Gas Turbine Fuel Nozzle Reconditioning via Electron Beam Welding

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Solution Overview

Problem

The reconditioning of gas turbine fuel nozzle assemblies is challenging due to the difficulty of removing and replacing materials, limited reconditioning cycles, and structural integrity issues, particularly with the use of costly ductile braze materials like gold, palladium, and platinum, which restrict the number of repairs to approximately three cycles.

Innovation Solution

A method for reconditioning fuel nozzle assemblies involves removing damaged components, fabricating replacement parts, and using advanced joining techniques such as Electron Beam (EB) welding to minimize material sacrifice and maintain structural integrity, allowing for repeated reconditioning cycles with minimal loss of material and preservation of existing components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of repair

If traditional brazing methods are used to join fuel nozzle components, then the components can be assembled, but the number of reconditioning cycles is limited to approximately three due to material sacrifice and structural integrity loss

Engineering Contradiction:
Improvereconditioning cyclesVSAvoidmaterial sacrifice
Core Design Contradiction:
Ease of repairVSLoss of substance

Solution Approach 1:

The patent changes the joining parameter from traditional brazing to electron beam welding, which fundamentally alters how components are joined. This parameter change eliminates the need for material sacrifice associated with brazing, allowing for repeated reconditioning cycles without the limitation of approximately three cycles that previously existed.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the thermal-chemical brazing process with electron beam welding, substituting a mechanical/electromagnetic joining method. This substitution eliminates the diffusion zone and material loss inherent in brazing, enabling components to be reconditioned multiple times while preserving structural integrity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Ease of repair

If traditional brazing methods are used to join fuel nozzle components, then assembly can be achieved, but structural integrity is compromised after multiple reconditioning cycles

Engineering Contradiction:
Improvereconditioning cyclesVSAvoidstructural integrity
Core Design Contradiction:
Ease of repairVSReliability

Solution Approach 1:

By changing the joining parameter from brazing to electron beam welding, the patent creates a stronger, more reliable joint that maintains structural integrity through multiple reconditioning cycles. The electron beam weld creates a metallurgical bond superior to the diffusion zone created by brazing.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The substitution of electron beam welding for brazing replaces a process that compromises structural integrity with one that preserves it. The electron beam welding process creates joints that maintain the strength and reliability of the fuel nozzle assembly through repeated heating and cooling cycles.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Stability of the object's composition

If costly ductile braze materials like gold, palladium, and platinum are used, then ductility requirements are met, but the cost increases and reconditioning cycles are limited

Engineering Contradiction:
ImproveductilityVSAvoidcostly braze materials
Core Design Contradiction:
Stability of the object's compositionVSQuantity of substance

Solution Approach 1:

The patent extracts and eliminates the need for costly ductile braze materials by replacing the brazing process with electron beam welding. This removal of the braze material requirement eliminates the associated costs and the limitation on reconditioning cycles that resulted from using these expensive materials.

Inventive Principle:
Principle #2Taking out (Extraction)

4Ease of repair

If material is removed from fuel nozzle assemblies during reconditioning, then damaged portions can be replaced, but the number of reconditioning cycles is limited due to cumulative material loss

Engineering Contradiction:
Improvecomponent replacementVSAvoidoperational life
Core Design Contradiction:
Ease of repairVSDuration of action of stationary object

Solution Approach 1:

By changing the joining parameter to electron beam welding, the patent eliminates cumulative material loss during reconditioning. Components can be replaced and rejoined without the material sacrifice that previously limited the operational life of the fuel nozzle assembly.

Inventive Principle:
Principle #35Parameter changes

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 approach extends the operational life of gas turbine fuel nozzle assemblies by enabling multiple reconditioning cycles with minimal material removal and preservation of structural integrity, reducing costs and improving efficiency compared to traditional brazing methods.

Implementation Method 1

using advanced joining techniques such as Electron Beam (EB) welding

Methodology Applied
Scientific EffectElectron Beam: Electron Beam

Data Source

PatentEP3377819B1Method for reconditioning fuel nozzle assemblies
Publication Date: 2019.10.16 ANSALDO ENERGIA SWITZERLAND AG
  • EP3377819B1 patent drawingFigure 1
  • EP3377819B1 patent drawingFigure 2
  • EP3377819B1 patent drawingFigure 3~4

AI summary

A method of reconditioning and fabricating turbine components is provided. In one embodiment, the method is performed on a fuel nozzle assembly of a gas turbine, and comprises providing a pre-assembled fuel nozzle assembly having a base, a body extending from the base to a fuel nozzle tip, an inner assembly, and an outer assembly. The method further comprises removing at least a portion of the fuel nozzle tip and the inner assembly, coupling and joining a replacement inner assembly to the base, and coupling and joining a replacement fuel nozzle tip to the replacement inner assembly and to the outer assembly to provide a reconditioned fuel nozzle.