Week 8

In week 8, the group began putting the pieces of the presentation and the final draft together. The group also continued brainstorming ideas to heat the heat pipe up from electricity. The one idea that will be tested is the idea of heat tape. This tape is electrically charged and creates heat. This tape we will wrap around the bottom of our heat pipe and that will generate the heat. For a heat tape with a voltage of 120 amps. This heat tape can generate heat of up to 900 F. This temperature will be able to achieve the heat we need for the top of the pipe. Once this idea is decided, the pot and heat pipe can be put together.

Week 7

In week 7, the group created a third heat pipe. With the first two, the water leaked out when testing. So, the group decided this time to solder one end of the heat pipe cap on and then attach a screw cap to the other side. Wrapped on the screw cap as well,  is Teflon tape that should hold the caps on tight and be able to withstand high heat. With this, hopefully it would prevent the leaking. Below show the materials used in this heat pipe.
Materials:
Copper Mesh
Copper pipe
10mL water
Copper caps
Teflon Tape

 The group created the heat pipe similar to the steps before.

Figure 1: Screw Cap and Teflon Tape

Figure 2: Materials

Also in week 7, the group tested the heat pipe.

Figure 3: Heat Pipe Test Setup

Testing went very well. The heat pipe didn't leak water as the first two experiments did. Below is the data gathered and a graph of the heat pipe temperature with time. The temperature seems to increase linearly with time.

Week Six:

     
In week six our group redesign the heat pipe. Due to the problem we encountered during testing we decide to rebuild our heat pipe. On testing day we found some leakage in our pipe as well we weren't sure the amount of water we put in will withstand the heat without being completely evaporated.
In our second design we, build the heat pipe with screw caps for easy access if we will need to add more water incase of evaporation.
 The picture below shows the redesign of the heat pipe.

Redesign heat pipe

After redesigning of the heat pipe, our next task is use the following equation to determine the working condition of our medium.

The following equation was used to determine the potential dissipation over time

  

Week Five

 

       In week five our group put the design into test, first we weld the copper pipe with caps on both sides and put a little bit of water inside to determine how fast the medium evaporates. We used silicon jell to ensure tight fight of the caps.

  We measured the water to about half the length of the copper pipe. We insert our wick, a mesh copper wire, and make sure that it leaves the room for the evaporation to take place.

       Also, a bit of mathematic equation were used to determine how fast the heat will transfer from the source to the top of the heat pipe. It was important for us to learn this because heat transfer through solid unevenly. We learned that the more we minimize the time for the heat to transfer the more efficiently our heat pipe works.

 The following equation was used to determine the length of the heat pipe to be heated to gain a much fast energy transfer:

                                              

                                       

Below is the images of the testing

The picture above shows a heat pipe being testes using a dryer,  clamps, temperature reader and heat sensor

     During testing we encounter the following problems, there was a leakage between the cap and the pipe, we assumed we didn’t solder it properly. Also the temperature went up very rapidly due to the higher electrical conductivity of the copper. 

Week Four

 

       In week four our group put the design into test, first we weld the copper pipe with caps on both sides and put a little bit of water inside to determine how fast the medium evaporates. We used silicon jell to ensure tight fight of the caps.

  We measured the water to about half the length of the copper pipe. We insert our wick, a mesh copper wire, and make sure that it leaves the room for the evaporation to take place.

       Also, a bit of mathematic equation were used to determine how fast the heat will transfer from the source to the top of the heat pipe. It was important for us to learn this because heat transfer through solid unevenly. We learned that the more we minimize the time for the heat to transfer the more efficiently our heat pipe works.

 The following equation was used to determine the length of the heat pipe to be heated to gain a much fast energy transfer:

                                       

Below are the images of equipment used to build the heat pipe and testing.

Figure 1; Shows the Copper pipe and mesh wire before the design

Figure 2; Shows the design of the heat pipe after being build

Figure 3; Shows the test of the heat pipe using a dryer.

Week Three  

   In week three our group visited the workshop to learn more about the tools that are going to be used to build the heat pipe. Apart from the copper pipe and media, other tools that can be used to build the heat pipe are welding torch that is attached to a gas and aluminum thin wires.

  Since we are designing something that can be used for cooking, our original plan is to fit the heat pipe inside a cooking pot. The heat pipe will measure 8inches and 0.5inch diameter. The picture below shows the original design of the heat pipe before attached to the cooking pot.

   Some of the problem we might encounter with our design is the use of water as our media. Copper has a very high electric conductivity, which might cause some of the water inside the copper to evaporate fast that we will want.

A copper pipe and mesh wire

 Week Two

     In week two, two major tasks were done to ensue a proper design of the heat pipe. 
       First, a simple sketch was design to gain a better understanding of the object. The diagram below shows the initial design of the heat pipe and how it will be attached to the cooking pot.

                               Figure 1. A cooking Pot with attached heat pipe.

The main cooking pot will be made using stainless steel and copper will be used to make the heat pipe. The initial design of the pot will be 30cm diameter and 30cm tall. The heat pipe inside the pot will measure 15cm tall and and half inch wide.
         Second, to determine the reliability of the materials chosen, more information was gathered on how a hollow copper and working fluid (water). Because copper has a high electrical conductivity and water have an ability to observe heat starting at 20C to 350C, these two materials were much more preferred.  
      
        Other advantages obtain using copper is its resistance to corrosion, hygienic property, easy to join by soldering or brazing, it allows minimum amount of energy to be lost as well it's cost effective compare to other materials. Also, in this application if copper-water is design properly it can withstand a high heat load as well as withstand a freezing temperature ranging from -55C to 180C  

The diagram below shows the inside of the heat pipe and its functionality. The inside of the heat pipe is installed with a wick- a porous structure that enable liquid to move back to the evaporation region after condensation.  Wick or capillary structure inside the heat pipe a design to overcome gravity due to the pressure different between evaporation zone and condensation.

              Figure 2. shows how heat pipe is design in inside


Reference:
      http://encyclopedia2.thefreedictionary.com/Heat+Pipe
      http://www.thermacore.com/products/copper-water.aspx