Calculating Heat Transfer for Portable Cooling Device

[Ushuaia]

I am trying to construct a portable personal cooling device. I am considering using tygon tubing and propylene glycol/water mixture as the coolant in the tubing circulating it through an ice water bath. The tubing would be connected to copper pipes, that would run into the bag containing the ice water to facilitate a better transferance of heat from the tubing into the water/ice mixture.

Now my question is how do I calculate the diameter of the tubing, the flow rate of the mixture, and material of tubing be to facilitate maximum heat transfer from a warm body let's say 100 °F into the cooling mixture? Let's assume the bath temp the copper tubing is imersed into is 32°F.

 

[Navin A S]

The diameter of the tubing and flow rate of the mixture will depend on several factors, including the type of coolant being used, the temperature differential between the body and the cooling bath, and the desired cooling power. To calculate the optimal diameter and flow rate, you will need to use equations to determine the thermal conductivity of the coolant, the heat transfer coefficient, the surface area of the tubing, and the overall heat transfer rate. In terms of the material of the tubing, you should use a material that has good thermal conductivity to maximise the efficiency of heat transfer. Copper is a good option as it is a very good conductor of heat. However, other materials such as stainless steel, aluminum, and PVC can also be used depending on the specific application.