Pilot Nozzle Heat Shield With Connected Tangs Against Warping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Prior art pilot nozzle heat shields in turbine engines suffer from warping or clogging due to extreme heat, pressure, and vibration, leading to decreased efficiency and increased maintenance downtime, as well as higher NOx emissions and operating costs.
Innovation Solution
A pilot nozzle heat shield with connected tangs and a stress relief hole to prevent cracking, manufactured from a heat-resistant weldable alloy, featuring an internal taper and retention pin cavities for secure mounting, which reduces the incidence of heat shield failure and maintenance downtime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If separated tangs are used in the heat shield, then fuel flow characteristics are improved and combustion efficiency increases, but the individual tangs warp or twist under heat, pressure, and vibration, disrupting fluid flow and reducing reliability
Solution Approach 1:
The patent merges the previously separate tangs into a single integrated tang structure that is radially extended and circumferentially positioned. This unified tang design maintains the flow-directed functionality while eliminating the warping issues of individual separate tangs, as the single piece structure does not have joints or connections that can fail under thermal and mechanical stress
2Strength
If heat shields are welded onto the pilot nozzle for secure mounting, then the heat shield is firmly attached, but removal and replacement require grinding or milling, increasing maintenance downtime and costs
Solution Approach 1:
The patent segments the mounting function from the heat shield body by using a separate retention ring with retention pins. This allows the heat shield to be easily installed and removed by simply securing or releasing the retention pins, eliminating the need for welding or grinding operations and significantly reducing maintenance downtime
3Object-affected harmful factors
If the heat shield is exposed to extreme heat, pressure, and vibration in the combustion chamber, then it protects the pilot nozzle, but the heat shield itself warps or changes shape, disrupting air and fuel flow
Solution Approach 1:
The patent employs a heat-resistant alloy composition containing nickel, chromium, and other elements that provide both thermal protection and dimensional stability. This composite material structure allows the heat shield to withstand extreme temperatures while maintaining its shape and structural integrity, preventing warping and flow disruption
Data Source
AI summary
A pilot nozzle heat shield includes a generally cylindrical body having a first end for receiving a pilot nozzle. The body includes a plurality of radial retention pin cavities for receiving retention pins. A frustoconical flow tip is located at a second end of the body that includes a proximal periphery and a distal periphery. A plurality of flow jets are circumferentially spaced about the proximal periphery of the frustoconical flow tip which further includes a plurality of slots extending distally from the plurality of flow jets. The plurality of slots define a plurality of tangs and the plurality of tangs define an aperture at the distal periphery of the flow tip. At least two of the tangs are connected about the distal periphery of the flow tip and the pilot nozzle heat shield generally includes at least two sets of connected tangs.