Experimental Studies on Heat Transfer Augmentation Using TMT Rods with and without Baffles as Inserts for Tube Side Flow of Liquids.

Abstract

This project deals with the introduction of TMT rods as inserts as passive augmentation device, in the flow path of inner tube side liquid flow. The effect of turbulence on heat transfer & pressure drop was compared with the values for smooth tube. The effect of baffles was also taken into account and again a comparative study was made on the basis of varying the baffle spacing. All the results and readings were compared with the standard data from the smooth tube. Whenever it comes to enhance the heat transfer between the surfaces or in other words augmenting the heat exchanger, the pressure drop does play an important role and becomes another important factor to be considered and to be kept in mind.

Two TMT Rods (di = 8 mm, 10 mm) were used for the experimental purpose. In the beginning we conducted the experiment without any insert to get the value for plane heat exchanger and thereafter the experiment was repeated with TMT Rods ( di = 8mm, 10 mm) without any baffles and with baffles with varying baffle spacing (β=10cm, 20cm, 30cm). The maximum value of performance evaluation criteria R1 was found to be around 2.46 for 10mm insert with β = 10cm and similarly the highest value for fa/fo was found to be around 21.
The friction factor was found to be significantly high and that has been an area of concern and which needs to be minimized.