R14 flow condensation heat transfer performance: Measurements and modeling based on two-phase flow patterns

•Flow condensation heat transfer characteristics of R14 were studied experimentally.•The effects of mass flux, saturation pressure, heat flux and vapor quality were analyzed.•Fifteen well-known flow condensation correlations were compared with the experimental data of R14.•An improved flow pattern-based heat transfer model was developed.•This new model can well predict 1370 data points from nine published literature.