Heat pipes are used to passively transfer heat from one area to another. On pcs they’re usually found moving heat from the processor to large heatsinks on the case exterior. Heat pipes contain liquids that vaporize when heated. The vapor moves up the pipe and is cooled by the external heatsink. This transfer of heat cools the vapor and returns it to liquid form. The liquid then returns to the processor end of the pipe. This project involved building a heat pipe and charging it with R134a. While testing the pipe in a water bath the refrigerant is bled off till the pipe maintains a steady state of phase change. Even though performance could not match that of manufactured heat pipes, it’s still impressive.
In other news, Team Hack-a-Day broke into the top 100 Folding @ Home teams yesterday. Come check us out at http://www.teamhackaday.com
NO grayskies you did it wrong thats to straight to the point. What you should ahve said was “Man these heat pipes would help my folding at home computer fold for team hackaday.”
I just started at a refrigeration company a couple months ago, and since I haven’t taken any classes for it (I’m not out of highschool yet), I’m not always sure how everything works. But this seems like a great project for me to try, especially since I can borrow all the tools I’d need from work, and maybe get some advice on how to do it too. That being said, I’m definitely going to have two pipes because I think one of the reasons it’s not getting great results is that the warm 134a is warming up the cool 134a as it’s coming down. So just figuring out a way to keep everything seperate and going in the same flow would improve things a bit, hopefully there’s just a device that can be placed inside to keep the liquid from going back into the vapor. Or maybe it can be done by bending the pipe. In any case, should be fun.
oblig. slashdot crosspollination:
IMAGINE A BEOWULF CLUSTER OF THESE FOLDING FOR HACKADAY!!
If you could make one out of glass, that would look cool.
Hum, Glass at 85 psi. You can, but I don’t want to be around. BTW, want you go blind from a piece of glass slicing your retina, remember, Joey told you sooo.
-Joey Dale
The only mistake I could see is that R-12 isn’t illegal, just wickedly expensive.
Maybe if we take a design consideration of the condenser for a moonshine still and make a “worm” of sorts and have a fan blow across it.
With this a double heat pipe shoud be easy enough, just add another hole and pipe.
“Hum, Glass at 85 psi. You can, but I don’t want to be around. BTW, want you go blind from a piece of glass slicing your retina, remember, Joey told you sooo.”
Yea but then we’d see some bitching hacks for the blind, which have the added advantage of allowing the sighted to keep our vision on someithingelse while remaining productive with our hands.
jack, its a pipe within a pipe, so the hot is outside (i think) to radiate any heat it might want to, and the inner pipe is the cooled liquid.
http://www.thermacore.com/hpt_animation.htm
would alcohol work?
Go to http://www.dairyfarmradio.co.uk and tell every one about it, to make suggestions, email info@dairyfarmradio.co.uk.
Just a side comment; that site is really old but a good starting point for those that are curious
I’ve been working on building my own heatpipes, hoping to offer custom sales on eBay. Using presurized freon/environ is an option, but its a poor one IMHO. My designs have been using alcohol and water mixtures under vacuum, same as the common industry, with a target of 45C holding temperature. A big part of my goal has been to include plastic tubing to make them flexible (and therefore of use to customizing designs).
The *HARDEST* part is figuring out a way to seal the pipe with the contents under vacuum while not spending a ton on valves for each pipe. Without a doubt, most of my cost will go into that component.
Anyone else been seriously looking at home-made heatpipes?
What I like about this particular design is how it get’s the CPU heat completely outside of the computer case. Ducting can only go do far and more often than not one still ends up trying to cool the CPU with the hot air inside the case.
IMHO, this is the direction more commercial heatpipes should go.
One of my buddies handed me a project for his father’s company to build 10 low power, inexpensive PCs to drive industrial LCD panels. One of the requirements was the cases must be sealed or at least be resistant to getting hosed down. I’ve been looking at fanless motherboards, but they still produce enough heat that I need to make sure it exits the case somehow. So far all the custom heat-pipe solutions I’ve seen will cost a significant amount, more than the mini-itx mobos I plan on using. I’d like to take a crack at creating my own pipes.
to #11, sealing it off without valves is not a very hard task…
You just need use a piece of capilary tubing between the heat pipe and your vac equipment. One it is filled and evacuated, you take a torch and melt through the capilary tubing. The vacuum from the system sucks the molten tube into the pipe and forms a perfect seal.
BTW, this is how refrigerators are sealed off.
I am not sure how well it would work with plastic, you might end up having to attach a little bit of copper capillary tubing to the plastic to make it seal well enough…
Good Luck!
To #13 Dennis
Serious Suggestion 1: I assume you’re using NEMA enclosures to make sure that you’re sealed. Depending on the internal space and wattage, you can mount some spare heatsinks to the *inside* of the metal enclosure walls with thermal adhesive. With each heatsink fan powered, you will dump quite a bit of heat into the case itself. Its also easy and cheap; and you can build one prototype to test.
Heatsink sources include ebay for OEM style spares, or numerous industrial sources. The aluminum heatsinks used on “1/2 brick solid state relays” are typically very good.
Serious Suggestion 2: consider using laptops with broken monitors as their overall power draw can be very low and they are already small.
I call BS. Someone didn’t sanity check his graphs.
Why is the “cold side” DECREASING in temp as the hot side INCREASES? That heat has to dissipate somewhere, it should increase roughly at the same rate as the hot side, minues a little bit of heat due loss of efficiency.
I have built refrigerators and have never heard of melting a piece of cap tube to seal them. Frankly that doesn’t make any sense at all to me. After any refrigeration system is complete it is evacuated to the highest vacuum one can attain. Then it is usually filled with nitrogen for leak testing. After leak testing it is common to again achieve a high state of vacuum and then to fill the unit with freon through a shrader valve. The shrader valve stays in place forever. The unit is then run tested and leak tested again and then shipped. As for cap tubes one problem with them is that when they are installed solder easily flows and clogs them. This can set the stage for an explosion if the unit is charged and run with a clog in place.
What I would like to know is if I place a bundle of heat pipes that are capped with a schroeder valve and have a refrigerant injected can I reduce the temperature of the medea surrounding this bundle if
for an example I use an 8′ high bundle which has a
pvc pipe housing and sink it in the ground?
All I HAVE TO SAY IS YOU ARE ALL WRONG. I HAVE BEEN BUILDING HEAT TRANSFER DEVICES INCLUDING HEAT PIPES FOR THE LAST 18 YEARS FOR THERMACORE INC. AND YOU ARE NOT EVEN CLOSE. YOU CANNOT MAKE A PLASTIC HEAT PIPE BECAUSE PLASTIC IS PERMEABLE ANS THE PIPE WILL EVENTUALLY LOOSE IT VACUME NOT TO MENTION THAT IT WOULD HAVE CONTAMINENTS THAT OFF GAS MAKING YOUR PIPE USELESS. I WILL BE WRITING A DIY ON A BASIC 1/4 OD PIPE. FEEL FREE TO E-MAIL ME IF YOU HAVE ANY QUESTIONS.
another update via research:
while i was researching propane and green gas i found
http://en.wikipedia.org/wiki/Red_Gas
red gas is r22 refrigerant (freon).
you cant get ahold of any cfc based gas without license (except for harvesting it from window ac units) however if you can get red gas legally from sports shop you can use that and it would be safer.
the only catch is there may be a lube in the tank to lube the gun and i am not sure if that would cause damage to the system.
sorry i posted it in the wrong place so you hack a day mods can deleted the above comment i meant to post to the other section
http://hackaday.com/2010/06/15/recharging-ac-with-propane