Wave-Shaped Combustor Seal with Impingement Cooling
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Solution Overview
Problem
In combustor designs, particularly in lean premixed gas turbine engines, the efficiency of cooling air in cooling channels decreases as it flows along the channels, necessitating larger air volumes to maintain adequate cooling, which can reduce the air available for fuel nozzles and impact performance.
Innovation Solution
A combustor seal assembly with a wave-shaped seal and through impingement holes is used, allowing cooling fluid to flow from upstream passageways through the seal cavity and into impingement holes, enhancing convective cooling of combustor components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If larger amounts of cooling air are directed through the cooling channels, then adequate cooling of the component is maintained, but the amount of air available for fuel nozzles is reduced
Solution Approach 1:
Cooling air is directed through impingement holes located at the upstream end of the seal support before the air enters the cooling channels. This preliminary impingement cooling action cools the combustor liner at the most critical location (where flame temperatures are highest) using fresh, high-velocity air, thereby maintaining effective cooling with less total air volume required in the channels downstream
Solution Approach 2:
The cooling system provides different cooling mechanisms at different locations: impingement cooling with high-velocity jets at the upstream end where heat flux is highest, and convective cooling through channels along the downstream length. This localized differentiation of cooling quality matches the thermal load distribution, maintaining adequate cooling efficiency while reducing overall air consumption
2Area of stationary object
If cooling air flows through entire length of the seal, then cooling coverage is maximized, but cooling efficiency decreases along the flow path
Solution Approach 1:
The most critical cooling action is performed preliminarily at the upstream end through impingement holes, where fresh cooling air with highest cooling capacity directly impinges on the liner surface. This ensures maximum cooling efficiency at the location with highest thermal load before the air loses cooling potential along the channel length
Solution Approach 2:
Different cooling mechanisms are applied at different locations along the seal: impingement cooling with high-velocity direct jets at the upstream end for maximum local efficiency, and extended convective cooling through channels for broader coverage downstream. This spatial variation in cooling quality maintains overall effectiveness while reducing total air requirements
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 configuration improves cooling efficiency by maintaining effective heat transfer along the entire length of the seal, reducing the need for excessive cooling air and enhancing combustor performance by optimizing air distribution between cooling and combustion processes.
Implementation Method 1
The cooling air flows within the cooling channels through an entire length of the seal, thereby cooling the first combustor component by convective heat transfer
Implementation Method 2
A wave-shaped seal includes at least one through passageway located upstream of the peak capable of flowing cooling fluid therethrough into the at least one seal cavity and through the plurality of impingement holes thereby cooling the first combustor component
Data Source
AI summary
Disclosed is a combustor seal including a seal support locatable at a first combustor component and having a plurality of through impingement holes. A wave-shaped seal located at the seal support and defining at least one seal cavity between the wave-shaped seal and the seal support. A peak of the wave-shaped seal is locatable at a second combustor component. The wave-shaped seal includes at least one through passageway located upstream of the peak capable of flowing cooling fluid therethrough into the at least one seal cavity and through the plurality of impingement holes thereby cooling the first combustor component. Further disclosed is a combustor including a combustor seal and a method for cooling a first combustor component.