Micro Channel Cooling Circuit for Gas Turbine Fuel Nozzle
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Solution Overview
Problem
High-energy combustion in gas turbine engines leads to high temperatures, causing structural wear and degradation, which necessitates cooling air to mitigate these issues but results in reduced engine efficiency.
Innovation Solution
A fuel nozzle with a micro channel cooling circuit that reduces thermal gradients and minimizes compressed air usage for thermal management, providing tailored thermal management to the aft body and combustor bulkhead while maintaining high-energy combustion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cooling air is utilized to mitigate wear and degradation of combustor assembly components, then structural performance is improved, but combustion efficiency deteriorates
Solution Approach 1:
The patent applies local quality by implementing micro channel cooling circuits specifically in the aft body of the fuel nozzle where thermal gradients are most severe, rather than uniformly cooling the entire combustor assembly. This localized cooling approach targets the critical regions experiencing highest thermal stress while minimizing the overall quantity of cooling air required, thus preserving combustion efficiency in other regions.
Solution Approach 2:
The patent utilizes parameter changes by employing micro channel geometry with specific dimensional parameters (channel diameter, length, and distribution) to optimize heat transfer efficiency. The micro channel dimensions and configuration are carefully selected to maximize cooling effectiveness in the aft body while minimizing the volume of cooling air needed, thereby resolving the contradiction between structural protection and combustion efficiency.
2Power
If high-energy combustion is produced, then power output is improved, but temperature increases causing structural wear and degradation
Solution Approach 1:
The patent applies segmentation by dividing the fuel nozzle into distinct functional zones: a forward body that maintains high-energy combustion conditions for power output, and an aft body with integrated micro channel cooling circuits that manage thermal gradients and protect against excessive temperatures. This segmentation allows simultaneous achievement of high power output and temperature control in different spatial regions.
Solution Approach 2:
The patent introduces cooling air as an intermediary substance that flows through the micro channel circuits in the aft body to absorb excess thermal energy. This intermediary cooling mechanism enables the forward body to maintain high combustion temperatures for power generation while the aft body uses the intermediary cooling air to prevent structural degradation from excessive heat.
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 micro channel cooling circuit improves structural performance of the fuel nozzle, reduces thermal gradients, and minimizes compressed air usage, thereby enhancing gas turbine engine efficiency and reducing wear while maintaining high-energy combustion.
Implementation Method 1
The micro channel cooling circuit comprises a plurality of serpentine passages within the aft body, each serpentine passage extending from one of the cooling collectors to at least one channel outlet orifice
Implementation Method 2
The micro channel cooling circuit reduces thermal gradients and minimizes compressed air usage for thermal management
Data Source
Figure 1
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AI summary
The present disclosure is directed to a fuel nozzle for a gas turbine engine, the fuel nozzle defining a radial direction, a longitudinal direction, a circumferential direction, an upstream end, and a downstream end. The fuel nozzle includes an aft body coupled to at least one fuel injector. The aft body defines a forward wall and an aft wall each extended in the radial direction, and a plurality of sidewalls extended in the longitudinal direction. The plurality of sidewalls couples the forward wall and the aft wall. The forward wall defines at least one channel inlet orifice. At least one sidewall defines at least one channel outlet orifice. At least one micro channel cooling circuit is defined between the one or more channel inlet orifices and the one or more channel outlet orifices.