To strengthen steam condensation heat transfer, superhydrophilic-hydrophobic hybrid surface is designed. The effects of parameters such as superhydrophilic grid line spacing and wall undercooling on steam condensation heat transfer are studied and superhydrophilic grid line spacing on hybrid surface is 1.5 mm, 2.5 mm and 3.5 mm respectively. The heat transfer performance of hybrid surface compares with smooth surface and hydrophobic surface, and the process of hybrid surface steam condensation is visualized using a high-speed camera. It is found that superhydrophilic-hydrophobic hybrid surface can better regulate the condensate droplet size, and its condensation heat transfer performance is better than that of smooth surface and hydrophobic surface. At △T=4.3 K, the heat transfer coefficient of the 2.5 mm grid spacing hybrid surface is 2.2 times and 1.6 times of the smooth surface and hydrophobic surface respectively. In the three superhydrophilic grid line spacings hybrid surface, the heat transfer performance of 2.5 mm grid spacing hybrid surface is overall best, and at △T=9.0 K, the heat transfer coefficient of the 2.5 mm grid spacing hybrid surface is 1.2 times and 1.8 times of 1.5 mm grid spacing hybrid surface and 3.5 mm grid spacing hybrid surface, respectively.
ZHOU Dongdong
,
JI Xianbing
,
DAI Chao
,
XU Jinliang
. Steam Condensation Heat Transfer Enhancement on Superhydrophilic-Hydrophobic Hybrid Vertical Surface[J]. Journal of Mechanical Engineering, 2018
, 54(10)
: 182
-187
.
DOI: 10.3901/JME.2018.10.182
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