Axial Turbo-Expander for Aircraft ECS Off-Design Efficiency
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Solution Overview
Problem
Aircraft environmental control systems (ECS) face inefficiencies due to operational conditions of the ECS turbine being outside the target design range, particularly in military, commercial, and supersonic aircraft, when utilizing high energy pressurized bleed air or alternative air sources.
Innovation Solution
An environmental control system incorporating a centrifugal compressor and an axial flow turbine, connected by a shaft, with conduits directing airflow through a heat exchanger to improve efficiency and energy extraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a traditional radial turbine configuration is used, then the system structure is simpler, but the operational efficiency deteriorates when operating conditions are outside the target design range
Solution Approach 1:
The patent combines a centrifugal compressor and an axial flow turbine into a single integrated turbo-expander unit, allowing the system to maintain high efficiency across varying operational conditions by leveraging the complementary characteristics of each component
Solution Approach 2:
The axial flow turbine is designed to efficiently extract energy from air sources across a wide range of pressures and flow rates, making the system adaptable to different air sources (engine bleed air, RAM air, or mixtures) while maintaining optimal performance
2Power
If high energy pressurized bleed air is used to power the ECS turbine, then the energy extraction capability is improved, but the turbine operational conditions move outside the target design range causing efficiency loss
Solution Approach 1:
The axial flow turbine is specifically designed to efficiently handle high-pressure air sources by optimizing blade geometry and flow passages, allowing it to maintain high efficiency even when operating with high energy pressurized bleed air that would cause traditional turbines to operate outside their design range
3Adaptability or versatility
If alternative air sources (RAM air or mixtures) are used, then the system flexibility is improved, but the specific speed of the ECS turbine moves outside the target design range leading to poor efficiency
Solution Approach 1:
The axial flow turbine design enables the system to efficiently process air from multiple sources including RAM air, engine bleed air, or mixtures thereof, maintaining optimal efficiency across different specific speed conditions that would challenge traditional turbine designs
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
The system enhances operational efficiency and energy conversion, reduces weight and space requirements, and provides thermal protection, offering improved performance compared to traditional radial turbine configurations.
Implementation Method 1
an axial flow turbine that receives a second airflow from a second air source, extracts energy from the second airflow
Implementation Method 2
a compressor that receives a first airflow from a first air source, compresses the first airflow
Implementation Method 3
the heat exchanger directs the first airflow to a cabin of the aircraft and directs the second airflow overboard
Data Source
AI summary
An environmental control system (ECS) of an aircraft, having a heat exchanger; a compressor that receives a first airflow from a first air source, compresses the first airflow, and directs the first airflow to the heat exchanger; an axial flow turbine that receives a second airflow from a second air source, extracts energy from the second airflow, and directs the second airflow to the heat exchanger, wherein the heat exchanger directs the first airflow to a cabin of the aircraft and directs the second airflow overboard; and a shaft connected between the turbine and the compressor.