Supplemental Air Pack Using Cabin Discharge Air to Cut Bleed Air Load

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Solution Overview

Problem

Conventional aircraft air conditioning systems are supplied with high-pressure bleed air, which penalizes aircraft performance by increasing fuel burn and drag due to the use of bleed air for ventilation.

Innovation Solution

A combined pack architecture that integrates air conditioning packs and supplemental packs, utilizing cabin discharge air and fresh ram air to power compressors through turbines, reducing the reliance on high-pressure bleed air.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If bleed air is used to ventilate the aircraft, then cabin ventilation is provided, but fuel burn and drag increase

Engineering Contradiction:

Improvecabin ventilationVSAvoidfuel burn

Core Design Contradiction:

Ease of operationVSLoss of energy

Solution Approach 1:

A supplemental pack is introduced as an intermediary system between the bleed air supply and the cabin ventilation requirement. This supplemental pack uses a turbine driven by cabin discharge air to compress ambient air, thereby reducing the direct dependence on bleed air for ventilation while maintaining cabin air quality.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system recovers cabin discharge air that would otherwise be wasted to drive the turbine in the supplemental pack. By utilizing this discarded air as a power source, the system reduces the need for additional bleed air while maintaining ventilation effectiveness.

Inventive Principle:

Principle #34Discarding and recovering

2Ease of operation

If bleed air is used for ventilation, then cabin air supply is maintained, but drag increases

Engineering Contradiction:

Improvecabin air supplyVSAvoiddrag

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The supplemental pack acts as an intermediary that provides cabin air supply through an alternative path. By using a turbine-driven compressor powered by cabin discharge air, the system maintains cabin air supply without requiring high volumes of bleed air that would increase drag.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The system uses cabin discharge air to power the turbine that drives the compressor, creating a self-sustaining cycle. This self-service mechanism reduces the need for external bleed air supply, thereby minimizing drag while maintaining cabin ventilation.

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

Reduces bleed air usage by 40-60% and ram air flow, thereby decreasing fuel burn and drag penalties, enhancing aircraft performance and efficiency.

Implementation Method 1

a turbine (215) that is driven by cabin discharge air to drive the compressor (213)

Methodology Applied

Scientific EffectTurbine: Turbine

Implementation Method 2

a heat exchanger (217) that receives bleed air and ambient air

Methodology Applied

Scientific EffectHeat exchanger: Heat Exchanger

Data Source

PatentEP3470337B1Supplemental pack driven by bleed air and cabin air

Publication Date: 2025.12.17 HAMILTON SUNDSTRAND CORP

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AI summary

An airplane is provided. The airplane includes a pack (200). The pack (200) includes a shaft (219), a compressor (213), and a turbine (211) coupled to the compressor (213) via the shaft (219). The turbine (211) receives and expands a first medium to provide power to the compressor (213) via the shaft (219). The compressor (213) receives and compresses a second medium in accordance with the power provided by the turbine (211) via the shaft (219). The turbine (211) is fluidly coupled to a heat exchanger of an air conditioning system.