Liquid Nitrogen

F

fenton06

2[H]4U
Joined
Mar 28, 2003
Messages
2,138
This is really just a hypothetical question,but would it be possible to build a liquid nitrogen cooling system? I am thinking along the lines of water-coolingesque, with a pump and blocks, etc, well obviosly not a radiator cause this stuff is colder than hell. Any ideas,comments, or general info?

 
It would evaporate too quickly to be practical. If not that it would freeze shit and break. Either way i dont see this being a viable cooling solution. But it would be cool if you could do it.
 
Liquid nitrogen... yes... well... let me explain a bit... it will be lengthy reading... :)
When you get tank of liquid nitrogen... is it cold? No.
Compressed liquid nitrogen isn't cold at all... it is just at the ambient temperature.
It does get cold when it evaporates. This is basic refrigeration concept really.
There are something called heat of vaporization, sublimation, etc when phase of matter (solid<->liquid<->gas) changes. In case of vaporization, it takes enermous heat to happen or absorbs heat. Liquid nitrogen itself is not cold. It is cold when it evaporates.
Critical temperature comes into question which is where liquid nitrogen will evaporates at atmopsheric pressure which is well below being "cold". - this temperature can change based on pressure it is under.
You see, LN pot works since all you do is pour it into the pot, and since temperature is well above critical temperature, it "boils" off absorbing heat around.
For to have loop for it involves actual refrigeration unit.
And in case of refrigeration unit, due to characterstics of it, you need to have 4 stage cascade at least or 5 stages... or autocascade with similar stages. Not cheap or quiet or easy to operate by any mean.
So simple answer... NO...
Possible with proper refrigeration loop... YES... (or else how do they make this liquid nitrogen :p)
Hope this was clear enough for you.
 
thank you...that makes complete sense as I just got done with my AP Chemistry exam and knew what you were talking about:D thanks for the insight.

Oh BTW...I think the exam went well :D :cool:
 
Correct me if I am wrong but a tank (actually a dewars) of liquid nitrogen contains liquid which boils at -320 F. The tank feels warm due to the vacume between the inner cold as hell walls and the outer ambient temp walls. I have never heard of compressed "liquid" nitrogen. The pressure in a dewars is directly related to the temp of the liquid inside which if you had a dewars full of liquid nitrogen and brought it to a normal ambient of say 70F you would have an extremely high pressure, so high it would blow a dewars apart.
 
racebanner said:
Correct me if I am wrong but a tank (actually a dewars) of liquid nitrogen contains liquid which boils at -320 F. The tank feels warm due to the vacume between the inner cold as hell walls and the outer ambient temp walls. I have never heard of compressed "liquid" nitrogen. The pressure in a dewars is directly related to the temp of the liquid inside which if you had a dewars full of liquid nitrogen and brought it to a normal ambient of say 70F you would have an extremely high pressure, so high it would blow a dewars apart.
Click to expand...

In order to get Nitrogen into a liquid form it has been compressed similar to dry ice being compressed. They start off with air compress it and cool it and viola liquid nitrogen. Dewars are made to let some of the nitrogen boil off. They are not 100% sealed.
 
I think it has to be compressed, because if the boiling point is -320 then it would be in a gas state if it was not compressed. maybe I am missing something, but its my understanding that the pressure raises the boiling point, so if there is liquid nitrogen in a sealed container and the temperature is 70 F in the room around it, it would be enevitable that the nitrogen over time would boil until it reaches a pressure at wich the boiling point is 70 F
 
It's not compressed (well barely, maybe a few PSI depending on the container), and it's not at room temperature. It's extremely cold. The dewar is vented and some LN2 is constantly boiling off; this takes away the heat that slowly makes it's way into the dewar. I work with this stuff all the time, mostly for cryo storage of cell lines, and I can assure you it is in fact quite cold in the dewar. :)
 
Blethrow said:
It's not compressed (well barely, maybe a few PSI depending on the container), and it's not at room temperature. It's extremely cold. The dewar is vented and some LN2 is constantly boiling off; this takes away the heat that slowly makes it's way into the dewar. I work with this stuff all the time, mostly for cryo storage of cell lines, and I can assure you it is in fact quite cold in the dewar. :)
Click to expand...

Exactly.... a while back there was a thread on XS where Fugger was experimenting with a closed (or semi closed) loop ln2 system using a block.
 
The idea's sound, just you'd need one mother of a phase change system. I don't even want to know how powerful a compressor it would take to maintain that.
Basically all phase change systems work on the same principle, wherein P1/T1 = P2/T2. (Meaning that pressure and temperature are related.) As matter expands it wicks heat, like how evaporating sweat keeps you cool. LN amounts to a one-shot phase change system, like jinu said.
 
Liquid nitrogen should not be taken lightly. Touch it, and you lose a finger. Poor it wrong and you can kiss the mobo and floor good bye. Liquid Nitrogen exposed to air and released in its liquid state will make fast work of super freezing anything and turn it into very brittle parts. Most normal matter will shatter when this stuff touches it. Its so cold it would shatter a person like a bullet to glass in only a moment.

You need special containment and tubes. NASA grade crap. Its just suiside to even use it as a coolent for even a insane person. lol Its too extreme for me unless I was in a sub-zero hazmad suit. I wouldn't get near that stuff. That maybe alittle much for the chip. Your slowing down those atom's quite abit. Your prob slowing down the chip itself. Liquid nitrogen is close to absolute zero by only about -100C or -200C you know.
 
Serge84 said:
Liquid nitrogen should not be taken lightly. Touch it, and you lose a finger. Poor it wrong and you can kiss the mobo and floor good bye. Liquid Nitrogen exposed to air and released in its liquid state will make fast work of super freezing anything and turn it into very brittle parts. Most normal matter will shatter when this stuff touches it. Its so cold it would shatter a person like a bullet to glass in only a moment.

You need special containment and tubes. NASA grade crap. Its just suiside to even use it as a coolent for even a insane person. lol Its too extreme for me unless I was in a sub-zero hazmad suit. I wouldn't get near that stuff. That maybe alittle much for the chip. Your slowing down those atom's quite abit. Your prob slowing down the chip itself. Liquid nitrogen is close to absolute zero by only about -100C or -200C you know.
Click to expand...

You're wrong. LN2 will roll off skin. It's safer to use it naked than it is with clothing ;)
 
Cpt.Planet said:
In order to get Nitrogen into a liquid form it has been compressed similar to dry ice being compressed. They start off with air compress it and cool it and viola liquid nitrogen. Dewars are made to let some of the nitrogen boil off. They are not 100% sealed.
Click to expand...

I beleive it was history channel, or discovery, which showed how liquid nitrogen/liquid oxegen is made. They use *huge* compressors, though they made it all sound so simple.
 
How about this?

LN2 > Argon > Methane > Ethylene > R23 > R134A > Pelt > Chiller > Water > Air

The ultimate 10-stage cooling system! :p

It's part of the "ultimate system" that I want to build someday.
 
all matter is made of atoms and molecules
as most people know a liquid is more compact or squished than a gas
when you compress a gas your literraly squishing it into a liquid :)
 
blue_dragon said:
all matter is made of atoms and molecules
as most people know a liquid is more compact or squished than a gas
when you compress a gas your literraly squishing it into a liquid :)
Click to expand...

That depends on how much you compress it.

But I remember now, here's how LN2 is made:

1. The gas is put under pressure by huge compressors. No doubt it turns to liquid under the pressure, but it's still at room temp.
2. The gas is allowed to expand through special nozzles that relieve the pressure very, very quickly. This rapid drop in pressure forces the liquid to evaporate.
3. As the liquid evaporates, the surrounding temp drops rapidly. It eventually drops low enough that N2 condenses at 1 bar.
4. The LN2 is collected and stored in the dewer. You now have very cold, unpressurized LN2.

So, it is cold, and it is not under pressure, but pressure is used to condense it.
 
HOCP4ME said:
That depends on how much you compress it.

But I remember now, here's how LN2 is made:

1. The gas is put under pressure by huge compressors. No doubt it turns to liquid under the pressure, but it's still at room temp.
2. The gas is allowed to expand through special nozzles that relieve the pressure very, very quickly. This rapid drop in pressure forces the liquid to evaporate.
3. As the liquid evaporates, the surrounding temp drops rapidly. It eventually drops low enough that N2 condenses at 1 bar.
4. The LN2 is collected and stored in the dewer. You now have very cold, unpressurized LN2.

So, it is cold, and it is not under pressure, but pressure is used to condense it.
Click to expand...

thnxs for the clarification
my chem skills are rusty yet I've never really researched the process of liquid N2 in a computer system :p
 
HOCP4ME said:
1. The gas is put under pressure by huge compressors. No doubt it turns to liquid under the pressure, but it's cooled or chilled to remain at or below room temp.
Click to expand...
fixed. compressing something and then just letting off the pressure won't do crap, gotta remove that heat somehow :p :D
 
(cf)Eclipse said:
fixed. compressing something and then just letting off the pressure won't do crap, gotta remove that heat somehow :p :D
Click to expand...

Oh yeah, thanks for clearing that up. Compression generates heat which needs to be removed.
 
as i read this, i am thinking if you need Liquid Nitrogen to cool your rig you have some problems... LoL :p That is some MAJOR OverClocking ;)
 
-(Xyphox)- said:
as i read this, i am thinking if you need Liquid Nitrogen to cool your rig you have some problems... LoL :p That is some MAJOR OverClocking ;)
Click to expand...

Generally it is used to break overclocking records, or to test hardware performance at extremely low temps (i.e. see if there is a "cold bug"). In either case, it isn't used for more than a few hours.
 
jinu117 said:
Liquid nitrogen... yes... well... let me explain a bit... it will be lengthy reading... :)
When you get tank of liquid nitrogen... is it cold? No.
Compressed liquid nitrogen isn't cold at all... it is just at the ambient temperature.
It does get cold when it evaporates. This is basic refrigeration concept really.
There are something called heat of vaporization, sublimation, etc when phase of matter (solid<->liquid<->gas) changes. In case of vaporization, it takes enermous heat to happen or absorbs heat. Liquid nitrogen itself is not cold. It is cold when it evaporates.
Critical temperature comes into question which is where liquid nitrogen will evaporates at atmopsheric pressure which is well below being "cold". - this temperature can change based on pressure it is under.
You see, LN pot works since all you do is pour it into the pot, and since temperature is well above critical temperature, it "boils" off absorbing heat around.
For to have loop for it involves actual refrigeration unit.
And in case of refrigeration unit, due to characterstics of it, you need to have 4 stage cascade at least or 5 stages... or autocascade with similar stages. Not cheap or quiet or easy to operate by any mean.
So simple answer... NO...
Possible with proper refrigeration loop... YES... (or else how do they make this liquid nitrogen :p)
Hope this was clear enough for you.
Click to expand...
So you're saying if LN was put in a sealed heatpip located on a cpu heatsink which was in action (cpu getting hot), the LN would not cool the cpu at all because there is no air in the heatpipe and the LN cannot evaporate?
 
alik4041 said:
So you're saying if LN was put in a sealed heatpip located on a cpu heatsink which was in action (cpu getting hot), the LN would not cool the cpu at all because there is no air in the heatpipe and the LN cannot evaporate?
Click to expand...


If LN was in a sealed heatpipe, two things could happen. First of all, heat would transfer from all the connected parts of the heatsink, and eventually the CPU would be cooled. Then, as the CPU was being used, it would of course release heat, which would then be absorbed by the heat sink. Eventually, the heatsink would be brought to a temperature above the LN's boiling point. As far as I know, LN is similar to other liquids and is incompressible. I reckon that the LN will cause a violent explosion or at least some type of issues.

LN exposed to room temperature absorbs heat from the ambient air and boils about VERY VIOLENTLY.

LN cannot be contained in a sealed vessel at room temperature. Plug it into a heatpipe, and that's what you're doing. If you include a venting valve so some of the LN can boil out safely, you'll eventually end up with no more nitrogen.

Also, nitrogen can still hurt you if you're not careful, but if you VERY QUICKLY dip your fingers into a dewer, it will scare a lot of people but not harm you a bit. What happens is the heat from your hand is instantly causing the LN around your fingers to instantly vaporize, creating a warm cushion around your hand. Keep your hand there long enough and the heat from the cushion will dissipae into the LN or disperse into the air, and your hand will suffer tissue damage.

Disclaimer: I know what I'm doing and accept the risks. Do NOT try what I just described, as you can and probably will get injured.
 
Stuey83 said:
Disclaimer: I know what I'm doing and accept the risks. Do NOT try what I just described, as you can and probably will get injured.
Click to expand...
Oh, I know. I'm here to learn :)
 
alik4041 said:
Oh, I know. I'm here to learn :)
Click to expand...

Nono, I meant the disclaimer so that nobody goes and sticks their hand into liquid nitrogen. I really don't need anybody losing a finger and then pointing at me while talking to their lawyer saying "he told me it was alright!".

But I also kinda meant it toungue in cheek. I've injured myself with liq N before. It's not pleasant. When I worked in the lab, we were told to not do the "dip the hand" thing because some undergrad lab instructors weren't telling their students that it was hazardous. One of the students told the lab coordinator that he could dip his hand under liquid N and it'd be alright.

But yea... liq N2 is highly volatile, but fun to play with.
 
Stuey83 said:
Nono, I meant the disclaimer so that nobody goes and sticks their hand into liquid nitrogen. I really don't need anybody losing a finger and then pointing at me while talking to their lawyer saying "he told me it was alright!".

But I also kinda meant it toungue in cheek. I've injured myself with liq N before. It's not pleasant. When I worked in the lab, we were told to not do the "dip the hand" thing because some undergrad lab instructors weren't telling their students that it was hazardous. One of the students told the lab coordinator that he could dip his hand under liquid N and it'd be alright.

But yea... liq N2 is highly volatile, but fun to play with.
Click to expand...
lol I know what you meant, but i'm still here to learn haha :D I like learning about this stuff. Like tomsahardware 5ghz LN project. I am waiting for them to do the samething on say the x6800 for example.
 
Liquid Helium requires a LOT more safety precautions than liq N, and is much more costlier.

I really don't think anyone would see any kind of cooling or performance boost by using Helium.
 
Liquid Helium is a lot colder than LN2. With LN2, you spill some on yourself and get a skin burn. With LHe, you spill some on yourself, it penetrates your skin, expands inside your body, and damages your internal organs.

Some forms of it also have the superfluid property. These are almost impossible to contain. Surface tension will cause the liquid to spread across all surfaces, even uphill, and it can go straight through most types of containers.

Not to mention the fact that the computer wouldn't boot anyway, as LHe is so cold, it causes a semiconducter to lose the "semi" part, switching all transistors the the "on" state.
 
Thank you for this thread. Its been an excellent read and I hope to read more of this.

Here's a question... What is the last element that would freeze at absolute zero?
 
HOCP4ME said:
... as LHe is so cold, it causes a semiconducter to lose the "semi" part, switching all transistors the the "on" state.
Click to expand...

Almost, but the exact reverse. It causes the material to become intrinsic again, all the dopants are deactivated. It's called Freeze-out.
 
qtwre said:
Here's a question... What is the last element that would freeze at absolute zero?
Click to expand...

At absolute zero, elements don't necessarily "freeze". At absolute zero, I highly doubt there will be any vapors, but you can possiby still have elements in the liquid phase.

Well, "freeze" in a non-literal sense is technically appropriate since all known substances will cease atomic-scale vibrations. In other words, at the smallest level possible, everything will stop moving. Well, in theory. Absolute zero has never actually been obtained - ever.
 
You must log in or register to reply here.
Back
Top