The effect of tube geometry and hydrophobic coating on the pool boiling heat transfer of refrigerant R134a
ZHANG Chaochao
JI Wentao
Abstract：Boiling heat transfer plays a crucial role in refrigeration and air-conditioning systems.This study experimentally investigates the boiling heat transfer of R134a on smooth tubes and two types of enhanced tubes(with/without hydrophobic coating)at boiling saturated temperatures of 6℃,10℃,and 16℃.The pool boiling heat transfer coefficients of smooth tubes were found to be 19.5％lower than the Cooper correlation.For conventional reentrant cavity tube,the hydrophobic coating showed negligible effects on heat transfer coefficients at low heat flux(q＜60 kW/m2).A heat transfer en-hancement(1.2％～15.0％)emerged when q≥60 kW/m2.For the serrated enhanced tube,the hy-drophobic coating demonstrated consistent heat transfer improvement(7.9％～34.5％)across the en-tire experimental heat flux range(q=20～100 kW/m2).
Keywords：boiling heat transferhydrophobic coatingheat transfer coefficient
Publication Date：2025-06-25
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：9( 72-80 )