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High heat flux flow boiling in silicon multi-microchannels. III. Saturated critical heat flux of R236fa and two-phase pressure drops.

Author(s) : AGOSTINI B., REVELLIN R., THOME J. R., et al.

Type of article: Article

Summary

New experimental critical heat flux results for saturated boiling conditions have been obtained for R236fa flowing in a silicon multi-microchannel heat sink composed of 67 parallel channels, 223 µm wide, 680 µm high and with 80 µm thick fins separating the channels. The microchannel length was 20 mm. The footprint critical heat fluxes measured varied from 112 to 250 W/cm2 and the wall critical heat fluxes from 21.9 to 52.2 W/cm2 for mass velocities from 276 to 992 kg/m2.s. When increasing the mass velocity, the wall critical heat flux was observed to increase. The inlet saturation temperatures (from 20.31 to 34.27°C) and the inlet subcoolings (from 0.4 to 15.3 K) were found to have a negligible influence on the saturated CHF. The best methods for predicting the data were those of Wojtan et al. and Revellin and Thome. They both predict the experimental CHF results with a mean absolute error of around 9%. Using the critical vapour quality, an annular-to-dryout transition is also proposed as a limit in a diabatic microscale flow pattern map. Pressure drop measurements were measured and analysed, showing that the homogeneous model could correctly predict the observed trends. [Reprinted with permission from Elsevier. Copyright, 2008]. See also this Bulletin, references 2009-0060 and 0061.

Details

  • Original title: High heat flux flow boiling in silicon multi-microchannels. III. Saturated critical heat flux of R236fa and two-phase pressure drops.
  • Record ID : 2009-0059
  • Languages: English
  • Source: International Journal of Heat and Mass Transfer - vol. 51 - n. 21-22
  • Publication date: 2008/10

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