Flexible Shell Subsea Housing for Pressure Balancing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing subsea electrical equipment protection solutions are complex, costly, and inefficient in preventing contamination and electric breakdowns due to impurities in dielectric liquids, especially at high pressures and corrosive seawater environments.

Innovation Solution

A subsea device with a protective housing featuring a flexible or permeable cover that forms a pressure-compensated chamber, allowing for compact and cost-effective assembly, with feed-throughs for electrical connections and filtering capabilities to prevent contamination and ensure reliable operation at depths of 3,000 meters or more.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a traditional protective housing with bellows structure is used to protect components from contamination, then the internal circuit elements are protected from environmental contamination, but the structure becomes complex, requires large space, and increases production cost

Engineering Contradiction:
Improveprotection from contaminationVSAvoidstructural complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies a flexible membrane as the cover of the protective housing, which can deform to accommodate volume changes of the dielectric liquid while maintaining the sealed enclosure. This flexible shell approach replaces the complex bellows structure with a simpler, more compact membrane-based solution that still provides effective protection against contamination while reducing structural complexity and space requirements

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent utilizes the compressibility parameter of the dielectric liquid to allow volume changes within the sealed enclosure. By permitting the liquid volume to vary with temperature changes and using the flexible membrane to accommodate these variations, the system maintains pressure balance and prevents contamination without requiring complex expansion compensation mechanisms

Inventive Principle:
Principle #35Parameter changes

2Reliability

If particles in dielectric liquid deposit at high electric field strength areas, then electric breakdown may occur, but filtering the liquid adds complexity to the system

Engineering Contradiction:
Improveprevention of electric breakdownVSAvoidfiltering system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs a self-filtering mechanism where the dielectric liquid passes through a filter integrated into the housing structure during filling or maintenance operations. The filter captures particles and impurities that could cause electric breakdown, and the system is designed to be filled with pre-filtered liquid or to allow in-situ filtering without requiring complex external filtration systems during operation

Inventive Principle:
Principle #25Self-service

3Reliability

If the protective housing is designed to be pressure compensated, then the component can operate reliably at high pressures, but the housing structure becomes more complex

Engineering Contradiction:
Improveoperation at high pressureVSAvoidpressure compensation structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The flexible membrane cover serves dual functions: it maintains the sealed enclosure for protection while simultaneously providing pressure compensation by deforming in response to pressure changes. This allows the housing to be pressure-compensated without requiring complex mechanical pressure equalization mechanisms, as the membrane naturally adjusts to pressure differentials between the internal and external environments

Inventive Principle:
Principle #30Flexible shells and thin films

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 solution effectively protects subsea power electronic components from contamination and electric breakdowns, enabling reliable operation in harsh marine environments by providing pressure balancing and filtering, while allowing for efficient cooling and assembly, thus ensuring the longevity and performance of subsea equipment.

Implementation Method 1

The cover comprises at least a flexible wall section that is deformable to allow the volume of the chamber to change for providing pressure balancing between a pressure inside the chamber and a pressure outside the chamber

Methodology Applied
Scientific EffectPressure balancing: Pascal's Law

Implementation Method 2

Such pressure compensated enclosure is generally filled with a dielectric liquid which is essentially incompressible and which further provides heat conduction

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 3

The permeable wall section is further configured to filter a fluid flowing through the permeable wall section

Methodology Applied
Scientific EffectFiltering: Filter (physical)

Data Source

PatentEP2980938B1Protective housing for a component of a subsea device
Publication Date: 2020.01.15 SIEMENS AG
  • EP2980938B1 patent drawingFigure 1
  • EP2980938B1 patent drawingFigure 2

AI summary

A protective housing (10) of a component (15) of a subsea device is provided. The component is an electric or an electronic component, and it is mounted to a support (16). The protective housing has a cover (11) that is mountable to the support of the component. The cover is formed so as to enclose the component when mounted to the support such that the component is directly located inside a chamber (13) formed by the cover and the support. The cover has at least a flexible wall section (12) or a permeable wall section (12).