Augmentation of Heat Transfer and Pressure Drop Characteristics Inside a Double Pipe U-Tube Heat Exchanger by using Twisted Tape Inserts

摘要

A twisted tape is inserted into a double pipe u-tube heat exchanger with a view to generate swirl flow, thereby enhancing the heat transfer rate of the fluids flowing in it. Experimental investigations of heat transfer enhancement and variation of friction factor have been presented for a typical test section of a u-tube double pipe heat exchanger involving a circular tube filled with a full length insert. The flow is under forced convection with Reynolds Number varying from 3,000 to 31,000. From the experimental data, heat transfer coefficient, friction factor, and thermal performance with the twisted tape inserts were calculated and compared with the plain tube data. The results show that there were a significant increase in heat transfer coefficient, friction factor, and it was found that the thermal Performance of smooth tube is better than the full length twisted tape by 2.0-2.2 times.