As the demand for faster and more reliable data processing is increasing in our daily lives, the power consumption of electronics and, correspondingly, Data Centers (DCs), also increases. It has been estimated that about 40% of this DCs power consumption is merely consumed by the cooling systems. A responsive and efficient cooling system would not only save energy and space but would also protect electronic devices and help enhance their performance. Although air cooling offers a simple and convenient solution for Electronic Thermal Management (ETM), it lacks the capacity to overcome higher heat flux rates. Liquid cooling techniques, on the other hand, have gained high attention due to their potential in overcoming higher thermal loads generated by small chip sizes. In the present work, one of the most commonly used liquid cooling techniques is investigated based on various conditions. The performance of liquid-to-liquid heat exchange is studied under multi-leveled thermal loads. Coolant Supply Temperature (CST) stability and case temperature uniformity on the Thermal Test Vehicles (TTVs) are the target indicators of the system performance in this study. This study was carried out experimentally using a rack-mount Coolant Distribution Unit (CDU) attached to primary and secondary cooling loops in a multi-server rack. The effect of various selected control settings on the aforementioned indicators is presented. Results show that the most impactful PID parameter when it comes to fluctuation reduction is the integral (reset) coefficient (IC). It is also concluded that fluctuation with amplitudes lower than 1 ᵒC is converged into higher amplitudes
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AN EXPERIMENTAL INVESTIGATION ON THE FLUID DISTRIBUTION IN A TWO-PHASE COOLED RACK UNDER STEADY AND TRANSIENT IT LOAD
Increasing power densities in data centers due to the rise of Artificial Intelligence (AI), high-performance computing (HPC) and machine learning compel engineers to develop new cooling strategies and designs for high-density data centers. Two-phase cooling is one of the promising technologies which exploits the latent heat of the fluid. This technology is much more effective in removing high heat fluxes than when using the sensible heat of fluid and requires lower coolant flow rates. The latent heat also implies more uniformity in the temperature of a heated surface. Despite the benefits of two-phase cooling, the phase change adds complexities to a system when multiple evaporators (exposed to different heat fluxes potentially) are connected to one coolant distribution unit (CDU). In this paper, a commercial pumped two-phase cooling system is investigated in a rack level. Seventeen 2-rack unit (RU) servers from two distinct models are retrofitted and deployed in the rack. The flow rate and pressure distribution across the rack are studied in various filling ratios. Also, investigated is the transient behavior of the cooling system due to a step change in the information technology (IT) load.
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- Award ID(s):
- 1738793
- NSF-PAR ID:
- 10157106
- Date Published:
- Journal Name:
- ASME 2019 International Electronic Packaging Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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