Fuel Nozzle and Swirler Architecture for Flame Holding Control
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Solution Overview
Problem
Existing combustors face durability risks and flame holding issues due to the use of high-temperature, fast-burning fuels required for improved efficiency and reduced emissions, particularly in turbine engines.
Innovation Solution
The design incorporates a fuel nozzle and swirler architecture with a splitter and vanes that create varying swirl numbers and converging cross-sectional areas to manage airflow velocity and position, reducing flame holding and flashback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high-temperature, fast-burning fuels are used to improve efficiency and reduce emissions, then fuel energy density and combustion temperature increase, but flame holding and flashback risks increase
Solution Approach 1:
The combustor is divided into multiple zones with different swirl numbers: an inner region with a first swirl number and an outer region with a second swirl number. This segmentation allows different parts of the combustor to handle different combustion requirements, with the inner region managing the high-temperature fuel combustion and the outer region providing flame stabilization
Solution Approach 2:
Different swirl numbers are applied to different radial zones of the combustor. The inner region receives a first swirl number optimized for fast-burning fuels, while the outer region receives a second swirl number optimized for flame holding. This local differentiation resolves the contradiction by providing locally optimized flow conditions for each functional requirement
2Reliability
If swirl number is increased to prevent flame holding, then flame stability improves, but airflow velocity distribution becomes less uniform
Solution Approach 1:
The airflow is segmented into inner and outer streams with different swirl characteristics. The inner airflow receives a first swirl number while the outer airflow receives a second swirl number, allowing each stream to maintain its own velocity distribution characteristics while collectively providing flame stability
Solution Approach 2:
The problem is solved by adding a radial dimension to the swirl number distribution. Instead of using a single swirl number throughout the combustor, the invention varies the swirl number in the radial direction, creating a two-dimensional swirl number field that simultaneously achieves flame stability and uniform velocity distribution
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 enhances combustor durability by preventing flame holding and flashback, allowing the use of high-temperature fuels like hydrogen without efficiency loss, and reduces carbon emissions.
Implementation Method 1
The swirler includes a first set of vanes arranged circumferentially about the fuel nozzle and a second set of vanes arranged circumferentially about the fuel nozzle at a radial position radially exterior to the first set of vanes
Data Source
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AI summary
An engine (10) can utilize a combustor (14) to combust fuel to drive the engine (10). A fuel nozzle assembly (130) can supply fuel to the combustor (14) for combustion or ignition of the fuel. The fuel nozzle assembly (130) can include a swirler (134) and a fuel nozzle (132) to supply a mixture of fuel and air for combustion. Increasing efficiency and emission needs require the use of alternative fuels, which combust at higher temperatures and faster burn speeds than traditional fuels, requiring improved fuel introduction without the occurrence of flame holding or flashback.