Experimental Investigation of Pressure Drop during Two-Phase Flow of R1234yf in Smooth Horizontal Tubes with Internal Diameters of 3.2 mm to 8.0 mm

Research output: Contribution to journalArticle


Research units

  • Universidade Federal de Itajubá
  • Universidade Federal de Minas Gerais


In this study, the two-phase pressure drop of R1234yf refrigerant (as an alternative to R134a) in a smooth horizontal tube is investigated. Tests are carried out and under several conditions of vapor quality (0% to 100%), mass velocity (200, 300 and 400 kg/m²s), heat flux (0, 7 and 14 kW/m²) and evaporation temperatures (20°C and 30°C). The internal diameters tested are 3.2 mm, 4.8 mm, 6.4 mm and 8.0 mm. A comparison of pressure drop between R1234yf and R134a is also carried out. The results demonstrate that the two-phase pressure gradient of R1234yf is approximately 20% lower than that of R134a. The experimental data is compared with 19 correlations from the literature. From this comparison, it is concluded that the experimental data are in accordance with the correlation proposed by Xu and Fang with a mean absolute error of 20% and with approximately 65% of the data predicted within a ± 30% error band.


Original languageEnglish
Pages (from-to)426-436
Number of pages11
Early online date18 May 2019
Publication statusPublished - 1 Aug 2019
MoE publication typeA1 Journal article-refereed

    Research areas

  • R1234yf, low GWP refrigerant, pressure drop, two-phase flow, Smooth horizontal tubes, R134a, Pressure drop, Two-phase flow, Low GWP refrigerant

ID: 33881434