Application of 3D laser printing technology to enhancing heat transfer during nucleate boiling of liquids

Significance 

The heat transfer intensity is a critical aspect of cooling systems. And to maintain the desired preservation conditions and integrity of the system requires the removal of the heat fluxes. Recently, modified surfaces have emerged as a promising approach for intensifying the heat transfer and increasing the critical heat fluxes (CHF). To date, numerous techniques for fabricating these modified porous surfaces have been proposed. In particular, a number of the reported studies focus on using three-dimensional (3-D) printing (selective laser melting / sintering (SLM / SLS) techniques) to develop efficient heat transfer systems. SLM / SLS methods allow the production of complex geometries, which eliminates the need for further processing.

Even though SLM/SLS techniques have been successfully used to produce different heat exchange units made of different materials, they have been sparsely applied to produce structured surfaces. Additionally, there are no reports on heat transfer enhancement on liquid boiling in subcooling and saturated conditions on the few structured surfaces constructed by SLM/SLS techniques. Therefore, structured coatings with controlled parameters are necessary to better understand their characteristics and influencing mechanisms on heat transfer and CHF during evaporation and boiling conditions.

Pressure is an independent parameter that significantly affects the heat transfer during boiling. Despite the good research progress, the heat transfer in varying liquid heights and at different pressures is rarely studied. To bridge the existing research gap, Professor Vladimir Zhukov from Novosibirsk State Technical University, Professor Aleksandr Pavlenko and Ph.D. student D.A. Shvetsov from Kutateladze Institute of Thermophysics SB RAS in Russia investigated heat transfer under evaporation and boiling conditions in thin horizontal layers. In particular, the effects of relative pressure and the height of the liquid layers on the heat transfer during boiling and evaporation on the microstructured surface with 2D modulated capillary porous coating was investigated. The original research article is now published in the International Journal of Heat and Mass Transfer.

In brief, the capillary-porous coating with a sinusoidal 2D modulated profile was obtained via 3D printing of selective laser sintering. And the same coating was used for the entire experiment. The height and pressure of the liquid layer varied over a wide range. The variation in the heat transfer coefficient with changes in the relative pressure and height of the liquid layers was studied in detail. Finally, the experimental results were compared with those obtained from boiling and evaporation under the same conditions on a smooth surface.

The authors observed an increase in the heat transfer coefficient with an increase in the relative pressure in the boiling regime. Compared to the capillary-porous surfaces, the smooth surface produced a high heat transfer coefficient during evaporation at low pressures. On the other hand, the coefficient on the capillary-porous coatings was significantly (more than three times) greater than that reported for smooth surfaces during boiling at moderate relative pressures. Furthermore, the CHF on the capillary-porous coating increased with an increase in the height of the liquid layers.

In summary, different heat transfer modes during boiling and evaporation on a porous coating in thin liquid layers under different pressures were investigated. The effects of the relative pressure and liquid height on the heat coefficient on the porous coating were critically discussed at boiling and evaporation regimes. A significant increase in the CHF on the surface of the porous coating was reported at a layer height greater than 4mm. In a statement to Advances in Engineering, Professor Aleksandr Pavlenko said the study pave way for future heat transfer studies on different microstructured surfaces.

Application of 3D laser printing technology to enhancing heat transfer during nucleate boiling of liquids. - Advances in Engineering

About the author

Shvetsov Dmitry received his bachelor’s degree and master’s degree at Novosibirsk State Technical University, Novosibirsk, Russia, in 2017 and 2019, respectively. Now he is a Ph.D. student at the Kutateladze Institute of Thermophysics SB RAS (IT SB RAS), Novosibirsk, Russia (from 2019). His research interests include chemical engineering and heat transfer during evaporation/boiling.

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About the author

Dr. Vladimir Zhukov is an Associate Professor at Novosibirsk State Technical University, Novosibirsk, Russia (since 1998). He graduated from the Department of Physics of Novosibirsk State University with a Speciality in Physics in 1982. He worked as an Еngineer at Novosibirsk Branch of the Chemical, Engineering Design Institute (1982-1993) and as a Lecturer at Siberian State University of Geosystems and Technologies (1995-1998). He received his Ph.D. in Engineering Sciences (Kutateladze Institute of Thermophysics SB RAS) in 1991.

To date, he has published more than 30 papers in peer-reviewed journals in the field of science and technology. The scope of his scientific interests includes experimental study of heat and mass transfer processes in vacuum diffusion pumps, enhanced heat transfer, swirling flows, heat transfer and crisis phenomena at boiling and evaporation the film of liquids.

About the author

Aleksandr Pavlenko is Corresponding Member of Russian Academy of Sciences, a Professor and Head of the Low-Temperature Thermophysics Laboratory of Kutateladze Institute of Thermophysics (Novosibirsk, Russia).

His areas of expertise: transfer processes and crisis phenomena at boiling and evaporation, dynamics of boiling regimes change; flow and decomposition of liquid films at intense evaporation and boiling, including nonsteady laws of heat release; heat/mass transfer in cryogenic systems, hydrodynamic and mass transfer processes in separation columns with regular packings; heat transfer enhancement in compact plate fin heat exchangers and on the structured surfaces.

The main scientific results: – developed the theory of boiling crisis in nonstationary heat generation, experimentally and theoretically investigated the mechanisms of the development of self-sustaining evaporation fronts in metastable liquids and the dynamics of change of boiling regimes; – for the first time the regularities of heat transfer and development of crisis phenomena in the falling wave liquid films at nonstationary heat release was investigated; methods of heat transfer enhancement during evaporation and boiling in falling films of liquids and their mixtures using microstructured surfaces were developed; – developed scientific bases of processes of mass transfer in distillation using structured packings serving as a base for the creation of new modern efficient energy and cryogenic technologies. He is the author and co-author of more than 400 research works and two monographs.

He is Member of the Research Council of the Intern. Comm. for Heat and Mass Transfer, the Editor-in-Chief of the “Journal of Engineering Thermophysics”, Editorial Board Member of the “Journal of Enhanced Heat Transfer”, “High Temperature” and “Heat Processes in Engineering“. Prof. A. Pavlenko was the Chairman of the Organizing Committee of the Intern. Conf. “5th Intern. Workshop on Heat /Mass Transfer Advances for Conservation and Pollution Control (IWHT2019)”, Organizer and Chairman of Organizing Committee of 7 Intern. Workshops ISHM-I–ISHM-VII (2014–2018), Co-Chairman, Deputy Chairman, Member of the Organizing Committee of 40 Intern. and Russian conferences.

Since 1995 Prof. A. Pavlenko has led research for over $12.5M in research grants from government and industry sources. In terms of application main practical achievements of Prof. A. Pavlenko are bound with the development of the methods increasing mixture separation efficiency in the cryogenic packed columns, heat transfer enhancement methods in compact plate fin heat exchangers. For successful and fruitful cooperation with the largest company of cryogenic machine building he was awarded with four Certificates of Recognition (“Air Products”, USA, 2002, 2009). A. Pavlenko working also in cooperation with foreign scientists: RWTH Aachen University (2003-2005); School of Chemical Engineering and Technology, Tianjin University (China, 2013-2018), Institute of Chemical Engineering, Sofia (Bulgaria, 2019-2021); under his supervision the research works are being carried out in accordance with the contract with “Air Products” (1992-2020), “BASF SE” (2011-2013). He is the laureate of the International A.V. Lykov award (2020), prize of academician S.S. Kutateladze (1998).

Reference

Zhukov, V., Pavlenko, A., & Shvetsov, D. (2020). The effect of pressure on heat transfer at evaporation/boiling in horizontal liquid layers of various heights on a microstructured surface produced by 3D laser printingInternational Journal of Heat and Mass Transfer, 163, 120488.

Go To International Journal of Heat and Mass Transfer

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