Replaceable Turbomachine Blade Tip Attachment for Cooling Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for attaching blade tips to gas turbine blades and nozzles face challenges in achieving advanced heat transfer designs, particularly in areas like the blade tip, leading, and trailing edges, which limits the efficiency of cooling systems and requires significant air usage, impacting overall gas turbine efficiency.
Innovation Solution
The use of a retention member and retention member seat attachment system allows for the secure coupling of a blade tip or edge coupon to the airfoil body, enabling fluid communication through coolant passages and allowing for advanced cooling arrangements, with the option to replace or upgrade components, thereby improving heat transfer and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If welding, brazing or bonding is used to attach the tip to the airfoil body, then the tip is securely coupled to the airfoil body, but the manufacturing complexity and difficulty increase
Solution Approach 1:
The tip attachment structure is divided into discrete components: a retention member with engagement features and a retention member seat with corresponding geometry. This segmentation allows the parts to be manufactured separately using standard investment casting processes, then assembled through simple mechanical interference fit, eliminating the need for complex welding, brazing, or bonding operations while maintaining secure attachment.
2Ease of manufacture
If monolithic structures are manufactured using investment casting, then manufacturing is simplified, but advanced heat transfer designs in blade tip and edge areas cannot be achieved
Solution Approach 1:
The blade is segmented into the airfoil body and a separate tip or edge coupon that can be independently manufactured. This allows the tip to be cast with complex internal coolant passages and heat transfer features that would be difficult to achieve in a monolithic structure, while the airfoil body maintains its structural integrity. The separate components are then assembled using the retention member attachment.
Solution Approach 2:
Advanced heat transfer designs are concentrated in the tip or edge coupon regions where they are most needed for thermal management. The retention member attachment system enables these locally optimized heat transfer features to be integrated with the overall blade structure, allowing different parts of the blade to have different functional characteristics optimized for their specific requirements.
3Temperature
If significant amounts of air are used for cooling the blades and nozzles, then cooling effectiveness is improved, but overall gas turbine efficiency decreases
Solution Approach 1:
The separate tip or edge coupon can be designed with specialized coolant passages and heat transfer features tailored to the specific thermal requirements of that region. This localized optimization allows for more efficient heat removal from critical areas, improving cooling effectiveness while minimizing the total amount of cooling air required compared to uniform cooling approaches.
Solution Approach 2:
The retention member attachment system enables the integration of tips with advanced coolant flow parameters, such as higher velocity flows or optimized passage geometries, in the blade tip regions. These parameter changes improve heat transfer coefficients and cooling effectiveness, allowing reduced cooling air flow rates to achieve the same thermal protection.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A blade for a turbomachine (100), a tip (154) for a blade (120) of a turbomachine (100) and a related method are disclosed. The blade (120) may include a tip body (160, 160A) having a shape at least partially configured for coupling to an airfoil body (124) of the blade (120); at least one coolant passage (145) in the tip body (160, 160A) configured for fluid communication with at least one coolant passage (145) in the airfoil body (124); and a retention member (180) extending from the tip body (160, 160A) for coupling to a tip retention member seat (170) in the airfoil body (124). The tip (154) can be replaced, allowing for changes in the coolant passages (162) in the tip (154) of a blade.