QUESTION 1: For the modules that we have, what size heat pipes are best and what are our options for buying them?
Answer: Considering the dimensions of our battery box, the best sized heat pipe options are probably --- The best options for buying heat pipes would be on DigiKey/Amazon websites as they provide a wide variety of typically copper heat pipes. Below will be linked a couple of options that could be viable for our size and application constraints:
QUESTION 2: How are we going to attach the heat pipes to the battery modules and in what orientation is the best to put them in the bb?
Answer: The heat pipes can be attached to the battery box modules by having dissipating plates (typically aluminum/nickel) with grooves in them to fit in the heat pipes. With these grooves, the heat pipes can be soldered (best way) or epoxied in (2nd best way) and can be placed above the battery modules and provide cooling through that way. In general, the best orientation for heat pipes is to be horizontal positioned (however many specific heat pipes can work in vertical conditions just as well) because you want to limit the effects of gravity. For heat pipes to properly work, the evaporation side has to be equal to OR above the condenser side, which is our main restricting condition. Considering the lengthy/rectangular dimensioning of our battery box, the way we want to attach the heat pipes to the battery box, and also the fact that it would be easier to design horizontal heat pipes versus vertical heat pipes, we should look towards a horizontal orientation. With a horizontal orientation, we would possibly have to consider an inclination angle (typically between 60-75 degrees), which can be defined through further ANSYSS and CFD testing.
QUESTION 3: How many heat pipes are we going to need to cool the battery box properly?
Answer: v
QUESTION 4: What's the best way to cool the heat pipes?
Answer: The best way to having a cooling heat pipe system is having copper heat pipes with inner wicks and water as the liquid from 25-150 Celsius. In addition, the heat pipes can be attached to fins which will provide a better way to dissipate the thermal conductivity. Essentially, the heat pipes would be routed through the grooved dissipating plates within the battery box and go out at the outtake section of the battery box. At the end, the heat pipes would be attached to fins that will allow the fans to push the hot air out and into the exterior duct.