Electrochemical Cell Oxygen Separation for Fuel Tank Inerting

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Solution Overview

Problem

Existing onboard inert gas generating systems for vehicles require a pressure differential to separate oxygen from air, necessitating a source of compressed air, which can be cumbersome and inefficient.

Innovation Solution

An electrochemical cell with a proton transfer medium separates the cathode and anode, using a voltage differential to electrolyze water and generate oxygen-depleted air, which is then directed to the protected space, such as a fuel tank ullage, without the need for compressed air.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If membrane-based gas separators with pressure differential are used to generate nitrogen-enriched air, then oxygen separation is achieved, but the system requires a source of compressed or pressurized air which increases device complexity

Engineering Contradiction:
Improveoxygen separation effectivenessVSAvoidcompressed air source requirement
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces the mechanical pressure differential system (compressors, pressure vessels) with an electrochemical system. The electrochemical cell uses electrical energy to drive the separation process through ion transport across a membrane, eliminating the need for mechanical compression equipment while achieving the same oxygen separation goal.

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

Solution Approach 2:

The invention changes the driving parameter from mechanical pressure to electrical potential. Instead of using pressure differential to force gas through the membrane, the system uses voltage applied across the electrochemical cell to drive ion transport, fundamentally changing the operational parameter and eliminating compressed air requirements.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If compressed air sources are used to create pressure differential across the membrane, then oxygen separation is enabled, but energy consumption increases

Engineering Contradiction:
Improveoxygen separation capabilityVSAvoidenergy for compression
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent substitutes the energy-intensive mechanical compression process with electrochemical energy conversion. The electrochemical cell directly converts electrical energy into the separation process through ion transport, avoiding the intermediate step of mechanical compression and the associated energy losses.

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

Solution Approach 2:

The system changes the energy input parameter from mechanical work (compression) to electrical energy. This parameter change enables a more direct and potentially more efficient energy pathway from power source to separation function, eliminating the inefficiencies of mechanical compression.

Inventive Principle:
Principle #35Parameter changes

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 effectively reduces the oxygen concentration in the fuel tank vapor space, preventing combustion and explosion, while eliminating the need for compressed air, thereby enhancing the efficiency and reliability of the inert gas generation process.

Implementation Method 1

A portion the process water is electrolyzed at the anode to form protons and oxygen

Methodology Applied
Scientific EffectElectrolysis: Electrolysis

Implementation Method 2

the protons are transferred across the separator to the cathode

Methodology Applied
Scientific EffectIon conduction: Conduction (electrical)

Implementation Method 3

a gas is transferred from the process water fluid flow path including a first side of the membrane to a second side of the membrane to form a de-gassed process water

Methodology Applied
Scientific EffectPhase separation: Phase Change

Data Source

PatentEP3800278B1Process water gas management of electrolyzer system with membrane
Publication Date: 2025.01.01 HAMILTON SUNDSTRAND CORP
  • EP3800278B1 patent drawingFigure 1A~1B
  • EP3800278B1 patent drawingFigure 2
  • EP3800278B1 patent drawingFigure 3~4

AI summary

A system and method are disclosed for inerting a protected space. Process water is delivered to an anode (16) of an electrochemical cell (10) where a portion of the process water is electrolyzed to form protons and oxygen. The protons are transferred across the separator to the cathode (14), and process water is directed through a process water fluid flow path including a first side of a membrane. Gas is transferred to a second side of the membrane to form a de-gassed process water on the first side of the membrane, and the de-gassed process water is recycled to the anode. Air is delivered to the cathode and oxygen is reduced at the cathode to generate oxygen-depleted air. The oxygen-depleted air is directed from the cathode of the electrochemical cell along an inerting gas flow path to the protected space.