Gas Turbine Combustor Air Flow Uniformization
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Solution Overview
Problem
The existing combustors in gas turbines experience non-uniform flow velocity distribution of high pressure air, leading to flow imbalances and increased NOx generation due to the reversal of air flow direction within the internal flow path.
Innovation Solution
A combustor design featuring an outer shell with an inside narrowing surface and an outside narrowing surface, where the outside narrowing surface extends inward radially and the inside narrowing surface extends outward, optimizing the flow velocity distribution by controlling the angles and positions of these surfaces to enhance air reversal and uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If air flow direction is reversed within the internal flow path, then air can be introduced from the downstream side toward the upstream side, but the flow velocity distribution becomes non-uniform
Solution Approach 1:
The inner peripheral surface of the outer shell is divided into multiple regions with different surface characteristics: a first region with a first surface inclination angle, a second region with a second surface inclination angle, and a third region with a third surface inclination angle. Each region has optimized local surface properties to control air flow velocity distribution, creating non-uniform flow in controlled areas while maintaining overall flow balance.
Solution Approach 2:
The surface inclination angles are designed to dynamically adapt to varying air flow conditions. The first, second, and third regions have different inclination angles that allow the air flow to adjust its velocity distribution dynamically as it passes through the internal flow path, ensuring optimal flow characteristics under different operating conditions.
2Ease of operation
If high pressure air is guided from downstream toward upstream in the internal flow path, then the air can reverse flow direction by 180 degrees, but flow imbalance occurs in the cylinder
Solution Approach 1:
Different regions of the inner peripheral surface have optimized local properties with specific inclination angles to control air flow distribution. The first region, second region, and third region each have tailored surface characteristics that work together to maintain flow balance during the 180-degree reversal process.
Solution Approach 2:
The problem of flow imbalance during direction reversal is solved by introducing a dimensional approach through multiple surface regions with different inclination angles. This multi-regional surface design allows control of air flow in multiple zones simultaneously, achieving stable flow distribution after 180-degree reversal.
3Object-generated harmful factors
If non-uniform flow velocity distribution of high pressure air occurs, then the air can reverse direction, but the amount of NOx generated increases
Solution Approach 1:
The inner peripheral surface is divided into first, second, and third regions with different surface inclination angles optimized to control local air flow velocity. This local quality optimization ensures uniform flow velocity distribution across all regions, preventing conditions that would lead to increased NOx generation during combustion.
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 effectively reduces NOx generation by uniformizing the flow velocity distribution, improving air flow balance and combustion efficiency.
Implementation Method 1
the outside narrowing surface is formed on the inner peripheral surface in the outer shell, it is possible to uniformize a flow velocity distribution of air flowing along the outside narrowing surface in the air introduction channel
Data Source
AI summary
A combustor includes: a first cylindrical body which is configured to hold a fuel nozzle extending in an axial line direction and through which air flows toward a downstream side thereof; a second cylindrical body that is connected to a downstream side of the first cylindrical body; and an outer shell that has an inner peripheral surface configured to define an air introduction channel through which air is introduced such that the air reverses course at an upstream end of the first cylindrical body and flows toward the downstream side together with an outer peripheral surface of the first cylindrical body. The inner peripheral surface has an outside narrowing surface that is formed to extend inward in a radial direction toward the upstream end of the first cylindrical body.