Double-Barrier Subsea Pressure Compensator Against Shock and Jamming

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Solution Overview

Problem

Existing double barrier pressure compensators for subsea installations are fragile and prone to lateral shocks, requiring additional compensation for volume variations and risking jamming, despite providing protection against high pressures and seawater.

Innovation Solution

A compact double barrier pressure compensator design featuring a housing with two bellows arranged one above the other, a moving separation element, and a third compartment filled with a barrier medium, which eliminates the need for additional compensation and provides lateral protection by using a housing and tight seals to manage volume variations and prevent jamming.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If two bellows are arranged one inside the other to provide double barrier protection, then protection against seawater and high pressure is improved, but the device becomes fragile and prone to lateral shocks

Engineering Contradiction:
Improveprotection against seawater and high pressureVSAvoidresistance to lateral shocks
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies nesting by placing one bellows inside another concentric arrangement, with the inner bellows containing the dielectric medium and the outer bellows containing the barrier medium. This nested configuration provides double barrier protection while maintaining structural integrity against lateral shocks through the distributed arrangement of protective layers.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If volume variations inside the space between two bellows are continuously compensated, then protection against tank deterioration is improved, but the device complexity increases

Engineering Contradiction:
Improveprotection against tank deteriorationVSAvoidcompensation mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The barrier medium in the space between the two bellows automatically compensates for volume variations caused by temperature and pressure changes. The system is self-regulating, requiring no external control mechanisms or additional compensators, as the fluid medium naturally adjusts to maintain pressure equilibrium and prevent tank deterioration.

Inventive Principle:
Principle #25Self-service

3Stability of the object's composition

If a rigid tank is used to contain the dielectric medium, then structural stability is improved, but volume variations cause tank deterioration

Engineering Contradiction:
Improvestructural stabilityVSAvoidresistance to volume variation stress
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent uses flexible bellows structures with double barriers to contain the dielectric medium. The bellows are designed to expand and contract axially in response to volume variations of the medium, absorbing stress without transmitting it to the rigid tank structure. This flexible containment prevents tank deterioration while maintaining structural stability.

Inventive Principle:
Principle #30Flexible shells and thin films

4Reliability

If multiple rods are used in the pressure compensator, then compensation functionality is improved, but the risk of jamming increases

Engineering Contradiction:
Improvepressure compensation functionalityVSAvoidjamming risk
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent eliminates the need for multiple rods and complex mechanical compensation mechanisms by using a fluid-filled chamber between the two bellows. The volume variations are compensated through the compressibility and expansibility of the barrier medium, removing all rod-like components that could potentially jam and simplifying the overall structure.

Inventive Principle:
Principle #2Taking out (Extraction)

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 enhances the robustness and reliability of pressure compensation, preventing jamming and offering lateral protection, while maintaining a compact and efficient design that effectively manages volume changes in subsea environments.

Implementation Method 1

Water temperature variations, hydrostatinc pressure and heat produced by the subsea installation while operating also result in volume variations of the medium inside the subsea installation

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

heat produced by the subsea installation while operating also result in volume variations of the medium

Methodology Applied
Scientific EffectPressure variation: Pressure Increase

Implementation Method 3

said third compartment being arranged to be in communication with sea water through the first opening

Methodology Applied
Scientific EffectCompressibility:

Implementation Method 4

opposite locations of said moving separation element being sealingly fixed to proximal ends of the first and second bellows

Methodology Applied
Scientific EffectSealing:

Data Source

PatentEP4038257B1Pressure compensator and assembly comprising a subsea installation and such a pressure compensator
Publication Date: 2024.08.28 FMC KONGSBERG SUBSEA AS
  • EP4038257B1 patent drawingFigure 1~2
  • EP4038257B1 patent drawingFigure 3
  • EP4038257B1 patent drawingFigure 4

AI summary

The invention proposes a double barrier pressure compensator for performing a pressure compensation between seawater surrounding a subsea installation and a medium filling a volume of the subsea installation. Said pressure compensator comprises: - a housing (20) having a first opening (202b) and a second opening (30); - a first bellows (4) and a second bellows (5) arranged one above the other within the housing (20) and each sealingly fixed to the housing (20) at their distal ends (43, 53); - a moving separation element (6) adapted to move inside the housing (20) and sealingly fixed to each of the proximal ends (44, 54) of the first and second bellows (4, 5) so as to separate a first compartment (21) from a second compartment (22) of the housing (20) sealed with respect to each other. Said pressure compensator (2) further comprising a third compartment (23) formed by a space between the housing (20) and the first and second bellows (4, 5), the first compartment (21) being arranged to be fluidly connected to the subsea installation (1) through the second opening (30), the second compartment (22) being arranged to be in communication with sea water through the first opening (202b), and said third compartment (23) being filled with a barrier medium.