An Experimental Study on Cooling of CPU using a Two Phase Closed Thermosyphon Loop

摘要

This paper reports on indirect cooling of high-power CPU of notebook computers using a two phase closed thermosyphon loop with Fluorinert (FC-72) as the working fluid. The experimental set-up consists of an evaporator and a condenser connected by flexible tubing. The evaporator corresponds to a high-power CPU, and the condenser represents a cooling plate located behind the display of notebook computer. The evaporator and the condenser have the outer dimensions of 50mm×50mm×20mm and 150mm×200mm×20mm, respectively. The effects of the heat input Q and the charged volume of Fluorinert liquid F on the heat transfer characteristics of the cooling system were studied experimentally. Further, the experiments using several types of evaporators to enhance the boiling in the evaporator were carried out. It has been confirmed that the back surface temperature of the evaporator with plate fin of roughness surface by blast (Type D) reduces about 18% in comparison with that of the evaporator without fin (Type A). In the case of the evaporator Type D, the temperature difference between the evaporator back surface and ambient is kept around 55K for the highest heat input Q=30W in the present experiments.