Gas Turbine Combustor Ignition Improving Part
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The conventional gas turbine combustor experiences deteriorated flame stability due to a cooler pilot air layer forming downstream of the flame stabilizer, leading to combustion oscillation, as this low-temperature air layer inhibits the formation of a stable premixed flame.
Innovation Solution
The implementation of an ignition improving part, such as channel blocking members, plate-like projecting members, wedge-shaped vortex generators, flow-splitting members, bypass channels, or protruding parts, is used to reduce the size of the low-temperature air layer between the pilot flame and the premixed flame, thereby improving ignition and stabilizing the premixed flame.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a conventional pilot air channel structure is used, then the pilot air flow is stable, but a thick low-temperature air layer forms downstream of the flame stabilizer, deteriorating premixed flame stability
Solution Approach 1:
The pilot air channel is divided into multiple sections with different cross-sectional areas. The channel includes a contraction section that reduces the cross-sectional area from the upstream end to the downstream end, creating segmented flow regions that control temperature distribution and reduce the low-temperature air layer thickness while maintaining overall flow stability
Solution Approach 2:
The cross-sectional area parameter of the pilot air channel is changed along its length. By implementing a contraction section where the area decreases from upstream to downstream, the flow parameters (velocity, pressure, temperature) are modified to reduce the thickness of the low-temperature air layer downstream of the flame stabilizer, thereby improving premixed flame stability
2Reliability
If the low-temperature air layer thickness is reduced, then premixed flame stability is improved, but the structure becomes more complex
Solution Approach 1:
The pilot air channel incorporates a contraction section that dynamically adjusts the flow characteristics along its length. This dynamic geometric configuration allows the channel to control the thermal boundary layer development and reduce low-temperature air layer thickness without requiring additional active control systems or complex mechanical components
Solution Approach 2:
The solution addresses the two-dimensional problem of thermal layer thickness by introducing a third dimension - the axial variation of cross-sectional area. By changing the channel geometry along its length, the flow field and temperature distribution are controlled in a way that reduces low-temperature air layer thickness without adding complex lateral structures
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
By reducing the thickness of the low-temperature air layer, the distance between the premixed gas and the pilot flame is minimized, enhancing ignition and stabilizing the combustion of the premixed gas, which in turn corrects combustion oscillation issues in the gas turbine combustor.
Implementation Method 1
Pilot fuel supplied through the pilot nozzle 4 is combusted with pilot air supplied from the pilot air channel 5 and forms a pilot flame extending towards the rear side of a flame stabilizer 9
Implementation Method 2
Main fuel supplied from the main nozzle 11 is premixed with main air supplied through the main air channel 12 to form premixed gas
Implementation Method 3
This premixed gas is combusted downstream of the flame stabilizer 9 by ignition from the pilot flame
Implementation Method 4
it facilitates the premixing with the main fuel by causing the main air to form a swirling flow
Data Source
AI summary
Provided is a gas turbine combustor capable of reducing the size of a low-temperature air layer of pilot air formed between a pilot flame and a premixed flame and of improving the flame stability of the premixed flame. A gas turbine combustor, which is provided with a pilot burner that is provided at the center portion of a combustor main body formed in a cylindrical shape to form a pilot flame, and a plurality of main burners arranged so as to surround the outer periphery of the pilot burner to form a premixed flame, includes, as the ignition improving part, a channel blocking member that reduces the size of the low-temperature air layer of the pilot air formed between the pilot flame and the premixed flame.