Air Flow Guide Cap for Gas Turbine Combustion Duct Cooling

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Solution Overview

Problem

Current air flow induction methods, such as the scoop, are insufficient to handle increased combustion heat and output in gas turbine engines, leading to inefficient cooling of combustion duct components due to turbulence and limited air volume induction.

Innovation Solution

The design of an air flow guide cap with an upwardly inclined upper surface and a downwardly extending wall surface, combined with a protrusion member that fits into the through holes, to increase the cross-sectional area of the inlet and guide air flow vertically, reducing turbulence and ensuring stable airflow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a scoop is used to induce air flow into through holes, then air volume induction is improved, but turbulence occurs and cooling efficiency becomes insufficient for high combustion heat

Engineering Contradiction:
Improveair volumeVSAvoidcooling efficiency
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The air flow guide cap employs a curved upper surface design that guides air flow smoothly into the through hole. The curved surface shape redirects the air flow direction gradually, preventing sudden flow direction changes that cause turbulence, thereby maintaining reliable cooling efficiency while still inducing sufficient air volume.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The air flow guide cap adds a vertical dimension to air flow induction by extending upward from the sleeve surface. This three-dimensional structure creates an additional flow path dimension, allowing air to be induced from both horizontal and vertical directions, increasing total air volume while maintaining smooth flow transition through the curved upper surface.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If the inlet cross-sectional area is increased to enhance air flow rate, then cooling air flow rate improves, but the structure becomes more complex

Engineering Contradiction:
Improveair flow rateVSAvoidstructure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The air flow guide cap is divided into distinct functional segments: a vertical cylindrical portion extending from the sleeve, an upper curved surface for flow guidance, and a protrusion member for mounting. This segmentation allows each part to perform its specific function efficiently while keeping the overall structure manageable and not excessively complex.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The air flow guide cap serves multiple functions simultaneously: it increases the inlet cross-sectional area for higher air flow rate, guides air flow smoothly to reduce turbulence, and provides a mounting structure via the protrusion member. This multi-functionality achieves enhanced productivity without proportionally increasing structural complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Quantity of substance

If air flow is induced horizontally, then air volume is increased, but uniform cooling distribution along the combustion duct is compromised

Engineering Contradiction:
Improveair volumeVSAvoidcooling distribution uniformity
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The curved upper surface of the air flow guide cap gradually redirects air flow from horizontal induction to vertical downward flow. This curved transition ensures uniform distribution of air flow along the combustion duct length, preventing concentrated cooling in specific areas and achieving uniform cooling distribution while still inducing sufficient air volume horizontally.

Inventive Principle:
Principle #14Spheroidality (Curvature)

4Quantity of substance

If the scoop shape is enlarged to increase air induction, then air volume improves, but turbulence increases and cooling effectiveness decreases

Engineering Contradiction:
Improveair volumeVSAvoidturbulence
Core Design Contradiction:
Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The air flow guide cap uses a curved upper surface design that provides a smooth, gradual transition for air flow direction change. This curved geometry prevents sudden flow direction changes that generate turbulence, allowing the structure to be sufficiently large for high air volume induction while maintaining laminar flow and avoiding turbulence-related cooling effectiveness degradation.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 design enhances the flow rate of cooling air, ensures uniform cooling distribution along the combustion duct, and improves the mounting efficiency of the air flow guide caps, providing effective cooling without turbulence and unequal distribution.

Implementation Method 1

an upwardly inclined upper surface and a downwardly extending wall surface, combined with a protrusion member that fits into the through holes, to increase the cross-sectional area of the inlet and guide air flow vertically, reducing turbulence and ensuring stable airflow

Methodology Applied
Scientific EffectFluid flow guidance:

Implementation Method 2

The air induced into the sleeve 4 cools the transition piece 3 and the liner 2 while ascending toward the burner 1

Methodology Applied
Scientific EffectConvection cooling: Convection

Implementation Method 3

proper cooling because it is a path for a flow of the combustion gas of high-temperature

Methodology Applied
Scientific EffectHeat absorption: Heat Sink

Data Source

PatentEP3258066B1Air flow guide cap for a combustion duct of a gas turbine engine
Publication Date: 2021.07.21 DOOSAN HEAVY IND & CONSTR CO LTD
  • EP3258066B1 patent drawingFigure 1
  • EP3258066B1 patent drawingFigure 2~3B
  • EP3258066B1 patent drawingFigure 4~5

AI summary

Disclosed is a combustion duct assembly (6) of a gas turbine engine in which air flows on the surface and which has a plurality of through holes (7) for inducing air; and a plurality of air flow guide caps (10) for inducing the air flow into the through holes of the floor. Each air flow guide cap includes an upper surface (20) upwardly inclined relative to a horizontal plane, and a wall surface (30) downwardly extending along edges of the upper surface except the edge adjacent to an air inlet (32).