Spring-Loaded Sleeve Valve With Pressure-Controlled Bleed Closure
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Solution Overview
Problem
Sleeve valves in aircraft compressor systems face challenges in maintaining stability at startup and low power conditions, leading to inefficiencies due to uncontrolled bleeding of compressed air, and require a mechanism to switch between open and closed positions based on engine operating conditions.
Innovation Solution
A sleeve valve design with a spring-biased open position and a pressure chamber that uses a selectively controlled high-pressure air source to move the sleeve to a closed position when line pressure exceeds a predetermined force, incorporating a solenoid and check valve system to manage airflow and ensure efficient operation across varying power conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the sleeve valve is biased open by a spring to allow airflow, then compressor stability at low power conditions is improved, but compressed air is wasted through uncontrolled bleeding
Solution Approach 1:
The valve uses the line pressure from the compressed air itself to trigger closure. When line pressure exceeds the spring force, the pressure automatically opens the selectively closed valve and actuates the sleeve to close, making the system self-regulating without external control signals.
Solution Approach 2:
The system incorporates feedback through the pressure chamber that monitors line pressure. When pressure exceeds a predetermined threshold, the feedback mechanism triggers the sleeve to close, preventing further energy waste. The check valve provides one-way feedback to maintain pressure in the pressure chamber for rapid closure actuation.
2Loss of energy
If a pressure chamber is used to close the sleeve valve, then energy waste is reduced by preventing compressed air bleeding, but device complexity increases due to additional components
Solution Approach 1:
The pressure chamber is integrated into the existing valve housing structure, merging the control mechanism with the valve body. The selectively closed valve, pressure chamber, and sleeve actuation system are combined into a single integrated assembly, reducing overall system complexity despite adding control functionality.
Solution Approach 2:
The system uses pneumatic pressure from the compressed air line itself to actuate the sleeve closure, eliminating the need for external actuators, motors, or complex mechanical linkages. The check valve and pressure chamber work together to store and release pneumatic energy for controlled actuation.
3Loss of energy
If the valve closes automatically when line pressure exceeds spring force, then efficiency is preserved at high power conditions, but the valve cannot remain open for stability at low power conditions
Solution Approach 1:
The system changes the effective spring force parameter dynamically. At low power, the spring force dominates keeping the valve open. At high power, the line pressure overcomes the spring force to close the valve. The selectively closed valve and check valve work together to maintain different pressure states that correspond to different operating conditions.
Solution Approach 2:
The valve system transitions from a static spring-biased design to a dynamic system where the balance between spring force and line pressure determines valve position. The selectively closed valve and check valve enable the system to adapt its state based on real-time operating conditions, allowing automatic adjustment between open and closed positions.
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 solution enables controlled and efficient airflow management, ensuring stability at low power conditions and preserving efficiency at high power conditions by actively closing the valve when necessary, thereby optimizing compressor system performance.
Implementation Method 1
A sleeve is movable to close flow from the inlet port to the outlet port. The sleeve valve has a sleeve biased to an open position at which it allows flow from the inlet port to the outlet port by a spring.
Implementation Method 2
Pressure in the pressure chamber urges the sleeve to a closed position at which it blocks flow from the inlet port to the outlet port.
Implementation Method 3
The selectively closed valve is opened to allow the flow of high pressure air from a pressure source into the pressure chamber to move the sleeve to a closed position.
Data Source
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AI summary
A sleeve valve includes an inlet port and an outlet port. A sleeve is movable to close flow from the inlet port to the outlet port. The sleeve valve has a sleeve biased to an open position at which it allows flow from the inlet port to the outlet port by a spring. Pressure in a pressure chamber urges the sleeve to a closed position at which it blocks flow from the inlet port to the outlet port. A line pressure conduit communicates the fluid chamber into the pressure chamber. Pressurized air is supplied to the pressure chamber through a selectively closed valve. The selectively closed valve is opened to allow the flow of high pressure air from a pressure source into the pressure chamber to move the sleeve to a closed position. A bleed air system for a gas turbine engine is also disclosed.