Gas Turbine Combustor Tail Pipe Flange Stiffness Management

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional gas turbine combustors experience thermal deformation and metal fatigue due to stiffness differences between upper, lower, and side walls, leading to leakage and reduced fatigue resistance.

Innovation Solution

The combustor design reduces the stiffness of upper and lower walls to match that of side walls by modifying flange structures, including reducing flange heights, using shield plates, and incorporating slits or openings, to minimize thermal stress and deformation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the thickness of structural plates in upper and lower walls is increased to provide sufficient stiffness, then the stiffness of the tail pipe section is improved, but thermal stress concentration and compulsory thermal deformation occur in the side walls, leading to low cycle fatigue and metal deformation

Engineering Contradiction:

Improvestiffness of tail pipe sectionVSAvoidfatigue resistance of side walls

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The patent applies local quality by providing reinforcement ribs only at specific locations where thermal stress concentrates (at the ends and intermediate positions of side walls), rather than uniformly increasing thickness throughout. This localized reinforcement maintains overall stiffness while preventing stress concentration in critical areas, thereby resolving the contradiction between structural strength and fatigue resistance.

Inventive Principle:

Principle #3Local quality

2Strength

If the thickness of structural plates in upper and lower walls is increased to provide sufficient stiffness, then the stiffness of the tail pipe section is improved, but thermal deformation occurs in the end portion, causing gas leakage

Engineering Contradiction:

Improvestiffness of tail pipe sectionVSAvoidsealing precision of tail pipe

Core Design Contradiction:

StrengthVSManufacturing precision

Solution Approach 1:

The patent applies local quality by concentrating reinforcement ribs at specific locations (ends and intermediate positions of side walls) rather than uniformly increasing thickness. This localized approach maintains overall structural stiffness while preventing excessive thermal deformation at critical sealing locations, thereby resolving the contradiction between structural strength and sealing precision.

Inventive Principle:

Principle #3Local quality

3Ease of manufacture

If uniform thickness is used for all structural plates in the tail pipe section, then manufacturing simplicity is maintained, but stiffness imbalance occurs between upper/lower walls and side walls, causing thermal stress and deformation

Engineering Contradiction:

Improvemanufacturing simplicity of tail pipeVSAvoidstiffness uniformity of tail pipe section

Core Design Contradiction:

Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent applies local quality by providing reinforcement ribs only at specific locations (ends and intermediate positions of side walls) rather than changing the uniform thickness of all plates. This selective reinforcement achieves stiffness balance in critical areas while maintaining manufacturing simplicity, thereby resolving the contradiction between ease of manufacture and structural stability.

Inventive Principle:

Principle #3Local quality

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 design effectively reduces thermal deformation and stress on side plates, enhancing fatigue resistance and preventing gas leakage, resulting in a more reliable gas turbine combustor.

Implementation Method 1

the stiffness of the flange is intentionally reduced so as to be equal to a stiffness of the side plate... compulsion deformation which is caused due to thermal stress generated in the end portion of the tail pipe section can be reduced

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentUS7908866B2Gas turbine combustor

Publication Date: 2011.03.22 MITSUBISHI POWER LTD

AI summary

An object of the present invention is to provide a gas turbine combustor with improved fatigue resistance of a combustor. It is possible to intentionally reduce a stiffness of each of flanges of upper and lower walls of an end portion (outlet) of the tail pipe of the gas turbine combustor. It is possible to reduce a stiff difference between the upper and lower walls of the end portion (outlet) of the tail pipe section and side walls. Thus, it is possible to reduce compulsion deformation caused due to thermal stress generated in the end portion (outlet) of the tail pipe section on the operation of the conventional gas turbine combustor, and to reduce high stress easy to generate in the side plate. As a result, the gas turbine combustor with high fatigue resistance can be realized.