Please Check my Heat Pipe logic for flaws.

I am trying to figure out how to make a heat pipe without having the correct materials.

this is a design for a "Two Pipe" heat pipe, that i saw on the web, but i still did not at all understand.
So i had to draw up some sort of logic for doing it, and this is what i have so far.

the "vapor" will make it Easily through the small holes, but the fluid heading back , which i assume is recondenced into a liquid, would head down the cooler middle pipe, that is Connected TO the cool side of the thing.

this Wickless, will ONLY work with the heat source at the bottom , and the cooling of the heat at the top.

i put in a top view so you could see that the holes in the inner pipe are not all the way around.

i have no idea what i am doing, but i used the logic of the principal, to create this picture, i would probably make it FLAT not round. as my project would prefer a nice big flat wide one anyways.
i was trying to understand the principal.

other questions
is the top (vapor condencing side) going to be hotter than the heat input side ?
what if the top becomes a Expander instead (liquid goes up center tube and expands, and cools), doent that then do the exact opposite?

i am so confused, its a CLOSED system, with no pump, it cant possibly work

Its possible with nothing more that a chunk of copper tubing, to make a heatpipe, been there, done that.

Without the internal microgrooves or wick structure, it has to remain somewhat vertical to work.


I fold over, smash shut, and solder one end. Fill it 1/5th the way with water, I prep the other end, getting it near flat and partly bent over.

I slowly bring the water up to a boil, so I see steam comming out. While it is boiling, I fold then end over and smash it shut, fold that end over and smash well with 20 lbs hammer.

I now have a copper pipe with a little water in it, and a vacuum.

Depending on how well you did it, you may and up with a working heatpipe.

Get some hot coffee, and while holding the end, put the other end in the coffee. Within seconds it gets too hot to hold. Stick same diameter copper bar in the coffee, and it takes quite awhile for it to reach your fingers. Solid Aluminum is the same.


It took a dozen tries to get a really good one made, here is one of the ones that still works, but isn't as good as my best one (couldn't find it):




Here is a set I purchased for only a few dollars, that have the internal wick structure, and work even better.

so you got the "effect" with just water, in a situation where it was not yet boiling point?
hmmm
i was going to use alcohol or something that would move fast, and not freeze.
i didnt realize that water worked even when it wasnt a steam engine.

Water works fine, it just needs to be in a good vacuum.

The better the vacuum, the lower the temperature it works at. Most PC heatpipes have nothing but water in them. Without the wick structure, you need to keep it near vertical, so gravity assists with the return of the condensed liquid.

The neat thing is you can feel it boil inside when you stick it in hot coffee. Not boiling hot, just hot. If the coffee is very hot, it only takes seconds to burn your fingers on the other end though.

oh oh, i just figured something stupid about my "return pipe", it would prefer to be not so heat conductive, beings its connected to the hot side via the liquid.

i was thinking they would both be copper, but now i am re-thinking.

i see , with reduced atmospheric pressure, the water would tend to boil faster.

Bingo!

Or boils at a lower temperature....