Aircraft Air Supply System Reducing Flight Deck Effective Altitude

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Solution Overview

Problem

Modern aircraft face increased differential pressure between the cabin and outside due to pressurized cabins at higher altitudes, requiring either structural reinforcement or flying at lower altitudes to reduce effective altitude, and nitrogen generating systems produce oxygen-enriched air that is currently wasted, reducing engine efficiency.

Innovation Solution

An aircraft air supply system that includes a primary duct for the flight deck and a secondary duct to channel oxygen-enriched air from the nitrogen generating system into the primary duct, controlled to reduce the effective altitude of the flight deck, eliminating the need for additional oxygen generators and minimizing bleed air loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the aircraft cabin is pressurized to reduce effective altitude, then the effective altitude is reduced, but the differential pressure between inside and outside increases causing greater stress on the structure

Engineering Contradiction:

Improveeffective altitudeVSAvoiddifferential pressure

Core Design Contradiction:

TemperatureVSStress or pressure

Solution Approach 1:

The patent changes the composition parameter of the air by enriching it with oxygen (increasing oxygen concentration from typical 21% to higher levels). This allows the effective altitude to be reduced through increased oxygen partial pressure without needing to increase the total pressure, thereby avoiding increased differential pressure and structural stress.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If the nitrogen generating system produces oxygen enriched air, then nitrogen enriched air is available for fuel tanks, but the oxygen enriched air is dumped overboard wasting engine efficiency

Engineering Contradiction:

Improveinert atmosphere for fuel tanksVSAvoidengine efficiency

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

Instead of discarding the oxygen-enriched air overboard, the system recovers and redirects it through a secondary duct to the flight deck air supply. This recovers the otherwise wasted oxygen-rich resource and puts it to useful purpose, improving engine efficiency while maintaining the inert atmosphere function in fuel tanks.

Inventive Principle:

Principle #34Discarding and recovering

Solution Approach 2:

The nitrogen generating system's output is made multi-functional: the oxygen-enriched air that would normally be discarded is now also used to supply the flight deck, allowing one system to serve multiple purposes (fuel tank inerting and flight deck oxygen enrichment).

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Temperature

If additional oxygen generators are installed to reduce flight deck altitude, then oxygen supply is improved, but device complexity increases

Engineering Contradiction:

Improveeffective altitude of flight deckVSAvoidoxygen generation system

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The existing nitrogen generating system is made multi-functional by adding a secondary duct to redirect its oxygen-enriched air output to the flight deck. This avoids the need for separate oxygen generators, maintaining simplicity while achieving flight deck oxygen enrichment.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The nitrogen generating system serves itself by providing its own waste product (oxygen-enriched air) to another part of the aircraft that needs it. The system's byproduct becomes the solution for flight deck oxygen requirements, eliminating the need for additional dedicated oxygen generation equipment.

Inventive Principle:

Principle #25Self-service

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 perceived altitude in the flight deck without increasing overall pressure, enhancing aircraft structural integrity and engine efficiency by utilizing otherwise wasted oxygen-enriched air.

Implementation Method 1

A nitrogen generating system is configured for generating nitrogen enriched air and oxygen enriched air

Methodology Applied

Scientific EffectNitrogen generation system separation:

Implementation Method 2

A secondary duct may be provided for channeling the oxygen enriched air from the nitrogen generating system to the primary duct

Methodology Applied

Scientific EffectGas flow through ducts:

Implementation Method 3

the effective altitude within the aircraft can be realized, without increasing the total pressure, by increasing the oxygen partial pressure to an equivalent lower altitude value

Methodology Applied

Scientific EffectPartial pressure effect:

Data Source

PatentUS10232947B2Aircraft air supply systems for reducing effective altitude of flight decks

Publication Date: 2019.03.19 THE BOEING CO

AI summary

An aircraft air supply system may include a primary duct to supply a primary air flow to a flight deck of an aircraft. A nitrogen generating system may be configured for generating nitrogen enriched air and oxygen enriched air. A secondary duct may be provided for channeling the oxygen enriched air from the nitrogen generating system to the primary duct. The flow of the oxygen enriched air into the primary duct and to the flight deck may be controlled to reduce an effective altitude of the flight deck.