CFD Study of Tube in Tube Heat Exchanger with Helical Insert of Different Height and Helical Groove

摘要

In the present study helical groove and helical insert of different height are introduced on the inside surface of inner tube of tube in tube heat exchanger, heat transfer and flow characteristics of the exchanger containing inserts and grooves are analysed and comparison is made. Width of insert and groove is taken 0.5mm and height of groove is taken 0.5mm, although for the inserts three different height are taken which are 0.5mm, 1mm, 1.5mm. Helix of pitch is 100 mm provided to all inserts and grooves. Heat exchangers with all the inserts and grooves are analysed numerically through ANSYS 14.5. Heat and flow parameter were calculated for four different Reynold number 1685.03, 3370.07, 5055.10 and 6740.13 corresponding to the flow rate of 50, 100, 150 and 200 LpH and then comparisons in made. By the study of results it is found that the values of heat transfer coefficient, pressure drop and friction factor are higher for heat exchanger with the insert then the exchanger with the groove. further heat transfer coefficient, friction factor and pressure drop all increases as the height of insert increases.