EXPERIMENTAL STUDY OF CONDENSATION HEAT TRANSFER CHARACTERISTICS OF HORIZONTAL TUBE BUNDLES IN VACUUM STATES

• Published in: Journal of hydrodynamics. Series B 2012-09, Vol.24 (4), p.628-634
• Main Authors: CHENG, Shen, SUN, Feng-zhong, SHI, Yue-tao
• Format: Article
• Language: English
• Subjects: Brasses; Bundles; condensation heat transfer coefficient; Condensing; dropwise condensation; Engineering; Engineering Fluid Dynamics; Heat transfer; heat transfer characteristics; Heat transfer coefficients; Hydrology/Water Resources; Nickel; Numerical and Computational Physics; Simulation; Steels; Tubes; vacuum; 不锈钢管; 冷凝传热系数; 实验; 换热特性; 水平管束; 真空态; 真空条件; 离子注入
• ISSN: 1001-6058; 1878-0342
• DOI: 10.1016/S1001-6058(11)60286-2

To develop an excellent heat transfer element under the vacuum condition, experiments about the heat transfer performance of horizontal tube bundles of different materials under various vacuum conditions were carried out, including the stainless steel tube, the brass tube, the Ni-based implanted steel tube and the ion implanted brass tube. The relative trends show that the condensation heat transfer coefficient and the overall heat transfer coefficient of bundles of four materials all increase with the vacuum degree, especially, those of the Ni-based implanted steel tube and the ion implanted brass tube. Under a high vacuum condition (0.07 MPa), the condensation heat transfer coefficient of the Ni-based implanted steel tube bundle is about 1.4 times of that of the stainless steel tube bundle, the condensation heat transfer coefficient of the ion implanted brass tube bundle is found to be about 1.3 times of that of the common brass tube bundle. Therefore, according to the condensation heat transfer characteristics studied under high vacuum conditions, it is believed that a dropwise condensation is partly achieved on the surface of these two implanted tube bundles, and the ion implantation is shown to be an effective method to achieve the dropwise condensation. Based on this study, it is believed that the Ni-based steel tube may replace the brass tube, which is more expensive as a heat transfer component.