ISSN Online: 2377-424X
ISBN Print: 978-1-56700-474-8
ISBN Online: 978-1-56700-473-1
International Heat Transfer Conference 16
CONDENSATION PRESSURE DROP CHARACTERISTICS OF R410A INSIDE HORIZONTAL THREE-DIMENSIONAL ENHANCED TUBES
Sinopsis
An experimental investigation was performed for condensation pressure prop characteristics inside three threedimensional
enhanced heat transfer tubes (1EHT-1, 1EHT-2 and 4LB).Three tested stainless steel tubes have the same outer diameter of 9.52mm and inner diameter of 8.32mm. The enhanced tubes are enhanced by grooves, dimples and protrusions in different arrangements. The surface of two 1EHT tubes consists of dimples and petal arrays, while patterns of 1EHT-1 tube is slightly deeper than that of 1EHT-2 tube. For the 4LB tube, the external
surface is enhanced by trapezoid grooves in a net arrangement. Data are for mass fluxes ranging from 150 kg/m2s to 460 kg/m2s and a nominal saturation temperature 45 °C with inlet quality of 0.8 and outlet quality of 0.2, respectively. The results show that the 1EHT-1 tube has the highest pressure drop, and those of 1EHT-2 and 4LB tube are similar. The 1EHT-1 tube shows a higher pressure drop than the 1EHT-2 and 4LB tube due to the deeper dimples, which is effective in increasing turbulence, producing secondary flow patterns and disrupting boundary layer. The Friedel correlation, Beattie and Whalley correlation can well predict the frictional pressure drop of three enhanced tubes compared with the Müller-Steinhagen and Heck correlation.