Skip to main content

Heat Pipe Fabrication/Materials

Materials:
To create a copper heat pipe as shown in the final design with meshed wick and Aluminum heat sink, the materials listed below are needed:
  • 2' of 1/2" thin walled copper pipe
  • 1/8" Male/Female NPT Ball Valve
  • 2" 6061-T5 Aluminum Round Stock
  • 1/2" Brass Round Stock
  • 31/64" Drill bit for tapping
  • 1/8" NPT Tap
  • 0.0045" Copper Mesh Sheet
  • High Temperature Solder/Silver Solder
  • Flux
  • 1/8" NPT Barbed Nipple for Vacuum Tubing
  • Vacuum Pump
Prototype Fabrication: April 19th, 2018
Prototypes 1 and 2 were constructed during Week 3 to gain valuable data and fabrication methods.

Raw Materials
Heat Pipe cut to length and copper mesh rolled into interior
Preparing to solder the ends of the mesh to prevent crinkling on the interior of the main body
Soldered end of the copper mesh
Crimped end of the main body to seal it off
Another shot of the crimped main body end
Prototype 1 in the testing apparatus
Prototypes 1 and 2 demonstrating their design and construction similarities

Heat Pipe Version 1
After reviewing the results from Prototypes 1 and 2, some design changes were implemented to further increase the efficiency and functionality of the heat pipe. It was decided that a smaller tube diameter would benefit capillary action within the heat pipe and transfer the working fluid more efficiently. These ideas were put into construction during Week 4.
 
Materials laid out for measuring
Smaller diameter copper pipe used as a forming tool for the mesh
Total length of the mesh and former
Mesh pushed into the interior of the copper pipe
Side by side view of Prototypes 3 and 4
Final Design Iteration
It was decided after some unexpected results from prototypes 3 and 4 that further design changes needed to be implemented. A partial vacuum was decided to be the best option to increase the performance of the heat pipe and reach the teams overall efficiency goal. Here are some of the fabrication pictures for the next version.

1/2" Brass round stock and 1/8" NPT Ball Valve
Facing the brass round stock
Drilling a tapping size hole for 1/8" NPT
Finished part
Bushing w/ Ball Valve
Ball Valve threaded into the bushing
Soldered bushing and copper heat pipe body
Completed valve assembly
Cutting off the 6061 stock to length
Facing the 2" round stock
Fin cutting for the heatsink

Comments

Popular posts from this blog

Week 5: Lab

The team conducted some more tests on Prototype 2 as it was the best performing heat pipe constructed thus far. The test was conducted in the angled orientation as Prototype 2 hadn't been tested in that configuration yet. The results were promising as Prototype 2 exceeded expectations and transferred heat effectively throughout the test. The condenser end increased by 52 degrees over 300 seconds which was an improvement over the horizontal test conducted with Prototype 2. In both tests, the difference between the condenser temperature and the evaporator temperature was calculated and displayed on the graphs. The graph below shows the first test for Prototype 2. To verify our results the test was run a second time but for a longer period of time in order to narrow down on where the heat pipe's maximum operating temperature would be. The results are shown below. For Prototype 2, the effective temperature limit of the heat pipe can be approximated to 125 F without a hea...

Week 6: Lab

This week in lab, the team worked on some more testing and the construction of our final iteration of the heat pipe. A specially designed bushing had to be machined to accept the threads of the 1/8" NPT ball valve. This bushing was then soldered into the copper tube. Another angled test of Prototype 2 was conducted to compare the results from the previous tests. The data is shown below: The graph of this data is shown below: The fluctuation of T1(the temperature at the evaporating end) may be partially due to experimental error. Otherwise, this prototype performed as expected.

Week 7

This week in lab the team finished the construction of the final heat pipe design and was able to find a vacuum pump to test how a heat pipe would perform under vacuum. Unfortunately, the results were not promising as the new heat pipe did not nearly work as it was expected to. For the final heat pipe, one end is closed, while the other end is equipped with a valve, as shown below, that can be used to add working fluid and connect to the vacuum pump to create vacuum. After the air is pumped out, the heat pipe is tested with acetone and with water as working fluids. The result is not as well as expected. More experiments will be conducted on this heat pipe next week. The results of the experimentation done are shown below: