Gas Turbine Combustor Auxiliary Guide Air Flow Separation
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Solution Overview
Problem
In gas turbine combustors employing uniform distribution combustion, air flow rate deviations lead to local high fuel concentrations, increasing NOx emissions and pressure loss, and can cause air flow separation in air holes, affecting efficiency.
Innovation Solution
A gas turbine combustor design featuring a ring-like turn guide and auxiliary guides on the air hole plate to guide compressed air flow uniformly, reducing flow rate deviations and separation within air holes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a ring-like turn guide is provided to guide compressed air flow, then air flow uniformity is improved, but air flow separation occurs more easily in air holes positioned farther from the turn guide
Solution Approach 1:
The patent applies local quality by providing auxiliary guides at specific locations on the air hole plate - specifically at outer circumferential portions positioned on the inner circumference side relative to the turn guide. These auxiliary guides are strategically placed only where needed (in air holes farther from the turn guide) rather than uniformly across all air holes, addressing the local flow separation problem while maintaining the overall benefits of the turn guide design.
Solution Approach 2:
The auxiliary guides act as intermediary elements between the turn guide and the air holes. They mediate the flow transition by providing additional guidance for compressed air entering air holes that are positioned farther from the turn guide, where the flow separation tendency is higher. This intermediary structure helps bridge the gap between the turn guide's flow direction and the air hole inlet requirements.
2Object-generated harmful factors
If air flow rates through air holes are made uniform, then NOx emissions are reduced, but pressure loss increases in areas where air flow rates are high
Solution Approach 1:
The patent employs parameter changes by modifying the flow path geometry through the turn guide and auxiliary guides. This changes the flow distribution parameters (velocity distribution, flow direction angles) to achieve more uniform air flow rates across all air holes. By adjusting these flow parameters, the system reduces local high fuel concentration areas that cause NOx emissions, while the overall pressure loss is managed through the optimized guide结构设计.
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 effectively suppresses air flow separation in air holes, improving the uniformity of air flow rates and reducing NOx emissions and pressure loss, thereby enhancing the overall efficiency of the gas turbine.
Implementation Method 1
a turn guide provided to the inner cylinder or the air hole plate and configured to guide a turn of the compressed air having passed through the outer circumference flow path
Implementation Method 2
an auxiliary guide that is provided at an outer circumferential portion of a surface of the air hole plate facing the fuel nozzles so as to be positioned on an inner circumference side with respect to the turn guide and has a shape protruding radially inward when seen from the end cover
Implementation Method 3
a gas turbine combustor configured to mix compressed air introduced from a compressor with a fuel to combust the fuel mixed with the compressed air
Data Source
AI summary
To suppress separation of air flows in air holes that are positioned in the outermost circumferential row in an air hole plate, but are far from a turn guide. A gas turbine combustor includes: an inner cylinder forming a combustion chamber; an outer cylinder forming a cylindrical outer circumference flow path through which compressed air flows, between the outer cylinder and the inner cylinder; an end cover closing an end portion of the outer cylinder; an air hole plate having air holes introducing the compressed air passed through the outer circumference flow path, into the combustion chamber; a plurality of fuel nozzles injecting a fuel into the combustion chamber via the air holes; a turn guide provided to the inner cylinder or the air hole plate and guiding a turn of the compressed air passed through the outer circumference flow path; and an auxiliary guide provided at an outer circumferential portion of a surface of the air hole plate facing the fuel nozzles, so as to be positioned on an inner circumference side with respect to the turn guide.