Gas Turbine Vane Sequential Cooling Segregation
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Solution Overview
Problem
The cooling air demand for gas turbine vanes negatively impacts the efficiency of gas turbines, as existing cooling designs do not optimally utilize cooling air, leading to inefficiencies and heat management challenges.
Innovation Solution
A sequential cooling configuration for the endwalls and airfoil of gas turbine vanes, where cooling air is segregated and reused, reducing cooling air demand by up to 20% through optimized passage designs and augmentation features, including impingement tubes and varying flow resistances in side wall cooling passages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional cooling designs are used to cool gas turbine vanes, then cooling effectiveness is achieved, but cooling air demand increases and gas turbine efficiency decreases
Solution Approach 1:
The cooling system is segmented into multiple independent cooling circuits: a first cooling circuit for the leading edge region with its own cooling air supply, and a second cooling circuit for the mid-chord and trailing edge regions that utilizes cooling air from the first circuit. This segmentation allows optimized cooling air distribution to different thermal zones, reducing overall cooling air demand while maintaining effective cooling.
Solution Approach 2:
Cooling air is pre-cooled in the first cooling circuit before being reused in the second cooling circuit. The cooling air passes through the leading edge cooling passage first, where it absorbs heat and is pre-conditioned, then this pre-cooled air is directed to cool the mid-chord and trailing edge regions, maximizing the cooling effectiveness of each unit of cooling air.
2Temperature
If cooling air is drawn from the compressor to cool turbine vanes, then vane temperature is controlled, but cooling air draw-off represents a direct loss in gas turbine efficiency
Solution Approach 1:
Instead of discarding the cooling air after a single use, the system recovers and reuses the cooling air in a sequential manner. The cooling air that has cooled the leading edge region is not exhausted but is redirected to cool other regions of the vane, effectively recovering its cooling potential and reducing the total amount of cooling air that needs to be drawn from the compressor.
Solution Approach 2:
The cooling air serves multiple functions by cooling different regions of the vane in sequence. The same cooling air stream performs cooling duties for the leading edge, mid-chord, and trailing edge regions, making the cooling air resource universally applicable to multiple cooling needs rather than requiring separate cooling air supplies for each region.
3Temperature
If cooling augmentation features are added to increase wall surface area and create wall turbulence, then cooling effectiveness is improved, but device complexity increases
Solution Approach 1:
The cooling augmentation features are integrated directly into the cooling passage walls rather than being separate components. The ribs and pins are formed as part of the passage structure itself, merging the cooling flow path with the heat transfer enhancement features, which reduces the number of separate parts while maintaining enhanced cooling effectiveness.
Solution Approach 2:
Different cooling augmentation features are strategically placed in different regions of the cooling passages based on local thermal requirements. The type, size, and distribution of ribs and pins are optimized for specific sections of the vane, providing locally tailored cooling enhancement that maximizes effectiveness while minimizing overall complexity.
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 cooling effectiveness by reducing cooling air demand and improving heat management across the vane, particularly in the mid chord and trailing edge regions, without the need for supplementary cooling air, thereby increasing overall gas turbine efficiency.
Implementation Method 1
cooling air drawn from the gas turbine compressor is commonly used to cool parts
Implementation Method 2
the airfoil cooling passage (21), extending from the first endwall cooling passage (11) to the second endwall cooling passage (31)
Implementation Method 3
an airfoil impingement cooling arrangement
Implementation Method 4
cooling augmentation features, which are features that improve cooling effectiveness by increasing wall surface area and/or creating wall turbulence
Implementation Method 5
convective cooling arrangements additionally may also include cooling augmentation features
Data Source
AI summary
The invention relates to a hollow gas turbine vane (1) that is cooled by an arrangement configured to sequential cooling an endwall (10) of the vane (1) and its airfoil (20) and, at the same time, the two endwalls (10,30) of the vane (1). This arrangement can reduce cooling air demand, which can have a positive effect on the turbines efficiency.