Cooling unit for high-density packaging ICT rack by using boiling heat transfer (Evaluation on basic cooling performance of low height type thermosyphon)

Abstract

We have developed the cooling unit for high-density packaging ICT racks by using the boiling heat transfer with the concept of transporting a heat generated from CPU into the outdoor atmosphere directly without exposure to air in the computer room. The aim of this paper is to evaluate the cooling and power saving performance of the cooling unit using the low height type thermosyhon installed in the 1U server and the heat exchanger cooled by the water from the outdoor chiller unit. First, we clarified some factors (tilt angle, flow passage length and cross sectional area of thermosyhon) influencing the cooling performance. Then we examined the power saving performance of this cooling system during operating 32 CPUs in the ICT rack and compared to the conventional system using the computer room air conditioner.