Study On Heat Transfer Enhancement In Tube With Swirl Flow Generators

In industry, a small improvement in efficiency can result in sizable economic benefits. Influence of strip self-rotating plastic spiral element inserted in a tube on heat transfer enhancement is studied experimentally. The strip consist of 100 self- rotating spiral elements made of plastic PC (Polycarbonate) inserted in the inner tube of counter-current heat exchanger with a view to generating swirl flow that helps to increase the heat transfer rate of the tube. The flow rate of the tube is considered in a range of Reynolds number between 6600 to 22000 based on the mean properties and inner tube diameter. The swirling flow devices inserted in the inner tube of a concentric tube heat exchanger. Cold water is flowed in the annulus whereas the hot water flowed in the inner tube. The experimental data obtained from the smooth tube are compared with the data available in literature. Experimental results confirmed that the uses of self-rotating plastic spiral elements give the higher overall heat transfer coefficient than the smooth tube. Also leads to higher Nusselt number which increases about 130% when compared with the smooth tube, the average Nusselt number obtained from the present work for the smooth tube differ than correlated values for the average Nusselt number presented by Dittus and Boelter with in 13.1%-20.8%, This technology not only use for heat transfer enhancement but also can be used for self cleaning deposition fouling in heat exchanger.