Aircraft ECS Compression Using Cabin Outflow and Ram Air

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Solution Overview

Problem

Aircraft environmental control systems face inefficiencies in fuel burn and energy usage, as current systems rely on bleed air or high engine pressure, which can be improved by utilizing electrical power and cabin outflow energy to compress outside air for better performance.

Innovation Solution

The system incorporates a ram air circuit with heat exchangers and a dehumidification system, using a combination of bleed air, fresh air, and cabin discharge air to power a compression device, allowing for efficient cabin pressurization and cooling by mixing mediums from different sources to optimize energy usage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If bleed air is used to power the environmental control system, then cabin pressurization and cooling can be achieved, but fuel burn increases

Engineering Contradiction:
Improvecabin pressurization and cooling capabilityVSAvoidfuel burn
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent extracts the compression function from the traditional bleed air system and separates it into an independent electric compression device. This allows the environmental control system to use electric power instead of bleed air, directly reducing fuel consumption while maintaining cabin pressurization and cooling capabilities

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical bleed air compression system with an electric compression system. The electric compression device substitutes the traditional engine-driven compression, converting mechanical energy from engine bleed air to electrical energy for compression, thereby reducing fuel burn

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

2Loss of energy

If electrical power is used to compress outside air, then fuel burn is reduced, but system complexity increases

Engineering Contradiction:
Improvefuel burnVSAvoidsystem complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent designs the electric compression device to perform multiple functions: compressing outside air for pressurization, driving the heat exchanger for cooling, and powering the dehumidification system. This multi-functionality reduces the need for separate systems, thereby managing complexity while achieving fuel savings

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the compression device, heat exchanger, and dehumidification system into an integrated environmental control unit. The electric compression device serves as a central component that drives multiple subsystems, merging previously separate functions into a unified system

Inventive Principle:
Principle #5Merging (Combining)

3Loss of energy

If cabin outflow air energy is used to compress outside air, then fuel efficiency is improved, but system complexity increases

Engineering Contradiction:
Improvefuel efficiencyVSAvoidsystem complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent converts the waste energy in cabin outflow air into a useful resource by directing it to drive the heat exchanger and dehumidification system. This energy recovery approach improves overall fuel efficiency by utilizing previously wasted thermal energy, while the integrated design manages the added system complexity

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 approach reduces fuel burn and enhances the efficiency of aircraft environmental control systems by leveraging mixed energy sources for improved performance and reduced fuel consumption.

Implementation Method 1

a ram air shell having at least one heat exchanger positioned therein

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 2

A compression device is arranged in fluid communication with the ram air circuit and the dehumidification system

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 3

a dehumidification system arranged in fluid communication with the ram air circuit

Methodology Applied
Scientific EffectCondensation: Condensation

Data Source

PatentEP3945026A1Aircraft environmental control system
Publication Date: 2022.02.02 HAMILTON SUNDSTRAND CORP
  • EP3945026A1 patent drawingFigure 1
  • EP3945026A1 patent drawingFigure 2
  • EP3945026A1 patent drawingFigure 3

AI summary

A compressing device for use in an environmental control system includes at least one turbine (44, 46, 48) configured to provide energy by expanding one or more mediums. The one or more mediums provided at an outlet of the at least one turbine form a heat sink within the environmental control system. A compressor (42) is configured to receive energy from the one or more mediums expanded across the at least one turbine. During a first mode of the compressing device, energy derived from a first medium and a second medium of the one or more mediums is used to compress a second medium at the compressor. During a second mode of the compressing device, energy derived from the first medium (A1), the second medium (A2), and a third medium (A3) of the one or more mediums is used to compress the second medium at the compressor.