Heat Shield Panel Midrail Segmentation for Gas Turbine Combustor Cooling
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Solution Overview
Problem
Gas turbine engine combustors face challenges in reducing NOx emissions and managing hot spots due to the complexity of combustion zones and cooling air distribution, particularly in rich burn, quick quench, lean burn (RQL) combustion strategies, where elevated flame temperatures and hot spots occur.
Innovation Solution
The introduction of a heat shield panel with a midrail design that segregates backside cavities and allows for increased cooling holes in hot areas, minimizing rail strike during manufacturing and maintaining structural integrity, while also optimizing the placement of cooling holes to avoid hot spots and enhance cooling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cooling holes are increased in hot areas to improve cooling efficiency, then cooling effectiveness is improved, but the risk of rail strike during manufacturing increases
Solution Approach 1:
The heat shield panel is segmented into multiple zones by introducing a midrail that divides the backside cavity into separate regions. This segmentation allows cooling holes to be strategically placed in hot areas while the midrail acts as a physical barrier to prevent manufacturing equipment from striking rails during the cooling hole formation process, thereby resolving the contradiction between cooling efficiency and manufacturing precision.
2Reliability
If a midrail is added to segregate backside cavities to improve cooling air distribution, then cooling efficiency is improved, but device complexity increases
Solution Approach 1:
The midrail segments the backside cavity into distinct regions, enabling independent control and optimization of cooling air distribution in different thermal zones. This segmentation improves cooling efficiency by directing cooling air precisely where needed while maintaining a relatively simple overall panel structure that integrates the midrail as a single structural element.
3Temperature
If cooling holes are placed in hot areas to reduce hot spots, then thermal management is improved, but manufacturing difficulty increases due to rail strike risk
Solution Approach 1:
The midrail creates segmented manufacturing zones that allow cooling holes to be formed in hot areas without risking strikes to structural rails. The midrail itself is positioned to serve as a safe boundary, enabling manufacturers to place cooling holes close to hot spots while the segmented structure prevents equipment from accidentally striking critical rails during the manufacturing process.
4Ease of manufacture
If the heat shield panel structure is simplified to reduce manufacturing complexity, then ease of manufacture is improved, but the ability to manage hot spots and optimize cooling is reduced
Solution Approach 1:
The midrail introduces a single segmentation element that maintains relative structural simplicity while enabling sophisticated hot spot management. By dividing the backside cavity into distinct zones, the midrail allows for optimized cooling hole placement in hot areas without requiring complex multi-component structures, thus balancing ease of manufacture with effective temperature control.
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 design enhances the robustness and cooling efficiency of the heat shield panel, reducing the risk of cooling air leakage and allowing for more effective film cooling, thereby improving the thermal management and reducing NOx emissions by better managing combustion temperatures and hot spots.
Implementation Method 1
allowing for more effective film cooling, thereby improving the thermal management
Implementation Method 2
improving the thermal management and reducing NOx emissions by better managing combustion temperatures and hot spots
Data Source
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AI summary
A heat shield panel (800) for a gas turbine engine combustor (24) may comprise a perimetrical rail (850) extending at least partially around a perimeter of the heat shield panel (800) and defining a main backside cavity (860), a plurality of air admittance holes (778), each air admittance hole (778) extending along a hole axis, and a midrail (858) dividing the main backside cavity (860) into a first backside cavity (861) and a second backside cavity (862), wherein at least a portion of the midrail (858) is axially offset from at least one of the hole axes.