Burner Bellows Radial Interference Mitigation

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Solution Overview

Problem

Burners in gas turbine engines face damage due to thermal and mechanical vibrations, which cause bellows to deform radially and interfere with surrounding structures, leading to potential damage.

Innovation Solution

A double tube structure burner with an outer and inner tube, where the inner tube has a tip-side and base-side support portion, bellows interposed between them, and a bulkhead member to manage thermal deformations and prevent radial interference, with a second gap between the bulkhead and outer tube smaller than the gap between the bellows and outer tube to restrict movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If bellows are used to accommodate thermal deformations in the burner, then the burner can flexibly cope with thermal expansions, but the bellows may be damaged through interference with surrounding structure due to radial deformation under heat and mechanical vibrations

Engineering Contradiction:

Improvethermal deformation accommodationVSAvoidbellows damage resistance

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

A bulkhead member is introduced as an intermediary component between the bellows and the outer tube. This bulkhead member has a smaller clearance with the outer tube compared to the bellows clearance, effectively acting as a mediator that restricts radial movement of the bellows while allowing axial thermal expansion. The bulkhead member thus protects the bellows from radial interference with surrounding structures during thermal deformation and vibration.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Temperature

If bellows are used to accommodate thermal deformations, then thermal expansion is allowed, but the bellows deform radially under heat and interfere with surrounding structure

Engineering Contradiction:

Improvethermal expansion toleranceVSAvoidradial deformation interference

Core Design Contradiction:

TemperatureVSObject-affected harmful factors

Solution Approach 1:

The bulkhead member serves as a mediator that permits axial thermal expansion of the bellows while restricting radial deformation. By positioning the bulkhead member between the bellows and outer tube with a controlled smaller clearance, it guides the thermal deformation primarily in the axial direction and prevents harmful radial interference with surrounding structures.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

Different clearance sizes are applied at different locations: a larger first clearance between the bellows and outer tube allows thermal expansion, while a smaller second clearance between the bulkhead member and outer tube restricts radial deformation. This local differentiation of clearance quality enables the system to simultaneously accommodate thermal expansion and prevent radial interference.

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 configuration allows flexible handling of thermal deformations while minimizing damage to the bellows and preventing interference with the surrounding structure, effectively damping vibrations and protecting the bellows from foreign matter and low-temperature fuel exposure.

Implementation Method 1

the bellows themselves deform in a radial direction under heat

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

Between an outer peripheral surface of the bulkhead member and an inner peripheral surface of the outer tube, a second gap smaller than a first gap between an outermost peripheral surface of the bellows and the inner peripheral surface of the outer tube is interposed

Methodology Applied

Scientific EffectMechanical constraint:

Data Source

PatentUS11953206B2Burner and combustor

Publication Date: 2024.04.09 MITSUBISHI HEAVY IND LTD

AI summary

Provided is a burner of double tube structure including an outer tube and an inner tube. The inner tube includes a tip-side support portion fixed on the outer tube, a base-side support portion fixed on the outer tube, a main body portion supported by the tip-side support portion, bellows interposed between the main body portion and the base-side support portion, and a bulkhead member attached at a position between the tip-side support portion and the base-side support portion. Between an outer peripheral surface of the bulkhead member and an inner peripheral surface of the outer tube, a second gap smaller than a first gap between an outermost peripheral surface of the bellows and the inner peripheral surface of the outer tube is interposed.