Gas Turbine Combustor Nozzle Cover Ring with Inclined Flow Passages
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Solution Overview
Problem
Conventional gas turbine combustors experience reduced combustion stability due to air jets from through-holes in the cover ring blowing the flame away from the combustion area, leading to inadequate cooling of the leading end part.
Innovation Solution
The combustor nozzle features inclined flow passages in the cover ring that jet air along the front surface of the leading end, ensuring the flame is maintained at an optimal distance and enhancing cooling performance while maintaining combustion stability through the use of swirling air and varied inclination angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If air is jetted out of through-holes in the cover ring along the central axis direction, then the leading end part is cooled, but the flame is blown away from the cover ring reducing combustion stability
Solution Approach 1:
The flow passages are designed with asymmetric inclination angles relative to the central axis. Specifically, flow passages on one side of the cover ring are inclined at a positive angle while those on the opposite side are inclined at a negative angle, creating asymmetric air jet patterns that prevent flame blowaway while maintaining cooling effectiveness.
Solution Approach 2:
The invention transitions from axial air jetting (one-dimensional along the central axis) to inclined air jetting (adding angular dimension). The air jets are directed at inclination angles relative to the central axis, creating a two-dimensional flow pattern that simultaneously achieves cooling and flame stabilization by directing air along the flame front rather than directly at it.
2Temperature
If air is jetted out to cool the leading end part, then temperature is reduced, but flame position is displaced reducing combustion stability
Solution Approach 1:
The flow passages are strategically positioned and inclined to direct air jets at specific locations along the flame front. By controlling the inclination angles and positions of individual flow passages, the air is delivered precisely where needed for cooling without disrupting the overall flame structure or position.
Solution Approach 2:
Instead of using strong axial jets that would completely blow away the flame, the invention uses multiple inclined jets at moderate angles. This partial action approach applies cooling air in a distributed manner that is sufficient for heat dissipation but insufficient to disrupt flame stability, achieving cooling without excessive flame displacement.
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 improves the cooling performance of the leading end part while securing combustion stability by efficiently directing air to cool the cover ring and maintaining the flame's position, preventing overheating.
Implementation Method 1
air jetted out of these inclined flow passages flows in the circumferential direction along the front surface of the leading end surface cover
Implementation Method 2
this jet of air flows along a front surface of the leading end surface cover and thereby keeps a flame at an appropriate distance. As a result, the cover ring is prevented from reaching a high temperature
Implementation Method 3
a swirling force application part that applies a swirling force to an air current flowing through the air flow passage
Implementation Method 4
the fuel gas and the air are mixed together and combusted in the vicinity of the cover ring
Data Source
Figure 1
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Figure 4~5
AI summary
Provided are a combustor nozzle, a gas turbine combustor, a gas turbine, a cover ring, and a combustor nozzle manufacturing method. The combustor nozzle includes: a nozzle body (71) provided with a fuel flow passage (72); a cover ring (75) that is disposed on an outer side of the nozzle body (71) so as to form air flow passages (76, 77) that allow air to jet out toward a front side; and fuel injection nozzles (79) that are provided in a leading end part of the nozzle body (71) at predetermined intervals in a circumferential direction and extend through the cover ring (75) so as to be able to inject fuel from the fuel flow passage (72) toward the front side. The cover ring (75) has an outer circumferential surface cover (75a) that covers an outer circumferential surface of the nozzle body (71), a leading end surface cover (75b) that covers a leading end surface of the nozzle body (71), and a plurality of inclined flow passages (101) that extend through the leading end surface cover (75b) in a thickness direction and are inclined in a predetermined direction relative to a direction of a central axis (C).