Segmented Diffuser Nozzle for Gas Turbine Emission Control
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Solution Overview
Problem
There is a need for improved systems and methods to treat combustion gas emissions from aircraft gas turbine engines, particularly to reduce the emission of undesirable compounds such as water vapor, nitrous oxide, and carbon-containing compounds.
Innovation Solution
A diffuser nozzle for a gas turbine engine is designed with a plurality of axially-extending duct segments, each containing a duct section with a unique cross-sectional area. This configuration allows for the inclusion of exhaust treatment systems in specific duct sections to remove water vapor, carbon compounds, and nitrogen oxides from the exhaust gas stream, optimizing the treatment process by varying the cross-sectional areas and catalyst locations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the exhaust gas velocity is reduced to increase treatment effectiveness, then the removal efficiency of undesirable compounds is improved, but the nozzle outlet area must be increased which increases the device size
Solution Approach 1:
The nozzle is divided into multiple axially-extending duct segments with different cross-sectional areas. Each duct segment can be independently configured with treatment systems, allowing velocity reduction and treatment in specific zones without requiring a uniformly large outlet area. The segmentation enables localized velocity control and treatment optimization.
Solution Approach 2:
The patent transitions from a conventional single-dimension nozzle design to a multi-dimensional structure with duct segments arranged in both axial and radial dimensions. This allows the exhaust gas to be treated at different axial positions and radial locations, enabling velocity reduction and treatment effectiveness improvement without proportionally increasing the outlet area.
2Productivity
If multiple exhaust treatment systems are integrated into the nozzle, then the removal of water vapor, carbon compounds, and nitrogen oxides is improved, but the device complexity increases
Solution Approach 1:
The exhaust treatment function is segmented across multiple duct segments, with each segment potentially containing different treatment systems. This segmentation allows for modular integration of treatment technologies, making the complex system more manageable and maintainable while achieving comprehensive removal of multiple undesirable compounds.
Solution Approach 2:
The nozzle structure is designed to perform multiple functions: velocity reduction, treatment of water vapor, carbon compounds, and nitrogen oxides, and exhaust discharge. By integrating these diverse functions into a single multi-functional device, the patent achieves comprehensive emission treatment without requiring separate standalone systems for each function.
3Productivity
If the nozzle length is increased to provide sufficient residence time for treatment, then the removal efficiency is improved, but the compact form factor required for aircraft engines is compromised
Solution Approach 1:
The patent utilizes both axial and radial dimensions to achieve treatment effectiveness. By arranging duct segments in a multi-dimensional configuration rather than a simple linear axial arrangement, the exhaust gas receives adequate treatment residence time without requiring excessive axial length, thus maintaining a compact form factor suitable for aircraft engine constraints.
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 diffuser nozzle effectively reduces the velocity of combustion exhaust gases, increasing the interaction time with the exhaust treatment systems, thereby enhancing the removal of undesirable compounds and reducing pressure losses, while also providing a compact form factor suitable for aircraft gas turbine engines.
Implementation Method 1
diffuser nozzle configured to reduce a velocity of the combustion exhaust gases passing through the diffuser nozzle
Data Source
Figure 1
Figure 2~3E
Figure 4~5H
AI summary
A diffuser nozzle (54) for a gas turbine engine (20) includes a housing (56) disposed about a nozzle axis (58) and extending between a first nozzle end (60) and a second nozzle end (62). The housing (56) defines a nozzle duct (70). A plurality of walls (72) is disposed within the nozzle duct (70). The plurality of walls (72) subdivides the nozzle duct (70) into a plurality of duct sections (74). The plurality of walls (72) further defines a plurality of axially-extending duct segments (88) of the nozzle duct (70) such that within a first axially-extending duct segment (88A), the duct cross-sectional area of a first duct section of the plurality of duct sections (74) is greater than the duct cross-sectional area of each other duct section (74) and within a second axially-extending duct segment (88B), the duct cross-sectional area of a second duct section of the plurality of duct sections (74) is greater than the duct cross-sectional area of each other duct section (74).