In the study

the flow condensation heat transfer characteristics of R410A inside a horizontal internal ribbed tube was experimentally investigated

and the influence of hydraulic conditions and structural parameters of a test tube on the refrigerant surface coefficient of heat transfer and pressure drop inside the tube was analyzed. The experimental results indicate that the surface coefficient of heat transfer and pressure drop increase with the increase in the mass velocity and the decrease in the condensation temperature. However

the surface coefficient of heat transfer decreases with the increase in Re of the water flow

and the pressure drop is slightly affected by the Re of the water flow. The surface coefficient of heat transfer under a unit pressure drop was used to evaluate the comprehensive performance of the heat exchanger. The results reveal that it decreases with the increase in the mass velocity

and increases with the increase in the condensation temperature. The experimental data was also compared with the prediction of some classical correlations. For the smooth tube

the correlations obtained by Shah and Thome et al. overestimate the experimental data

and the Thome et al. correlation exhibits the highest prediction accuracy although the correlation obtained by Akers et al. underestimates the experimental data. With respect to the internal ribbed tube

the Cavallini et al. correlation exhibits the highest prediction accuracy

and correlations obtained by Koyama et al. and Miyara et al. underestimate the experimental data.