Submarine Fuel Cell Energy Supply with Buffer Storage

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Solution Overview

Problem

Submarines face challenges in supplying energy to their power grids using fuel cells due to the weight and expense of metal hydride storage tanks for hydrogen, and the delay in responding to power fluctuations caused by reformers, which also pose safety risks with large intermediate storage volumes.

Innovation Solution

A method utilizing a reformer with liquid fuel, such as diesel or ethanol, to supply fuel cells, coupled with an electrical storage unit to quickly compensate for load changes, allowing for stable and efficient energy supply with reduced weight and space requirements, and using a DC converter to control power output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If metal hydride storage tanks are used to store hydrogen, then hydrogen storage is achieved, but the system becomes heavy and expensive

Engineering Contradiction:
Improvehydrogen storageVSAvoidstorage tank weight
Core Design Contradiction:
Quantity of substanceVSWeight of moving object

Solution Approach 1:

The patent changes the physical state of hydrogen storage from gaseous (in metal hydride tanks) to liquid form. Liquid hydrogen can be stored in lighter, simpler containers compared to high-pressure gas storage systems, thereby reducing the overall weight and cost of the storage system while maintaining adequate hydrogen supply capacity.

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If reformers are used to supply fuel to the fuel cell, then fuel production is achieved, but the response to load fluctuations is delayed by several seconds

Engineering Contradiction:
Improvefuel productionVSAvoidresponse speed
Core Design Contradiction:
Quantity of substanceVSSpeed

Solution Approach 1:

The patent introduces a buffer storage system that pre-stores reformer-generated fuel (such as syngas) before it reaches the fuel cell. This buffer acts as a preliminary storage stage that decouples the slow reforming process from the immediate fuel cell demand, allowing the system to respond quickly to load changes without requiring the reformer to adjust its slow chemical reactions in real-time.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If large volumes are provided for intermediate storage in the fuel supply, then stable operation of the fuel cell is achieved, but the device complexity and safety risks increase

Engineering Contradiction:
Improvefuel cell operation stabilityVSAvoidintermediate storage facility
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces a buffer storage system as an intermediary component between the reformer and the fuel cell. This buffer serves as a mediator that smooths out fluctuations in fuel supply from the reformer, providing stable fuel flow to the fuel cell without requiring large-scale storage facilities. The buffer acts as a small-capacity shock absorber that maintains stability while minimizing system complexity and safety concerns associated with large hydrogen storage volumes.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Enables stable and efficient energy supply to submarines with rapid adaptation to power fluctuations, reducing the need for large hydrogen storage and minimizing safety risks, while maintaining stable fuel cell operation and efficient power distribution.

Implementation Method 1

hydrogen is catalytically burned with oxygen to form water, with the resulting combustion energy being converted into electrical energy

Methodology Applied
Scientific EffectFuel cell electrochemical reaction: Fuel Cell

Implementation Method 2

the at least one fuel cell is fed by at least one reformer with fuel. The reformer is operated with liquid fuel, usually with a hydrocarbon such as diesel, methanol or ethanol

Methodology Applied
Scientific EffectReforming reaction: Chemical Transport Reactions

Data Source

PatentEP2112707B1Method for supplying energy to a submarine
Publication Date: 2012.12.05 THYSSENKRUPP MARINE SYST GMBH
  • EP2112707B1 patent drawingFigure 1
  • EP2112707B1 patent drawingFigure 2

AI summary

The method involves using a fuel cell (5) for energy supply, and energizing the fuel cell by a fuel processor (20). Power from the fuel cell is received by an electrical storage (40) e.g. super capacitor, through the fuel processor, when the power of the fuel cell exceeds a system load. The power is released from the storage, when the power of the fuel cell falls below the system load. Supply of fuel to the fuel reservoir is controlled in dependence of the release and reception of the power from and/or in to the storage. The fuel cell is loaded with constant pressure at an input side. An independent claim is also included for a device for performing a method for supplying energy of a power supply system i.e. submarine boat.