Gas Turbine Combustor Sealing via Elastomeric Flexibility

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Solution Overview

Problem

Gas turbine combustors with complex structures to accommodate various fuels face issues with fuel leakage due to thermal expansion and deformation, leading to unreliable sealing and increased maintenance costs.

Innovation Solution

The design incorporates an annular second manifold in the burner flange and an annular third manifold in the end cover, allowing gaseous fuel to flow uniformly and cool components, reducing temperature differences and preventing deformation, thereby enhancing sealing reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple sealing components (gaskets, metal O-rings) are placed at coupling portions to prevent fuel leakage, then sealing function is improved, but the components cannot maintain even contact between sealing surfaces due to thermal elongation differences caused by temperature differences, resulting in spoiled sealing

Engineering Contradiction:
Improvesealing reliabilityVSAvoidcontact evenness of sealing surfaces
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent changes the physical state of the sealing component from rigid (gasket, metal O-ring) to flexible (elastomeric material), allowing it to adapt to thermal expansion and maintain sealing contact under temperature variations. The elastomeric material's ability to deform elastically compensates for the thermal elongation differences between components, preserving even contact between sealing surfaces.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs an elastomeric sealing component that functions as a flexible element between the fuel passage components. This flexible sealing member can accommodate dimensional changes and maintain conformal contact with the sealing surfaces, ensuring reliable sealing despite thermal expansion and contraction of the rigid components.

Inventive Principle:
Principle #30Flexible shells and thin films

2Ease of repair

If components are mechanically combined by bolting to allow independent exchange when damaged, then ease of repair is improved, but sealing components cannot maintain even contact due to thermal elongation differences, causing fuel leakage

Engineering Contradiction:
Improvecomponent exchangeabilityVSAvoidsealing reliability
Core Design Contradiction:
Ease of repairVSReliability

Solution Approach 1:

The patent changes the material properties of the sealing component to elastomeric, which provides both flexibility for maintaining contact and durability for reliable operation. This elastomeric sealing member can be easily replaced while maintaining effective sealing, combining ease of repair with sealing reliability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The elastomeric sealing component acts as an intermediary element between the bolted components, absorbing the effects of thermal expansion and maintaining sealing contact. This intermediary sealing member allows the rigid components to be easily assembled and disassembled while ensuring continuous reliable sealing during operation.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If welding is used to fasten coupling portions to prevent fuel leakage, then sealing reliability is improved, but each component cannot be exchanged independently when damaged, requiring overall combustor exchange at higher cost

Engineering Contradiction:
Improvefuel leakage preventionVSAvoidcomponent exchangeability
Core Design Contradiction:
ReliabilityVSEase of repair

Solution Approach 1:

The patent segments the fuel passage into multiple independently replaceable components (end cover, burner flange, burner body) connected by bolting rather than welding. The elastomeric sealing components are placed at each coupling portion to ensure fuel leakage prevention, allowing individual components to be exchanged without replacing the entire combustor assembly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The elastomeric sealing components serve as intermediaries at the bolted coupling portions, providing reliable fuel leakage prevention while enabling easy disassembly and reassembly. This approach maintains the integrity of the fuel passage sealing while allowing individual components to be replaced for maintenance.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 effectively prevents fuel leakage and maintains reliable sealing by minimizing thermal expansion and stress on components, ensuring consistent performance and reduced maintenance costs.

Implementation Method 1

allowing gaseous fuel to flow uniformly and cool components, reducing temperature differences and preventing deformation

Methodology Applied
Scientific EffectThermal cooling by fluid flow: Convection

Implementation Method 2

the sealing components for such portions use a gasket, a metal O-ring, etc. Each sealing component needs to make sealing surfaces be in contact with each other evenly to provide its sealing function

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2735800B1Gas turbine combustor
Publication Date: 2019.02.20 MITSUBISHI HITACHIPOWER SYST LTD
  • EP2735800B1 patent drawingFigure 1
  • EP2735800B1 patent drawingFigure 2~3
  • EP2735800B1 patent drawingFigure 4~5

AI summary

A gas turbine combustor (3) includes: multiple gaseous fuel nozzles (9) to inject gaseous fuel; a manifold (17) to distribute gaseous fuel to the multiple gaseous fuel nozzles; a burner flange (11) to secure a burner (200) to an end cover (6); and a burner body (10) to connect the manifold and the burner flange. Gaseous fuel passages (15, 18) are provided in the end cover, the burner flange, and the burner body. The gaseous fuel passage communicates with the manifold. A second manifold (16) is provided in the burner flange. The gaseous fuel passage is provided in the burner body to make the second manifold communicate with the first mentioned manifold.