Pack-and-a-half aircraft environmental control system

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Solution Overview

Problem

Conventional pack-and-a-half environmental control system architectures for aircraft are too large for certain installations, requiring alternative locations on the aircraft, such as the tail cone, and there is a need to reduce their size while maintaining performance.

Innovation Solution

The design includes a ram module with primary and secondary heat exchangers and a refrigeration module with an air cycle machine and condenser heat exchanger, connected by conduits, allowing for separate installation in two volumes, featuring a condenser heat exchanger with a bypass valve, recirculated air inlet, and compact mixer to condition air for the cabin, along with variable speed fans for airflow control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If pack-and-a-half environmental control system architecture is used, then system size is reduced compared to two-pack architecture, but the system is still too large for certain aircraft locations

Engineering Contradiction:
Improvesystem volumeVSAvoidinstallation location flexibility
Core Design Contradiction:
Volume of moving objectVSAdaptability or versatility

Solution Approach 1:

The environmental control system is divided into separate modules (pack module and condenser module) that can be installed in different locations. The pack module containing the air cycle machine and the condenser module with heat exchangers are separated and connected via conduits, allowing flexible installation in distributed aircraft volumes rather than requiring a single large space.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If conventional two-pack architecture is used, then installation locations are available, but system size and weight are excessive

Engineering Contradiction:
Improveinstallation location availabilityVSAvoidsystem weight
Core Design Contradiction:
Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The system merges the functions of two separate packs into a single integrated pack-and-a-half architecture, combining one full pack with a reduced condenser module. This consolidation reduces overall system weight and volume while maintaining the necessary environmental control capabilities for the aircraft.

Inventive Principle:
Principle #5Merging (Combining)

3Volume of moving object

If system size is reduced, then installation in smaller spaces becomes possible, but system complexity may increase

Engineering Contradiction:
Improvesystem volumeVSAvoidsystem complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The system transitions from a single-volume configuration to a multi-volume distributed architecture, utilizing multiple spatial dimensions within the aircraft. The pack module and condenser module are separated and installed in different locations, connected by conduits, thereby reducing the footprint in any single location while managing complexity through modular design.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 configuration enables reduced size and weight, improved performance, and reduced part count compared to conventional two-pack architectures, allowing for installation in smaller spaces while maintaining operational efficiency and redundancy.

Implementation Method 1

a ram module having a primary heat exchanger and a secondary heat exchanger

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

a condenser heat exchanger that conditions air received from turbines of the air cycle machine module to supply the conditioned air to a cabin of the aircraft

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

a refrigeration module having an air cycle machine module

Methodology Applied
Scientific EffectCompression and expansion: Gas Compressor

Data Source

PatentEP3219618B1Pack-and-a-half architecture for environmental control systems
Publication Date: 2019.09.18 HAMILTON SUNDSTRAND CORP
  • EP3219618B1 patent drawingFigure 1A~1B
  • EP3219618B1 patent drawingFigure 2A
  • EP3219618B1 patent drawingFigure 2B

AI summary

Environmental control system (200) for aircraft are provided having a ram module (202) having a primary heat exchanger (208a) and a secondary heat exchanger (280b), a refrigeration module (204) having an air cycle machine (218) module and a condenser heat exchanger (216) module, and at least one conduit fluidly connecting the ram module (202) to the refrigeration module (204) such that the ram module (202) and the refrigeration module (204) can be installed in two separate volumes of the aircraft.