Passive saltwater heatsink, increasing CPU performance by approximately 33%
With the increasing demand for high-performance electronic and communication technologies and the continuous reduction of electronic component sizes, the power density of electronic components continues to rise. This puts forward higher requirements for the thermal management strategy of electronic components. Passive thermal management technology has attracted increasing interest due to its zero energy consumption, higher compactness, and lower maintenance costs.
The traditional cooling methods for CPUs include not only general air cooling, but also water cooling, PCM cooling, and thermoelectric (TEC) cooling. Novel passive cooling systems, such as those based on adsorption evaporation, can play a crucial role in managing heat load by providing effective gas-phase heat transfer. Researchers are exploring how to optimize the adsorption process to improve cooling efficiency and overall thermal performance of computing systems.
Recently, a passive thermal management technology based on the evaporation process of water in a hygroscopic salt solution has been tested and shown to effectively suppress the temperature rise of electronic components. Utilize the water decomposition and absorption process in a low-cost hygroscopic salt solution to extract the heat generated during the operation of electronic components, in order to prevent overheating of electronic components. Importantly, this passive technology can automatically restore the cooling capacity of electronic components during non working hours (or off peak hours). Experiments have shown that this technology can provide an effective cooling capacity of approximately 400 minutes（ Δ Tmax=11.5 ° C), with a tested heat flux of up to 75 kW/m2. Applying this technology to practical computing devices can improve device performance by 32.65%.
Lithium bromide is trapped in a porous membrane that only allows water vapor to pass through, and sandwiched between metal plates to prevent contact between the salt solution and electronic devices, while a metal radiator can effectively dissipate heat to the external environment.
The passive cooling system can be divided into two working stages: desorption cooling process and absorption regeneration process. Firstly, the cooling process removes heat by evaporating water from the lithium bromide salt solution. Afterwards, the system enters the absorption regeneration process, where a high concentration salt solution absorbs moisture from the surrounding air and automatically restores its cooling capacity.
Compared with conventional heat sinks, this technology can cool the processor to below 64 ℃ for about 400 minutes, which is 10 times better than the most advanced metal organic skeleton (MOF) material and successfully improves device performance by 32.65%.
