Circumferential Air Blowhole Spacing for Combustor Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbine power-generating plants face challenges in reducing nitrogen oxides (NOx) emissions while enhancing power-generating efficiency, particularly when using hydrogen-containing fuels, which can lead to combustor reliability issues due to high flame temperatures and pressure fluctuations.
Innovation Solution
The design incorporates a plurality of independently operable burners with a circumferential array of air blowholes, where the spacing between air blowholes is increased to prevent interference and promote swirling flows, reducing pressure fluctuations and maintaining combustor reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the combustion gas temperature is increased to improve power-generating efficiency, then power-generating efficiency is improved, but nitrogen oxides (NOx) emissions increase exponentially
Solution Approach 1:
The combustor is divided into multiple independently operable burners (at least three) arranged circumferentially, with each burner having its own air blowholes. This segmentation allows independent control of combustion zones, enabling temperature management that improves efficiency while controlling NOx formation in each segment
Solution Approach 2:
Different regions of the combustor are given different properties through the circumferential arrangement of burners with varying air blowhole configurations. Each burner zone can be optimized for local combustion characteristics, creating zones of different temperature and mixing intensity to balance efficiency and emissions
2Object-affected harmful factors
If hydrogen-containing fuel is used to prevent global warming, then environmental performance is improved, but flame temperature increases and combustor reliability deteriorates
Solution Approach 1:
The combustor is divided into multiple independently operable burners (at least three) arranged circumferentially, with each burner having its own air blowholes. This segmentation allows independent control of combustion zones, preventing localized high-temperature flames that would otherwise occur with hydrogen-containing fuels
Solution Approach 2:
Air blowholes positioned between the fuel injection point and combustion chamber act as intermediaries, introducing air to mix with and moderate the high-velocity fuel jet. This intermediary air flow prevents direct high-temperature flame contact with combustor walls, maintaining reliability when using hydrogen-containing fuels
3Object-generated harmful factors
If air blowholes are arranged at equal intervals to enhance fuel dispersibility, then NOx reduction is achieved, but flame interference and pressure fluctuations occur
Solution Approach 1:
The air blowhole configuration is made dynamic and position-dependent rather than static and uniform. The number, arrangement, and dimensions of air blowholes are varied according to specific angular positions around the combustor circumference, allowing the system to adapt to the dynamic combustion process and prevent flame interference
Solution Approach 2:
Different angular positions around the combustor are given different air blowhole configurations. Certain positions have more or fewer air blowholes, or different blowhole dimensions, to locally optimize combustion characteristics and prevent flame interference in specific zones while maintaining overall NOx reduction
4Productivity
If fuel flow rate is increased to improve power output, then productivity is improved, but flame temperature increases and wall contact is worsened
Solution Approach 1:
The fuel flow is divided among multiple independently operable burners (at least three) arranged circumferentially. This segmentation distributes the total fuel load across multiple zones, allowing high power output while preventing excessive temperature concentration in any single location, thereby reducing wall contact risk
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 configuration enhances combustion stability, reduces NOx emissions, and prevents combustor liner damage by minimizing flame interference and contact with the wall, thereby improving overall combustor reliability and efficiency.
Implementation Method 1
forming a fuel flow and an air flow at the outer circumferential side of the fuel flow, inside air blowholes provided in the air blowhole plate, and jetting the fuel flow and the air flow into the combustion chamber
Implementation Method 2
Power-generating plants that support industrial electric power services include gas turbine power-generating plants fueled by a natural gas, petroleum, or other fossil resources
Implementation Method 3
increasing the temperature of the combustion gases released from the gas turbine combustor
Data Source
Figure 1A~1B
Figure 2~3
Figure 4
AI summary
This invention is intended to maintain combustor reliability. The invention provides a combustor 100 that includes: a fueling nozzle 22 that jets a fuel towards a combustion chamber 1 located downstream; and a flat-plate-shaped air blowhole plate 20 facing the upstream side of the combustion chamber 1 and disposed between the fueling nozzle 22 and the combustion chamber 1, the air blowhole plate 20 having a plurality of air blowholes 21 arranged at equal intervals in a circumferential direction relative to the center of the air blowhole plate 20, in order to jet towards the combustion chamber 1 a flow of fuel and a flow of air that is formed at the outer circumferential side of the fuel flow; wherein, in a phase that the fuel flow and the air flow reach an inner wall of the combustion chamber 1 after being jetted from each of a plurality of independently operable burners and from part of the circumferentially arrayed air blowholes 21, or in a phase that the fuel flow and the air flow interfere with two of the adjacent burners, a spacing between air blowholes 21 that are the part of the circumferentially arrayed air blowholes, is greater than in other phases of the air blowholes 21. According to the invention, combustor reliability can be maintained.