Combustor Flow Sleeve Pressure Maintenance
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Solution Overview
Problem
In gas turbine engines, maintaining the pressure of compressed air for complete air/fuel mixing and convective cooling in combustors is challenging due to pressure drops along the flow path, which affects combustion efficiency and liner cooling.
Innovation Solution
A combustor design featuring a flow sleeve system with multiple injection points and passages that stratify fluid flow to maintain pressure and reduce pressure drops, utilizing a first passage with apertures and a second passage with openings that inject fluid upstream to interact and maintain pressure along the first passage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If compressed air is forced to travel upstream from the plenum toward the head end for mixing and cooling, then complete air/fuel mixing and convective cooling are achieved, but pressure drops occur along the flow path
Solution Approach 1:
The flow path is segmented into multiple injection points along the liner, with each point receiving compressed air from separate passages. This segmentation allows pressure to be maintained at each injection location independently, ensuring complete mixing at each stage while compensating for pressure drops along the flow path.
Solution Approach 2:
Compressed air is injected upstream at multiple points before the combustion zone, allowing the air to stratify and maintain pressure along the first passage. This preliminary injection ensures that sufficient pressure is available at each mixing location to achieve complete air/fuel mixing before the fluids reach the combustion chamber.
2Temperature
If compressed air is used for impingement cooling of the transition piece, then cooling effectiveness is improved, but pressure maintenance becomes more challenging
Solution Approach 1:
The cooling function is segmented from the mixing function by providing separate injection points and passages. One set of passages delivers compressed air for mixing at the head end, while another set delivers air for cooling the transition piece. This segmentation allows each function to operate at optimal pressure without compromising the other.
Solution Approach 2:
The flow sleeve acts as an intermediary structure that distributes compressed air through multiple passages to different locations. It mediates between the single plenum source and multiple injection points, maintaining pressure by providing direct flow paths to both mixing and cooling zones without requiring the air to travel the entire upstream distance.
3Device complexity
If a single passage is used to deliver compressed air to the head end, then device complexity is reduced, but pressure drops increase
Solution Approach 1:
The single passage is segmented into multiple passages within the flow sleeve, each delivering compressed air to different injection points. This segmentation reduces the length each passage must span, minimizing pressure drops while adding manageable complexity only where needed to maintain pressure.
Solution Approach 2:
The flow sleeve introduces a radial dimension to the air distribution system by providing multiple passages arranged circumferentially. This allows compressed air to be delivered simultaneously to multiple locations around the liner, reducing the axial distance each passage must cover and minimizing pressure drops without significantly increasing overall system complexity.
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 design achieves low pressure drop and effective convective cooling for the combustor liner, ensuring efficient air/fuel mixing and reducing damage to the transition piece from high-temperature fluids.
Implementation Method 1
fluid entering and flowing through the second passage via the opening stratifies and thereby maintains a pressure of fluid entering and flowing through the first passage via the apertures
Implementation Method 2
the compressed air is used for impingement cooling of the transition piece before it is directed toward the head end
Implementation Method 3
this compressed air is forced to travel upstream from the plenum toward the head end where it is mixed with the other fuels
Data Source
AI summary
A combustor is provided and includes a liner through which fluid fed from at least two injection points flows from a head end to an interior of a transition piece, a first one of the at least two injection points being axially proximate to a fluid impenetrable coupling between the liner and the transition piece and defining apertures disposed in fluid communication with a first passage leading to the head end, and a second one of the at least two injection points being disposed axially between the apertures and the head end and upstream from the apertures relative to a direction of fluid flow through the first passage, the second one of the at least two injection points being formed of openings disposed in fluid communication with a second passage leading to the head end.