Flow patterns of some new low GWP refrigerants during evaporation in small tube

Houpei Li, Pega Hrnjak

Research output: Chapter in Book/Report/Conference proceedingConference contribution


This paper reports visualization results of two-phase flow of R1233zd(E) and R1336mzz(Z) in a 24-port microchannel tube. The tube has an averaged hydraulic diameter of 0.643 mm. Mass flux is in the range from 50 to 200 kg-m-2s-1. Flow patterns are classified as plug/slug, transitional, and annular flow. In plug/slug flow, a clear interface between liquid slug and vapor plug is observed. In transitional flow, the interface between vapor plug and liquid slug is broken and becomes a thick liquid ring and vapor bridge. In annular flow, only liquid film is observed in the tube. Both mass flux and vapor density strong affect the flow pattern because they affect the flow velocity. The results are compared to other fluids tested on the same facility: R32, R134a, R1234ze(E), and R1234yf. R134a, R1234ze(E), and R1234yf have similar flow patterns at the same condition. Both R1233zd(E) and R1336mzz(Z) also have similar flow patterns because they have similar properties.

Original languageEnglish (US)
Title of host publicationICR 2019 - 25th IIR International Congress of Refrigeration
EditorsVasile Minea
PublisherInternational Institute of Refrigeration
Number of pages8
ISBN (Electronic)9782362150357
StatePublished - 2019
Event25th IIR International Congress of Refrigeration, ICR 2019 - Montreal, Canada
Duration: Aug 24 2019Aug 30 2019

Publication series

NameRefrigeration Science and Technology
ISSN (Print)0151-1637


Conference25th IIR International Congress of Refrigeration, ICR 2019


  • Flow pattern
  • HFO
  • Microchannel
  • Refrigerant
  • Visualization

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Electrical and Electronic Engineering
  • Mechanical Engineering
  • Condensed Matter Physics


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