Fabrication of Hydrophobic Coated Tubes for Boiling Heat Transfer Enhancement

Abstract

The hot wire chemical vapor deposition method was applied for fabrication of hydrophobic fluoropolymer coatings on the surface of tubular heaters. The effect of hydrophobic surfaces (with static contact angle of 125°) on the local and integral heat transfer characteristics was studied during boiling of saturated water at atmospheric pressure, including high speed visualization. The heat transfer enhancement by 30% was observed in the range of low heat fluxes during boiling on the hydrophobic coated tubes. It was shown that the value of the bubble departure diameter and the nucleation site density significantly increased, and the bubble separation frequency was significantly reduced in comparison with the data obtained on the uncoated tube. The analysis of the operational characteristics of the synthesized coatings was carried out.

Acknowledgement

We express our gratitude to the Novosibirsk State University for providing an access to the library.

Additional information

Funding

The work was supported by the Russian Science Foundation [project No. 18–79–10119]. The high-speed visualization was carried out in the framework of the Program of Fundamental Scientific Research of the Russian Academy of Sciences for 2013–2020 [theme III.18.2.3, AAAA-17-117030310025-3].

Notes on contributors

Alexey I. Safonov

Alexey Safonov is a senior researcher of Kutateladze Institute of Thermophysics SB RAS and Novosibirsk State University, Novosibirsk, Russia. He received his doctoral degree in 2011 from Institute of Thermophysics, Russia; Master of Science in 2006 and Bachelor degree in 2004 from Novosibirsk State Technical University, Russia. His current research interests include research of synthesis and deposition processes of micro/nanostructured metal and fluoropolymer coatings for different applications.

Denis V. Kuznetsov

Denis Kuznetsov is currently a researcher at the laboratory of low-temperature thermophysics at the Kutateladze Institute of Thermophysics of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia. He received a master's degree from Novosibirsk State University in 2015. Currently, he is working in the direction of studying heat transfer processes and crisis phenomena during boiling and evaporation of liquids on micro/nanomodified surfaces.

Anton S. Surtaev

Anton Surtaev is senior researcher at Kutateladze Institute of Thermophysics and Novosibirsk State University, Russia. He received his Ph.D. in 2011 from Kutateladze Institute of Thermophysics, Novosibirsk, Russia. His current research interests include phase change phenomena (boiling, condensation, evaporation), development of new techniques for enhancement of heat and mass transfer, energy efficiency and micro/nanotechnology.