Air Cycle Machine Internal Routing to Eliminate External Ducting

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Solution Overview

Problem

Existing air cycle machines for environmental control systems in vehicles require external ducting for routing overboard air flows to and from scavenging turbines, which complicates assembly and maintenance.

Innovation Solution

The air cycle machine design allows the scavenging turbine to exhaust directly into the ambient air fan circuit without external ducting, enabling a more compact and efficient configuration with reduced duct length and number, allowing for higher speed operation and a smaller, lighter design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If external ducting is used to route overboard air flow to and from the scavenging turbine, then the air cycle machine can extract work from the overboard air flow, but the device complexity increases and assembly/maintenance becomes more difficult

Engineering Contradiction:
Improvework extraction from overboard air flowVSAvoidexternal ducting assembly
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The patent merges the scavenging turbine outlet directly with the ambient air fan inlet by positioning them adjacent to each other within the housing, eliminating the need for external ducting. The turbine and fan share a common interface where the turbine outlet fluidly connects to the fan inlet through the housing structure itself, combining multiple functions into a integrated assembly.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent extracts the external ducting component from the system entirely. By routing the overboard air flow internally through the housing from the turbine outlet directly to the fan inlet, the design removes the separate external ducting assembly that would otherwise be required to connect these components.

Inventive Principle:
Principle #2Taking out (Extraction)

2Power

If external ducting is used to route overboard air flow, then the scavenging turbine can be integrated into the air cycle machine, but the manufacturing and assembly complexity increases

Engineering Contradiction:
Improvescavenging turbine integrationVSAvoidassembly and maintenance
Core Design Contradiction:
PowerVSEase of manufacture

Solution Approach 1:

The scavenging turbine is merged with the ambient air fan assembly by positioning the turbine outlet adjacent to the fan inlet within the same housing. This integration allows the turbine to be part of the core air cycle machine assembly rather than a separate component requiring external ducting connections, simplifying both manufacturing and maintenance.

Inventive Principle:
Principle #5Merging (Combining)

3Power

If traditional ducting is used, then the air cycle machine can operate, but the size and weight of the system increase

Engineering Contradiction:
Improveoverboard air flow routingVSAvoidsystem weight
Core Design Contradiction:
PowerVSWeight of moving object

Solution Approach 1:

The patent removes the external ducting components from the system, eliminating the weight of separate ducts, connectors, and associated mounting hardware. The overboard air flow is routed internally through the housing structure, which already exists to contain the turbine and fan, thereby eliminating additional material weight.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The housing structure serves dual purposes: containing the scavenging turbine and fan assemblies while simultaneously providing the flow path for overboard air from the turbine outlet to the fan inlet. This eliminates the need for separate ducting components and their associated weights.

Inventive Principle:
Principle #5Merging (Combining)

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 simplifies the assembly and maintenance of air cycle machines, enhances operational efficiency by eliminating external ducting, and allows for higher speed operation and reduced size and weight, improving overall system performance.

Implementation Method 1

a scavenging turbine supported for rotation within the housing and arranged to receive the overboard air flow and expand the overboard air flow

Methodology Applied
Scientific EffectExpansion:

Implementation Method 2

The work extracted from the overboard air flow can be employed to power the compressor and/or to force ambient air across the heat exchangers

Methodology Applied
Scientific EffectWork extraction: Turbine

Implementation Method 3

force ambient air across the heat exchangers, e.g., via an ambient air fan

Methodology Applied
Scientific EffectForced convection: Forced Convection

Implementation Method 4

heat exchangers to successively cool, compress, further cool, and expand air

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Data Source

PatentEP3875372B1Air cycle machines and methods of communicating fluid through air cycle machines
Publication Date: 2023.07.26 HAMILTON SUNDSTRAND CORP
  • EP3875372B1 patent drawingFigure 1
  • EP3875372B1 patent drawingFigure 2
  • EP3875372B1 patent drawingFigure 3

AI summary

An air cycle machine (100) includes a housing (110) having an exterior wall (132) and an interior wall (134), a scavenging turbine (120) supported for rotation within the housing, and an ambient air fan (122). The ambient air fan is supported for rotation within the housing and is operably associated with the scavenging turbine. The interior wall defines therethrough a turbine-fan port (146) that fluidly couples the ambient air fan to the scavenging turbine for communication of an overboard air flow to an ambient air flow without external ducting. Environmental control systems (102) and methods (200) of flowing fluid through air cycle machines are also described.