Rotating Off-Take Passage for Gas Turbine Cooling
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Solution Overview
Problem
Existing gas turbine engines are not efficiently utilizing the dynamic head of compressed air for cooling rotating components, leading to suboptimal cooling efficiency.
Innovation Solution
A compressor section with a rotatable off-take passage system that increases the static pressure and tangential velocity of compressed air, allowing it to be delivered to rotating components at a higher static pressure and matched tangential velocity, thereby enhancing cooling efficiency without additional compression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If air is bled from the compressor through conventional off-take ports to cool rotating components, then cooling is provided, but the dynamic head of the compressed air is not efficiently utilized and additional compression may be required
Solution Approach 1:
The off-take passage is designed to rotate with the compressor rotor, transforming the static bleeding system into a dynamic one. This rotation allows the passage to capture and utilize the dynamic head and tangential velocity of the compressed air, converting kinetic energy into useful cooling flow without requiring additional compression work.
Solution Approach 2:
The invention changes the flow parameters of the bled air by utilizing the rotational motion to increase tangential velocity and optimize static pressure. By aligning the off-take passage rotation with the compressor rotor, the system transforms the air flow parameters to match the requirements of rotating components, improving cooling efficiency without additional energy input.
2Temperature
If the off-take passage is made rotatable to match the velocity of rotating components, then cooling efficiency is improved, but the device complexity increases
Solution Approach 1:
The off-take passage is merged with the compressor rotor structure, so that the passage and rotor rotate together as a single unit. This integration eliminates the need for separate rotating mechanisms and simplifies the overall structure, as the cooling system becomes an inherent part of the compressor assembly rather than an add-on component.
Solution Approach 2:
The rotating off-take passage serves multiple functions: it acts as both a structural component of the compressor rotor and a cooling air delivery system. By making the passage rotatable, it can simultaneously maintain its position relative to rotating turbine components while delivering cooled air, reducing the need for separate systems for each function.
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 enables more efficient cooling of rotating components, reducing the relative total temperature of the air and minimizing the need for further upstream or downstream compression, resulting in improved cooling efficiency and reduced engine fuel consumption.
Implementation Method 1
As will be appreciated, the air in the off-take passage will pick up tangential velocity due to conservation of angular momentum as it approaches the principal rotational axis of the engine.
Implementation Method 2
the off-take passage includes a diffuser portion downstream of the rotor and upstream of the discharge end, shaped to increase the static pressure of the air in the off-take passage
Data Source
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AI summary
A gas turbine engine has a compressor section with rotational compressor components rotatable with respect to static compressor components. A compressed air bleed arrangement is provided to cool one or more other rotational components of the gas turbine engine. The compressed air bleed arrangement takes a flow of compressed air from the compressor section along an off-take passage. The off-take passage opens in the compressor section at an off-take port. The off-take passage is rotatable, in use, with the rotational compressor components. The compressed air bleed arrangement is operable to provide the air in the off-take passage with higher static pressure than the air in the compressor section at the off-take port, by diffusing the air in the off-take passage. The off-take passage further includes off-take vanes, operable to increase the tangential velocity of the air in the off-take passage compared with the air at the off-take port.