| GAN Yuan-yuan,JI Xian-bin,ZHAO Chang,MENG Yu-hang,MIAO Zheng.Heat Transfer Characteristics of Superhydrophobic High Adhesion Surface and Superhydrophobic Low Adhesion Surface[J],51(7):288-296, 323 |
| Heat Transfer Characteristics of Superhydrophobic High Adhesion Surface and Superhydrophobic Low Adhesion Surface |
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| DOI：10.16490/j.cnki.issn.1001-3660.2022.07.028 |
| KeyWord:superhydrophobic adhesion steam flow dropwise condensation condensation heat transfer air-liquid interface shear force |
| Author | Institution |
| GAN Yuan-yuan |
The Beijing Key Laboratory of Low-grade Energy Multiphase Flow and Heat Transfer,Beijing , China |
| JI Xian-bin |
The Beijing Key Laboratory of Low-grade Energy Multiphase Flow and Heat Transfer,Beijing , China ;The Key Laboratory of Power Station Energy Transfer and System of Ministry of Education, North China Electric Power University, Beijing , China |
| ZHAO Chang |
The Beijing Key Laboratory of Low-grade Energy Multiphase Flow and Heat Transfer,Beijing , China |
| MENG Yu-hang |
The Beijing Key Laboratory of Low-grade Energy Multiphase Flow and Heat Transfer,Beijing , China |
| MIAO Zheng |
The Beijing Key Laboratory of Low-grade Energy Multiphase Flow and Heat Transfer,Beijing , China ;The Key Laboratory of Power Station Energy Transfer and System of Ministry of Education, North China Electric Power University, Beijing , China |
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| Abstract: |
| To further study the condensation heat transfer performance of superhydrophobic surfaces with different adhesion characteristics. Hydrophilic surface, superhydrophobic high adhesion surface and superhydrophobic low adhesion surface were prepared using copper as a substrate. The effects of factors such as surface adhesion, steam volume flow and cooling water flow on the condensation heat transfer were studied. When the volume flow of steam is small, among the three types of surfaces, the superhydrophobic low adhesion surface has the largest condensation heat transfer coefficient due to the lower adhesion force of the droplets. As the steam volume flow rate was equal to 5.0 L/min, the heat transfer coefficients of superhydrophobic high or low adhesion surfaces are 14.5 kW/(m2.K) or 19.8 kW/(m2.K), respectively, which are stronger than hydrophilic surfaces 3.6 times and 4.9 times. With the increase of steam flow, the condensation heat transfer coefficients of the three types of surfaces gradually increase. However, the droplets on the highly adherent surface were subjected to a stronger shearing effect at the gas-liquid interface, and the increase in the heat transfer coefficient was the most significant among the three types of surfaces. When the steam volume flow was large, the condensation heat transfer coefficient of the superhydrophobic high adhesion surface was slightly larger than that of the superhydrophobic low adhesion surface. However, the condensation heat transfer coefficient of the superhydrophobic high adhesion surface was slightly larger than that of the superhydrophobic low adhesion surface when the steam volume flow was large. When the steam volume flow rate was 6.3 L/min, the condensation heat transfer coefficient of the superhydrophobic high adhesion surface can reach 105 kW/(m2.K), which was slightly larger than the condensation heat transfer coefficient of the superhydrophobic low adhesion surface. The size of the adhesive force on the droplet and the degree of shear at the gas-liquid interface determine the droplet shedding diameter and the condensation heat transfer coefficient. Therefore, the curves of the condensation heat transfer coefficient of the two types of superhydrophobic surfaces with the change of the steam volume flow rate have intersection points, and the steam volume flow rate corresponding to the intersection point increases correspondingly with the increase of the cooling water flow rate. |
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