Internal Torch Igniter Mounting for Gas Turbine Combustors
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Solution Overview
Problem
Torch igniters mounted externally to gas turbine engines face challenges due to high pressure differentials, which can cause stress and potential damage, and their external mounting is complicated by other engine components like fuel manifolds.
Innovation Solution
Mounting the torch igniter within the high-pressure section of the gas turbine engine eliminates the need for it to withstand the high pressure differential, allowing for improved positioning and reduced stress on temperature-sensitive components, with the igniter secured via a support and oriented coaxially with the engine axis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the torch igniter is mounted externally to the high pressure case, then the igniter can be positioned outside the high-pressure section, but the igniter must withstand high pressure differential which causes stress and potential damage
Solution Approach 1:
The torch igniter is extracted from the external mounting position and relocated to an internal mounting position within the high pressure case. This removes the igniter from the harmful high pressure differential environment while maintaining its ignition function, as the igniter is now surrounded by high pressure on both sides and experiences minimal pressure differential stress
2Device complexity
If the torch igniter is mounted externally to the high pressure case, then the igniter positioning can be simplified, but mounting is complicated by other engine components such as fuel manifolds
Solution Approach 1:
The torch igniter is nested within the high pressure case internal volume, utilizing the available space inside the pressure-containing structure. This internal nesting arrangement allows the igniter to be positioned in a dedicated internal mounting location that is free from external component interference, while the high pressure case itself serves as the mounting structure
3Ease of repair
If the torch igniter is mounted externally to the high pressure case, then the igniter can be accessed for maintenance, but the igniter is exposed to high pressure differential which increases risk of mechanical failure
Solution Approach 1:
The torch igniter is designed as a separable component that can be independently removed from the high pressure case through a dedicated access opening. This segmentation allows the igniter to be protected within the pressure-containing environment during operation, while still enabling easy removal and replacement for maintenance without requiring disassembly of the entire high pressure case
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 prevents damage to the torch igniter, allows for improved positioning, and reduces the risk of mechanical failure by containing the combustion chamber within the high-pressure case, enabling efficient ignition and combustion within the combustor.
Implementation Method 1
a support (23) positioning the combustion chamber (22) within the high-pressure case (20) with the combustion chamber oriented coaxially with the engine axis
Implementation Method 2
Torch igniters provide a flame as an ignition source for a combustor rather than the electric current provided by spark igniters
Data Source
Figure 1
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AI summary
An embodiment of a combustor for a gas turbine engine includes a combustor case (20), a combustor liner (24) disposed within the combustor case, a fuel nozzle (27), and a torch igniter (10) within the combustor case. The torch igniter (10) includes a combustion chamber (22), a cap (18) defining the upstream end of the combustion chamber, a tip (14) defining the downstream end of the combustion chamber, an annular igniter wall (32) extending from the cap to the tip and defining a radial extent of the combustion chamber, a structural wall (36) coaxial with and surrounding the igniter wall, and an outlet passage (34) within the tip that fluidly connects the combustion chamber to the combustor. The tip (14) is mounted through the combustor liner, the cap (18) is downstream of the tip, and the torch igniter (10) is downstream of the fuel nozzle and disposed radially between the combustor liner and the combustor case.