Nozzle Air Jet Section Prevents Flashback in Gas Turbine Combustors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In gas turbine combustors using the premix type combustion method, flashbacks can occur at the tip of the main nozzle due to low flow velocity, potentially leading to flame backflow and nozzle tip burnout, which existing configurations with fluid jet holes cannot effectively prevent.
Innovation Solution
A nozzle design with an air jet section at the tip, featuring a cylindrical part forming an airflow path and a pressure loss section, along with multiple air inlet sections and a flow path-forming section that merges air to increase flow velocity and reduce fuel concentration, preventing flashback by jetting air from the tip portion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fluid jet hole is provided in the vicinity of the downstream end portion of the swirler, then flashback prevention is improved in limited portions, but flashback prevention effect cannot be achieved at the tip of the main nozzle where flow velocity is low
Solution Approach 1:
The invention applies local quality by providing a fluid jet hole specifically at the tip of the main nozzle where flashback is most likely to occur due to low flow velocity. This localized placement ensures that the high-speed jetted fluid effectively prevents flashback at the critical area, rather than distributing jet holes uniformly throughout the nozzle structure.
Solution Approach 2:
The invention inverts the conventional approach by positioning the fluid jet hole at the tip of the main nozzle rather than in the vicinity of the downstream end portion of the swirler. This inversion allows the jetted fluid to directly counteract the low flow velocity at the nozzle tip, achieving effective flashback prevention at the previously unreachable location.
2Stability of the object's composition
If the flow velocity becomes low at the tip portion of the main nozzle serving as vortex core, then the swirling flow structure is maintained, but flashback occurs and flame flows back toward the tip portion causing potential burnout
Solution Approach 1:
The invention applies preliminary anti-action by jetting fluid at high speed from the tip of the main nozzle in advance to prevent flashback before it can occur. The high-velocity jet creates a protective barrier that counteracts the low flow velocity condition, preventing the flame from flowing back toward the nozzle tip while preserving the swirling flow structure upstream.
3Reliability
If existing configurations with fluid jet holes are used, then flashback prevention is achieved in limited portions, but the complexity of the system increases without achieving complete protection
Solution Approach 1:
The invention extracts the essential function of flashback prevention by providing a single fluid jet hole at the tip of the main nozzle, rather than distributing multiple jet holes throughout the system. This extraction approach achieves complete protection at the critical location with minimal additional complexity, eliminating the need for complex multi-hole configurations.
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 reliably prevents flashback and nozzle tip burnout by increasing flow velocity and reducing fuel concentration at the nozzle tip, effectively addressing the limitations of existing configurations.
Implementation Method 1
a fluid jet hole from which a fluid such as air is jetted
Implementation Method 2
a pressure loss section causing a loss of pressure in the air that flows through the air flow path
Implementation Method 3
The swirler is provided on the outer peripheral side of the main nozzle and causes the compressed air fed from the compressor to be swirled
Data Source
AI summary
A combustor provided with: a nozzle having formed therein an air jet section that causes air to be jetted from a nozzle section; a cylindrical part covering the nozzle from the outer peripheral side thereof and forming an air flow path between the cylindrical part and the nozzle; and a pressure loss section provided to the air flow path. The pressure loss section causes a loss of pressure in the air that flows through the air flow path. The nozzle is provided with: at least one air inlet section that takes in air from an outer peripheral surface that is an upstream side from the pressure loss section; and a flow path-forming section forming a discharge air flow path that guides air that is taken in from the at least one air inlet section to the air jet section.