For high power and high power density applications, conventional air-cooling system’s thermal performance may not be sufficient to maintain the heat source under safe operating temperature, the liquid cooling system with high heat transfer capability shall be then considered. A complete liquid cooling system contains several important components underneath: a cold plate, a radiator, a fan, and a reservoir.
The cold plate made of metal is attached to heat source(s) to remove heat energy, the cool water flows into the cold plate and leaves it with heat through the pipeline to the condenser, then dissipate heat to the ambient. The liquid is returned to the reservoir after heat exchange via the pipeline, and then is pumped to cold plate for next cycle.
The advantages of liquid cooling is that the specific heat of the liquid is much higher than the air, thus the heat transfer coefficient (h) is very high and the efficiency is much higher than the conventional air cooling.
Take an example, people feel comfortable at 20℃ with short-sleeved clothes; however in a 20℃ pool, if you do not swim intensely, you will soon feel chilly and have to 上岸. It’s the same 20℃, but we loss much heat in water than in the air.
Liquid cooling key advantages:
- High heat convection coefficient (h) Air 1~1,000 (W/m² K) Water and liquids 50~10,000 (W/m² K)
- With pumping and routing design the system is more scalable
- Capable to high power and high heat flux
The development and progress of various industries mostly with of system power and performance increase. The performance of water cooling system is superior to air cooling system, however it is also more complicated to do the design It is often used in power electronics, laser systems and medical systems.
There are several aspects and parameters to be balanced when developing a water cooling system. Engineers need to minimize development and manufacturing costs while meeting the thermal target:
- Thermal performance
- Heat exchange area and pressure drop
- Pipeline distribution, pump load and capacity
- Flow volume distribution and stability