Numerical analysis of double pipe heat exchanger using heat transfer augmentation techniques

In the present work, the performance of a Double Pipe Heat Exchanger [DPHE] has been evaluated by Computational Fluid Dynamics (CFD) package [FLUENT 14.0] and the results so obtained have been compared wherever possible. The entire analysis has been done by selecting an existing design of a double pipe heat exchanger with specified flow conditions at the inlet to the heat exchanger. Investigations have been carried out for different heat exchanger configurations by employing twisted tape insert with different twist ratios, regularly spaced twisted tape, and twist in themiddle as well as with protrusion in the outer. Effects of all these inserts on the performance of the heat exchanger have been analyzed in detail. The improved performance with each of the configurations has been reported graphically as well as in the tabular form and the optimum performance has also been indicated. However it has been observed that the enhancement in heat transfer rate is at the expense of pressure drop which has also been evaluated in terms of friction factor.