Turbine Blade Platform Cooling via Branch Passages
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Solution Overview
Problem
Existing cooling configurations for turbine blade platforms suffer from inadequate cooling, lower efficiency, and backflow of hot combustion gas due to insufficient feed pressure, which can lead to thermal-induced fatigue and reduced operational durability.
Innovation Solution
The design incorporates an airfoil, root, and platform with interior cooling passages, including a first leg, a second leg, and an arcuate portion, along with first and second feed passages and branch passages, where the cooling fluid flows through the passages to effectively distribute cooling air and prevent backflow by directing it to exit the platform and impinge on adjacent blades.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If compressed air is used for turbine component cooling, then component lifespan is improved, but engine efficiency decreases
Solution Approach 1:
The system uses the turbine's own operating conditions (high-temperature environment and existing compressed air supply) to provide cooling, rather than requiring external cooling systems. The compressed air is bled from the compressor and used to cool the blade platform, making the system self-sufficient while minimizing additional energy loss.
2Temperature
If existing cooling configurations are used for the turbine blade platform, then some cooling is provided, but inadequate cooling and backflow of hot combustion gas occur due to insufficient feed pressure
Solution Approach 1:
The cooling system is specifically designed for the platform region with dedicated feed passages and branch passages that deliver cooling air directly to the platform area. The outlets are positioned to provide localized cooling where thermal-induced fatigue is most sensitive, rather than using a generic cooling approach for the entire blade.
Solution Approach 2:
The system prevents backflow of hot combustion gas by providing adequate feed pressure through the feed passages before hot gas can enter the cooling passages. The cooling air is supplied at sufficient pressure to maintain forward flow and prevent reverse flow of hot gases into the platform.
3Reliability
If cooling passages are added to the turbine blade platform, then thermal-induced fatigue is reduced, but device complexity increases
Solution Approach 1:
The cooling system is segmented into distinct functional components: feed passages that supply cooling air, branch passages that distribute it, and outlets that discharge it. The arcuate cooling passage is divided into legs and an arcuate portion. This segmentation allows for modular manufacturing and assembly, reducing overall complexity despite the multiple passages.
Solution Approach 2:
The feed passages and branch passages are integrated within the blade structure, with the cooling passages nested within the solid material of the blade. The arcuate portion is disposed at least partially within the platform, connecting the legs while maintaining a compact configuration that fits within the blade geometry.
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 efficiency, reduces thermal-induced fatigue, and improves the operational durability of turbine blade platforms by ensuring adequate cooling and minimizing the impact of hot combustion gases.
Implementation Method 1
cooling of the turbine component may be provided by the use of compressed air that flows through various passages within, and exiting, the turbine component
Implementation Method 2
The arcuate portion is disposed at least partially within the platform and connects the first and second legs
Implementation Method 3
the outlet of each branch passage is arranged such that cooling gas exiting the outlets of the branch passages impinges on a pressure side wall of a platform of an adjacent turbine rotor blade
Data Source
AI summary
A turbine rotor blade includes an airfoil, root, and platform that is between the root and a proximate end portion of the airfoil. The blade defines a passage having a first leg, second leg, and arcuate portion. The arcuate portion is at least partially within the platform and connects the first and second legs. The first leg extends between a distal end portion of the airfoil and an inlet of the arcuate portion. The second leg extends from an outlet of the arcuate portion to the distal end portion of the airfoil. The platform includes a first feed passage and branch passages. The first feed passage is open through an extrados of the arcuate portion and is in fluid communication with the branch passages. The inlet of each branch passage is connected with the first feed passage while the outlet is open to an exterior of the platform.