Modeling of pressure drop and heat transfer for flow boiling in a mini/micro-channel of rectangular cross-section

• Published in: International journal of heat and mass transfer 2019-09, Vol.140, p.1029-1054
• Main Authors: Jain, Shashwat, Jayaramu, Prasanna, Gedupudi, Sateesh
• Format: Article
• Language: English
• Subjects: Boiling; Bubbles; Compressibility; Flow boiling; Flow reversal; Heat transfer; Heat transfer coefficient; Heat transfer coefficients; Microchannel; Microchannels; One dimensional models; Pressure drop; Pressure effects; Shear stress; Variations
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2019.05.089

•A flow boiling model combining pressure and heat transfer coefficient is proposed.•The heat transfer model considers five zones for a rectangular mini/micro-channel.•Transient and time-averaged pressure drop and heat transfer coefficient are evaluated.•Effect of shear stress at liquid-vapour interface on thin film depletion is considered.•Heat transfer characteristics are studied without and with flow reversal. In the present study, a one-dimensional model is proposed to estimate the pressure drop and heat transfer coefficient for flow boiling in a rectangular microchannel. The present work takes into account the pressure fluctuations caused due to the confined bubble growth and the effect of pressure fluctuations on the heat transfer characteristics. The heat transfer model considers five zones, namely, liquid slug, partially confined bubble, fully confined (elongated) bubble, partial dryout and full dryout. The model incorporates the thinning of liquid film due to shear stress at liquid-vapour interface in addition to evaporation. The transient fluctuations in pressure and heat transfer coefficient, along with the time-averaged ones, are verified with the experimental data available in the literature. Heat transfer characteristics with flow reversal caused by inlet compressibility are also presented.