsorb methane at room temperature and pressure, eliminating the need for a degassing apparatus and reducing processing time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional degassing process is used to remove methane by-products, then methane removal is achieved, but processing time increases and manufacturing cost increases

Engineering Contradiction:
Improvemethane removal effectivenessVSAvoidprocessing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The microporous material is incorporated into the cable core during manufacturing, performing the methane adsorption function in advance rather than requiring a separate post-manufacturing degassing process. This preliminary action eliminates the need for time-consuming degassing chambers and reduces manufacturing cycle time while maintaining effective methane removal.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The degassing function is extracted from the traditional thermal degassing process and transferred to a microporous adsorption material. This extraction allows methane removal to occur passively through adsorption rather than requiring active heating and ventilation systems, significantly reducing processing time and infrastructure requirements.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If traditional degassing process is used to remove methane by-products, then methane removal is achieved, but manufacturing cost increases

Engineering Contradiction:
Improvemethane removal effectivenessVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The expensive thermal degassing infrastructure (large heated chambers, ventilation systems) is extracted and replaced with a simple microporous material incorporation step. This extraction eliminates capital equipment costs and reduces operational expenses while maintaining methane removal effectiveness.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The microporous material serves as a low-cost, single-use adsorbent that is incorporated into the cable core during manufacturing. Unlike expensive reusable degassing chambers, this material provides effective methane removal at minimal cost and requires no complex infrastructure investment.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Loss of time

If microporous materials are used for methane adsorption, then processing time is reduced, but the materials must operate at unsuitable pressure and temperature conditions

Engineering Contradiction:
Improveprocessing timeVSAvoidoperating condition compatibility
Core Design Contradiction:
Loss of timeVSAdaptability or versatility

Solution Approach 1:

The invention selects microporous materials with specific pore size distributions (0.55-0.65 nm and 0.75-0.85 nm peaks) that are optimized for methane adsorption at ambient temperature and pressure. This parameter optimization allows the material to function effectively under normal cable operating conditions, unlike other microporous materials that require extreme temperatures or pressures.

Inventive Principle:
Principle #35Parameter changes

4Strength

If crosslinking process is used to achieve mechanical and electrical properties, then material strength is improved, but methane by-products are generated

Engineering Contradiction:
Improvemechanical and electrical propertiesVSAvoidmethane by-products
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The invention converts the harmful methane by-products generated during crosslinking into an adsorbable target for the microporous material. By incorporating the adsorbent material into the cable core, the system transforms the crosslinking process from a harmful methane-generating reaction into a controlled process where methane is immediately captured and removed, preventing its accumulation and harmful effects.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

This approach significantly reduces the duration and cost of cable manufacturing by allowing methane removal without detrimental effects on cable performance, ensuring efficient methane uptake and absorption within the cable core, thus enhancing productivity and safety.

Implementation Method 1

porous materials capable of reversibly capturing gaseous methane through physico-chemical adsorption

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP3659159B1Energy cable having a crosslinked electrically insulating layer, and method for extracting crosslinking by-products therefrom
Publication Date: 2024.01.10 PRYSMIAN SPA
  • EP3659159B1 patent drawingFigure 1~2
  • EP3659159B1 patent drawingFigure 3a~3b
  • EP3659159B1 patent drawingFigure 4a~4b

AI summary

The present invention relates to an energy cable comprising a cable core comprising an electric conductor and a crosslinked electrically insulating layer, wherein the cable core further comprises a microporous material having a bimodal pore volume distribution with a first peak of the distribution having a maximum at a pore diameter value within the range 5.5–6.5 Å and a second peak of the distribution having a maximum at a pore diameter value within the range 7.5–8.5 Å, the maximum values of the first and the second peak corresponding to an incremental pore volume of at least 4x10-3 cm3/g. The present invention also relates to a method for extracting methane crosslinking by-products from a crosslinked electrically insulating layer of an energy cable.