Star-Coupled Polyphase Cable Redundancy for Pipeline Heating

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Solution Overview

Problem

Existing electric heating systems for underwater hydrocarbon pipelines face inefficiencies due to the need for redundant three-phase electrical circuits, which result in excessive numbers of electrical cables and unnecessary cable scrapping when a single cable fails.

Innovation Solution

An electrical installation with a star-coupled polyphase circuit and an additional separate cable connected to a zero potential point, allowing for identification and replacement of faulty cables, reducing the number of cables required for redundancy and minimizing unnecessary cable disposal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If redundant three-phase electrical circuits are provided for each circuit used, then system reliability is improved, but the number of electrical cables increases excessively

Engineering Contradiction:
Improvesystem reliabilityVSAvoidnumber of electrical cables
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent merges the function of redundant cables into a single shared additional cable that can replace any faulty main cable through switching mechanisms, thereby reducing the total number of cables while maintaining reliability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The additional cable is designed to serve multiple functions: it can replace any of the main cables (L1, L2, L3) when they fail, making a single cable universal for multiple redundancy purposes

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If a complete additional three-phase circuit is provided for redundancy, then system reliability is improved, but the number of additional electrical cables increases by one third

Engineering Contradiction:
Improvecircuit redundancyVSAvoidadditional electrical cables
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent combines the redundancy function of three separate cables into a single shared additional cable that can serve any phase through switching, reducing cable quantity by two-thirds while maintaining full redundancy capability

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system uses dynamic switching mechanisms that allow the additional cable to be connected to different phases (L1, L2, or L3) depending on which cable fails, enabling adaptive redundancy rather than static dedicated spare cables

Inventive Principle:
Principle #15Dynamics

3Ease of manufacture

If a three-phase circuit fails, then the entire circuit is discarded including non-faulty cables, but this leads to unnecessary cable scrapping and resource waste

Engineering Contradiction:
Improvecircuit replacement simplicityVSAvoidcable waste
Core Design Contradiction:
Ease of manufactureVSLoss of substance

Solution Approach 1:

The patent segments the circuit into individual cable units with independent fault detection, allowing only the specific faulty cable to be replaced rather than replacing the entire three-phase circuit as a unit

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system implements fault detection and identification mechanisms that provide feedback about which specific cable has failed, enabling targeted replacement of only the defective cable rather than blanket replacement of all cables

Inventive Principle:
Principle #23Feedback

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 achieves reduced cable redundancy while maintaining system reliability, allowing for efficient heating of pipelines with fewer cables and minimizing waste by only replacing faulty cables.

Implementation Method 1

heating the pipes by means of electrical cables, round or flat, which are wound around the steel pipes over their entire length in order to heat these pipes by the Joule effect

Methodology Applied
Scientific EffectJoule effect: Joule Heating

Data Source

PatentEP3446540B1Electrical installation for an electric trace heating system for a metal pipe for transporting fluids and electric trace heating method for such a pipe
Publication Date: 2020.07.29 SAIPEM SA
  • EP3446540B1 patent drawingFigure 1
  • EP3446540B1 patent drawingFigure 2
  • EP3446540B1 patent drawingFigure 3~4

AI summary

The invention relates to an electrical installation for an electric trace heating system for a metal pipe (8) for transporting fluids, comprising at least one polyphase electrical circuit having at least three main electrical cables (6-1, 6-4 and 6-7) coupled in star configuration, at least one additional electrical cable (6-2, 6-3, 6-5, 6-6, 6- 8 and 6-9) that is separate from the main cables, the main cables and the additional cable of the polyphase circuit being intended to be positioned around the pipe and being linked at the end of the line to one and the same connection ring (10) forming a point having an electric potential of zero, and means for detecting a potential fault in the polyphase circuit with a view to identifying the faulty main cable that has caused the fault in the polyphase circuit and replacing it with the additional cable. Another subject of the invention is an electric trace heating method using such an electrical installation.