Gas Turbine Blade Aperture Sealing via TIG Welding
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Solution Overview
Problem
Conventional methods for sealing the aperture on the tip end of a gas turbine blade, such as using tip caps or inserts, complicate the process and can lead to premature failure, resulting in increased maintenance and repair costs.
Innovation Solution
A method employing Tungsten Inert Gas (TIG) welding along the peripheral edge of the aperture in a spiral manner to close it without an insert, which can include heat treatment, bevelling, cleaning, and overlaying to ensure a strong and even weld, eliminating the need for tip caps or inserts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tip caps or inserts are used to seal the aperture, then the aperture can be sealed, but the process becomes complicated and the blade may fail prematurely
Solution Approach 1:
The invention removes the tip cap or insert from the sealing system entirely. Instead of adding a separate sealing component, the aperture is sealed directly by welding material deposited through the aperture itself, eliminating the need for additional parts and simplifying the overall structure.
Solution Approach 2:
The sealing function is merged with the welding process. The weld material serves dual purposes: it creates the weld joint and simultaneously seals the aperture. This combines two functions (joining and sealing) into a single operation, reducing process complexity.
2Reliability
If tip caps or inserts are used to seal the aperture, then the aperture can be sealed, but maintenance costs increase due to premature failure
Solution Approach 1:
By removing the tip cap or insert, the invention eliminates the interface between separate components that could become failure points. The direct weld seal reduces potential failure mechanisms such as loosening, corrosion at interfaces, or improper installation, thereby reducing maintenance needs.
3Device complexity
If a simple welding process is used without inserts, then the process is simplified, but the aperture may not be sealed reliably
Solution Approach 1:
The invention performs preliminary cleaning and preparation of the aperture edges before welding. This includes removing oxides, contaminants, and irregularities from the aperture periphery to ensure proper weld penetration and sealing. The preliminary action of edge preparation enables reliable sealing through the simple weld process.
Solution Approach 2:
The welding parameters are specifically optimized for aperture sealing, including controlling heat input, welding speed, and material deposition rate. The weld material composition may be adjusted to ensure proper flow, penetration, and sealing characteristics, transforming the standard welding process into a reliable sealing method.
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 method simplifies the sealing process, reduces costs, and prevents premature blade failure by forming a robust and reliable weld that matches the blade's surface, enhancing operational efficiency and reducing maintenance needs.
Implementation Method 1
closing the aperture with a weld formed by means of a Tungsten Inert Gas (TIG) welding process
Implementation Method 2
performing a butt-weld at the butting section between the tip plug and the tip of the turbine blade by using a laser beam
Data Source
Figure 1~3
AI summary
The invention relates to a method for closing an aperture on a blade of a gas turbine, wherein the blade of the gas turbine comprises a tip end with a top surface and a bottom surface, the aperture is formed on the tip end of the blade, and the aperture comprise a peripheral edge, the method comprise a step of :closing the aperture with a weld formed by means of a Tungsten Inert Gas(TIG) welding process without an insert placed in the aperture. With the technical solution of the present invention, it provides a simple and cost effective solution to close the aperture on the tip end of the blade, dispensing with the conventionally utilized "letter-box", insert, tip cap and the like. In view of this, process of closing the aperture may be simplified, and the cost incurred may be reduced. Further, premature failure of the blade is prevented.