Heat Pipe Wick Crimping via Diffusion Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Heat pipes used in nuclear systems face challenges in sealing and maintaining the internal wick structure under extreme temperatures and pressure differences, as standard welding methods can cause delamination and fail to hold pressure effectively.
Innovation Solution
A wick assembly is created using an end plug with a wick receiving area and a crimp, where the wick and crimp are diffusion bonded together using an external heat source, ensuring the wick can withstand pressure differences without compromising its functionality in transferring fluid between the condenser and evaporator sections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If standard welding methods are used to attach the wick to the end plug, then the attachment strength is improved, but the wick structure delaminates and pressure integrity is lost
Solution Approach 1:
The patent changes the bonding parameters from standard welding temperatures to lower temperature diffusion bonding conditions (approximately 700-900°C for 10-60 minutes), which prevents wick delamination while achieving sufficient attachment strength to maintain pressure integrity
Solution Approach 2:
The patent replaces the mechanical welding process with a diffusion bonding process that uses controlled heat and pressure to create a metallurgical bond without the harmful effects of welding, thereby maintaining both attachment strength and wick integrity
2Productivity
If the wick is made thinner to reduce pressure drop, then the fluid transfer efficiency is improved, but the wick becomes more susceptible to delamination under pressure differences
Solution Approach 1:
The patent changes the bonding process parameters to lower temperatures and controlled pressure application, enabling thin-wick construction to achieve sufficient bond strength without delamination while maintaining low pressure drop for efficient fluid transfer
3Reliability
If diffusion bonding is used to attach the wick, then the wick integrity is maintained, but the bonding process requires precise temperature and time control
Solution Approach 1:
The patent introduces a diffusion bonding process as an intermediary method between welding and mechanical assembly, using controlled heat and pressure as mediators to achieve reliable wick attachment while maintaining wick integrity, with the added benefit of being suitable for automated manufacturing
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 diffusion bonding method securely attaches the wick to the end plug, maintaining pressure integrity and fluid transfer efficiency across the heat pipe, even under extreme conditions, preventing delamination and ensuring reliable operation.
Implementation Method 1
the crimp, the wick, and the end plug are diffusion bonded
Implementation Method 2
The condensed liquid is then returned to the evaporator section 102 through the wick structure 108 by capillary action
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A wick assembly for use with a heat pipe is disclosed. The wick assembly includes an end plug including a wick receiving area, a wick, and a crimp. A portion of the wick is positioned about the wick receiving area. The crimp is positioned about the portion of the wick and the wick receiving area. The end plug, the portion of the wick, and the crimp are diffusion bonded.