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Indexed by:期刊论文

Date of Publication:2016-09-01

Journal:EXPERIMENTAL THERMAL AND FLUID SCIENCE

Included Journals:SCIE、EI、Scopus

Volume:76

Page Number:45-56

ISSN No.:0894-1777

Key Words:Microchannel; Condensation; Frictional pressure drop; Two-phase pressure drop multiplier

Abstract:The characteristics of two-phase pressure drop for steam condensation in trapezoidal microchannels with different cross-sectional geometries via novel experimental facility and specific analytical method were investigated in this study. Three types of multi-port trapezoidal microchannels with hydraulic diameter range of 134-166 mu m and aspect ratio range of 3.1-6.7, were employed. The pressure drop was determined under steam mass flux between 130 and 340 kg m(-2) s(-1) accompanied with various cooling water volume flow rate ranging from 20 to 40 L h(-1). The results showed that the total frictional, deceleration and contraction pressure drop were more obvious than other local pressure drop. It also presented that not only the steam mass flux, steam quality, cooling water volumetric flow rate and hydraulic diameter but also the aspect ratio had a significant influence on the two-phase frictional pressure drop. The comparison between the experimental data and existing models were finally carried out to verify their predictive accuracy for steam condensing flows in microchannels, and accordingly a modified Friedel model was proposed. The model considering the effect of geometrical parameters of microchannels, the forces acting on fluid and fluid properties, can be available to predict the steam condensing two-phase flow pressure drop multiplier for liquid flowing alone. (C) 2016 Elsevier Inc. All rights reserved.