Fuel Nozzle Insert Welding for Repairable Gas Turbine Joints
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Solution Overview
Problem
Existing fuel nozzles in gas turbines face issues with braze joint failures leading to leaks and limited repair capabilities, requiring complex and expensive repairs, with only three iterations of repeated repair being feasible due to the complex geometry and difficulty in accessing certain areas.
Innovation Solution
The use of welding processes such as beam welding and solid state welding to secure the fuel nozzle insert to the end cover, allowing for removable and repeatable insertion and removal of the insert without damage, using cladded build-ups and intermediate materials to facilitate secure welding and prevent leaks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If brazing is used to secure the insert to the end cover, then the insert can be initially secured, but the braze joints are subject to failure and leaking, and can only be repaired three times
Solution Approach 1:
The patent replaces the brazing process (thermal joining method) with a mechanical fastening system using bolts and fasteners. This substitution allows the insert to be securely attached to the end cover while enabling repeated removal and reinstallation without damage to the joining mechanism, thereby eliminating the three-repair limitation inherent in brazed joints.
2Ease of repair
If the insert is removed for repair, then repairs can be performed, but the braze joints are severed and repeated severing results in leaking that cannot be adequately repaired
Solution Approach 1:
The patent segments the fuel nozzle assembly into removable components (insert and end cover) connected by mechanical fasteners. This segmentation allows the insert to be independently removed for repair or replacement while maintaining the integrity of the sealing surfaces, enabling multiple repair cycles without compromising sealing integrity.
3Strength
If welding is used to secure the insert to the end cover, then the insert can be securely attached, but the complex geometry and difficulty reaching certain portions makes welding difficult
Solution Approach 1:
The patent replaces welding (thermal process requiring direct access) with mechanical fastening using bolts and fasteners. This mechanical system can be implemented from accessible locations on the assembly, avoiding the need to reach into complex internal geometries, while still providing secure attachment and allowing for disassembly and reassembly.
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 solution extends the operational life of fuel nozzles, simplifies repairs, and allows for more than three iterations of repair, reducing operational costs and preventing leaks, while avoiding the limitations of braze joints.
Implementation Method 1
The fuel nozzle insert is welded to the fuel nozzle end cover by a welding process selected from the group consisting of beam welding, solid state welding, and combinations thereof.
Implementation Method 2
The fuel nozzle insert is welded to the fuel nozzle end cover by a welding process selected from the group consisting of beam welding, solid state welding, and combinations thereof.
Implementation Method 3
The fuel nozzle insert is welded to the fuel nozzle end cover by a welding process selected from the group consisting of beam welding, solid state welding, and combinations thereof.
Data Source
AI summary
Disclosed is a fuel nozzle and a process of fabricating a fuel nozzle. The fuel nozzle includes a fuel nozzle end cover and a fuel nozzle insert. The fuel nozzle insert is welded to the fuel nozzle end cover by a welding process selected from the group consisting of beam welding, solid state welding, and combinations thereof and/or the fuel nozzle insert includes a first fuel nozzle insert portion and a second fuel nozzle insert portion. The process includes welding the fuel nozzle insert to the fuel nozzle end cover.