Composite Hydro-Pneumatic Heave Compensation for Lighter High-Pressure Loads

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Solution Overview

Problem

Existing heave compensation devices, particularly those using steel gas cylinders, are too heavy, reducing the net load that can be suspended and are cumbersome for larger loads and higher heaving motions.

Innovation Solution

A heave compensation device with a configurable hydro-pneumatic spring system using fiber overlayed pressure vessels, which includes a fiber layer for weight reduction while maintaining strength and resistance to high pressures, allowing for high-frequency operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If steel gas cylinders are used for heave compensation, then high strength and pressure resistance are achieved, but weight increases significantly

Engineering Contradiction:
Improvepressure resistanceVSAvoidweight of heave compensation device
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent applies composite materials by combining a fiber-reinforced plastic layer with a metal liner to create a pressure vessel that maintains the strength and pressure resistance of steel while significantly reducing weight. The fiber layer provides structural strength, while the thin metal liner provides gas barrier properties, achieving both lightweight construction and high pressure resistance.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent uses a fiber-reinforced plastic shell as the primary structural component of the pressure vessel. This flexible composite shell replaces traditional thick steel cylinders, providing sufficient strength through fiber reinforcement while being much lighter and allowing for more efficient gas storage volume.

Inventive Principle:
Principle #30Flexible shells and thin films

2Quantity of substance

If larger gas volumes are used for higher loads and heaving motions, then heave compensation performance improves, but device weight and cumbersomeness increase

Engineering Contradiction:
Improvegas volumeVSAvoidweight of heave compensation device
Core Design Contradiction:
Quantity of substanceVSWeight of moving object

Solution Approach 1:

The fiber-reinforced composite pressure vessel enables larger gas volumes to be stored without proportionally increasing weight. The high strength-to-weight ratio of the composite material allows the vessel to expand in volume while maintaining structural integrity and keeping the added weight minimal compared to steel alternatives.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the material parameter from steel to fiber-reinforced plastic, which fundamentally alters the weight-volume relationship. This parameter change allows the system to achieve larger gas volumes for higher loads without the proportional weight increase that would occur with steel cylinders.

Inventive Principle:
Principle #35Parameter changes

3Weight of moving object

If fiber overlayed pressure vessels are used, then weight is reduced and fatigue resistance is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveweight of pressure vesselVSAvoidmanufacturing complexity
Core Design Contradiction:
Weight of moving objectVSEase of manufacture

Solution Approach 1:

The patent employs fiber overlaying technology to create the composite pressure vessel structure. This manufacturing process, while more complex than simple steel fabrication, enables the weight reduction and fatigue resistance benefits by layering fibers in specific orientations to optimize strength-to-weight ratio and resistance to cyclic loading.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The fiber-reinforced plastic shell is manufactured as a thin-walled structure that requires specialized forming and curing processes. While this increases manufacturing complexity compared to steel welding, it achieves the desired weight reduction and fatigue performance through the thin-film composite construction.

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 device achieves significant weight reduction compared to steel cylinders, enabling the suspension of larger loads with improved fatigue resistance and corrosion resistance, suitable for offshore operations.

Implementation Method 1

The fiber layer provides strength and has little wear even though the vessel is at least partially filled and emptied at high frequencies

Methodology Applied
Scientific EffectComposite materials: Composite Materials

Implementation Method 2

a preferably configurable (gas- or) hydro-pneumatic spring system, preferably coupled to first and second frame

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 3

A hydro-pneumatic spring comprises a medium separator in between the cylinder and the gas: an oil volume acts on the cylinder and the gas acts on a piston between the gas and the oil volume

Methodology Applied
Scientific EffectHydraulic press: Hydraulic Press

Implementation Method 4

A gas spring comprises a gas volume acting on a cylinder directly

Methodology Applied
Scientific EffectGas pressure: Pressure Increase

Data Source

PatentEP4674800A1Heave compensation device
Publication Date: 2026.01.07 NHLO HLDG BV
  • EP4674800A1 patent drawingFigure 1
  • EP4674800A1 patent drawingFigure 2
  • EP4674800A1 patent drawingFigure 3A~3B

AI summary

Heave compensation device comprising a first frame 2, a second frame 3 for connection to the load (35), the second frame arranged to move decoupled with respect to the first frame, and a configurable (gas- or) hydro-pneumatic spring (401), which includes at least one pressure accumulator (405) that has a fiber layer (61).