Hot Gas Path Component Trailing Edge Near Wall Cooling
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Solution Overview
Problem
Conventional gas turbine systems face inefficiencies in cooling hot gas path components, particularly at the trailing edge, due to insufficient cooling performance, leading to potential component failure and reduced system efficiency.
Innovation Solution
The implementation of micro-channel cooling systems on the surfaces of hot gas path components, including airfoils, with pressurized air flowing through micro-channels and outlet passages, is used to efficiently transfer heat and maintain a uniform temperature profile, enhancing cooling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cooling schemes with internal cooling passages and discharge holes are used, then cooling coverage is improved, but device complexity increases and cooling efficiency at the trailing edge becomes insufficient
Solution Approach 1:
The cooling system is segmented into distinct functional zones: impingement cooling inserts for the airfoil cavity surfaces and micro-channel cooling systems for the trailing edge. This segmentation allows each zone to be optimized independently, with the impingement inserts handling bulk cooling and micro-channels providing intensive trailing edge cooling where heat flux is highest.
Solution Approach 2:
Different cooling methods are applied to different locations based on local thermal requirements. The trailing edge, which experiences the highest temperatures and heat flux, receives intensive micro-channel cooling with cooling features positioned within 0.5 inches of the external surface. Other areas use conventional impingement and film cooling, creating a locally optimized cooling strategy that improves overall effectiveness without uniformly increasing complexity.
2Reliability
If additional trailing edge cooling circuits are added, then cooling coverage is improved, but device complexity and space requirements increase
Solution Approach 1:
The micro-channel cooling system merges multiple cooling functions into a single integrated structure. The micro-channels are formed directly in the trailing edge component, combining the cooling passage function with the structural component itself. This eliminates the need for separate trailing edge cooling circuits and reduces overall system complexity while providing intensive cooling where needed.
Solution Approach 2:
The cooling features are nested within the trailing edge component structure itself rather than being added as external attachments. The micro-channels are formed within the component material, and cooling features are positioned close to the external surface, creating a nested arrangement that provides effective cooling without increasing external dimensions or requiring additional space.
3Reliability
If pin cooling is used, then cooling efficiency is improved, but pressure drop increases and it is only practical for very short distances
Solution Approach 1:
The system uses pressurized cooling air delivered through micro-channels to achieve intensive cooling. The micro-channel geometry is optimized to balance cooling efficiency with acceptable pressure drop, allowing the system to benefit from the high heat transfer coefficients of forced convection while maintaining practical pressure requirements for the cooling air supply system.
4Reliability
If cooling features are placed near the heated region, then cooling efficiency is improved, but manufacturing complexity increases
Solution Approach 1:
The micro-channel dimensions and geometry are optimized to achieve effective cooling with feasible manufacturing parameters. The channels are sized and shaped to provide high heat transfer coefficients while remaining manufacturable using conventional or near-net-shape manufacturing processes. This allows cooling features to be positioned close to the external surface without creating insurmountable manufacturing challenges.
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 significantly reduces cooling requirements by placing cooling features near the heated region, increasing the temperature difference for a given heat transfer rate, thereby extending the life and performance of gas turbine engines by enabling operation at higher temperatures.
Implementation Method 1
micro-channel cooling systems on the surfaces of hot gas path components, including airfoils, with pressurized air flowing through micro-channels and outlet passages, is used to efficiently transfer heat
Implementation Method 2
efficiently transfer heat and maintain a uniform temperature profile
Data Source
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AI summary
A hot gas path component (38) includes a substrate (48) having an outer surface (50) and an inner surface (52). The inner surface defines an interior space (54). The outer surface defines a pressure side surface (58) and a suction side surface (60). The pressure and suction side surfaces are joined together at a leading edge (36) and at a trailing edge (40). A first cooling passage (30) is formed in the suction side surface of the substrate. It is coupled in flow communication to the interior space. A second cooling passage (30), separate from the first cooling passage, is formed in the pressure side surface. The second cooling passage is coupled in flow communication to the interior space. A cover (68) is disposed over at least a portion of the first and second cooling passages. The interior space channels a cooling fluid to the first and second cooling passages, which channel the cooling fluid therethrough to remove heat from the component.