Two-phase heat transfer and pressure drop of propane during saturated flow boiling inside a horizontal tube

• A study of flow boiling for propane in a horizontal tube was performed.
• HTC increases with mass and heat flux, for saturation temperature at high heat flux conditions.
• HTC can either increase with quality, remain constant, or decrease with quality.
• Pressure gradient increases with mass and heat flux, but decreases with saturation temperature.
• Both the HTC and pressure gradient results were compared to several predicted correlations.

Comprehensive heat transfer coefficient and pressure drop data of the two-phase saturated flow boiling for propane were obtained in a smooth horizontal tube at conditions covering mass fluxes from 62 to 104 kg m−2 s−1, heat fluxes from 11.7 to 87.1 kW m−2, and saturated temperatures from −35.0 to −1.9 °C. Results indicate that heat transfer coefficients increase with mass and heat flux. For saturation temperature and vapor quality, distinct variation trends were observed depending on different test conditions. The heat transfer experimental data were compared with five well-known correlations. Among those, Liu–Winterton correlation shows the best agreement with a mean absolute relative deviation less than 10%. For two-phase frictional pressure gradients, the influences of saturation temperature, mass flux and vapor quality were also presented. The predicted method of Müller-Steinhagen & Heck correlation gives the best fit to the data with a mean absolute relative deviation less than 20%.