In this study

one smooth tube and two double-sided enhanced tubes with the same size were used in an experimental study and the boiling heat transfer performance outside the tube with a near-azeotropic refrigerant (R410A) was compared. For the boiling heat transfer outside the smooth tube

the internal surface coefficients of heat transfer calculated by the Cooper and Gorenflo formulas were compared with the empirically calculated value. The results showed that the errors between the two was less than 15%

which verifies the accuracy of the experimental results. With the help of Wilson diagram method

the heat transfer enhancement ratios of the two double-sided enhanced tubes are 1.85–2.05 and 2.02–2.25

respectively. By changing the heat flux

the total heat transfer coefficients of heat exchange tube #1 and heat exchange tube 2# and surface coefficients of heat transfer on both sides of the tube were comprehensively compared. The results showed that the outer surface structure of heat exchange tube 1# was more conducive to the formation of bubbles in the vaporization core because of the different types of reinforced ribs. The total heat transfer coefficients of heat exchange tube 1# was approximately 10% higher than that of heat exchange tube 2#

and the surface coefficient of heat exchange tube 1# was approximately 20%–25% higher than that of heat exchange tube 2#. It indicates that heat exchange tube 1# is more in line with the requirements of pool boiling heat transfer enhancement for horizontal single pipe.