Subsea Pipeline Direct Electric Heating via Segmented Modules
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Solution Overview
Problem
Conventional direct electric heating systems for subsea pipelines are limited by short heating distances, lack of control, significant energy losses, and high costs, with single-phase systems being inefficient and costly, especially in deep water environments where hydrate formation can restrict flow.
Innovation Solution
A three-phase direct electric heating system using subsea power cables and modular DEH modules with symmetrisation and compensation units to distribute load evenly, allowing longer heating distances and reducing energy losses, while enabling remote control and fault tolerance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If conventional single-phase heating systems are used, then the system structure is simple, but the heating distance is limited and energy losses are significant
Solution Approach 1:
The pipeline heating system is divided into multiple independent single-phase heating sections, each controlled by its own DEH module. This segmentation allows each section to be optimized for efficient heating while extending the total heated distance along the pipeline without proportionally increasing energy losses in any single section.
Solution Approach 2:
Each DEH module provides localized heating control tailored to specific pipeline sections. The symmetrisation unit balances the load distribution across three phases locally at each module, optimizing energy efficiency for that specific section while maintaining overall system balance.
2Ease of manufacture
If conventional single-phase heating systems are used, then the system structure is simple, but the costs are high
Solution Approach 1:
The system uses multiple identical single-phase DEH modules that can be manufactured using standard equipment and procedures. Each module is a self-contained unit with standardized components, making them easy to manufacture, install, and replace while achieving superior overall heating efficiency through the combined multi-phase architecture.
Solution Approach 2:
The invention transitions from conventional single-phase system thinking to a multi-dimensional approach by combining three independent single-phase modules into an effective three-phase system. This dimensional expansion in the electrical phase domain achieves higher efficiency without requiring complex custom-manufactured three-phase equipment.
3Length of stationary object
If longer pipeline sections are heated, then the coverage is improved, but the energy losses increase
Solution Approach 1:
Long pipeline sections are divided into multiple heating zones, each served by a separate DEH module. This segmentation ensures that energy is delivered locally to each zone rather than being transmitted over long distances through a single cable, significantly reducing cumulative energy losses while maintaining coverage of the entire long pipeline section.
Solution Approach 2:
The symmetrisation unit acts as an intermediary that balances the electrical load across three phases at each DEH module. This intermediary function optimizes power distribution efficiency, reducing energy losses in the power transmission to each heating section while enabling longer overall pipeline coverage.
4Length of stationary object
If the heating system is extended to remote locations, then the coverage is improved, but the cable currents increase
Solution Approach 1:
The power distribution system is segmented into multiple sections, each with its own DEH module located at different positions along the pipeline. This segmentation allows power to be drawn from the pipeline at multiple points rather than transmitting high currents over the entire length from a single remote location, reducing the cumulative current burden on any single cable section.
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 heats longer subsea pipeline sections with reduced energy losses and costs, maintaining efficient power transmission over long distances and preventing hydrate formation, thus ensuring reliable hydrocarbon transport.
Implementation Method 1
The subsea DEH module comprises a three phase transformer; first electric connections adapted to couple the three phase transformer of the subsea DEH module to the subsea power cable for supplying three phase electric power to the three phase transformer
Implementation Method 2
A 50/60 Hz AC current is passed through the cable and the pipeline, and the pipeline is heated due to its electric resistance
Data Source
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AI summary
A direct electric heating (DEH) system for heating a subsea pipeline is provided. The DEH system has a subsea power cable adapted to be coupled to a three phase electric power source. It further includes two or more subsea DEH modules, each module being provided for heating a different pipeline section of the subsea pipeline.