Combustor Fuel Manifold Support for Thermal Expansion Mismatch
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Solution Overview
Problem
Conventional combustor section support structures in gas turbine engines face issues with thermal mismatch between components, leading to high stresses, improper air metering, and increased weight and cost due to complex sealing systems and reliance on hot components with low high-temperature strength.
Innovation Solution
A combustor section support structure that allows radial movement of the fuel manifold relative to the engine case while preventing axial movement, using radial stud assemblies and a fuel inlet assembly with transfer tubes and biasing members to maintain engagement and sealing, reducing thermal stresses and improving structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If rigid connections are used to support the combustor section, then structural stability is improved, but thermal stresses increase due to thermal expansion mismatches
Solution Approach 1:
The support structure incorporates movable joints and expansion joints that allow dynamic adjustment of component positions to accommodate thermal expansion. The fuel manifold support structure includes a movable joint between the manifold and engine case, and an expansion joint in the dome plate, enabling the structure to adapt its configuration in response to thermal changes while maintaining operational stability.
Solution Approach 2:
The design changes the physical parameters of the support structure by using materials with different thermal expansion coefficients and incorporating gaps and joints that modify the mechanical properties. The dome plate is designed with a specific gap to the engine case, and the fuel manifold support structure uses materials that can accommodate dimensional changes without generating excessive stress.
2Stress or pressure
If burner seals and labyrinth seals are used to accommodate thermal expansion, then thermal stress is reduced, but device complexity and weight increase
Solution Approach 1:
The invention extracts and eliminates the need for complex burner seals and labyrinth seals by implementing a simplified support structure. The fuel manifold support structure directly accommodates thermal expansion through movable joints and proper structural design, removing the requirement for additional sealing components while maintaining stress reduction.
Solution Approach 2:
The support structure is designed to perform multiple functions simultaneously: it provides structural support, accommodates thermal expansion, and maintains sealing. The movable joint and expansion joint design integrates these functions into a single structure, eliminating the need for separate sealing components and reducing overall system complexity.
3Stress or pressure
If traditional sealing systems are used, then thermal expansion is accommodated, but air metering accuracy deteriorates
Solution Approach 1:
The support structure is segmented into independent components (fuel manifold, dome plate, engine case) that can move relative to each other. This segmentation allows each component to expand independently without interfering with air metering functions, as the movable joints and expansion joints are positioned to accommodate thermal growth without restricting airflow paths.
Solution Approach 2:
The movable joint and expansion joint act as intermediaries that decouple the thermal expansion of the fuel manifold and dome plate from the engine case. These joints allow the internal components to expand while maintaining proper sealing and air metering relationships, preventing thermal stresses from affecting airflow measurement accuracy.
4Strength
If hot components carry the load, then structural support is provided, but strength decreases at high temperatures
Solution Approach 1:
The support structure uses the cooler fuel manifold and engine case as intermediaries to carry the primary structural load, rather than relying on the hot combustor components. The fuel manifold support structure and dome plate expansion joint design allow the cooler external components to bear the mechanical load while the hot internal components focus on containing combustion pressures.
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
The solution effectively manages thermal expansion mismatches, reduces component stresses, and minimizes weight and cost by allowing radial movement of the fuel manifold, ensuring proper air metering and sealing, and distributing load through a cooler internal manifold.
Implementation Method 1
radial thermal expansion can occur within circular components which are heated (such as engine case). If a circular component remains cold (such as an internal fuel manifold), it may not grow radially.
Implementation Method 2
The one or more transfer tubes can be biased toward the fuel inlet socket with one or more biasing members.
Data Source
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AI summary
A combustor section support structure can include a fuel manifold (101) and one or more radial stud assemblies connected to the fuel manifold (101) and configured to allow the fuel manifold (101) to move radially relative to an engine case (105) and to fix the fuel manifold (101) axially relative to the engine case (105). Each of the one or more radial stud assemblies can include a first portion mounted to the fuel manifold (101) and a second portion configured to mount to an engine case (105). The first portion and the second portion can be configured to slide relative to each other to allow relative radial movement, but to prevent axial relative movement. A system can include a fuel manifold (101) configured to distribute fuel to one or more fuel nozzles of a turbomachine, and a fuel inlet assembly (1001) configured to connect to the fuel manifold (101) through an engine case (105). The fuel inlet assembly (1001) can be configured to axially retain the fuel manifold (101) relative to the engine case (105) and to allow radial movement of the fuel manifold (101) relative to the engine case (105).