Cast Turbine Blade Tip Structure for Tight Clearance Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas turbines face efficiency reduction due to non-uniform turbine tip clearance caused by thermal expansion, leading to either gas leakage or blade damage from direct contact with the housing, and existing tip restoration methods alter the blade's metallurgy or surface treatment, reducing service life.
Innovation Solution
A turbine blade with a cast tip having a similar airfoil cross-section to the blade part, featuring a slot and protrusion for secure coupling, and integrated cooling holes for efficient cooling, allowing for easy replacement of the cast tip to maintain uniformity and prevent damage, thus enhancing service life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermal gap is placed between turbine blades and housing to prevent direct contact, then blade damage is prevented, but combustion gas leakage increases reducing turbine efficiency
Solution Approach 1:
The turbine blade incorporates a replaceable cast tip that can be dynamically adjusted or replaced based on thermal expansion conditions. This dynamic component allows the system to adapt to thermal changes while maintaining optimal tip clearance, preventing both direct contact damage and excessive gas leakage that would reduce turbine efficiency.
Solution Approach 2:
The turbine blade is segmented into a blade body and a separate cast tip portion. This segmentation allows the tip to be independently managed - it can be replaced when worn or damaged without replacing the entire blade, and the tip can be designed with specific materials or geometries to optimize the balance between preventing contact damage and minimizing gas leakage.
2Duration of action of moving object
If turbine blade tip is restored using conventional methods, then blade service life is extended, but metallurgy or surface treatment is altered reducing overall service life
Solution Approach 1:
The blade is divided into the original blade body and a separate cast tip. When the tip wears or damages, only the tip portion needs replacement rather than restoring the entire blade. This avoids conventional restoration methods that would alter the metallurgy or surface treatment of the original blade, preserving its integrity and extending overall service life.
Solution Approach 2:
The cast tip can be manufactured with different materials, coatings, or surface treatments optimized for the specific operating conditions. This allows parameter changes to be applied only to the tip portion that experiences the most wear, while the main blade body retains its original metallurgical properties and treatment.
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
The cast tip design minimizes turbine tip clearance, prevents blade damage, and allows for efficient cooling, extending the service life of the turbine blade by enabling simple and effective restoration without altering the blade's metallurgy or surface treatment.
Implementation Method 1
integrated cooling holes for efficient cooling
Data Source
AI summary
Provided is a turbine blade of a gas turbine including a turbine blade part having an airfoil shape including an internal cavity therein, a cast tip disposed at an upper portion of the turbine blade part, and a braze joint to attach the turbine blade part and the cast tip to each other. The turbine blade part and the cast tip has substantially the same cross-sectional shape in a top plan view. In addition, the turbine blade part further includes a protrusion disposed at a surface where the turbine blade part is attached to the cast tip. In a similar manner, the cast tip may have a concave portion at a surface where the cast tip is attached to the turbine blade part to allow the concave portion to be coupled to the protrusion of the turbine blade part.