Copper-Based Ultrathin Nickel Nanocone Films with High-Efficiency Dropwise Condensation Heat Transfer Performance

2015 ◽  
Vol 7 (22) ◽  
pp. 11719-11723 ◽  
Author(s):  
Ye Zhao ◽  
Yuting Luo ◽  
Jie Zhu ◽  
Juan Li ◽  
Xuefeng Gao
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Performance ◽  
High Efficiency ◽  
Condensation Heat Transfer ◽  
Transfer Performance ◽  
Dropwise Condensation

Fabrication of copper-based ZnO nanopencil arrays with high-efficiency dropwise condensation heat transfer performance

RSC Advances ◽  
2016 ◽  
Vol 6 (64) ◽  
pp. 59405-59409 ◽  
Author(s):  
Mengnan Qu ◽  
Jia Liu ◽  
Jinmei He
Keyword(s):  
Heat Transfer ◽  
Zinc Oxide ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat Transfer Performance ◽  
High Efficiency ◽  
Condensation Heat Transfer ◽  
Transfer Performance ◽  
Dropwise Condensation ◽  
Condensation Heat Transfer Coefficient

A copper-based zinc oxide nanopencil array film was reported. Compared with hydrophobic flat Cu surface, it exhibits condensate microdrop self-propelling function and maximal ∼140% enhancement in dropwise condensation heat transfer coefficient.

Influence of Ni-P Coating Microstructure on Condensation Heat Transfer

2010 ◽  
Author(s):  
Lin Cheng ◽  
Yanhai Cheng ◽  
Gongming Xin ◽  
Yong Zou
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Performance ◽  
Water Flow Rate ◽  
Amorphous State ◽  
Steel Tube ◽  
Condensation Heat Transfer ◽  
Nanocrystalline Phase ◽  
Transfer Performance ◽  
Dropwise Condensation ◽  
Cooling Water Flow Rate

The higher heat transfer performance due to dropwise condensation as compared with filmwise condensation has been of considerable interest to many researchers around the world. In this study, the effect of microstructure of Ni-P coating on condensation heat transfer performance was reported. The Ni-P deposits with various microstructures, such as nano-crystalline, amorphous and co-existence of both, could be obtained on the low carbon steel tube by adjusting the electroless plating processing parameters. The experimental results show that the steel tube with electroless Ni-P coating can greatly improve the performance of condensation heat transfer compared to un-coated steel tubes. The condensation state on tubes with Ni-P coating depends on the cooling water flow rate and steam temperature, it shows the co-existence state of both dropwise and filmwise on most working conditions. At the same time, the heat transfer efficiency of condensation is improved with the decreasing of the amounts of nanocrystalline phase in Ni-P deposit, because it can increase the free surface energy of surface. Therefore, increasing the degree of amorphous state of Ni-P coating will provide a better dropwise condensation effect.

Influence of Pattern Geometry of Hybrid Surfaces on Dropwise Condensation Heat Transfer and Droplet Dynamics

2018 ◽  
Author(s):  
Karim Egab ◽  
Saad K. Oudah ◽  
M. Alwazzan ◽  
Jamil Khan ◽  
Chen Li
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Rate ◽  
Significant Influence ◽  
Atmospheric Pressure ◽  
Transfer Rate ◽  
Heat Transfer Performance ◽  
Condensation Heat Transfer ◽  
Transfer Performance ◽  
Droplet Dynamics ◽  
Lower Performance

The scope of combining two wettability regions is to impact the droplet dynamic behaviors, manipulate the droplets’ mobility and enhance condensation heat transfer. Hydrophobic-hydrophilic hybrid patterns can promote the heat transfer, droplet-renewal frequency and enhance the droplets’ removal during condensation. With regard of condensation on hybrid surfaces, the geometry of the patterns has a significant influence on droplets departure frequency and heat transfer performance. Therefore, different patterns geometries (circle, ellipse, and diamond) have been developed on horizontal copper tubes at atmospheric pressure. All the patterns have the same size, and the same identical gap as well between the adjacent patterns. Results show that the diamond hybrid surface has the best performance compared with ellipse, circles hybrid surfaces at the same pattern area with same neighbor gap between two patterns and complete dropwise However, the circle and ellipse hybrid surfaces outperform lower performance compared to complete dropwise surface. The heat transfer rate for the diamond hybrid surface is 15% higher than complete dropwise surface when the gap is 0.5mm. This study clearly demonstrated the effect of pattern’s geometry regarding maximum condensation heat transfer rate and droplet departure frequency.

scholarly journals Experimental Study on the Evaporation and Condensation Heat Transfer Characteristics of a Vapor Chamber

Energies ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 11
Author(s):  
Yanfei Liu ◽  
Xiaotian Han ◽  
Chaoqun Shen ◽  
Feng Yao ◽  
Mengchen Zhang
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Transfer Performance ◽  
Condensation Heat Transfer ◽  
Transfer Performance ◽  
Vapor Chamber ◽  
Filling Rate ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Evaporation And Condensation

A vapor chamber can meet the cooling requirements of high heat flux electronic equipment. In this paper, based on a proposed vapor chamber with a side window, a vapor chamber experimental system was designed to visually study its evaporation and condensation heat transfer performance. Using infrared thermal imaging technology, the temperature distribution and the vapor–liquid two-phase interface evolution inside the cavity were experimentally observed. Furthermore, the evaporation and condensation heat transfer coefficients were obtained according to the measured temperature of the liquid near the evaporator surface and the vapor near the condenser surface. The effects of heat load and filling rate on the thermal resistance and the evaporation and condensation heat transfer coefficients are analyzed and discussed. The results indicate that the liquid filling rate that maximized the evaporation heat transfer coefficient was different from the liquid filling rate that maximized the condensation heat transfer coefficient. The vapor chamber showed good heat transfer performance with a liquid filling rate of 33%. According to the infrared thermal images, it was observed that the evaporation/boiling heat transfer could be strengthened by the interference of easily broken bubbles and boiling liquid. When the heat input increased, the uniformity of temperature distribution was improved due to the intensified heat transfer on the evaporator surface.

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