Effect of straight micro fins on heat transfer and pressure drop of R410A during evaporation in round tubes

Cheng Min Yang, Predrag Stojan Hrnjak

Research output: Contribution to journalArticlepeer-review

Abstract

The objective of this paper is to present the influence of straight micro-fins on heat transfer coefficient and pressure drop. R410A flow boiling experiments were conducted in both smooth tube and the axial micro-finned tube. Data are taken at 10 °C saturation temperature for the vapor quality from 0.1 to 0.9, mass flux from 100 to 450 kg/s-m2, and heat flux from 10 to 20 kW/m2. The results in the smooth tube were compared with several correlations and used as a baseline. It was observed that straight micro-fin structure played an important role in the evaporative heat transfer. The heat transfer coefficient was significantly enhanced in the axial micro-finned tube, whose enhancement factor ranged from 1.03 to 1.48 with average of 1.34. As the mass flux and vapor quality was low, the straight micro-fins had stronger influence of the heat transfer coefficient since the liquid-phase refrigerant was easily trapped in the grooves of the axial micro-finned tube. The pressure drop penalty factor of the axial micro-finned tube ranged from 0.66 to 1.6, and the average was around 1.23.

Original languageEnglish (US)
Pages (from-to)924-939
Number of pages16
JournalInternational Journal of Heat and Mass Transfer
Volume117
DOIs
StatePublished - Feb 2018

Keywords

  • Axial micro-finned tube
  • Evaporation
  • HTC
  • Pressure drop
  • R410A
  • Straight micro fin

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Mechanical Engineering
  • Fluid Flow and Transfer Processes

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