Hot Gas Path Component Cooling via Impingement Channels
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Solution Overview
Problem
Conventional cooling systems for hot gas path components in gas turbine systems result in low heat transfer rates and non-uniform temperature profiles, limiting the ability to operate at higher temperatures efficiently.
Innovation Solution
A cooling system with small channels formed on the surface of hot gas path components, utilizing backside impingement cooling to increase heat transfer rates and achieve uniform temperature profiles, where the channels are created through processes like laser machining and are designed to optimize convective cooling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional internal cooling passages (serpentines) are used to cool hot gas path components, then cooling coverage is provided, but heat transfer rates are low and temperature profiles are non-uniform
Solution Approach 1:
The cooling system is segmented into multiple functional zones: impingement cooling zones with arrays of cooling holes directed at specific regions, followed by serpentine passages that distribute cooling fluid throughout the component. This segmentation allows different cooling mechanisms to address different thermal requirements of various component regions, achieving both high heat transfer rates and uniform temperature profiles
Solution Approach 2:
The invention transitions from two-dimensional serpentine surface cooling to three-dimensional cooling by introducing impingement cooling holes that penetrate through the component thickness. Cooling fluid is injected from the backside through arrays of holes at specific angles, creating direct impingement on the hot gas path surface, thereby adding a third dimension (depth/thickness) to the cooling approach and dramatically increasing heat transfer efficiency
2Power
If higher temperature flows are used to increase gas turbine performance and efficiency, then power output increases, but component failure risk increases due to thermal damage
Solution Approach 1:
Cooling fluid is introduced through impingement holes before the hot gas flows over the component surface, pre-cooling critical areas that will be exposed to highest thermal loads. This preliminary cooling action creates a thermal buffer that protects the component substrate and coatings from immediate thermal damage, enabling safe operation at higher power outputs
Solution Approach 2:
The invention changes the thermal parameters of the component by implementing a multi-zone cooling strategy that maintains the metal substrate temperature below critical thresholds even when exposed to high-temperature hot gas flows. By controlling the temperature parameter through active cooling, the component can withstand higher operating temperatures and pressures, thereby increasing power output without compromising durability
3Reliability
If cooling fluid is provided through impingement cooling holes from a plenum, then heat transfer rate increases, but manufacturing complexity increases
Solution Approach 1:
The complex impingement cooling hole patterns are extracted and formed as integral features of the component during manufacturing, rather than being added as separate components. The cooling holes are directly machined or formed into the component substrate, and the serpentine passages are integrated into the same structure, reducing assembly complexity while maintaining high heat transfer rates
Solution Approach 2:
The component structure serves multiple functions: it acts as both the hot gas path component and the cooling fluid distribution system. The impingement holes and serpentine passages are formed directly in the component material, making the component itself the cooling device. This multi-functionality eliminates the need for separate cooling assemblies and reduces manufacturing steps
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 cooling system enhances heat transfer rates and maintains relatively uniform temperature profiles, extending the life of hot gas path components and allowing them to handle higher temperature flows, thereby increasing the performance and efficiency of the gas turbine system.
Implementation Method 1
A cooling fluid may be provided to the channels from a plenum, and the cooling fluid may flow through the channels, cooling the hot gas path component substrate and coatings
Implementation Method 2
backside impingement cooling to provide cooling fluid to a cooling channel and then allows the cooling fluid to flow through the channels, cooling the cover layer at an increased heat transfer rate
Data Source
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AI summary
A cooling system (110) for a hot gas path component (100) is disclosed. The cooling system (110) may include a component layer (120) and a cover layer (125). The component layer (120) may include a first inner surface (122) and a second outer surface (124). The second outer surface (124) may define a plurality of channels (130). The component layer (120) may further define a plurality of passages (140) extending generally between the first inner surface (122) and the second outer surface (124). Each of the plurality of channels (130) may be fluidly connected to at least one of the plurality of passages (140). The cover layer (125) may be situated adjacent the second outer surface (124) of the component layer (120). The plurality of passages (140) may be configured to flow a cooling medium (90) to the plurality of channels (130) and provide impingement cooling to the cover layer (125). The plurality of channels (130) may be configured to flow cooling medium (90) therethrough, cooling the cover layer (125).