Heat Pipe Construction ...

[redleader]

Does heat of vaporization really even matter? I'd think that other factors like molecular weight and vapor pressure would be much more important. Afterall you can just boil more coolant if the heat of vaporization per mol is low. You can't really do anything to compensate for low vapor pressure or slow propigation of superheated vapor.

I'm not well versed in this area though, so I could be completely wrong.

[BillA]

Originally Posted by redleader

Does heat of vaporization really even matter? I'd think that other factors like molecular weight and vapor pressure would be much more important. Afterall you can just boil more coolant if the heat of vaporization per mol is low. You can't really do anything to compensate for low vapor pressure or slow propigation of superheated vapor.

I'm not well versed in this area though, so I could be completely wrong.

correct, you are wrong
focus on the basics, which need to be learned
try that book (3ed rep)

[Jabo]

Originally Posted by Brians256

The best bet really is the intra-library loan. Really, the reason that the book is there is that the necessary information can't be boiled down into a 4-page article on the web. It's a multivariate system that depends upon too many factors to have one simple "best" design and manufacturing technique.

I'm just barely smart enough to realize how ignorant I am on the subject (and I have doubts about that smartness on a daily basis).

Totally agreed here
This discussion bares frightening amount of similarities to one of colours between blind folk

As all phase-change systems a heat pipe must be designed for a PARTICULAR application which means given thermal output of heat source, heat pipe physical dimensions and layout all of which govern energy vehicle choice and operating parameters (pressure in such a heat pipe). There's also lots of other much more complicated variables to consider here i.e. avoidance of flooding/drying of evaporation surface etc. Difficulty level is much increased by the fact that heat pipe is a CLOSED SYSTEM and no regulation is possible (like with regular phase change contraptions)

To do it at home and avoid total waste of time one needs good vacuum pump and acces to refrigerants (water is difficult to handle and requires more stringent oprating conditions) not to mention prerequisitive top notch DIY skills and tools.
Some theoretical knowledge wouldn't go amiss neither .

To sum it up - there are more rewarding ways of wasting your time

[8-Ball]

Couldn't have put it better myself.

8-ball

[BillA]

MOST distressing is the rush to type, w/o reading anything at all on the subject

for the google challenged, try "pulsating heat pipe" - and open your eyes
there is a huge amount of very interesting technology out there
-> i.e. NOT in a forum

[Jabo]

Originally Posted by unregistered

MOST distressing is the rush to type, w/o reading anything at all on the subject

for the google challenged, try "pulsating heat pipe" - and open your eyes
there is a huge amount of very interesting technology out there
-> i.e. NOT in a forum

Why do find 'MOST' distressing the rush to type? It is known problem solving technique to introduce 'layman' into the process with views on obtaining unorthodox/fresh problem apprach...

I followed your priceless advice and read through 3 different pieces on thsi technology and last one was quite decisive in forming of my opinion of it.
This site showed working example of such a device ( I skip over the theory here since I could not be asked to retype all of this stuff here...). Its working characteristics proved to be enlightening. Performance of 450w from 80x80mm base size device was achieved at 40C temp difference which translated into CPU temp means 60C operating temp with 20C ambient... <- point #1
Imo this technology is another way keep heat pipes going by finding a way of decreasing diameter of a heat ppe and therefore being able to cram more of them into smaller foot print... <-point #2
Lastly I still find distressing thought of having no cooling periods (bubble time) corresponding in time with heat flux spike and with such high operational temp it means potential CPU burn-out...
Hence I find constantly evaorating classical heat pipe a better solution here.
3mm dia classical heatpipes in large numbers with low temp boiling point liquid should offer better performance.
Nice find anyway

[BillA]

priceless ?
if nothing was paid it could also be called 'free', or 'without value'

3 pieces, ooof; I've hundreds and would not conclude the technology is a dead end, merely not yet developed
the marketplace is illustrating your valid conclusion, as of this time
and tomorrow ?

what your in-depth research possibly failed to identify were the creation of microclimates, and the means of enhancement of same; and there are some physics issues relating to the heat transfer mechanism itself

- now it is a brand new game, now being researched - and patented
end of my comments on such

[Jabo]

You see, I work to pay my mortgage and this stuff is only my hobby and reading three articles on the subject (there are only 7 bigger pieces quoted as sources in every one of them - I not talking The Sunday Times technology column here ) in 30 mins is a LOT for me and sufficient to generate pretty well informed opinion.

I never said it is a dead end.

I was not concerned about market value since you very well know that this kind of technologies have VERY long lead-in time befor becoming widely used in industry. Heat pipes have been around for more than 30 years, well before PCs ever existed not to mention cooling issues.

I was only intereted in employment of this 'invention' in PC cooling applications and you are right I failed to indentify microclimates applications (?)

I dunno about physics issue since to me there's nothing new here. Physics going on there are extremely simple! It's all about pressure/viscosity/phase change in closed environment (I disregard open PHPs on purpose here). As far as I could read into my ONLY THREE articles ( ) the prblem faced by researches was not physics behind it but mathematical modelling of the whole process. They simply are not able (were not able) to calculate it and design it properly wothout experimentation.

I find this technology to be a potential gold mine in free, self sustaining and 100% green power generation using thermal gradients of our mother earth's crust . All the pieces of this puzzle are there, just put them together and bingo

I think there's lot more into traditional heat pipe technology than current state of affairs. If low boiling point heat pipes could be feasibly mass produced (even if such designs were to have lower thermal energy throughoutput, but used in 'parallel' would compensate) I think we would have a winner here. Reasons are quite simple. fully closed system and as easily installed as air HSF

end of my comments on such

P.S. I love your sercasm m8

[BillA]

you are on quite the correct track
when you have time (and interest ?), chase it beyond google

many interesting things evolving, materials based
most elegant

re the physics: can heat 'tunnel' ? (tunnel as used in the semiconductor industry)

[Jabo]

Originally Posted by unregistered

you are on quite the correct track
when you have time (and interest ?), chase it beyond google

many interesting things evolving, materials based
most elegant

re the physics: can heat 'tunnel' ? (tunnel as used in the semiconductor industry)

intyerest immense, time... none ( I should be working now...)
elegancy... mmmm... that's why I like TECs, so powerful, so simple, so reliable, so cold . When I divulge on an eng problem I alwyas start form writing down my frind Albert's most famous scrible E=mc^2 ( Ihope it did not look as pompous as I think i does).
What I mean is that it is all about energy in different states and forms. matter is only a vehicle for it and as with cars we have fiats and F1 bolids here - price is corresponding in both worlds..
The other thing is that everything works thanks to entropy and all-embracing tendency of all systems to settle at the lowets energy level state possible.

I am not quite sure about your tunneling comment but will sleep on it and see tomorrow.
I once seeded an idea of using electrons as ultra high capacity coolant in microchip design (channels built in into chips, sth like sandwiches) - nano-scale peltier effect utilisation. I think it is doable with current state of technology

P.S. I just wish I had better academic priming in chemistry and molecular physics...

[8-Ball]

Originally Posted by unregistered

re the physics: can heat 'tunnel' ? (tunnel as used in the semiconductor industry)

I presume you are aware of "cool chips".

As I understand it, they use tunneling, though the real breakthrough on their part was managing to manufacture a sandwich with a uniform gap between the two layers.

I do hope they hurry up and get commercial units up and running.

8-ball

[Jabo]

Originally Posted by 8-Ball

I presume you are aware of "cool chips".

As I understand it, they use tunneling, though the real breakthrough on their part was managing to manufacture a sandwich with a uniform gap between the two layers.

I do hope they hurry up and get commercial units up and running.

8-ball

Drop a linky m8!

[BillA]

we are here to serve (the google challenged, lol)

http://www.coolchips.gi/

[Jabo]

QUite clever, even impressive I must say.
Thanks for the linky

[UNDERBYTE]

Originally Posted by 8-Ball

I presume you are aware of "cool chips".

As I understand it, they use tunneling, though the real breakthrough on their part was managing to manufacture a sandwich with a uniform gap between the two layers.

I do hope they hurry up and get commercial units up and running.

8-ball

Do not count on cool chips

Cool chips is on the "Pink Sheets" Does not even rate penny stock status. No funds and probably bankrupt. This is about as low as you can go. Probably means they have not been able to make more of it other than a lab demo.

[BillA]

cool chips is still in R&D, who knows

here is one to chew on
http://quenergy.net/technology/qutec...-transfer.html

[jaydee]

Isn't the purpose of a heat pipe to move heat from the source to a location on the other end of the pipe? What then? Doesn't the heat need to be dissipated from there? If so, how is dissipating that heat going to be any different than now. 100watts is a 100watts. Just because it is moved to a different area doesn't mean your going to get any great performance improvements or quieter computers. You are still going to need a rad (of some kind) and a fan to get anything resembling performance no? If that is the case then what's the point? :shrug:

I can see the uses in a laptop or notebook but not in a Desktop.

[UNDERBYTE]

Originally Posted by jaydee116

Isn't the purpose of a heat pipe to move heat from the source to a location on the other end of the pipe? What then? Doesn't the heat need to be dissipated from there? If so, how is dissipating that heat going to be any different than now. 100watts is a 100watts. Just because it is moved to a different area doesn't mean your going to get any great performance improvements or quieter computers. You are still going to need a rad (of some kind) and a fan to get anything resembling performance no? If that is the case then what's the point? :shrug:

I can see the uses in a laptop or notebook but not in a Desktop.

Agree. Dead on. Air is the final destination in 99% of the cases, soooo.... you still need a radiator and fans

[LPorc]

Originally Posted by jaydee116

Isn't the purpose of a heat pipe to move heat from the source to a location on the other end of the pipe? What then? Doesn't the heat need to be dissipated from there? If so, how is dissipating that heat going to be any different than now. 100watts is a 100watts. Just because it is moved to a different area doesn't mean your going to get any great performance improvements or quieter computers. You are still going to need a rad (of some kind) and a fan to get anything resembling performance no? If that is the case then what's the point? :shrug:

I can see the uses in a laptop or notebook but not in a Desktop.

Isn't the purpose of water cooling to move heat from the source to another location in the loop?

Stop and think about it for a moment, you've got this very small, very hot spot. You move the heat to a much larger spot.

[jaydee]

Originally Posted by LPorc

Isn't the purpose of water cooling to move heat from the source to another location in the loop?

Stop and think about it for a moment, you've got this very small, very hot spot. You move the heat to a much larger spot.

Yes. So why is a heat pipe a better solution? Is it more efficent (better performance)? Can anyone build one? cheaper? ect....

[jlrii]

Yes. So why is a heat pipe a better solution? Is it more efficent (better performance)? Can anyone build one? cheaper? ect....

Pehaps performance gains are to be made because the heat transfer can be focused on the die and spead out on the water side. Considering the QuTech device posted earlier and that its optimum heat flux is 158 W/cm² and up to 270 W/cm², and assuming the material it is made of would mot distort under clamping pressure, it sould be be able to deal the heat poduced fron an Athlon without any consderation of increasing baseplate thickness to obtain the heat spread that would be required by a typical water based heatpipe. Negating the losses associated with passing 100w or so through a monolith of copper just to obtain enough contact area would be significant. Considering the water side, since the heat transfer is so good cooling can take place over an extended area without concern for the W/mk limitations of cu to spread the heat and get enough contact area.

Me cringes in preparation for BillA ripping me apart.

[BillA]

no idea why ??? (and such would be for content, not You)

I have reservations about the QuTech bit, it is a consumable coating
for sure there are other means of facilitating their 'effect'

[jlrii]

Originally Posted by unregistered

no idea why ??? (and such would be for content, not You)

I have reservations about the QuTech bit, it is a consumable coating
for sure there are other means of facilitating their 'effect'

Meaning they will wear out?...Any ideas on life expectancy didn't come across any info there.

[BillA]

would assume the depletion is a function of the reaction rate, ?
its in their data somewhere