Torch Igniter Removable Glow Plug for Gas Turbine Maintenance
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Solution Overview
Problem
Torch igniters mounted internally within the high-pressure case of a gas turbine engine face accessibility issues during maintenance due to the high pressure differential, which complicates the replacement and maintenance of glow plugs.
Innovation Solution
A design where the torch igniter is partially or fully situated within the high-pressure case, with a removable glow plug configuration that allows for easy access and replacement through the high-pressure case, minimizing stress on the combustion chamber and utilizing a flange and seal system to secure the glow plug, enabling efficient maintenance without compromising the integrity of the high-pressure case.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the torch igniter is mounted externally to the high pressure case, then the torch igniter can withstand the high pressure differential, but the glow plug becomes inaccessible for maintenance
Solution Approach 1:
The torch igniter is divided into separate components: the main body is mounted within the high pressure case while the glow plug is positioned to extend through the case wall, allowing independent access to the glow plug for maintenance while keeping the pressure-containing portion inside the sealed environment
Solution Approach 2:
A seal assembly acts as an intermediary component that allows the glow plug to pass through the high pressure case wall while maintaining the pressure differential. The seal enables maintenance access to the glow plug without compromising the pressure resistance of the case
2Ease of repair
If the torch igniter is mounted within the high pressure case, then the glow plug becomes accessible for maintenance, but the combustion chamber experiences increased stress
Solution Approach 1:
The glow plug, which requires frequent maintenance, is extracted from the internal combustion chamber environment and positioned to extend through the case wall. This allows the glow plug to be accessed from the external low-pressure side, eliminating the need to open the high pressure case for maintenance while keeping the combustion chamber sealed and stress-free
3Ease of repair
If the glow plug is made removable for maintenance, then ease of replacement is improved, but the risk of leaks at the connection interface increases
Solution Approach 1:
A seal assembly is pre-installed in the glow plug receptacle before the glow plug is inserted. This preliminary sealing action ensures that when the glow plug is removed and reinstalled, the seal is already in place, reducing the risk of leaks during the maintenance process while allowing easy replacement
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 allows for stress reduction on the combustion chamber, improved accessibility for maintenance, and reliable operation by ensuring the glow plug can be easily replaced or refurbished, extending the lifespan of the torch igniter components.
Implementation Method 1
Torch igniters mounted externally to a high pressure case of the gas turbine engine must be able to withstand a high pressure differential to prevent leaks
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
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AI summary
An embodiment of a combustor for a gas turbine engine includes a combustor case, a combustor liner (124) disposed within the combustor case, a fuel nozzle (127) at an upstream end of the combustor liner (124), a torch igniter (110) at least partially within the combustor case, and a removable surface igniter. The torch igniter (110) includes a combustion chamber, a cap configured to receive a fuel injector, a tip, an annular igniter wall extending from the cap to the tip and defining a radial extent of the combustion chamber, an aperture, a structural wall coaxial with and surrounding the igniter wall, and an outlet passage within the tip which fluidly connects the combustion chamber to the combustor. The torch igniter (110) is configured to receive the removable surface igniter through the aperture. An internal end of the removable surface igniter extends through the aperture into the combustion chamber of the torch igniter (110).