Segmented Impingement Tube for Turbine Blade Cooling
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Solution Overview
Problem
Modern turbines face efficiency and operational risks due to high temperatures, which can lead to distortion and failure of blades or vanes, and existing cooling methods are inefficient, especially when the cooling medium temperature is too high.
Innovation Solution
A turbine assembly with a hollow aerofoil featuring an impingement tube formed from leading and trailing pieces, where the leading piece extends through the cooling chamber from the platform to the cover plate, and the trailing piece terminates at the platform, allowing for independent control of aerofoil and platform cooling, reducing cooling feed temperatures, and enhancing heat transfer coefficients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a combined platform and aerofoil cooling system is used in series, then the cooling system is simpler to implement, but the cooling efficiency is insufficient when the cooling medium temperature is too high
Solution Approach 1:
The impingement tube is divided into a leading piece and a trailing piece that can be independently controlled. The leading piece receives compressor discharge flow for the leading edge region, while the trailing piece receives platform cooling flow for the trailing edge region, allowing independent optimization of cooling parameters for each region.
Solution Approach 2:
Different regions of the aerofoil receive cooling flows with different temperatures and characteristics. The leading edge region receives cooler compressor discharge flow, while the trailing edge region receives platform cooling flow, optimizing heat transfer coefficients in each specific location based on its thermal requirements.
2Adaptability or versatility
If the impingement tube is formed from separate leading and trailing pieces, then independent control of cooling flows is achieved, but the device complexity increases
Solution Approach 1:
The impingement tube is segmented into a leading piece and a trailing piece with distinct functions. The leading piece extends through the cooling chamber from the platform to the cover plate and receives compressor discharge flow, while the trailing piece terminates at the platform and receives platform cooling flow, enabling independent control of cooling parameters for different aerofoil regions.
Solution Approach 2:
The platform serves as an intermediary structure that separates the cooling chamber into distinct zones. It allows the leading piece to extend through it while the trailing piece terminates at it, creating a natural division point for independent cooling flow control without requiring complex external control mechanisms.
3Temperature
If high cooling flows are used, then cooling efficiency improves, but performance losses increase due to high cross-flow velocities
Solution Approach 1:
The cooling system optimizes heat transfer coefficients locally in the trailing edge region by directing platform cooling flow through the trailing piece. This localized enhancement allows for reduced overall cooling flow rates while maintaining effective cooling, thereby reducing cross-flow velocities and associated performance losses in the main aerodynamic path.
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 improves cooling efficiency, minimizes performance losses, and allows for effective cooling of both the leading and trailing edge regions, reducing the need for high cooling flows and maintaining low cross-flow velocities, thus enhancing the overall performance and longevity of turbine components.
Implementation Method 1
impingement tube, which is insertable inside the cavity of the hollow aerofoil and is used for impingement cooling of at least an inner surface of the cavity
Implementation Method 2
cooling chamber used for cooling of at least the platform
Data Source
AI summary
A turbine assembly is provided having a hollow aerofoil having a cavity with an impingement tube insertable inside the cavity and used for impingement cooling of an inner surface of the cavity, and a platform arranged at a radial end of the hollow aerofoil, and a cooling chamber used for cooling of the platform which is arranged relative to the hollow aerofoil on an opposed side of the platform. The cooling chamber is limited at a first radial end from the platform and at an opposed radial second end from a cover plate. The impingement tube is formed from a leading piece and a trailing piece. The leading piece extends in span wise direction at least completely through the cooling chamber from the platform to the cover plate and the trailing piece terminates in span wise direction at the platform.