Aircraft Bleed Air Pressure Selection for Engine Efficiency
Solution Overview
Problem
The existing gas turbine engine compressor bleed systems in aircraft experience efficiency losses due to high-temperature bleed air, which requires cooling via heat exchangers, reducing thrust and increasing weight and space requirements, while also affecting engine performance with higher pressure bleed air.
Innovation Solution
A compressor bleed supply system that optimizes air pressure and temperature by utilizing high, intermediate, and low pressure ports, along with a precooler and bypass valves, to minimize cooling needs and maintain efficient engine operation across various flight conditions, thereby reducing the overall bleed-related penalties and improving fuel efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If bleed air is taken from the compressor at high pressure to power the environmental control system, then the environmental control system can operate independently of engine thrust, but the engine efficiency is reduced due to thrust loss
Solution Approach 1:
The system dynamically selects between three different compressor ports (high, intermediate, and low pressure) based on real-time engine operating conditions. This dynamic adaptation allows the ECS to draw bleed air at the optimal pressure level for current engine state, minimizing thrust penalty while ensuring adequate power supply to the environmental control system.
Solution Approach 2:
The invention changes the pressure parameter of bleed air by providing multiple port options across different pressure levels. By varying the pressure level at which bleed air is extracted based on engine operating conditions, the system optimizes the balance between ECS power availability and engine thrust efficiency.
2Temperature
If bleed air is cooled using a heat exchanger, then the air temperature is reduced to acceptable levels, but the system weight and space requirements increase
Solution Approach 1:
Instead of always using extensive cooling, the system applies cooling only when necessary by selecting appropriate bleed ports. By drawing bleed air from lower pressure ports during certain operating conditions, the air temperature is already more suitable for ECS operation, reducing or eliminating the need for additional cooling capacity and associated heat exchanger weight.
Solution Approach 2:
The system changes the temperature parameter of bleed air by selecting from multiple pressure ports rather than relying solely on post-cooling. Different pressure ports provide bleed air at different temperatures, allowing the system to match temperature requirements directly from the source and minimize cooling equipment needs.
3Productivity
If bleed air pressure is increased to improve environmental control system performance, then the ECS can operate more effectively, but the engine efficiency debit increases
Solution Approach 1:
The system dynamically adjusts bleed air pressure by selecting from three different compressor ports based on real-time engine operating conditions. During high-power engine operation, lower pressure ports are selected to minimize thrust penalty. During low-power operation or ground operations, higher pressure ports can be selected to maximize ECS performance when engine efficiency concerns are less critical.
Solution Approach 2:
The invention changes the pressure parameter of bleed air by providing multiple discrete pressure levels from different compressor ports. This allows the ECS to operate at higher pressures when needed for performance while minimizing engine efficiency losses by selecting appropriate pressure levels matched to current engine operating state.
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 the operational efficiency of the aircraft's environmental control system by optimizing air pressure and temperature, reducing the need for extensive cooling and minimizing the impact on engine performance, leading to improved fuel burn and reduced weight and space requirements.
Implementation Method 1
a precooler and bypass valves, to minimize cooling needs
Data Source
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AI summary
An engine compressor bleed system of an engine for an aircraft is provided including a plurality of compressor pressure ports (204, 206, 208) configured to supply bleed air to satisfy a cooling load for at least a first stage of a flight profile of an aircraft. A first pressure port of the plurality of compressor pressure ports (204, 206, 208) is configured to provide bleed air having a pressure at least equal to a cabin pressure of an aircraft and a temperature that does not exceed a predetermined threshold.