Replaceable Fuel Injector Panels for Gas Turbine Combustor Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional line replaceable fuel injectors in gas turbine engines face issues with mechanical stress due to cantilevered masses, requiring strong flanges and feedarms, and suffer from thermal expansion mismatches leading to air leaks and fretting at burner seals.
Innovation Solution
A system where fuel injectors are integrated into a dome panel supported by a combustor frame, distributing stress loads and eliminating the need for burner seals, with each injector component seated across rails and flanges, and featuring fuel tubes for fluid communication and thermal accommodation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of repair
If the fuel injector is made line replaceable with mechanical load carried by the engine case, then the injector can be easily replaced, but the engine case experiences large cantilevered mass and requires substantial strength in the flange and feedarm
Solution Approach 1:
The fuel injector system is segmented into modular components: the injector body, the dome panel with integrated mounting features, and the engine case. The dome panel acts as an intermediate structural element that carries the injector mounting loads, separating the injector replacement function from the engine case structural loads. This allows the injector to be line-replaceable while the engine case flange and feedarm experience reduced mechanical stress.
2Adaptability or versatility
If burner seals are used to accommodate thermal expansion mismatch, then axial and radial movement is allowed, but air leaks occur between injector and dome and thermal cooling on the dome is reduced
Solution Approach 1:
The burner seals are completely removed from the system. Instead of using seals to accommodate thermal expansion, the patent integrates the fuel injector mounting directly into the dome panel structure with built-in compliance features. The dome panel itself accommodates thermal expansion through its structural design, eliminating the need for separate sealing components that would compromise integrity and cooling efficiency.
Solution Approach 2:
The fuel injector mounting structure is merged with the dome panel structure. The injector is mounted directly to the dome panel which is itself attached to the engine case, creating an integrated assembly where thermal expansion is accommodated by the dome panel's structural design rather than by separate sealing components. This integration eliminates air leaks and maintains thermal cooling efficiency.
3Ease of repair
If the access opening is sized to admit only one fuel injector component, then individual injectors can be replaced, but the opening requires precise dimensional control
Solution Approach 1:
The fuel injector system is segmented into modular components with standardized dimensions. The access opening is designed with specific dimensional tolerances (e.g., 0.5-1.5 inches in diameter) that accommodate the modular injector components. This segmentation approach allows precise control of the access opening dimensions while maintaining ease of repair through standardized component sizes that can be manufactured with controlled tolerances.
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 reduces mechanical stress on the engine case, minimizes air leaks, and enhances thermal management by integrating fuel injectors within the combustor dome, allowing for efficient line replaceable units.
Implementation Method 1
The fuel tube can include a coiled section and a fuel inlet fitting for connection of the final fuel injector component to an external fuel manifold
Implementation Method 2
A heat shield can extend around the fuel tube from a radially outward flange to the fuel injector
Implementation Method 3
The fuel injector can include passages for air and fuel injection into the combustion space
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A system includes an engine case (102) for a gas turbine engine defined around a longitudinal axis. A combustor (108) is housed in the space inside the engine case (102). The combustor (108) includes an inner annular wall (110) and an outer annular wall (112) radially outboard from the inner annular wall (110). The inner annular wall (110) includes a first rail (114) on an upstream end thereof with a radially outward opening slot (116). The outer annular wall (112) includes a second rail (118) on an upstream end thereof. The combustor (108) includes a plurality of circumferentially spaced apart dome liners extending from the first rail (114) to the second rail (118). A plurality of fuel injector components (122) can be assembled across the first and second rails to form a combustor dome together with the dome liners at an upstream end of a combustion space defined between the inner and outer annular walls of the combustor (108).