Hydrocarbons vaporization inside a 4 mm ID horizontal smooth tube

This paper presents some new experimental data collected during R600a flow-boiling inside a 4 mm ID horizontal copper smooth tube. Tests were carried out at 20 °C of saturation temperature, with heat flux ranging from 15 to 30 kW m−2 and refrigerant mass flux in the range 100–300 kg m −2 s −1 at increasing vapor quality up to incipient dryout. On the basis of the heat transfer data, the influence of forced convection and nucleate boiling contributions was investigated. The experimental data were then used to assess some classical literature correlations. Finally, isobutane heat transfer performance was compared with other hydrocarbons (isobutane, and propylene). These latest data were obtained by the same authors under similar working conditions (Longo et al., 2017).