Combustor Liner Jet Wall for Cooling Air Reduction
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Solution Overview
Problem
Turbine engines face inefficiencies in fuel consumption due to high cooling air requirements for combustor cooling, which reduces thrust production and increases undesirable combustion byproducts like NOx, as existing cooling methods do not effectively utilize compressed air for optimal heat management.
Innovation Solution
The implementation of combustor liners featuring dilution openings in a staggered overlapping arrangement, a convergent channel, a jet wall, and a multi-cornered film cooling slot, which together reduce cooling air needs by enhancing convective heat transfer and film cooling coverage, thereby improving fuel efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If additional cooling air is used to protect engine components from high temperatures, then component protection is improved, but fuel efficiency deteriorates due to energy expended on compressing cooling air
Solution Approach 1:
The patent changes the physical parameters of the cooling system by introducing a convergent channel that increases cooling air velocity and a multi-cornered film cooling slot that optimizes cooling air distribution. These parameter changes enable more effective cooling with less air, resolving the contradiction between temperature protection and fuel efficiency
Solution Approach 2:
The patent applies local quality by using film cooling slots positioned at specific locations on the combustor liner to provide targeted cooling where heat flux is highest. The multi-cornered slot design creates localized cooling zones that protect critical areas without requiring uniform cooling across the entire liner, reducing total cooling air requirements
2Use of energy by moving object
If combustion temperature and pressure are increased to improve fuel efficiency, then fuel efficiency is improved, but NOx formation increases at an increased rate
Solution Approach 1:
The patent applies preliminary action by introducing cooling air through dilution openings before the combustion gases contact the combustor liner, creating a protective cooling layer in advance. This preliminary cooling action allows higher combustion temperatures to be maintained without excessive heat transfer to the liner, enabling higher fuel efficiency while controlling NOx formation through better temperature management
3Temperature
If conventional cooling methods are used for combustor cooling, then cooling is provided, but cooling air requirements are high which reduces thrust production
Solution Approach 1:
The patent applies pneumatic principles by utilizing the compressibility and flow characteristics of cooling air through a convergent channel design. The channel geometry is optimized to accelerate cooling air to higher velocities, increasing convective heat transfer coefficients and cooling effectiveness per unit of cooling air, thereby reducing total cooling air requirements
Solution Approach 2:
The patent introduces a multi-cornered film cooling slot that distributes cooling air in multiple directions and dimensions along the combustor liner surface. This multi-dimensional cooling approach maximizes the cooling coverage area with a given quantity of cooling air, improving cooling effectiveness while reducing the total volume of cooling air required
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
These features significantly decrease the cooling air requirements for the combustor, leading to reduced NOx formation and improved fuel efficiency by optimizing the use of compressed air for heat management, resulting in enhanced engine performance.
Implementation Method 1
A flow of cooling air is directed through a cooling passage in the combustor liner to cool an outer surface of the combustor liner
Implementation Method 2
These features significantly decrease the cooling air requirements for the combustor, leading to reduced NOx formation and improved fuel efficiency by optimizing the use of compressed air for heat management
Data Source
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AI summary
A shell for a combustor liner includes a cold side, a hot side, a row of cooling holes and a jet wall. The jet wall projects from the hot side for creating a wall shear jet of increased velocity cooling flow in a tangential direction away from the row of cooling holes and along an adjacent heat shield cold side wall.