Experiment on condensation heat transfer and pressure drop characteristics in dimpled flat duct for data center cooling
An experimental study on the condensation heat transfer and pressure drop characteristics in a dimpled flat duct is conducted.The influences of vapor quality,mass flux,saturation temperature and heat flux on the surface heat transfer coefficient and fric-tional pressure gradient are analyzed.The results indicate that under different operation conditions,the surface heat transfer coefficient of R245fa increases with the increase of va-por quality.Increasing mass flux is conducive to the increase of surface heat transfer coef-ficient,especially for the high vapor quality region.The change of saturation temperature affects the surface heat transfer coefficient little in the low vapor quality region,but when the vapor quality is higher than 0.4,the increase of saturation temperature leads to a slight decrease of the surface heat transfer coefficient.Meanwhile,in the whole vapor quality region,different heat fluxes basically affect the surface heat transfer coefficients little.The influences of mass flux and heat flux on friction pressure gradient are similar to those on surface heat transfer coefficient,but the pressure drop decreases obviously with the increase of saturation temperature.Compared with conventional flow paths,the surface heat transfer coefficient and friction pressure gradient of dimpled flat duct are in-creased to 1.7-2.9 times and 4.3-10.9 times,respectively.
data centerheat transfercondensation enhanceddimpled flat ductvapor qualityheat fluxpressure
万方数据
维普
