Convex Profile Combustor Liner for Gas Turbine Emissions Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current gas turbine engine combustor configurations face challenges in meeting stringent emissions standards due to increased thrust specific fuel consumption (TSFC), leading to higher NOx, CO, unburned hydrocarbons (UHC), and smoke emissions.
Innovation Solution
A liner assembly for the combustor with a convex profile, exit splitter, film holes, impingement holes, and pin fins or hemispherical dimples is used to enhance flow acceleration and cooling, reducing emissions by optimizing the inlet-to-exit area ratio and improving heat transfer coefficients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If combustor configurations are optimized for improved thrust specific fuel consumption (TSFC), then engine efficiency is improved, but emissions (NOx, CO, UHC, smoke) increase
Solution Approach 1:
The patent applies parameter changes by modifying the combustor liner geometry, specifically implementing a convex profile with a controlled inlet-to-exit area ratio (approximately 4.5:1) and optimizing the convergent section to achieve flow acceleration toward 0.5 Mach. These geometric parameter changes enable the combustor to maintain improved TSFC while reducing emissions by optimizing flow distribution and combustion characteristics.
Solution Approach 2:
The patent introduces dynamics through the convex profile design that creates flow acceleration along the convergent section. The varying cross-sectional area dynamically adjusts the flow velocity profile, accelerating the flow toward 0.5 Mach at the exit of the convergent section. This dynamic flow control optimizes combustion efficiency and reduces emissions simultaneously.
2Productivity
If compressor discharge pressure and temperature are increased, then engine performance is improved, but combustor exit temperatures increase leading to higher emissions
Solution Approach 1:
The patent addresses this contradiction by changing the geometric parameters of the combustor liner, specifically the convex profile shape and the inlet-to-exit area ratio. These parameter changes enable the system to handle increased compressor discharge conditions while controlling combustor exit temperatures through optimized flow acceleration and distribution, thereby maintaining engine performance without excessive temperature rise.
3Speed
If a convex profile with controlled inlet-to-exit area ratio is implemented, then flow acceleration is enhanced, but manufacturing complexity increases
Solution Approach 1:
The patent employs spheroidality by implementing a convex profile based on a hyperbolic cosine function. This curved geometric form naturally achieves the desired flow acceleration characteristics while providing a mathematically defined shape that can be manufactured using standard forming techniques. The curvature is optimized to achieve approximately 0.5 Mach flow acceleration without requiring complex multi-stage manufacturing processes.
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 solution effectively reduces emissions by accelerating flow and enhancing cooling efficiency, thereby meeting stringent emissions standards while maintaining operational efficiency.
Implementation Method 1
The convex profile provides an approximate 4.5 inlet-to-exit area ratio and provides a flow acceleration toward approximately 0.5 Mach
Implementation Method 2
The heat shield includes a number of film holes which are approximately equal to a number of impingement holes through the support shell
Implementation Method 3
The heat shield includes a multiple of pin fins or a multiple of hemi-spherical dimples
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A liner assembly for a combustor of a gas turbine engine according to one disclosed non-limiting embodiment of the present disclosure includes a support shell with a convex profile which faces the heat shield. A further embodiment of the foregoing embodiment of the present disclosure is where the convex profile is defined by a hyperbolic cosine function. A further embodiment of any of the foregoing embodiments of the present disclosure is where the convex profile provides an approximate 4.5 inlet-to-exit area ratio. A further embodiment of any of the foregoing embodiments, of the present disclosure wherein the convex profile provides a flow acceleration toward approximately 0.5 Mach towards an end of a convergent section.