Offshore Cooling System with Closed Circuit and Ballast Tank Heat Dissipation

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Solution Overview

Problem

Offshore wind farms face challenges with open cooling systems, including clogging, corrosion, and high maintenance due to seawater aggression, as well as significant power losses from waste heat dissipation in existing cooling systems.

Innovation Solution

A closed secondary cooling circuit with a double-walled shell and floodable cavities, where the second heat exchanger releases waste heat into a ballast tank instead of open water, reducing corrosion and clogging risks, and enhancing safety and cooling efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If an open cooling system with direct seawater contact is used, then cooling efficiency is improved, but corrosion and clogging increase

Engineering Contradiction:
Improvecooling efficiencyVSAvoidcorrosion and clogging
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The cooling system is segmented into two separate circuits: a primary circuit with direct seawater contact for heat dissipation, and a secondary circuit with treated cooling water for equipment cooling. This segmentation allows each circuit to be optimized independently - the primary circuit handles corrosion and clogging through its open design, while the secondary circuit maintains reliability through controlled water quality

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A heat exchanger serves as an intermediary between the primary and secondary cooling circuits. The first heat exchanger transfers heat from the secondary circuit's cooling water to the primary circuit's seawater, enabling thermal coupling while preventing direct mixing of the two water systems. This intermediary protects equipment from both corrosion and clogging by isolating them from direct seawater contact

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of energy

If power electronic components are used for voltage rectification, then transmission losses are reduced, but waste heat generation increases

Engineering Contradiction:
Improvetransmission lossesVSAvoidwaste heat
Core Design Contradiction:
Loss of energyVSTemperature

Solution Approach 1:

The waste heat generated by power electronic components is extracted from the primary cooling circuit and transferred to the secondary circuit through the first heat exchanger. This separation allows the waste heat to be handled independently in the primary circuit while the secondary circuit maintains optimal cooling conditions for equipment

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The waste heat from power electronic components, which is normally a harmful byproduct, is converted into a beneficial resource by using it to pre-heat the cooling water in the secondary circuit. This reduces the overall thermal load on the cooling system and improves overall energy efficiency

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Reliability

If a double-walled shell with floodable cavities is used, then safety against leaks is improved, but device complexity increases

Engineering Contradiction:
Improvesafety against leaksVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The double-walled shell structure is implemented with nested functional elements: the inner wall contains the equipment, the cavity between walls serves as a floodable air cushion chamber, and the outer wall provides structural protection. This nested arrangement integrates multiple safety functions into a single structural system, reducing overall complexity while maintaining high reliability

Inventive Principle:
Principle #7Nested doll (Nesting)

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 closed system minimizes corrosion, reduces maintenance, and increases cooling capacity while ensuring safe operation by containing potential leaks within the ballast tank, providing effective heat dissipation through a large contact area with seawater.

Implementation Method 1

at least one first heat exchanger (22) for absorbing a heat output (26) occurring in the interior (42)

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

at least one second heat exchanger (24) for releasing the absorbed heat output (28)

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 3

heat release to the sea or sea water... the seawater absorbs the waste heat to be dissipated during the cooling process

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2426353B1Cooling system for an offshore assembly
Publication Date: 2013.04.17 ABB AG(DE)
  • EP2426353B1 patent drawingFigure 1~2

AI summary

The system (10) has an external cover wall (16) and an internal cover wall (14) for limiting an inner chamber (12), and a cavity (18) formed between the cover walls, where water flows through the cavity. A closed coolant circuit (20) has a heat exchanger (22) for receiving heat emission (26) formed in the inner chamber and another heat exchanger (24) for outputting the received heat emission (28). The latter heat exchanger is partially arranged in the cavity, where the cavity is formed as a ballast tank. The external cover wall has cooling ribs (38) projecting into the cavity.