An Updated Review of Heat Transfer Enhancement Techniques in Tube-Type Heat Exchangers

The present study reviews the heat transfer intensification techniques utilized by the researchers in recent decades. By discussing the methods of augmentation of heat transfer, the study confined to passive techniques which are being used in tube-type heat exchangers. The passive techniques of heat transfer intensification in tubular heat exchangers include surface modification, extended surfaces, artificial roughness, and the insertion of turbulence enhancement devices like winglets, baffles, twisted tape inserts, etc. The prime objective of the enhancement devices is to break the thermal boundary layer and to change the pattern of the flow inside the tube. Nanofluids additionally play a sizable position due to their better thermal conductivity. In the present review, the vital investigations associated with nanofluid usage in tubular heat exchangers have additionally included.