Liquid immersion cooling technology with natural convection in data center

We proposed a liquid immersion cooling technology with natural convection for high power server boards used in data centers with high cooling-efficiency. The cooling performance was evaluated by CFD simulation and actual experiments. As the refrigerants, several non-conductive, thermally and chemically stable fluids were applied, including silicone oil, soybean oil, and perfluorocarbon structured liquids. The CPU temperature in the refrigerant monotonically decreases with the Rayleigh numbers of the refrigerant. The smoother refrigerant is better for cooling the high power CPU. The changes in any CPU task and any slot-removal give limited cooling effects to other slots and other CPUs. These are quite useful features for stable operation of servers in data center. As a result, this proposed technology with natural convection exhibits promising potential for low energy and space-saving board cooling which demonstrates a Power Usage Efficiency (PUE) below 1.04.