Nozzle Assembly with Segmented Swirlers for Gas Turbine Combustion
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Solution Overview
Problem
Conventional gas turbines face challenges in achieving uniform fuel-air mixing, leading to increased NOx emissions.
Innovation Solution
The proposed solution involves a nozzle assembly with a unique design that includes multiple fuel supply flow paths, swirlers, and a specific geometry to enhance fuel-air mixing characteristics, specifically in a radial direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fuel is directly ejected from swirl vanes forming a vortex to introduced compressed air, then the combustion process is simplified, but the compressed air and fuel are not uniformly mixed leading to increased NOx emissions
Solution Approach 1:
The nozzle assembly is divided into multiple independent fuel injection systems: a central fuel injection system with a first swirler and multiple fuel injection holes, and an outer fuel injection system with a second swirler and fuel injection holes. This segmentation allows different fuel streams to be injected and mixed separately before combining, improving overall mixing uniformity and reducing NOx emissions while maintaining structural simplicity
Solution Approach 2:
Different regions of the nozzle assembly have specialized functions: the central region injects fuel through the first swirler with specific vortex characteristics, while the outer region injects fuel through the second swirler with different vortex characteristics. Each region is optimized for its specific mixing requirements, creating locally optimal mixing conditions that result in globally uniform fuel-air mixing and reduced NOx emissions
2Device complexity
If a single fuel injection system is used, then the device complexity is reduced, but the fuel-air mixing uniformity is insufficient
Solution Approach 1:
The fuel injection system is segmented into multiple independent subsystems (central and outer fuel injection systems) that operate simultaneously. Each subsystem has its own swirler and fuel injection holes, allowing independent optimization of fuel distribution patterns. This segmentation enables superior mixing uniformity compared to a single injection system while adding only moderate complexity
Solution Approach 2:
The central fuel injection system is nested within the outer fuel injection system, with the first swirler positioned at the center and the second swirler positioned outward. This nested configuration allows compact arrangement of multiple injection systems within the nozzle assembly, achieving good mixing uniformity without excessive increase in device complexity
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 effectively improves fuel-air mixing, resulting in reduced NOx emissions by ensuring a more uniform and efficient combustion process.
Implementation Method 1
a first swirler mounted on the first main cylinder; a second swirler mounted on the second main cylinder
Data Source
AI summary
Proposed are a nozzle assembly, a combustor, and a gas turbine including the same. The nozzle assembly mixes compressed air supplied from a compressor of the gas turbine with fuel supplied from the outside, and ejects a mixture of the compressed air and the fuel to a combustion chamber of the combustor. The nozzle assembly includes a nozzle flange receiving the fuel from the outside, a nozzle shroud, a first main cylinder forming a first main flow path, a first swirler, a second main cylinder forming a second main flow path, and a second swirler. The nozzle flange includes a plurality of fuel supply flow paths, and a supplied fuel is distributed to the first swirler and the second swirler along the fuel supply flow paths.