ATS Exhaust Buffer Air Routing for Engine Compartment Pressurization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing gas turbine engines face challenges in providing adequate pressurization to engine compartments during start-up, leading to potential contamination of cabin ventilation air with engine oil, especially when compressor rotor speeds are below idle.
Innovation Solution
A buffer air augmentation system that utilizes ATS exhaust gas to pressurize engine compartments through flow ducting and control devices, ensuring adequate pressure differential to prevent oil contamination, controlled by a controller and sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If compressor bleed air is used to pressurize engine compartments during start-up, then cabin ventilation air can be provided, but engine oil may contaminate the compressor bleed air due to inadequate pressurization
Solution Approach 1:
The system performs preliminary pressurization of the engine compartment using ATS exhaust gas before the compressor reaches sufficient speed to provide clean bleed air. This advance action establishes the pressure differential needed to prevent oil contamination before the contamination risk occurs during start-up
Solution Approach 2:
ATS exhaust gas serves as an intermediary pressurization medium during the transition period. Instead of relying directly on compressor bleed air (which may be contaminated), the system uses ATS exhaust gas as a temporary mediator to maintain compartment pressure and prevent oil migration until clean bleed air is available
2Object-affected harmful factors
If compressor rotor speed is increased to provide adequate bleed air pressure, then oil contamination is prevented, but engine start-up time is extended
Solution Approach 1:
The system establishes adequate compartment pressurization in advance using ATS exhaust gas before the compressor reaches the speed required for sufficient bleed air generation. This preliminary pressurization prevents oil contamination during the entire start-up process without requiring extended rotor acceleration
Solution Approach 2:
The system changes the pressurization source parameter from compressor bleed air (which requires high rotor speed) to ATS exhaust gas (which provides immediate pressurization). This parameter change allows adequate compartment pressure to be maintained at lower rotor speeds, reducing start-up time while preventing oil contamination
3Reliability
If an electrically powered starter is used to rotate the engine, then start-up can be achieved, but the starter weight is appreciably heavier than an air turbine starter
Solution Approach 1:
ATS exhaust gas serves as an intermediary energy source that supplements the starting process. The air turbine starter provides initial rotation, and the exhaust gas provides additional energy during the transition to self-sustaining operation, enabling the use of a lighter air turbine starter instead of a heavier electric motor
Solution Approach 2:
The engine's own exhaust system is utilized to provide additional energy for the starting process. The ATS exhaust gas is redirected to drive the compressor and turbine sections, allowing the engine to help itself reach self-sustaining speed without requiring an oversized external power source
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
Effectively maintains compartment pressure during engine start-up, preventing oil contamination and ensuring smooth operation by providing controlled ATS exhaust gas flow.
Implementation Method 1
The ATS is configured to receive a flow of compressed air from a compressed air source
Implementation Method 2
The flow ducting is configured to selectively provide fluid communication of the flow of ATS exhaust gas between the exhaust port of the air turbine starter and the engine compartment
Implementation Method 3
ensuring adequate pressure differential to prevent oil contamination
Data Source
AI summary
A gas turbine engine is provided that includes compressor and turbine sections, an engine compartment, an air turbine starter (ATS), and a buffer air augmentation system. The compressor and turbine sections are engaged by a shaft. The ATS is disposed to drive the compressor and turbine sections. The air turbine starter is configured to receive a flow of compressed air from a compressed air source. The air turbine starter has an exhaust port configured to pass a flow of ATS exhaust gas flow. The buffer air augmentation system includes flow ducting configured to selectively provide fluid communication of the flow of ATS exhaust gas between the exhaust port of the air turbine starter and the engine compartment. The system is configured to provide the flow of ATS exhaust gas to the engine compartment during a start-up segment of an engine operational cycle.