Flow condensation heat transfer on surfaces with different wettability in mini-channel

YUAN Jindou1 WANG Yanbo1 HU Han1 YU Xiongjiang1 XU Jinliang1

(1.Beijing Key Laboratory of Multiphase Flow and Heat Transfer for Low Grade Energy, North China Electric Power University, Beijing, China 102206)

【Abstract】The hydrophobic surface embedded with arrayed hydrophilic dots was prepared on a copper surface with mesh screen and Teflon solution. Completely hydrophilic copper surface, completely hydrophobic Teflon-coated surface and hydrophilic/hydrophobic hybrid surface are taken into consideration which serve as the bottom heat transfer area of rectangular mini-channels (1.5 mm hydraulic diameter). In this experiment, the vapor mass velocity ranges from 10 kg·m−2·s−1 to 60 kg·m−2·s−1, while the vapor quality from 0.3 to 1. According to the experimental investigation, the steam condensation heat transfer coefficient on hybrid surface is about 454.6% higher than that of the completely hydrophilic surface and 107.3% higher than the completely hydrophobic surface at most. A high-speed camera provides the photos of two-phase flow pattern, especially the periodic behavior of the droplets nucleation, coalescence and flush which can explain the mechanism of heat transfer enhancement.

【Keywords】 condensation; hydrophilic/hydrophobic surface; mini-channel; heat transfer coefficient;

【DOI】

【Funds】 Key Program of the National Natural Science Foundation of China (51436004) National Natural Science Foundation of China (51676071)

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(Translated by REN XF)

    References

    [1] SHARMA C S, TIWARI M K, ZIMMERMANN S, et al. Energy efficient hotspot-targeted embedded liquid cooling of electronics [J]. Applied Energy, 2015, 138: 414–422.

    [2] UCKERMAN D B, PEASE R F W. High-performance heat sinking for VLSI [J]. IEEE Electron Device Letters, 1981, 2 (5): 126–129.

    [3] CHO H J, PRESTON D J, ZHU Y, et al. Nano-engineered materials for liquid–vapour phase-change heat transfer [J]. Nature Reviews Materials, 2016, 2 (2): 16092.

    [4] FLETCHER N H. Size effect in heterogeneous nucleation [J]. Journal of Chemical Physics, 1958, 29 (3): 572–576.

    [5] KIM S, KIM K J. Dropwise condensation modeling suitable for superhydrophobic surfaces [J]. Journal of Heat Transfer, 2011, 133 (8): 081502.

    [6] DANIEL A, CHRISTOPHE F, BETZ A R, et al. Surface engineering for phase change heat transfer: a review [J]. MRS Energy & Sustainability—A Review Journal, 2014, 1: 1–40.

    [7] MILJKOVIC N, ENRIGHT R, WANG E N. Effect of droplet morphology on growth dynamics and heat transfer during condensation on superhydrophobic nanostructured surfaces [J]. ACSNano, 2012, 6 (2): 1776–1785.

    [8] NAM Y, KIM H, SHIN S. Energy and hydrodynamic analyses of coalescence-induced jumping droplets [J]. Applied Physics Letters, 2013, 103 (16): 161601.

    [9] PARKER A R, LAWRENCE C R. Water capture by a desert beetle [J]. Nature, 2001, 414: 33–34.

    [10] HOU Y, YU M, CHEN X, et al. Recurrent filmwise and dropwise condensation on a beetle mimetic surface [J]. ACS Nano, 2015, 9 (1): 71–81.

    [11] BOREYKO J B, HANSEN R R, MURPHY K R, et al. Controlling condensation and frost growth with chemical micropatterns [J]. Scientific Reports, 2016, 6: 19131.

    [12] XIE J, XU J, HE X, et al. Large scale generation of micro-droplet array by vapor condensation on mesh screen piece [J]. Scientific Reports, 2017, 7: 39932.

    [13] WANG Y, ZHANG L, WU J, et al. A facile strategy for the fabrication of a bioinspired hydrophilic–superhydrophobic patterned surface for highly efficient fog-harvesting [J]. Journal of Materials Chemistry A, 2015, 3 (37): 18963–18969.

    [14] CHATTERJEE A, DERBY M M, PELES Y, et al. Condensation heat transfer on patterned surfaces [J]. International Journal of Heat & Mass Transfer, 2013, 66 (66): 889–897.

    [15] CHATTERJEE A, DERBY M M, PELES Y, et al. Enhancement of condensation heat transfer with patterned surfaces [J]. International Journal of Heat & Mass Transfer, 2014, 71 (4): 675–681.

    [16] CHEN X, DERBY M M. Combined visualization and heat transfer measurements for steam flow condensation in hydrophilic and hydrophobic mini-gaps [J]. Journal of Heat Transfer, 2016, 138 (9): 091503.

    [17] FANG C, STEINBRENNER J E, WANG F M, et al. Impact of wall hydrophobicity on condensation flow and heat transfer in silicon microchannels [J]. Journal of Micromechanics & Microengineering, 2010, 20 (4): 045018.

    [18] DERBY M M, CHATTERJEE A, PELES Y, et al. Flow condensation heat transfer enhancement in a mini-channel with hydrophobic and hydrophilic patterns [J]. International Journal of Heat & Mass Transfer, 2014, 68 (1): 151–160.

    [19] KUMAGAI S, TANAKA S, KATSUDA H, et al. On the enhancement of filmwise condensation heat transfer by means of the coexistence with dropwise condensation sections [J]. Experimental Heat Transfer, 2007, 4 (1): 71–82.

    [20] PENG B, MA X, ZHONG L, et al. Experimental investigation on steam condensation heat transfer enhancement with vertically patterned hydrophobic–hydrophilic hybrid surfaces [J]. International Journal of Heat & Mass Transfer, 2015, 83: 27–38.

    [21] GARIMELLA M M, KOPPU S, KADLASKAR S S, et al. Difference in growth and coalescing patterns of droplets on bi-philic surfaces with varying spatial distribution [J]. Journal of Colloid & Interface Science, 2017, 505: 1065–1073.

    [22] BAI H, WANG L, JU J, et al. Efficient water collection on integrative bioinspired surfaces with star-shaped wettability patterns [J]. Advanced Materials, 2014, 26 (29): 5025–5030.

    [23] MACNER A M, DANIEL S, STEEN P H. Condensation on surface energy gradient shifts drop size distribution toward small drops [J]. Langmuir the ACS Journal of Surfaces & Colloids, 2014, 30 (7): 1788–1798.

    [24] GHOSH A, BEAINI S, ZHANG J, et al. Enhancing dropwise condensation through bioinspired wettability patterning [J]. Langmuir the ACS Journal of Surfaces & Colloids, 2014, 30 (43): 13103–13115.

    [25] HOLMAN J P, GAJDA W J. Experimental Methods for Engineers [M]. 4th ed. New York: McGraw-Hill, 1994

    [26] KIM S M, MUDAWAR I. Universal approach to predicting heat transfer coefficient for condensing mini/micro-channel flow [J]. International Journal of Heat & Mass Transfer, 2013, 56 (1/2): 238–250.

    [27] CAREY V P. Liquid–vapor Phase-change Phenomena [M]. 2nd ed. CRC Press, 2007: 169–172.

    [28] MA X H, LAN Z, WANG K, et al. Dancing droplet: interface phenomena and process regulation [J]. CIESC Journal, 2018, 69 (1): 9–43 (in Chinese).

    [29] WANG H, LIAO Q, ZHU X, et al. Mechanism of liquid droplet movement on surface with gradient surface energy [J]. Journal of Chemical Industry and Engineering (China), 2007, 58 (9): 2313–2320 (in Chinese).

    [30] XIE J, LIU Q, HE X T, et al. Dimensionless critical criterion for the sliding of droplet on tilt surface in shear flow [J]. Journal of Engineering Thermophysics, 2017, 38 (5): 1033–1038 (in Chinese).

This Article

ISSN:0438-1157

CN: 11-1946/TQ

Vol 69, No. 10, Pages 4156-4166+4496

October 2018

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Article Outline

Abstract

  • Introduction
  • 1 Surface preparation and characterization
  • 2 Mini-channel packaging and experimental system
  • 3 Experimental results and discussion
  • 4 Mechanism of enhanced heat transfer in hydrophobic–hydrophilic hybrid channel
  • 5 Conclusion
  • Symbol description
  • References