@Article{fdmp.2020.010951,
AUTHOR = {Daoming Shen, Xia Zhang, Wei He, Jinhong Xia, Songtao Xue},
TITLE = {Heat Transfer Enhancement Using R1234yf Refrigerants in Micro-Ribbed Tubes in a Two-Phase Flow Regime},
JOURNAL = {Fluid Dynamics \& Materials Processing},
VOLUME = {16},
YEAR = {2020},
NUMBER = {6},
PAGES = {1259--1272},
URL = {http://www.techscience.com/fdmp/v16n6/40845},
ISSN = {1555-2578},
ABSTRACT = {Experiments about heat transfer in the presence of a two-phase flow due
to the condensation of a R1234yf refrigerant have been performed considering a
smooth tube and two micro-fin tubes. The following experimental conditions have
been considered: Condensation temperatures of 40°C, 43°C and 45°C, mass
fluxes of 500–900 kg/(m<sup>2</sup>
·s), vapor qualities at the inlet and outlet of the heat
transfer tube in the ranges 0.8–0.9 and 0.2–0.3, respectively. These tests have
shown that: (1) The heat transfer coefficient increases with decreasing the condensation temperature and on increasing the mass flux; (2) The heat transfer coeffi-
cient inside the micro-fin tube is larger than that for the smooth tube; (3) The
heat transfer enhancement factors for the micro-fin tube with a fin helical angle
of 8° and 15° are 2.51–2.89 and 3.11–3.57, respectively; both are higher than
the area increase ratio. These experimental results have been compared with correlations available in the literature: the Cavallini et al. correlation has the highest
accuracy in predicting the heat transfer coefficient inside the smooth tube, the
related percentage error and the average prediction error are ±8% and 0.56%,
respectively; for the micro-fin tube these become ±25% and 6%, respectively.},
DOI = {10.32604/fdmp.2020.010951}
}