What are the types of liquid cooled server?
liquid cooled server can be divided into three mainstream technology types based on the contact heat exchange between coolant and heating components. Among them, cold plate and immersion are the mainstream solutions for data center applications:
1. Cold plate liquid cooled server (indirect contact)
Cold plate liquid cooling belongs to non-contact (indirect) liquid cooling, where the coolant does not come into direct contact with electronic components and transfers heat through the cold plate. The liquid cooling plate made of copper/aluminum alloy is attached to heating elements such as CPU and GPU, and the coolant circulates in the closed flow channel of the cold plate to take away heat.
Characteristics: With the highest level of technological maturity and the widest range of applications, it requires minimal modifications to the existing server architecture, has strong compatibility, is easy to maintain, and has low renovation costs; But only for the heat dissipation of the main heating components, it is impossible to achieve 100% liquid cooling heat dissipation, and the energy consumption reduction is about 60% to 90%.
Market share: Currently, the liquid cooled server market in China accounts for about 90%, and the overall market share of the industry is about 65%, making it the mainstream solution.
2. Immersion liquid cooled server (direct contact)
Immersion liquid cooling belongs to direct contact liquid cooling, which immerses the entire server or core heating components directly in insulating cooling liquid, and takes away heat through the temperature rise or phase change of the liquid. It can be further divided into two subcategories:
Single phase immersion liquid cooling: The coolant only absorbs heat through heating and remains liquid throughout the entire process. By relying on circulating flow heat exchange, it can achieve 100% liquid cooling, with obvious advantages in heat dissipation and energy saving, and almost no noise.
Phase change immersion liquid cooling: The cooling liquid absorbs heat and heats up to the boiling point, then undergoes a phase change (from liquid to gas). The heat is carried away by the vaporization heat belt, reducing the thermal resistance during the heat transfer process, and the heat dissipation efficiency is higher than that of a cold plate.
Features: The cooling fan can be completely removed, and the PUE (energy efficiency) can be reduced to 1.13 or even lower, supporting higher power density deployment; But the cost of server renovation is higher than that of cold plate, requiring dedicated cabinets.
Market share: The overall market share of the industry is about 34%, which is currently the fastest-growing technology route.
3. Spray type liquid cooled server (direct contact)
Spray type liquid cooling also belongs to direct contact liquid cooling. The working principle is that the coolant is sprayed from the top of the server chassis and accurately sprayed onto the surface of the heating element for convective heat exchange. The heated coolant will be recovered to the liquid tank for circulation.
Features: It can also achieve 100% liquid cooling, with PUE reduced to around 1.1 and high heat dissipation efficiency; But the technology is still in its early stages of development and the application scale is very small.
Market share: approximately 1%.
