@Article{hmt.15.15,
AUTHOR = {Teng Huang, Xuefang Li

, Lin Cheng},
TITLE = {MODELING OF THE FLOW AND HEAT TRANSFER OF  SUPERCRITICAL CO2 FLOWING IN SERPENTINE TUBES},
JOURNAL = {Frontiers in Heat and Mass Transfer},
VOLUME = {15},
YEAR = {2020},
NUMBER = {1},
PAGES = {1--8},
URL = {http://www.techscience.com/fhmt/v15n1/52908},
ISSN = {2151-8629},
ABSTRACT = {As a non-flammable, non-toxic refrigerant, supercritical CO<sub>2</sub> (ScCO<sub>2</sub>) has been increasingly used for heat transfer applications. In this study, the ScCO<sub>2</sub> flow and heat transfer in a set of full-size three-dimensional serpentine tubes were modeled with different inner diameters and tube pitches. The standard 
k-epsilon model was used for the turbulence modeling. The results show the effect of the different tube inner diameters and tube pitches on the flow 
and heat transfer of ScCO<sub>2</sub> for a given flow flux or inlet Reynolds number. The heat transfer coefficient decreases as both the tube pitch and the inner 
diameter increase for a given mass flow rate. However, for a given inlet Reynolds number, the heat transfer coefficient first increases but then decreases 
with increasing tube inner diameter. The effect of the flow direction on the heat transfer performance was also studied for various inlet conditions. 
Downward flow results in a higher heat transfer coefficient than upward flow for inner diameters larger than 0.5 mm and the buoyancy effect can be 
ignored for <i>Bo</i><1×10<sup>-7</sup> for the conditions studied here. These results can be used to optimize the tube shape and size in heat exchanger designs.},
DOI = {10.5098/hmt.15.15}
}