Bundle Tube Fuel Injector Tube Tips
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional bundled tube fuel injectors in gas turbines face degradation due to extreme temperatures, leading to high maintenance and replacement costs, as materials resistant to high temperatures are expensive and impractical for widespread use.
Innovation Solution
The implementation of a two-part tubing system with dissimilar high-temperature alloy tube tips that are brazed or welded to the pre-mix tubes, providing thermal shielding and mechanical support, allowing for cost-effective design flexibility and extended part life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pre-mix tubes are made entirely from high-temperature resistant materials, then thermal degradation is reduced and service life is extended, but manufacturing cost increases significantly
Solution Approach 1:
The pre-mix tube is divided into two distinct segments: a proximal portion made from conventional material and a distal tube tip made from high-temperature resistant material. This segmentation allows the expensive material to be used only where thermally necessary (at the combustion interface) while the longer, cooler portion uses cost-effective conventional material, thus resolving the contradiction between reliability and manufacturing cost.
Solution Approach 2:
The invention applies local quality by concentrating the high-temperature resistant material specifically at the tube tip region that experiences extreme thermal conditions near the combustion chamber, while the upstream portion of the tube uses standard materials. This localized application of premium material optimizes thermal performance exactly where needed without incurring excessive manufacturing costs across the entire tube length.
2Productivity
If the distal end of pre-mix tubes is positioned closer to the combustion chamber to improve mixing, then combustion efficiency increases, but thermal exposure and degradation accelerate
Solution Approach 1:
The invention employs a composite structure combining conventional tube material with a high-temperature resistant tube tip material. This composite construction enables the tube to withstand the increased thermal exposure resulting from closer positioning to the combustion chamber, thereby allowing optimization of combustion efficiency without sacrificing tube integrity due to thermal degradation.
3Ease of manufacture
If conventional materials are used for pre-mix tubes, then manufacturing cost is reduced, but service life decreases due to thermal degradation
Solution Approach 1:
By segmenting the tube into conventional and high-temperature resistant portions, the invention achieves an optimal balance: the majority of the tube length uses inexpensive conventional materials for cost-effective manufacturing, while the critical tube tip segment uses expensive high-temperature material to prevent degradation and extend overall service life in the harsh thermal environment.
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
The tube tips enhance the mechanical and thermal performance of pre-mix tubes, reducing maintenance costs and extending the life of bundled tube fuel injectors by offering a cost-effective solution to thermal degradation issues.
Implementation Method 1
providing thermal shielding and mechanical support
Implementation Method 2
brazed or welded to the pre-mix tubes
Implementation Method 3
brazed or welded to the pre-mix tubes
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A bundled tube fuel injector (100) includes a fuel plenum (110) that is defined within the bundled tube fuel injector (100) and a plurality ofpre-mix tubes (130) that extend downstream from the fuel plenum (110) substantially parallel to one another. Each pre-mix tube (130) includes an end portion (136) and a radially extending end surface (138). The bundled tube fuel injector (100) further includes a tube tip (200) that is fixedly connected to the end portion (136) of a corresponding pre-mix tube (130).