Composite Hull Heating Elements for Ice Prevention

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Solution Overview

Problem

Watercraft, particularly submarines, face challenges with ice formation and water accumulation on their outer surfaces, which can impede functionality and signal transmission, and existing de-icing and drying methods are inefficient or require additional equipment.

Innovation Solution

The use of a fiber-reinforced composite material for the outer skin, where fibers act as electrical heating elements to prevent icing and dry surfaces, combining structural integrity with de-icing and drying functionality, and utilizing a protective layer to prevent short circuits and corrosion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate de-icing and drying devices are installed on watercraft, then ice removal and drying functionality is improved, but device complexity and resource usage increase

Engineering Contradiction:
Improvede-icing functionalityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The heating function is merged into the outer skin structure itself by embedding conductive fibers within the composite material layers. This integration eliminates the need for separate de-icing devices attached to the hull, as the outer skin directly generates heat to prevent and remove ice formation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The outer skin is designed to perform multiple functions simultaneously: structural protection, thermal insulation, and active heating for de-icing. The conductive fibers embedded in the composite material enable the outer skin to serve as both a structural element and a heating element, reducing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If high pressure heated liquid is sprayed from nozzles in the outer skin, then ice removal is improved, but device complexity and energy consumption increase

Engineering Contradiction:
Improveice removal capabilityVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The heating function is extracted from a separate fluid-based system and integrated directly into the structural material itself. Instead of spraying heated liquid through nozzles, the conductive fibers within the composite material generate heat directly at the ice-forming surfaces through electrical resistance, eliminating the need for fluid delivery systems.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The mechanical fluid spray system is replaced with an electrical heating system. Conductive fibers embedded in the outer skin convert electrical energy directly into thermal energy at the precise locations where ice formation occurs, eliminating the need for pumps, nozzles, and fluid circulation systems.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Strength

If the outer skin is formed from fiber-reinforced composite material, then structural strength and lightness are improved, but electrical conductivity for heating purposes deteriorates

Engineering Contradiction:
Improvestructural strengthVSAvoidelectrical conductivity
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The outer skin uses a composite material structure combining non-conductive structural layers with conductive fiber layers. The conductive fibers (such as carbon or metal) are embedded within the composite material, providing both structural reinforcement and electrical conductivity for heating purposes, thus resolving the contradiction between structural requirements and electrical functionality.

Inventive Principle:
Principle #40Composite materials

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

This solution efficiently prevents icing and drying of the outer skin without the need for separate de-icing or drying devices, utilizing the outer skin itself as a heating element, ensuring reliable operation and resource efficiency.

Implementation Method 1

The fiber is electrically conductive but has an electrical resistance. The electrical resistance forms a heating resistor, which heats up when energized.

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

In particular, this protective layer is water-repellent or waterproof, so that surrounding seawater cannot penetrate the fiber composite material and thus does not impede the power supply to the fiber through short circuits or leakage currents.

Methodology Applied
Scientific EffectWater repellency: Hydrophobe

Data Source

PatentEP2266872B1Water vehicle
Publication Date: 2011.10.12 HOWALDTSWERKE DEUT WERFT AG
  • EP2266872B1 patent drawingFigure 1~2
  • EP2266872B1 patent drawingFigure 3
  • EP2266872B1 patent drawingFigure 4

AI summary

The watercraft has a body shell, where a part of the body shell is formed from a composite material i.e. plastic, that is reinforced with fibers (17) i.e. carbon fibers. The fibers are formed as electric heating elements, and are formed for feeding with direct current (DC). The fibers of an outer side (18) of the shell are arranged closer than an inner side of the shell. A protective layer (40) is provided between the outer side of the shell and the fibers that are arranged in a deck area of the shell.