CPU cooling with a thermosiphon loop with tapered manifold (OMM)

摘要

Data center cooling presents unique challenges to reduce global energy consumption and fluid inventory. The current work addresses these challenges by employing a thermosiphon system using two-phase cooling which improves the system efficiency through a drastic increase in heat dissipation ability. The latent heat transfer is more effective than its sensible heat counterpart. The system performance is typically characterized by its Critical Heat Flux (CHF) and Heat Transfer Coefficient (HTC). An increase in CHF offers wider operating ranges while HTC dictates the efficiency of the heat transfer process. In the current design of the cooling solution, a tapered manifold with a gap over the heater surface is employed to effectively remove the vapor away from the surface. A 3.43° tapered manifold is analyzed with HFE7000 as the working fluid in a benchtop thermosiphon. A copper chip with microchannels of width and depth of 200 μm was used for the heater surface, resulting in a CHF of 44.2 W/cm at a wall superheat of 16.4°C, and a maximum HTC of 27.3 kW/m°C. This design is then arranged to be implemented as a thermosiphon Central Processing Unit (CPU) cooler. The results are compared to current cooling techniques tested on a data center server. The efficacy of the system is evaluated against its air-cooling and liquid-cooling counterparts. The thermal footprint and the system performances are evaluated for each case in this study. The cooling solution presented here has immense potential to replace existing technologies, although certain obstacles identified here will need to be considered going forth.