New Approach To Immersion Cooling Powers HPC In a High Rise
miller60 writes "How do you cool a high-density server installation inside a high rise in Hong Kong? You dunk the servers, immersing them in fluid to create an extremely efficient HPC environment in a hot, humid location. Hong Kong's Allied Control developed its immersion cooling solution using a technique called open bath immersion (OBI), which uses 3M's Novec fluid. OBI is an example of passive two-phase cooling, which uses a boiling liquid to remove heat from a surface and then condenses the liquid for reuse, all without a pump. It's a slightly different approach to immersion cooling than the Green Revolution technique being tested by Intel and deployed at scale by energy companies. Other players in immersion cooling include Iceotope and Hardcore (now LiquidCool)."
Nucleate boiling is what keeps the lights on if you depend on coal or gas for your electricity. It precedes the zone where your Leidenfrost effect is relevant, and actually increases the heat transfer coefficient by factors.
Tuning a closed system to exploit this is an exercise (fluid chemistry, pressure, temperature), but it is also ubiquitous. As for cavitation, it's a red herring in the nucleate boiling zone- the size of the bubbles is so small, and hence the driving frequency is so high, there is a) less mechanical coupling for the vibration, and b) the energy of cavitation is so low as to not be an issue.
The Liedenfrost Effect only really causes problems when you have to remove a great deal of heat very rapidly without pumps - I.E. inside a boiler. Inside a PC, it's very unlikely to be a problem. The same goes for cavitation, it's only a problem when there's a large number of bubbles forming and collapsing very rapidly or if there is a high pressure differential. Inside a PC, these conditions are unlikely to obtain and are thus unlikely to be a problem. (Not to mention, current PC's have constant vibration due to fans, hard drives, CD/DVD players, etc... and don't seem to suffer from any problems.)