Rotary Joint Dielectric Mist Injection for Arc Prevention

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Solution Overview

Problem

High voltage electric rotary joint devices in offshore hydrocarbon exploitation installations face challenges in maintaining dielectric strength and preventing breakdowns due to pollution and partial electrical discharges, leading to frequent maintenance needs and safety concerns in explosive atmospheres.

Innovation Solution

The introduction of a system generating and injecting a mist of dielectric fluid into the internal chamber, combined with a recovery and reinjection system, along with an optical monitoring and control unit, to enhance dielectric strength, clean the chamber, and reduce maintenance by capturing polluting particles and detecting electrical discharges.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a dielectric fluid is introduced into the internal chamber to insulate conductive tracks, then the dielectric strength is improved and electric arcs are prevented, but the fluid becomes polluted by particles and decomposes over time, requiring frequent maintenance

Engineering Contradiction:
Improvedielectric strengthVSAvoidmaintenance frequency
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The system enables self-service through the mist injection system that continuously purifies the dielectric fluid by capturing polluting particles and replenishing degraded fluid with fresh dielectric fluid, allowing the system to maintain its own dielectric strength without external intervention

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The invention changes the physical state of the dielectric fluid by introducing it as a mist (aerosol) rather than pure liquid, and dynamically adjusts the composition ratio between mist and liquid phases to optimize both insulating performance and self-purification capabilities

Inventive Principle:
Principle #35Parameter changes

2Volume of moving object

If the distance between conductive tracks is reduced to improve compactness, then the device size is reduced, but the risk of electric arcs increases without sufficient dielectric strength

Engineering Contradiction:
Improvedevice compactnessVSAvoidelectric arc risk
Core Design Contradiction:
Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The invention changes the dielectric medium parameters by introducing mist (aerosol) which has different dielectric properties than pure liquid, enabling higher dielectric strength in smaller distances between conductive tracks

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system uses a composite dielectric medium combining liquid dielectric fluid and mist (aerosol) phases, creating a multi-phase composite that provides enhanced dielectric strength and self-purification properties for compact track spacing

Inventive Principle:
Principle #40Composite materials

3Object-affected harmful factors

If the internal chamber is sealed to maintain dielectric fluid integrity, then contamination is prevented, but partial electrical discharges and pollution accumulate, reducing dielectric strength over time

Engineering Contradiction:
Improvecontamination preventionVSAvoiddielectric strength maintenance
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The mist injection system extracts and removes polluting particles from the sealed internal chamber by capturing them in the mist, which is then separated and the purified dielectric fluid returned to the chamber

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system discards degraded dielectric fluid and captured contaminants through the separation system, while recovering and reinjecting the purified dielectric fluid back into the internal chamber to maintain dielectric strength

Inventive Principle:
Principle #34Discarding and recovering

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 solution significantly reduces the frequency of maintenance operations, enhances dielectric strength, and minimizes the risk of electric arcs, thereby improving the reliability and safety of high voltage electric rotary joint devices in offshore applications.

Implementation Method 1

the dielectric strength of the medium in which they are located, which dielectric strength is expressed in kV/mm (kilovolts per millimeter) and characterizes the electric field that can be applied between two different electrodes before an electric arc occurs

Methodology Applied
Scientific EffectDielectric strength: Dielectric

Implementation Method 2

an optical monitoring and control unit, to enhance dielectric strength, clean the chamber, and reduce maintenance by capturing polluting particles and detecting electrical discharges

Methodology Applied
Scientific EffectOptical detection:

Data Source

PatentEP3736919B1Electrical rotary joint device configured to equip an installation for exploiting fluids, in particular on an offshore platform
Publication Date: 2023.04.19 ETI GRP
  • EP3736919B1 patent drawingFigure 1~2
  • EP3736919B1 patent drawingFigure 3~4
  • EP3736919B1 patent drawingFigure 5~6

AI summary

The invention relates to an electrically rotating joint device (10) comprising a first part (11), a second part (12) movable in rotation relative to the first part, the first and second parts forming a closed internal chamber (15) and each being provided with at least one electrical connector (26, 27), at least one electrical track (29) housed in the chamber and electrically connected to a connector of one of the first and second parts, at least one contacting block (30) housed in the chamber and electrically connected to a connector of the other of the second and first parts, the contacting block cooperating with the electrical track to establish electrical contact, the chamber comprising a dielectric fluid, the device comprising a system for generating and injecting a mist of dielectric fluid into the chamber,and a system for recovering and reinjecting (50) the dielectric medium formed from the dielectric fluid and the dielectric fluid mist into the chamber.