Published Papers
     Search Papers (Springer,
   After 2008)
     Search Papers (Dbpia,
   Until 2007)
     Search Papers (JMST
   own data base)
       - Classification By Year   
       - Classification By Topic
     Special Issues
   
           
   
 
 
Subject Keyword Abstract Author
 
 
Two-phase flow heat transfer of R-134a in microtubes

Yun Wook Hwang/Min Soo Kim
The Journal of Mechanical Science and Technology, vol. 23, no. 11, pp.3095-3104, 2009

Abstract : The characteristics of the two-phase flow heat transfer of R-134a in microtubes with inner diameters of 430 ¥ìm and 792 ¥ìm were experimentally investigated. The effect of the heat flux on the heat transfer coefficient for microtubes was significant before the transition quality. The boiling number expressed the interrelation between the heat flux and the mass about the heat transfer coefficients. The smaller microtube had greater heat transfer coefficients; the average heat transfer coefficient for the tube A (Di = 430 ¥ìm) was 47.0% greater than that for the tube B (Di = 792 ¥ìm) at G = 370 kg/m2⋅s and q" = 20 kW⋅m2. A new correlation for the evaporative heat transfer coefficients in microtubes was developed by considering the following factors: the laminar flow heat transfer coefficient of liquid-phase flow, the enhancement factor of the convective heat transfer, and the nucleate boiling correction factor. The correlation developed in present study predicted the experimental heat transfer coefficients within an absolute average deviation of 8.4%.

Keyword : Microtube; Two-phase flow; Evaporation; Heat transfer coefficient; Correlation

 
 
 
 
 
JMST Editorial Office: #702 KSTC New Bldg, 22 7-gil, Teheran-ro, Gangnam-gu, Seoul 06130, Korea
TEL: +82-2-501-3605, E-mail: editorial@j-mst.org
JMST Production Office: #702 KSTC New Bldg, 22 7-gil, Teheran-ro, Gangnam-gu, Seoul 06130, Korea
TEL: +82-2-501-6056, FAX: +82-2-501-3649, E-mail: editorial@j-mst.org