Gas Turbine Torch Igniter With External Injector Access
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Solution Overview
Problem
Torch igniters mounted internally within the high pressure case of a gas turbine engine face accessibility issues and are subjected to high pressure differentials, leading to potential leaks and maintenance challenges.
Innovation Solution
The torch igniter is positioned externally to the high pressure case, with a removable fuel injector design that allows easy access for maintenance, using a flange and seal system to secure the fuel injector within the high pressure case, ensuring a tight seal and reducing stress on the combustion chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the torch igniter is mounted externally to the high pressure case, then accessibility for maintenance is improved, but the torch igniter must withstand high pressure differential which increases device complexity
Solution Approach 1:
The torch igniter system is segmented into modular components including the fuel injector, cap, and body sections. The fuel injector is made separately replaceable through the use of a flange connection, allowing maintenance personnel to access and replace individual components without disassembling the entire igniter assembly, thus maintaining ease of operation while managing pressure containment requirements through modular design
Solution Approach 2:
A flange connection serves as an intermediary element between the fuel injector and the cap assembly. This flange provides a standardized interface that simplifies installation and removal of the fuel injector while maintaining the pressure seal, thereby improving accessibility for maintenance without compromising the pressure containment capability of the external mounting configuration
2Reliability
If the fuel injector is made permanently fixed within the high pressure case, then sealing integrity is improved, but replacement and maintenance become difficult
Solution Approach 1:
The fuel injector connection transitions from a fixed permanent installation to a dynamic removable configuration. The flange-based connection allows the fuel injector to be easily inserted and removed while maintaining sealing integrity through the flange seal interface, enabling both reliable operation and straightforward maintenance replacement
Solution Approach 2:
The fuel injector is segmented as a separate replaceable component rather than being permanently integrated into the high pressure case. The flange connection creates a distinct interface that allows the fuel injector to be detached and replaced independently, maintaining sealing integrity through the flange seal while enabling easy replacement and maintenance
3Device complexity
If the torch igniter is mounted internally within the high pressure case, then pressure containment is simplified, but accessibility for maintenance is reduced
Solution Approach 1:
The fuel injector is extracted from the internal high pressure case mounting and repositioned to an external location. The flange connection provides a secure interface that maintains pressure containment while allowing the fuel injector to be accessed and maintained from outside the high pressure case, thereby improving accessibility without complicating the pressure containment structure
4Ease of repair
If a removable flange connection is used for the fuel injector, then ease of replacement is improved, but risk of leaks increases
Solution Approach 1:
The flange connection provides a dynamic sealing interface that maintains sealing integrity during both operation and replacement. The flange seal design ensures reliable sealing when the fuel injector is installed, while allowing for easy removal and reinstallation, thus achieving both ease of repair and maintained reliability
Solution Approach 2:
The flange connection segments the fuel injector assembly into separable components with a dedicated sealing interface. This segmentation allows for easy replacement while the flange seal maintains reliable sealing during operation, balancing ease of repair with sealing integrity through the specialized flange connection design
Data Source
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AI summary
An embodiment of a combustor for a gas turbine engine includes a combustor case (20), a combustor liner (22) disposed within the combustor case, a fuel nozzle (25) at an upstream end of the combustor liner, a torch igniter (10) within the combustor case, and a removable fuel injector. The torch igniter includes a combustion chamber (30), a cap (18) configured to receive a removable fuel injector and a surface igniter, a tip (14), 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 which fluidly connects the combustion chamber to the combustor. The removable fuel injector extends through a fuel injector opening of the combustor case. The diameter of the fuel injector opening is wider than a fuel injector diameter of the removable fuel injector.