In-depth analysis! Advantages and challenges of two-phase cold plate liquid cooling system

In recent years, AI big models, cloud computing, supercomputing and other fields have put forward higher requirements for computing power. With the rapid iteration of servers and the continuous upgrading of chips, the demand for heat dissipation has also increased rapidly. In the face of high-density heat dissipation needs, liquid cooling technology has developed multiple routes, mainly including cold plate liquid cooling, immersion liquid cooling and spray liquid cooling. Among them, cold plate liquid cooling is the current mainstream mature technical solution, which can be divided into single-phase cold plate liquid cooling and two-phase cold plate liquid cooling. Today, let's focus on two-phase cold plate liquid cooling technology with Jialede and deeply analyze the advantages and challenges of this technology.

Based on a large amount of market research, we will explore the technical advantages of two-phase cold plate liquid cooling from the following three aspects:

Architecture and compatibility of liquid cooling system

Compared with immersion liquid cooling, cold plate liquid cooling has better adaptability to the traditional architecture of servers, and the overall weight does not change much, and the load-bearing requirements of the computer room are not high. It is suitable for upgrading and renovating existing stock computer rooms, and is more conducive to upgrading single-phase cold plates to two-phase cold plates in the later stage. At the same time, cold plate liquid cooling requires less modification of the CPU/GPU, and the supporting electrical rack changes are relatively small. The coolant does not directly contact the electrical components, which can avoid many compatibility issues. In addition, under the same heat dissipation, the pump drive energy consumption of the two-phase cold plate liquid cooling system is lower than that of the single-phase cold plate and immersion liquid cooling circulation system.

Economic efficiency

During the circulation of low-pressure phase change coolant, aluminum can replace copper to avoid the use of high-priced metals such as stainless steel and copper in the pipeline, thereby reducing the system pipeline cost. Compared with the use of a large amount of electronic fluorinated liquid/mineral oil in immersion liquid cooling, the use of coolant in the cold plate liquid cooling system and the loss during daily maintenance are much lower than those of immersion liquid cooling, and the initial investment can be reduced.

Coolant characteristics

The conductivity of electronic fluorinated liquid/refrigerant is very low, and it is often used to clean electrical components. Even if leakage occurs, it will not cause damage to the electrical components; electronic fluorinated liquid/refrigerant is a pure substance, and no additives such as corrosion inhibitors/fungicides need to be added in the system circulation, which ensures the cleanliness of the system and reduces the risk of system corrosion. Thanks to the mature traditional refrigeration system technology, after the system is installed with a dry filter, it can remain clean for a long time, and the probability of clogging and corrosion of the pipeline is greatly reduced; the boiling heat transfer efficiency generated by the phase change of the coolant is about 3 to 10 times the heat transfer efficiency of single-phase convection, which can meet the needs of high-density heat dissipation. At the same time, the heat carrying capacity of the phase change coolant is also higher than the sensible heat of the single-phase coolant. The system can meet the heat dissipation requirements at a small flow rate and reduce the power consumption of the circulation pump.

Although the two-phase cold plate liquid cooling system has a series of advantages, most domestic suppliers are currently in the research and development stage, with few mass production projects, and still face some technical challenges:

Find or develop suitable electronic fluorinated liquids or refrigerants to ensure the appropriate phase change temperature and pressure to avoid condensation of electronic components when the evaporation temperature is too low or leakage;

Require mature node-level liquid flow control and phase change pressure control;

Component size issues (miniaturization/integration), ease of use;

Even if the two-phase cold plate liquid cooling technology still has a long way to go, with the increase in high-density heat dissipation or the increase in the demand for overclocking of low-version chips under low temperature conditions, two-phase cold plate liquid cooling will eventually occupy a place in the liquid cooling market. Jialede actively follows up on the cutting-edge technology exploration of data center cooling systems, and is conducting two-phase cold plate liquid cooling technology exploration with a number of international server and thermal management system suppliers, aiming to work with customers for win-win cooperation and escort the future computing market of informatization, intelligence and commercialization!