Turbine Blade Cooling Passage with Variable Height Turbulators
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Solution Overview
Problem
In gas turbines, the increasing load on turbine blades requires optimized internal cooling passages to enhance cooling efficiency while managing varying blade widths and pressure losses, as the blade width in the suction-pressure direction often differs, affecting the effectiveness of turbulators in cooling passages.
Innovation Solution
The turbine blade design features turbulators with increasing height from the first end portion to the second end portion along the blade height direction, with varying passage widths, and specific ratios of turbulator height to passage width and pitch, optimized to maintain high heat transfer rates and minimize pressure loss across the blade height direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the blade width in the suction-pressure direction is increased on one side to improve strength, then the strength of the turbine blade is improved, but the passage width of the cooling passage becomes non-uniform, making it difficult to optimize turbulator configuration
Solution Approach 1:
The patent applies local quality by configuring turbulators with different heights at different locations within the cooling passage. Specifically, the first turbulator has a first height and the second turbulator has a second height that is different from the first height, allowing each turbulator to be optimized for its local passage width conditions while the overall blade maintains non-uniform width for strength requirements
2Device complexity
If constant-height turbulators are used in cooling passages with varying passage widths, then the device complexity is reduced, but the heat transfer rate cannot be optimized in regions with different passage widths
Solution Approach 1:
The patent implements local quality by varying the height of turbulators according to their local position in the cooling passage. The first turbulator positioned in a first region has a first height, while the second turbulator positioned in a second region has a second height different from the first, enabling each turbulator to effectively promote heat transfer in its specific local environment with varying passage width
3Temperature
If turbulator height is increased to improve heat transfer rate in wide passage regions, then heat transfer rate is improved, but pressure loss increases in narrow passage regions
Solution Approach 1:
The patent resolves this contradiction by applying local quality through spatially varying turbulator heights. The first turbulator with a first height is positioned in a region with a first passage width, while the second turbulator with a second height is positioned in a region with a second passage width. This allows each turbulator to be optimally sized for its local passage width, improving heat transfer where the passage is wide while minimizing pressure loss where the passage is narrow
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 efficiently cools the turbine blade by maintaining high heat transfer rates and reducing pressure loss, even with varying passage widths, thereby improving the thermal efficiency of the gas turbine.
Implementation Method 1
a rib turbulator may be provided to promote turbulence of the cooling fluid flowing through the cooling passage in order to improve heat transfer rate between the cooling fluid and the turbine blade
Implementation Method 2
the turbine blade exposed to high-temperature gas flow is cooled by flowing a cooling fluid through a cooling passage formed inside the turbine blade
Implementation Method 3
improve heat transfer rate between the cooling fluid and the turbine blade
Data Source
AI summary
A turbine blade includes: an airfoil body; a cooling passage extending along a blade height direction inside the airfoil body; and a plurality of turbulators disposed on an inner wall surface of the cooling passage and arranged along the cooling passage. The airfoil body has a first end portion and a second end portion which are opposite end portions in the blade height direction. A passage width of the cooling passage in a suction-pressure direction of the airfoil body at the second end portion is greater than a passage width of the cooling passage at the first end portion. A height of the plurality of turbulators increases from a first end portion side to a second end portion side in the blade height direction.