In this study, the non-conductive fluids FC-72 and HFE-7100 were used to investigate the condensation heat transfer performance outside the tubes, and to simulate the condensation conditions of the immersion computer cooling system. There are four types of tubes: round tube, smooth elliptical tube, reinforced round tube and reinforced elliptical tube, and the condensation phenomenon is observed by visual cavity. The cooling water flow in the tube is 1.5 and 2LPM. The experimental results show that FC-72 and HFE-7100 have the highest condensation heat transfer coefficient in the elliptical reinforced tube. Overall, the condensation heat transfer of FC-72 is better than that of HFE-7100, and the highest condensation heat of FC-72 and HFE-7100. The transmission coefficient can reach 3400 and 2491W/m respectively2K. Compared with the surface type, the condensation heat transfer coefficient of the reinforced tube is higher than that of the smooth tube; compared with the cross-sectional shape of the tube, the condensation heat transfer coefficient of the elliptical tube is higher than that of the circular tube; because of the large curvature of the wall surface, the condensation film on the tube wall Affected by gravity, it is easier to detach from the surface of the condensing pipe, so that the condensing pipe is not easy to thicken due to the increase of condensation amount, and can maintain better heat transfer performance.
