What type of cooling is that?
- Thread starter Xochielt
- Start date
i dare you to put your willy on it
LMAO!
I'd think you cool down the earth to prevent global warming with that one
i dare you to put your willy on it
The guy from mainentance ( who also couldn't tell me what
type of cooling this is - serious? ) told me, that even
touching it may result in getting fixed to it, so this idea
is quite... uhm... bad
What do you mean "what kind of cooling?". The nitrogen is kept under high pressure and at low temperature. When liquid nitrogen is released from the tank (by a tube at the bottom), it starts boiling, the boiling temperature is 77K (ish). As it doesn't all boil off instantly the effect of some of it evaporating takes heat out of the liquid.
Rapid expansion of a gas needs work against the air pressure, thus the heat is taken from either the liquid nitrogen or from surrounding heat sources. The reason for the ice build up on tanks and dewars is due to the expansion of the gas and cooling effect of a cold liquid on the pipes which in this case is sufficient to condense water from the air.
If you want a more visual representation, try turning a lighter gas refil can upside down and squirting the resulting liquid into something plastic. Despite the can being at room temp, the liquid formed is at the boiling point of the gas which is about -30, The gas expands, cooling the liquid until an equilibrium is established. If you're really keen look up the zeroth and first law of thermodynamics and derive the phase change equations from there.
Rapid expansion of a gas needs work against the air pressure, thus the heat is taken from either the liquid nitrogen or from surrounding heat sources. The reason for the ice build up on tanks and dewars is due to the expansion of the gas and cooling effect of a cold liquid on the pipes which in this case is sufficient to condense water from the air.
If you want a more visual representation, try turning a lighter gas refil can upside down and squirting the resulting liquid into something plastic. Despite the can being at room temp, the liquid formed is at the boiling point of the gas which is about -30, The gas expands, cooling the liquid until an equilibrium is established. If you're really keen look up the zeroth and first law of thermodynamics and derive the phase change equations from there.
Could it simply be called phase change cooling then? That was my initial thought, but I had nothing to back it up.
thestepster
New member
and i was thinking aswell doesnt the cold come from the nitrogen being put under pressure? not actually being cooled from something
No, the exact oposite. I'll try to make it simpler than Diablo's very thorough (Kudos, sir) explanation. Basically when a liquid goes into a gas form it gets quite cold and tries to keep the reaction at equilibrium thus, possibly condensing from the cold. That's what happens when you spray deodorant into the plastic cap that's on top. Try it
thestepster
New member
u learn something new everyday
