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

• The heat flux strongly affects the local heat transfer coefficient at low quality.
• The effect of inlet pressure becomes weak with inlet pressure increase.
• The heat transfer coefficient will increase with the mass flux increase.
• Zou et al. correlation gives good agreements with the experimental data.
• Friedel model is recommended to predict the pressure drop roughly.

Two-phase heat transfer and pressure drop of LNG (liquefied natural gas) have been measured in a horizontal smooth tube with an inner diameter of 8 mm. The experiments were conducted at inlet pressures from 0.3 to 0.7 MPa with a heat flux of 8–36 kW m−2, and mass flux of 49.2–201.8 kg m−2 s−1. The effect of vapor quality, inlet pressure, heat flux and mass flux on the heat transfer characteristic are discussed. The comparisons of the experimental data with the predicted value by existing correlations are analyzed. Zou et al. (2010) correlation shows the best accuracy with 24.1% RMS deviation among them. Moreover four frictional pressure drop methods are also chosen to compare with the experimental database.