Abstract
A high-height thermo siphon cooling apparatus for high-density packaging ICT racks has been developed. An evaporator is provided at the side face of the server, a heat exchanger with cooling water is set on the ceiling of the rack. The evaporator is connected to the heat exchanger each other by the grooved tube which vapor and condensed water pass through. A heat transfer plate of 3mm thick is vertically arranged in the evaporator. The grooves of equal pitch of groove radius 0.1mm are provided on this boiling heat transfer surface. The water in the evaporator could be supplied to the boiling heat transfer surface by the capillarity. The heat transfer coefficient K of the evaporation surface is more than 10kW/(m^2K) at heat input 200W. A temperature difference between vapor and the heater surface was 4℃ or less.
