Open AccessNumerical study of cooling heat transfer of supercritical carbon dioxide in a horizontal helically coiled tube
Author(s) -
Xiaoxiao Xu,
Yangyang Wu,
Chao Liu,
Kaizheng Wang,
Jian Ye
Publication year - 2015
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.64.054401
Subject(s) - heat transfer coefficient , materials science , heat flux , heat transfer , supercritical fluid , thermodynamics , turbulence , mass flux , nucleate boiling , critical heat flux , tube (container) , churchill–bernstein equation , mechanics , nusselt number , physics , composite material , reynolds number
In the present study, cooling heat transfer of supercritical CO2 in a horizontal helically coiled-tube 4 mm in diameter, 2000 mm in length, a pitch of 10 mm and 0.1 in curvature is numerically investigated with RNG turbulence model. Influences of mass flow rate, heat flux and pressure on heat transfer of supercritical CO2 are studied. The characteristics of the flow and heat transfer are compared with those in a horizontal straight tube. Results show that the secondary flow and heat transfer coefficient in a helically coiled tube is obviously larger than in a horizontal straight tube. The heat transfer coefficient of supercritical CO2 increases with increasing mass flow rate, and the heat transfer coefficient increases slightly as the heat flux increases in the gas-like region, while the heat transfer coefficient is unaffected by heat flux in the liquid-like region. The peak of the heat transfer coefficient decreases and shifts to a higher temperature region as the pressure increases.