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Originally Posted by talcum
Could you use this to efficiently cool the hot side of a TEC and maintain a 20 - 30 C cpu temp? For a Prescott it might be worth it. Or would bubbles form in the cooling block and ruin the heat transfer when the stuff vaporized? Anyone cooled a TEC with a phase change system?
:shrug:
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Heat is absorbed from vaporization so the bubbles may be a good thing. I am unsure how well it would work but they are experimenting with allowing bubbles to form from vaporization
HERE . Granted the experiments deal with much higher temps than we see but changing the fluid used would drop vaporization into our range and possibly keep pressures low enough to avoid more expensive fittings, tubing, and other pieces-parts.
The fluid that began the thread would work but not too well as it only absorbs about 40 BTUs per pound as it vaporizes while R123 absorbs about 357 BTUs per pound. The pump used may become an issue with alternate coolants not only becuse of material compatibility issues, but also because the bubbles that form will be passing through the pump. Much potential for cavitation noise and bearing damage there I suppose.
Lots of stuff online about using this setup to cool anyting from electronics to nuclear reactors. I found a couple of real interesting articles that get down to the nitty gritty details on using this process with micro channels in th 1-2 mm range. It should work...how well it would work for this aplication and how expensive it would be are questionable.
In short, if the lessened heat carying capacity of the coolant used as compared to water is more than offset by the heat absorbed from vaporization there are gains to be made there. The systen may be viewed as a hybrid of liquid cooling and phase change. The power of the pump has the potential to increase cooling more so than with a system using water as the coolant as, with a restriction imposed before the block, the fluid cooling will be under a slight vacuum, lowering the temperature at which the coolant evaporates. The rad will be under slight pressure lowering the temperature at which the bubbles condense.