Solid Oxide Electrochemical Gas Separator for Aircraft Fuel Tank Inerting

Solution Overview

Problem

Conventional methods for generating inert gas for fuel tank inerting and fire suppression are energy-inefficient and heavy, and they require humidity removal, whereas existing fire extinguishing agents like Halon are environmentally harmful.

Innovation Solution

The use of solid oxide electrochemical gas separator (SOEGS) cells, which reduce oxygen from incoming air using an applied DC voltage, generating oxygen-depleted air efficiently and reducing system weight, and replacing ozone-depleting agents with an inert gas system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional membrane-based technologies are used to inert fuel tank air, then oxygen concentration can be reduced below 12%, but the system becomes energy-inefficient and heavy

Engineering Contradiction:

Improveinerting effectivenessVSAvoidenergy efficiency

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces conventional membrane-based mechanical separation technologies with solid oxide electrochemical gas separator cells that use electrochemical reactions to separate oxygen from air. This substitution of the underlying physical principle enables more efficient oxygen removal without the energy penalties and weight constraints of membrane systems.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention operates the solid oxide electrochemical gas separators at elevated temperatures (typically 500-1000°C), fundamentally changing the operational parameters compared to ambient-temperature membrane systems. This temperature parameter change enables the electrochemical reactions to proceed efficiently and produces oxygen-depleted air without the energy inefficiencies of conventional methods.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If conventional membrane-based technologies are used to inert fuel tank air, then oxygen concentration can be reduced below 12%, but the system weight increases

Engineering Contradiction:

Improveinerting effectivenessVSAvoidsystem weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The patent replaces conventional membrane-based mechanical separation technologies with solid oxide electrochemical gas separator cells that use electrochemical reactions to separate oxygen from air. This substitution of the underlying physical principle enables more efficient oxygen removal without the energy penalties and weight constraints of membrane systems.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If conventional methods are used for inert gas generation, then oxygen-depleted air can be produced, but humidity removal is required

Engineering Contradiction:

Improveinerting effectivenessVSAvoidsystem complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The invention operates the solid oxide electrochemical gas separators at elevated temperatures (typically 500-1000°C), fundamentally changing the operational parameters compared to ambient-temperature membrane systems. This temperature parameter change enables the electrochemical reactions to proceed efficiently and produces oxygen-depleted air without the energy inefficiencies of conventional methods.

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

The SOEGS system provides energy-efficient, lightweight inert gas generation with no humidity removal needed, offering a more environmentally benign alternative for fuel tank inerting and fire suppression.

Implementation Method 1

solid oxide electrochemical gas separator cells, which reduce oxygen from incoming air using an applied DC voltage

Methodology Applied

Scientific EffectElectrochemical reduction: Electrolysis

Implementation Method 2

an electrolyte for conducting oxygen ions from the cathode to the anode

Methodology Applied

Scientific EffectIon conduction: Conduction (electrical)

Implementation Method 3

oxygen ions which are subsequently conducted across the electrolytes of the plurality of solid oxide electrochemical gas separator cells from the cathode to the anode where they oxidize to evolve oxygen molecules

Methodology Applied

Scientific EffectOxidation: Oxidation

Data Source

PatentUS10337111B2Solid oxide electrochemical gas separator inerting system

Publication Date: 2019.07.02 HAMILTON SUNDSTRAND CORP

AI summary

An air inert gas generating system consists of heat exchangers, a heating element, and a plurality of solid oxide electrochemical gas separator (SOEGS) cells. The SOEGS cells are interconnected in series to create a stack. A voltage is applied to the stack causing oxygen ions to be transported from the air flowing through the cathode through the electrolyte to the anode side of the SOEGS, resulting in oxygen-depleted gas. The oxygen-depleted gas can be used to inert the ullage of aircraft fuel tank or support the fire suppression system in the cargo hold. The oxygen-enriched gas can be used for other purposes.