Our Design

Construction

When designing our heat pipe, the main limitation we faced was a lack of access to typical machinery and materials for industrial heat pipe construction. As a result, we had to design our heat pipe using easily accessible consumer products found online or in local hardware stores. The following list describes the materials used in our design:

• 1/2" copper air chambers
• 1lb copper mesh
• 1" copper nonstop coupling
• 1" x 3/4" copper adapter
• 3/4" galvanized steel plug
• 1" aluminum LED heatsinks
• 10mL syringe of aluminum thermal paste
• Water (in varying amounts)

The main body of the air chambers have a 1" diameter and taper down to 1/2" at one end. Since 1" was the desired heat pipe diameter, the tapered end was cut off of two air chambers. On one of the air chambers, the other, closed end was also removed to create room to attach the adapter.

The heat pipe was constructed as follows:

1. After removing both ends from one air chamber, solder on the copper adapter.
2. File down the inside of each heat sink until they fit tightly on the air chamber, but do not fix to the chamber yet.
3. Spread thermal paste onto the same air chamber, near the newly added adapter.
4. Add all of the heat sinks to the air chamber, making sure that each is oriented in the same direction as the others. Simultaneously twist the heatsinks to align the fins.
5. Add more thermal paste as necessary.
6. After removing the open end of another air chamber, solder the open end to the remaining open end of the initial air chamber using the copper coupling to link the ends.
7. Cut a length of copper mesh that is twice the length of the heat pipe.
8. Fold the mesh in half so that it is now the length of the heat pipe, then roll it tightly.
9. Using a wooden dowel, insert the mesh into the heat pipe.
10. Add the desired amount of water to the heat pipe.
11. Heat the heat pipe with a torch until water vapor begins to exit the adapter end of the pipe.
12. Wrap the threads of the steel plug with teflon tape before screwing into the copper adaptor.

The image below shows our completed heat pipe.

Design Explanation

In our heat pipe, the copper piping and fittings serve as the main body of the heat pipe. Copper was chosen as the material for the pipe due to its high thermal conductivity. The steel plug on one end allows for easy access to the inside of the pipe. This allows more optimization of the heat pipe's function by testing various amounts of working fluid (water) and possibly different types of working fluids. The heatsinks serve to more quickly dissipate heat acquired at the condenser end of the heat pipe as the working fluid changes from the vapor to liquid phase thereby releasing all of the latent heat within the fluid. The copper mesh inside of the provides additional surface area within the pipe for condensing the working fluid and also serves to direct condensed liquid back to the evaporator end of the pipe via capillary action.