Combustor Tube Plate Joint Flexible Coupling Thermal Expansion
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Solution Overview
Problem
The joint between tubes and plates in combustors experiences axial and radial thermal expansion and contraction, leading to leaks and reduced mechanical life due to compromised seals, limiting the operational efficiency and lifespan of gas turbines.
Innovation Solution
Incorporating a shroud that surrounds radially and circumferentially extending plates with flexible couplings connected to the tubes and plates, allowing for axial movement and maintaining seals during thermal cycles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If tubes are rigidly connected to plates through brazing or welding, then structural strength is improved, but thermal expansion and contraction causes seal compromise and fuel leaks
Solution Approach 1:
The patent employs flexible couplings instead of rigid brazed or welded joints to connect tubes to plates. These flexible couplings can accommodate thermal expansion and contraction movements while maintaining seal integrity, preventing fuel leaks that would occur with rigid connections subjected to thermal cycling.
Solution Approach 2:
The invention transitions from a static rigid connection to a dynamic flexible coupling that can adapt its configuration in response to thermal changes. The flexible coupling allows for movement and deformation during thermal cycles, maintaining the seal between tubes and plates despite dimensional changes in the connected components.
2Ease of manufacture
If rigid joints are used between tubes and plates, then manufacturing simplicity is improved, but mechanical life is reduced due to thermal expansion and contraction
Solution Approach 1:
The flexible coupling replaces complex rigid joint assemblies with a simpler flexible component that naturally accommodates thermal movements. This reduces the complexity of achieving reliable thermal expansion compensation and extends the combustor's operational life by preventing seal failure and fatigue cracking.
Solution Approach 2:
The invention changes the mechanical parameters of the joint from rigid to flexible, allowing the coupling to deform elastically during thermal cycles. This parameter change enables the joint to absorb thermal stresses without permanent deformation or failure, significantly extending the combustor's mechanical life.
3Reliability
If flexible couplings are introduced to accommodate thermal expansion, then seal reliability is improved, but device complexity increases
Solution Approach 1:
The flexible coupling uses a simple flexible element design that provides seal integrity while accommodating thermal movements. Although it introduces an additional component, the flexible coupling's simple structure and ease of installation offset the increased complexity, providing reliable sealing without requiring complex rigid joint configurations with multiple seals and alignment features.
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 flexible couplings enable the tubes to expand and contract without compromising the seal, reducing fuel leaks and extending the mechanical life of the combustor components while maintaining efficient operation across varying thermal conditions.
Implementation Method 1
the joint between the tubes and the one or more plates may be compromised due to axial and radial thermal expansion and contraction of both the tubes and the plate
Implementation Method 2
axial and radial thermal expansion and contraction of both the tubes and the plate
Data Source
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AI summary
A combustor generally includes a plate (32) that extends radially and circumferentially within at least a portion of the combustor. The combustor may also include a shroud (50) that at least partially surrounds the plate (32) and a plurality of tubes (44) that extend through the plate (32). One or more flexible couplings (54) may at least partially surround at least some of the plurality of tubes (44) and the one or more flexible couplings (54) may be connected to the plate (32).