An analysis of saturated critical heat flux in micro/mini-channels

Research output: Chapter in Book/Report/Conference proceedingPaper in conference proceeding

Abstract

This paper verified the macro-to-micro-scale transitional criterion BoRel 0.5 = 200 proposed by Li and Wu [W. Li, Z. Wu, A general criterion for evaporative heat transfer in micro/minichannels, International Journal of Heat and Mass Transfer 53 (2010) 1967-1976] because data points where BoRel 0.5 ≤ 200 and BoRel 0.5 > 200 show very different trends for the entire database (1,672 data points). For the 859 data points with BoRel 0.5 ≤ 200, the boiling number at CHF decreases greatly with length-to-diameter ratio Lh/dhe when Lh/dhe is small, while Lh/dhe presents negligible effect on the boiling number when Lh/dhe < 150. For the region where L h/dhe ≤ 150 and BoRel 0.5 ≤ 200, a simple saturated CHF correlation was proposed by using the boiling number, length-to-diameter ratio, and exit quality. Heated length and heated equivalent diameter were adopted in the length-to-diameter ratio, considering the actual heat transfer conditions. A combined dimensionless number We mCal 0.8was introduced to correlate the micro/mini-channel database for the region: Lh/dhe > 150 and BoRel 0.5 ≤ 200. The new method can predict the overall micro/mini-channel database accurately on the whole. It can predict almost 95.5% of the non-aqueous data and 93.5% of the water data within the ± 30% error band.

Details

Authors
External organisations
  • Zhejiang University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Energy Engineering

Keywords

  • Boiling number, Capillary number, Length-to-diameter ratio, Microchannel, Saturated critical heat flux (CHF), Weber number
Original languageEnglish
Title of host publicationASME 2010 8th International Conference on Nanochannels, Microchannels, and Minichannels Collocated with 3rd Joint US-European Fluids Engineering Summer Meeting, ICNMM2010
Pages137-146
Number of pages10
EditionPARTS A AND B
ISBN (Electronic) 978-0-7918-3880-8
Publication statusPublished - 2010 Dec 1
Publication categoryResearch
Peer-reviewedYes
Externally publishedYes
EventASME 2010 8th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM2010 Collocated with 3rd Joint US-European Fluids Engineering Summer Meeting - Montreal, QC, Canada
Duration: 2010 Aug 12010 Aug 5

Conference

ConferenceASME 2010 8th International Conference on Nanochannels, Microchannels, and Minichannels, ICNMM2010 Collocated with 3rd Joint US-European Fluids Engineering Summer Meeting
CountryCanada
CityMontreal, QC
Period2010/08/012010/08/05