What's phase change cooling?

[uOpt]

Subject says it all. What is phase change cooling?

 

[Greenman]

The cooling medium changes from a liquid to a gas, releasing stored heat.

 

[SVT Cobra]

its works like a refirgerator....

do a google search for..."vapochill"

 

[Red and black]

Originally posted by: Greenman
The cooling medium changes from a liquid to a gas, releasing stored heat.

Hey, I think you got that backwards.

 

[icarus4586]

its works like a refirgerator....

do a google search for..."vapochill"

i think you're confused - Vapochill and others like it are compressor coolers, and work like a refrigerator or air conditioner.

Phase change coolers are different, and are used in "heat pipe" systems. Say you want a really big radiator area on a HSF, so big that it would interfere with components around the CPU. Many designs use heat pipes to elevate this radiator and allow for a larger surface area. Inside a heat pipe, there's a compound that is liquid under normal temperature. Once heat is applied, it boils and moves up the pipe, taking the heat energy with it. Once it reaches the radiator, it cools until it moves back to the liquid phase. Hence the name "phase change."

 

[cbehnken]

Umm no, phase change is refrigeration.

As Greenman said refrigerant is pumped through a closes system by a compressor.

1. The system has an evaporator core that refrigerant goes through(cpu block in this case)
2. The system has a condensor core that cools the refrigerant
3. The system has a compressor that actively pumps the refrigerant.

The cooling medium does change from a liquid to a gas. As the liquid evaporates into a gas it absorbs a lot of ambient kinectic energy to maintain it's gaseous state. That's why the evaporator core gets very cold.

Someone can correct me if I missed something, but this is the basics.

 

[theMan]

this oughta help

http://www.ocforums.com/showthread.php?t=287576

 

[morpheus2963]

Phase change cooling refers to the change of state of the cooling medium in most cases some form of refrigerant is used but this is also true with the cooling system used by water cooled automobiles. Essentially how it works is this: a compressed gas (compressed to its liquid state) flows through a tubule know as a capilary. it flows from the High pressure side of the compressor through this tube into an area that is much larger than the diameter of the capilary. when any liquid under pressure is released into an area of lower density than that from which it came the surface pressure of the liquid drops rapidly and (in the case of commercial refrigerants) the liquid boils thus absorbing heat into the medium and since there is no such thing as "cold" only the lack of heat energy the area immediately around such a boiling vapor has the heat energy sucked out of it thus reducing its ambient temperature to that of the container holding the medium ( to test this get a can of canned air or dust remover from your workbench, then open the valve on the can and hold it that way for as long as you can stand it. your hand gets very cold because the metal gets very cold becuause the boiling vapor released by the can has leeched the heat energy right out of the inner and outer surfaces of the can and from your hand). if such a container is made from a thermally efficient conductor (copper or aluminum for example) the heat from the surronding area will be transfered into the boiling gas and then carried away to be radiated through either a large fan or a HSA heat sink or both. This is all based on known laws of Thermal mechanics and the capilary action of gases as described by Boyle's Law (also known as the Master Gas law). Interestingly enough this is also the way that most Whiskey Distilleries work. See Dewar and Boyle for more info

 

[SVT Cobra]

Originally posted by: icarus4586

its works like a refirgerator....

do a google search for..."vapochill"

i think you're confused - Vapochill and others like it are compressor coolers, and work like a refrigerator or air conditioner.

Phase change coolers are different, and are used in "heat pipe" systems. Say you want a really big radiator area on a HSF, so big that it would interfere with components around the CPU. Many designs use heat pipes to elevate this radiator and allow for a larger surface area. Inside a heat pipe, there's a compound that is liquid under normal temperature. Once heat is applied, it boils and moves up the pipe, taking the heat energy with it. Once it reaches the radiator, it cools until it moves back to the liquid phase. Hence the name "phase change."

no you are wrong as others stated....

Originally posted by: morpheus2963
Phase change cooling refers to the change of state of the cooling medium in most cases some form of refrigerant is used but this is also true with the cooling system used by water cooled automobiles. Essentially how it works is this: a compressed gas (compressed to its liquid state) flows through a tubule know as a capilary. it flows from the High pressure side of the compressor through this tube into an area that is much larger than the diameter of the capilary. when any liquid under pressure is released into an area of lower density than that from which it came the surface pressure of the liquid drops rapidly and (in the case of commercial refrigerants) the liquid boils thus absorbing heat into the medium and since there is no such thing as "cold" only the lack of heat energy the area immediately around such a boiling vapor has the heat energy sucked out of it thus reducing its ambient temperature to that of the container holding the medium ( to test this get a can of canned air or dust remover from your workbench, then open the valve on the can and hold it that way for as long as you can stand it. your hand gets very cold because the metal gets very cold becuause the boiling vapor released by the can has leeched the heat energy right out of the inner and outer surfaces of the can and from your hand). if such a container is made from a thermally efficient conductor (copper or aluminum for example) the heat from the surronding area will be transfered into the boiling gas and then carried away to be radiated through either a large fan or a HSA heat sink or both. This is all based on known laws of Thermal mechanics and the capilary action of gases as described by Boyle's Law (also known as the Master Gas law). Interestingly enough this is also the way that most Whiskey Distilleries work. See Dewar and Boyle for more info

good explanation

 

[morpheus2963]

Thank you Son of a N00b I do try to get my science right. it helps when I run into a problem installing something and I cant figure out whats wrong, I fallback on logic and known physical laws to try and define the problem before i just jump into it with both feet