Aircraft Engine Bleed Air Switching Valve for Standby Mode
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Solution Overview
Problem
Current engine air systems in multi-engine aircraft do not efficiently optimize the operation of compressed air systems, particularly in terms of fuel consumption and power output differential between engines, especially during varying power modes.
Innovation Solution
A method and system for operating a multi-engine aircraft where one engine operates in a powered mode and the second engine can be switched between powered and standby modes, utilizing different bleed locations within the compressor section to manage air flow and reduce fuel consumption, with a switching valve controlling the air flow between low and high-pressure sources.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If an engine operates in powered mode to provide motive power to the aircraft, then the aircraft receives sufficient thrust, but fuel consumption increases
Solution Approach 1:
The patent segments the engine operation into two distinct modes: powered mode for providing motive power and standby mode for providing substantially no motive power. This segmentation allows the aircraft to use one engine for propulsion while the other engine operates in standby mode to provide bleed air for aircraft systems, thereby reducing overall fuel consumption while maintaining sufficient thrust
Solution Approach 2:
The patent enables the second engine to perform multiple functions by switching between powered mode and standby mode. In standby mode, the engine provides substantially no motive power but continues to generate bleed air from the compressor section for aircraft systems such as cabin pressurization, air conditioning, and hydraulic systems. This multi-functionality allows a single engine to replace the dual-role engine, reducing fuel consumption
2Quantity of substance
If bleed air is taken from the high pressure compressor stage, then sufficient pressurized air is available for aircraft systems, but engine efficiency decreases during high power operation
Solution Approach 1:
The patent dynamically switches the bleed air source between high pressure and low pressure compressor stages based on engine operating conditions. During high power operation, bleed air is taken from the low pressure stage to maintain engine efficiency, while during low power operation or descent, bleed air is sourced from the high pressure stage to ensure sufficient pressurized air availability for aircraft systems
Solution Approach 2:
The patent changes the operating parameters of the bleed air system by switching between different compressor stages. The switching valve changes the pressure parameter of the bleed air source according to engine power settings, ensuring optimal engine efficiency during high power operation while maintaining sufficient pressurized air quantity for aircraft systems during all phases of flight
3Use of energy by moving object
If an engine operates in standby mode to provide substantially no motive power, then fuel consumption is reduced, but the ability to provide motive power when needed is limited
Solution Approach 1:
The patent prepares the standby engine by maintaining it in a state where it can quickly transition from standby mode to powered mode when needed. The engine remains rotating at a reduced speed in standby mode, keeping the compressor and turbine operational, so that it can provide motive power immediately if one engine fails or additional thrust is required, thereby maintaining reliability without continuous fuel consumption
Solution Approach 2:
The patent incorporates a switching valve controlled by aircraft systems to dynamically select between high pressure and low pressure bleed air sources based on engine operating conditions. This feedback mechanism ensures that the standby engine can seamlessly transition between modes and that the appropriate bleed air source is selected to maintain both fuel efficiency and power availability
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 approach reduces fuel consumption by allowing the second engine to operate in a low-power standby mode while maintaining essential engine functions, with a power output differential between engines ranging from 20% to 95%, optimizing compressed air usage and engine efficiency.
Implementation Method 1
Bleed air produced by a gas turbine engine is compressed air from the compressor stage
Implementation Method 2
a switching valve operable to fluidly interconnect an inlet of the bleed air system with the first bleed location or the second bleed location
Data Source
AI summary
A multi-engine aircraft includes a first engine drivingly engaged to a common rotatable load and a second engine drivingly engaged to the common rotatable load, the second engine having a bleed air system and a control system in communication with a compressed air switching system. The control system controls operation of the second engine and/or the compressed air switching system. The compressed air switching system includes a switching valve that is displaceable between at least a first position and a second position, the first position interconnecting a lower pressure inlet and a switch outlet, and the second position interconnecting a high pressure inlet and the switch outlet. The switch outlet is in communication with the bleed air system of the second engine. The control system actuates the switching valve to switch between the first and second positions.