Diverging small channel for condensation heat transfer enhancement

• Published in: International journal of heat and mass transfer 2019-04, Vol.133, p.218-225
• Main Authors: Bai, Chao, Cao, Hongzhen, Zhang, Guanmin, Tian, Maocheng
• Format: Article
• Language: English
• Subjects: Channel size; Channels; Condensation; Condensation heat transfer enhancement; Diverging channel; Flux density; Heat transfer; Product design; Refrigerant mass flux density; Small channel
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2018.11.144

•Diverging channel can significantly enhance condensation heat transfer.•Reducing channel size is more efficient in improving condensation performance.•As diverging angle increases, condensation is improved more efficiently.•As refrigerant mass flux density increases, condensation is improved more efficiently.•As channel size decreases, condensation performance can be more efficiently improved. Small channel heat transfer with condensation or boiling is utilized to handle the more and more intense heat dissipation load nowadays. To further enhance the annular condensation heat transfer inside these channels, diverging-shaped small channel is considered in this work analytically. It is testified that diverging channels do improve condensation heat transfer significantly compared to small channels with constant cross-sectional area. With refrigerant mass flux density increasing or channel size decreasing, diverging channels become more and more efficient in enhancing condensation heat transfer.