Subsea Pressure Compensation via Dead Weight and Nested Barriers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing underwater pressure compensation systems for subsea equipment face challenges in maintaining internal pressure equal to or slightly higher than ambient seawater pressure, requiring effective pressure differential management to prevent water ingress and ensure equipment reliability.
Innovation Solution
A double barrier pressure compensation system using fluid-filled enclosures with bellows and dead weights to generate overpressure, ensuring separation of fluids and reducing the risk of leakage, with pressure compensators located either outside or inside the enclosures for enhanced protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a spring is used to pressurize hydraulic fluid within an enclosure, then the internal pressure can be maintained slightly higher than ambient pressure, but the system becomes prone to leakage and inefficient operation
Solution Approach 1:
The invention extracts and removes the spring component from the pressure compensation system. Instead of using a spring to pressurize the hydraulic fluid, the system uses a piston-cylinder arrangement where external ambient pressure directly acts on the piston to maintain pressure balance, eliminating the leakage-prone spring mechanism entirely
Solution Approach 2:
The invention introduces a piston as an intermediary element between the ambient pressure environment and the hydraulic fluid. The piston transmits ambient pressure to the fluid through a sealable interface, providing a more reliable and leakage-free pressure transmission mechanism compared to direct spring contact with the fluid
2Device complexity
If a single barrier enclosure is used for pressure compensation, then the structure is simpler, but the protection against seawater ingress and pressure differential is insufficient
Solution Approach 1:
The invention segments the pressure compensation function into two independent barrier systems: an inner barrier (first enclosure with first hydraulic fluid) and an outer barrier (second enclosure with second hydraulic fluid). Each barrier has its own piston-cylinder arrangement, creating redundant protection against seawater ingress and pressure differentials
Solution Approach 2:
The invention implements a nested enclosure structure where the first fluid-filled enclosure is positioned inside the second fluid-filled enclosure. The inner enclosure protects the equipment, while the outer enclosure provides an additional protective barrier, with both enclosures independently pressure-compensated by their respective pistons
3Reliability
If dead weights are used to generate overpressure instead of springs, then uniform operation and reliability are enhanced, but the device complexity increases
Solution Approach 1:
The invention replaces the elastic mechanical system (spring) with a gravitational mechanical system (dead weight). The dead weight provides a constant force that, when combined with ambient pressure acting on the piston, generates a stable and uniform overpressure in the hydraulic fluid without the variability inherent in spring systems
Solution Approach 2:
The invention changes the pressure generation mechanism from an elastic parameter (spring constant, variable compression) to a gravitational parameter (constant weight force). This parameter change results in more uniform pressure generation that is independent of temperature, wear, and compression variations that affect spring-based systems
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 maintains internal pressure, prevents seawater ingress, and ensures reliable operation even with cracks in the outer enclosure, offering a more uniform and reliable pressure compensation without the need for springs, thus enhancing the protection of subsea equipment.
Implementation Method 1
the first bellow and/or the second bellow each have an element with a weight, particularly a dead weight, the element being arranged in respect of a bellow such that the weight of the element results in a force to reduce the stroke of the bellow
Implementation Method 2
the first chamber of the first pressure compensator is separated from the second chamber of the first pressure compensator via a first bellow
Data Source
AI summary
A system for pressure compensation, e.g., for pressure compensation in a subsea environment, may include a fluid filled enclosure surrounding a cavity, a first pressure compensator having a first chamber and a second chamber, the first chamber being in fluid communication with the cavity, and a second pressure compensator having a third chamber and a fourth chamber, wherein the third chamber of the second pressure compensator is in fluid communication with the second chamber of the first pressure compensator.