Boiling heat transfer of co- and counter-current microchannel heat exchangers with gas heating

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

6 Scopus Citations
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Author(s)

Detail(s)

Original languageEnglish
Pages (from-to)20-29
Journal / PublicationInternational Journal of Heat and Mass Transfer
Volume56
Issue number1-2
Online published23 Oct 2012
Publication statusPublished - 1 Jan 2013
Externally publishedYes

Abstract

In this paper, we present an experimental study on a two-phase boiling heat transfer of liquid methanol in co- and counter-current microchannel heat exchangers (MCHEs) with gas heating. The silicon-based MCHE with dimensions of 20 × 20 × 2 mm is designed with 18 microchannels. The working fluids on the hot and cold sides of the MCHE are helium and liquid methanol, respectively. During the study, the helium fluid inlet temperature is varied from 40 to 250 °C, while the mass flux is fixed at 10 kg/m2s; additionally, the mass flux of the liquid methanol is varied from 3 to 9 kg/m2s, and the inlet temperature is varied from room temperature to the saturation temperature of methanol, depending on the hot-side heat flux. The results demonstrate that the convective boiling heat transfer increases with the mean vapor quality until approaching the critical heat flux (CHF) condition. The counter-current MCHE exhibits a higher CHF due to a higher inlet subcooling temperature than the co-current MCHE. The single-phase and convective boiling heat transfer coefficients are measured and compared with the existing correlations. Moreover, two empirical correlations for the two-phase boiling heat transfer coefficient for the MCHEs are proposed in this study.

Research Area(s)

  • Boiling heat transfer, Microchannel heat exchanger, Two-phase flow