Abstract: Heat transfer enhancement techniques are widely used in areas such as process industries, air conditioning and refrigeration system, heat recovery process, chemical reactors etc. Passive techniques, where inserts are used in the flow passage to augment the heat transfer are advantageous compared to the active techniques, because they are simple to manufacture, cheap and they can be easily employed in an existing heat exchanger. Presently passive methods are most popular to enhance the heat transfer in heat exchanger. A wide range of inserts are used, particularly when turbulent flow is considered. This paper presents a critical review on different passive heat transfer augmentation techniques such as twisted tapes, wire coils, fins and ribs, which are the most commonly used passive heat transfer augmentation tools.

Keywords: Baffles, Fins, Heat Transfer Enhancement, Ribs, Twisted Tape, Wire Coil.

| DOI: 10.17148/IARJSET.2020.7506