What is Immersion cooling

Immersion cooling, also referred to as liquid submersion cooling, involves immersing computer parts (or entire servers) in a thermally but not electrically conducting liquid (dielectric coolant). Although it is still infrequently utilized for IT hardware cooling, cutting-edge datacenters all around the world are starting to use it more frequently. When IT hardware or servers are cooled using immersion cooling, no fans are used, and a heat exchanger is typically used to transfer heat from the warm coolant to the cool water circuit (i.e. heater core or radiator).

Some extremely dense supercomputers, such the Cray-2 and Cray T90, remove heat via massive liquid-to-chilled heat exchangers. The fluid must have a sufficiently low electrical conductivity to avoid affecting the computer's regular operation. It might be necessary to insulate specific areas of components vulnerable to electromagnetic interference, like the CPU, if the fluid has some electrical conductivity. It is preferred that fluid be dielectric for these reasons.

Is water cooling equivalent to immersion cooling?

Using the working fluid, heat is transmitted directly from the heat source in immersion cooling. Yet in water-cooling, the working fluid might be damaging to electronics, therefore it circulates in a sealed loop separate from the heat source. The heat from the heat source is indirectly transferred to the working fluid using a watertight waterblock. Since the working fluid for immersion cooling must be non-conductive, only four families of fluids may typically be used;

• de-ionised water;

• mineral oil;

• fluorocarbon-based fluids, and;

• synthetic fluids.

The fluid cost of immersion cooling systems used to be higher than that of water cooling, however that has changed recently.

There are many other fluids that can be used for immersion cooling, but transformer oils and other electrical cooling oils work well. Cooking, motor, and silicone oils, among other all-purpose oils, have all been used to effectively cool computer servers.

What various kinds of immersion cooling are there?

There are numerous immersion cooling techniques depending on the characteristics of the coolant:

1. Single-Phase Immersion Cooling

Single-Phase coolant never boils or freezes, and it always remains in a liquid condition. Pumping the coolant into a heat exchanger allows heat to be transferred from the coolant to a cooler water circuit. As there is little to no chance of the coolant evaporating, this method employs "open baths":

2. Two-Phase Immersion Cooling (sometimes known as evaporative cooling or flow boiling) (also known as evaporative cooling or flow boiling)

The working fluid in two-phase cooling can be either a liquid or a gas. The heat (thermal energy) needed to change a fluid's condition is known as latent heat, and this technique makes use of it. When the working fluid reaches its boiling point, it cools and stays at this saturation temperature. The working fluid receives energy from the heat source, which causes some of it to boil off as gas. The gas then rises above the fluid pool and condenses back to saturation temperature after this has happened. The fluid fall (rain) returns to the fluid pool as a result.