Gas Turbine Combustor Obstacle Design for Flow Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In reverse-flow gas turbine combustors, existing methods to reduce pressure loss and airflow deviation in the flow path reversing portion either result in a larger combustor structure or increased pressure loss due to the need for complex flow path modifications and flow control mechanisms.
Innovation Solution
A gas turbine combustor design featuring an obstacle with specific hole configurations in the airflow path upstream of the reversing portion, which alters flow velocity and turbulence to guide air uniformly through the combustor, reducing pressure loss and deviation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the flow path cross-sectional area is increased to lower the flow velocity during reversal, then the pressure loss and flow deviation are reduced, but the gas turbine combustor structure becomes larger
Solution Approach 1:
The patent applies local quality by creating different flow conditions in different regions of the flow path. Specifically, the flow path cross-sectional area is designed to be locally enlarged at specific positions (such as at the reversal section or upstream/downstream areas) rather than uniformly throughout the entire combustor. This localized expansion reduces flow velocity and pressure loss only where needed, while maintaining a compact overall combustor structure.
2Stability of the object's composition
If a baffle plate or guide plate is mounted in the flow path to suppress flow deviation, then the airflow direction is controlled, but the pressure loss increases due to the additional flow resistance
Solution Approach 1:
The patent extracts or removes the traditional baffle plates and guide plates from the flow path design. Instead of adding these flow control components that create resistance, the invention achieves airflow control through the geometric design of the flow path itself, specifically through localized cross-sectional area changes. This eliminates the need for additional flow resistance elements while still suppressing flow deviation.
Solution Approach 2:
The patent uses the flow path geometry itself as an intermediary to control airflow, rather than introducing separate control components. The cross-sectional area changes act as a passive mediator that naturally guides and stabilizes the flow through pressure gradient effects, avoiding the need for active flow control devices that would increase pressure loss.
3Stability of the object's composition
If the flow path cross-sectional area is increased to lower the flow velocity, then the flow deviation is suppressed, but the combustor axial length increases
Solution Approach 1:
The patent addresses the axial length issue by transitioning to a different dimensional approach. Instead of uniformly increasing the axial length to accommodate larger cross-sectional areas, the invention uses radial or circumferential dimension changes at specific locations. The cross-sectional area is enlarged in the radial direction or through optimized circumferential distribution rather than extending the axial dimension, thus maintaining a compact axial length while achieving flow uniformity.
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 design achieves reduced pressure loss and airflow deviation, enabling uniform fuel and air mixing, thereby improving combustion performance and reducing NOx emissions.
Implementation Method 1
providing an obstacle having a low opening ratio on the inner circumferential side and a high opening ratio on the outer circumferential side in an airflow path on the upstream side of a flow path reversing portion... Much turbulence occurs because of the difference in flow velocity from the ambient gas.
Implementation Method 2
the flow velocity of air lowers after its passage through the holes (opening portions) in the obstacle on the inner circumferential side of the airflow path because the flow path widens after the passage through the holes
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A gas turbine combustor 10 comprising: a burner that injects air and a fuel, an inner casing 18 that surrounds the burner, an outer casing 19 that surrounds the inner casing 18, an airflow path that supplies air is provided between the inner casing 18 and the outer casing 19, an opening portion that introduces the air flowing down the airflow path 26 from an outer circumferential side to an inner circumferential side of the inner casing of the combustor is provided in a part of the inner casing 18, wherein, an obstacle that impedes flow of the air is provided in the airflow path 26 on an upstream side of the opening portion, and the obstacle is formed by a perforated plate comprising a plurality of holes that flow a stream of the air, and the obstacle is configured such that an opening ratio representing a ratio of cross-sectional area of an opening portion of the hole formed in the obstacle to the sum of the cross-sectional area of the opening portion of the hole and cross-sectional area of a shielding portion that shields the flow of the air is low on an inner circumferential side of the obstacle and high on an outer circumferential side of the obstacle.