Aircraft Dried Inert Gas System Using Electrochemical Oxygen Removal
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Solution Overview
Problem
Existing aircraft onboard inert gas systems rely on compressed air, which can reduce engine power and increase fuel consumption, and are heavy with moving parts, posing maintenance challenges, while halocarbons used for fire suppression are detrimental to the ozone layer and lack viable alternatives.
Innovation Solution
An onboard aircraft dried inert gas system using a source of water-containing inert gas generated through reactions with hydrogen or hydrocarbons, employing PEM electrochemical cells or catalytic reactors, and an air cycle cooling system to produce oxygen-depleted air with water vapor, which is then condensed to remove water, reducing the need for compressed air and halocarbons.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If compressed air is used to provide pressure differential for membrane gas separator, then oxygen-depleted air can be generated, but engine power is reduced and fuel consumption increases
Solution Approach 1:
The patent replaces the mechanical compressed air system with an electrochemical cell that uses electrical energy to directly generate oxygen-depleted air. The electrochemical cell electrolyzes water to produce hydrogen and oxygen, with the oxygen removed from the air stream, eliminating the need for mechanical compression and reducing fuel consumption.
Solution Approach 2:
The patent changes the fundamental parameter of how pressure differential is achieved - instead of using mechanical compression of air, it uses electrochemical reactions to directly produce oxygen-depleted air at the required pressure, fundamentally changing the energy conversion pathway from mechanical to electrochemical.
2Reliability
If separate compressor is used to provide pressurized air to membrane gas separator, then inert gas generation is maintained, but aircraft payload increases and maintenance issues arise
Solution Approach 1:
The patent merges the functions of air compression and oxygen removal into a single electrochemical cell system. The electrochemical cell simultaneously performs water electrolysis and oxygen separation from air, eliminating the need for separate compressors and reducing overall system complexity.
Solution Approach 2:
The patent extracts the core function of oxygen removal from the mechanical compression system and places it at the heart of the electrochemical cell, where oxygen is selectively removed through electrochemical reactions, simplifying the overall system architecture.
3Object-affected harmful factors
If halocarbons are used for fire suppression, then combustion is suppressed, but ozone layer is depleted and greenhouse gas emissions increase
Solution Approach 1:
The patent creates an inert atmosphere in fuel tanks by generating oxygen-depleted air through electrochemical cells. By removing oxygen from the air stream and introducing this oxygen-depleted air to the fuel tank ullage, the system prevents combustion without using harmful halocarbons, thereby protecting the ozone layer while maintaining fire suppression capability.
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 system effectively reduces the risk of fuel tank combustion by generating oxygen-depleted air without the need for compressed air, minimizing fuel consumption and maintenance issues, and avoids the environmental drawbacks of halocarbons by using water vapor-based inert gas generation and condensation.
Implementation Method 1
oxygen-depleted air generated through reactions with hydrogen or hydrocarbons, employing PEM electrochemical cells
Implementation Method 2
oxygen-depleted air generated through reactions with hydrogen or hydrocarbons, employing PEM electrochemical cells or catalytic reactors
Implementation Method 3
oxygen-depleted air with water vapor, which is then condensed to remove water
Data Source
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AI summary
An on-board aircraft dried inert gas system includes a source inert gas (38) containing water, an air cycle or vapor cycle cooling system (140), and a heat exchanger condenser (118). The heat exchanger condenser has a heat absorption side in thermal communication with the air cycle or vapor cycle cooling system. The heat exchanger condenser has a heat rejection side that receives the inert gas containing water and outputs dried inert gas.