Weekly Progress

April 3, 2015 - Albert Manginelli, Calvin Tang, James Sepelyak, Zhenying Wu [In Class]

The group discussed possible designs for a heat pipe. Different materials were researched to find what would conduct heat well and is of an affordable price. Metals such as copper, iron, and steel were potential candidates for the pipe. There were also several ideas for the shape of the pipe including cylindrical, tapered, and right cones. Several applications for a heat pipe were discussed such as cooking something on the outside and inside and cooling heated cookware after use. Finally, the proposal that was discussed with the professor was cooling heated cookware by using heat pipes shaped in a grill or plate shape.

April 6, 2015 - Albert Manginelli, Calvin Tang, James Sepelyak, Zhenying Wu [Outside of Class]

On this day, other ideas were discussed for the project. The mentioned ideas include turning heat into electrical energy by using peltier tiles. There was also an idea for a container to place hot objects into so that the heat isn’t dispersed into the air. Testing methods were discussed so that the product can successfully cool down objects and convert heat into electrical energy. Each section of the report was discussed among the group. The sections of the design proposal were then distributed accordingly to each group member.

April 10, 2015 - Albert Manginelli, Calvin Tang, James Sepelyak, Zhenying Wu [In Class]

The first task accomplished today was the setup of the blog. The blog was formatted according to the provided guidelines and the layout and design of the blog was finalized. Next, the group discussed mechanical designs of the heat pipe prototype with the professor. The proposed idea was to coil a copper tube and have one end of it extend vertically upwards. A series of two T-fittings would be soldered onto this end in order to allow the pipe to branch into three segments and thus have more surface area. The option of using screw-on end-caps was proposed in order to facilitate the testing of different fluids inside the pipe.

April 16, 2015 - Albert Manginelli [Outside of Class]
The materials for the construction of the heat pipe were purchased on this day. The materials purchased include a 10 ft flexible 3/8 in copper coil, two T-fittings, two solder-on end-caps, and two screw-on end-caps.

April 17, 2015 - Albert Manginelli, Calvin Tang, James Sepelyak, Zhenying Wu [In Class]

Most of the materials needed for construction of the prototype have been gathered. We have the copper pipe, the caps for sealing the pipe, and the peltier tiles. The copper pipe is 10 feet in length with a diameter of 3/8 of an inch. We calculated the volume of the pipe to get a sense of the amount of liquid we would need to put inside of the pipe.

Calculations:

(πr2)h

h = 120 in, 304.8 cm. r = 3/16 in, 0.476 cm
[π(0.476)2](304.8 cm) = 217.19 cm3

217.19 cm^3=217.19 mL

Based on the calculations, we would need 217.19 mL of liquid to fill up the whole pipe. We are probably going to aim to fill up about half of the pipe. We discussed the type of liquid we would use, water will be tested first and if that doesn’t work well, we would use acetone.

We were also given a tour of the labs that we will be able to use for constructing the prototype.


April 22, 2015 - Albert Manginelli, Calvin Tang, James Sepelyak, Zhenying Wu [Outside of class]

The group went to the machine shop and began to cut the copper coil into the appropriate segments using a tube cutter. Figure 1 below shows the copper coil cut into its segments.

Figure 1. Heat pipe before the segments were soldered.

April 24, 2015 - Albert Manginelli, Calvin Tang, James Sepelyak, Zhenying Wu [In Class]

The group finished constructing the heat pipe at the machine shop. First the flexible copper tubing was cut into two pieces each about 5 feet long with a tube cutter. One of these segments was drawn into a coil shape for the heat input/source part of the pipe. The other was cut into three roughly equal segments which were to function as the output/sink part of the pipe. A single 3 inch segment was cut off from one of the three segments to go between the two T-fittings. The ends of all these segments were cleaned with steel wool and flux was applied to the as well. The pipe was then assembled. A cap was placed on the inside of the coil while a T-fitting was placed on the other end. The second T-fitting was attached to the first by means of the 3 inch segment. The three heat sink segments were placed in the T-fittings. Two of these have screw-on caps. All the fittings were soldered on and allowed to cool. Figure 2 below shows the completed heat pipe.

Figure 2. Completed heat pipe. 

May 1, 2015 - Albert Manginelli, Calvin Tang, James Sepelyak, Zhenying Wu [In Class]

The group completed the construction of the heat pipe by filling it partially with hot tap water and screwing on the two end-caps. The pipe was then tested in Professor Speidel's lab with a hot blower. Unfortunately, it did not transfer heat very well at all. There is a lot of surface area to heat on this pipe, so it is suspected that there was not enough water in the pipe. The group was not able to fill the heat pipe with a known volume of water because there was no measuring equipment present at the time the pipe was filled. Next time, appropriate measuring equipment will be used to ensure that more than half of the pipe is filled. There also could be leaks in the pipe contributing to the fact that it isn't working, but no one observed any.

May 8, 2015 - Albert Manginelli, Calvin Tang, James Sepelyak, Zhenying Wu [In Class]

The group drained the water out of the heat pipe and added hot tap water in a larger quantity than before. New Teflon tape was applied to the threads and the end-cap was screwed on once more. The group decided to then test the prototype on a stove and see if it worked any better than before. The heat sink parts of the pipe did eventually get hot, but it is thought that this was more due the heat traveling along the copper than being transferred inside the pipe because it took too long. The group then discussed the possibility of simultaneously making a new and more straightforward heat pipe while continuing to improve the original one. It is thought that part of the problem might be the difficulty we are having getting the water to fill the spiral portion of the pipe. Next time we fill the pipe, we are going to try to unravel it to ensure that the water is filling it. We are also going to boil the water first to help in creating the vacuum inside the pipe. 

May 9, 2015-Albert Manginelli [Outside of Class]

It was determined that the reason there was difficulty filling the spiral pipe with water was that there was air trapped in the pipe. It was thought that this could be worked out by slowly coaxing the water in, but this didn't work because there was nowhere for the air to escape out of. To fix this a screw-on end cap was used in place of the regular end cap on the inside portion of the coil. The cap was able to let out air as the pipe was being filled with fluid and tightened once the pipe was full.

May 12, 2015-Calvin Tang [Outside of Class]

The second heat pipe was constructed on this day. It is a conventional straight heat pipe. A regular end-cap was soldered on a segment of 1 inch copper pipe. An adapter was soldered onto the other end, followed by a 1/2 inch pipe segment. A screw on cap was used for the end. Figure 3 below shows the straight heat pipe.

Figure 3. Completed Straight Heat Pipe

May 15, 2015 -Albert Manginelli, Calvin Tang, James Sepelyak, Zhenying Wu [In Class]

Today, the straight heat pipe was filled with fluid and tested. The pipe was suspended by a ring stand and a hot blower was placed on one end. Thermometers were used to measure the temperature on each end of the pipe. In a few minutes, the pipe began to transfer heat. The heat sink end got almost as warm as the the heat source end.

May 22, 2015-Albert Manginelli, Calvin Tang, James Sepelyak, Zhenying Wu [In Class]

On this day the group worked on the blog and discussed our heat pipes and our plans for the rest of the course.

May 29, 2015-Albert Manginelli, Calvin Tang, James Sepelyak, Zhenying Wu [In Class]

The group discussed the coiled pipe once more and tried to determine if it could be made to transfer heat. It was decided to remove the two vertical segments connected to the pipe by the two T-fittings and test the pipe once more. The final report and presentation were also discussed and worked on.

May 31, 2015-Albert Manginelli [Outside of Class]

The two vertical segments connected by the two T-fittings were removed from the coiled pipe. The L-shaped end was soldered onto the coiled portion with a coupling.

June 3, 2015-Albert Manginelli, James Sepelyak, Zhenying Wu [Outside of Class]

The group tested the coiled pipe at the lab once more. Unfortunately, it did not transfer heat very effectively. Part of the problem may be the experimental apparatus. The hot blower is not capable of providing enough heat to heat the entire heat source end all at once. This would be ideal because the whole coiled end is designed to act as the heat source end. With uneven heating, any evaporated fluid may condense prematurely before reaching the heat sink end.