Application of soft computing techniques to optimize thermal parameters in a double heat exchanger with cylindrical turbulators

In the present study, the dimensions of the cylindrical turbulators have been optimized to achieve the highest thermal performance. A double pipe heat exchanger with cylindrical turbulators placed in the annulus side is modeled and a numerical simulation is carried out for different operating conditions. The simulation is conducted for different diameters of the turbulators for various Re for the annulus fluid. The Nusselt number (Nu), friction factor (f), and thermohydraulic performance index (THPI) are the responses simulated for the above different cases of input conditions. Response surface methodology has been used to study the influence of operating parameters on the responses. It is observed that Nu, f, and THPI increased as the Re and turbulator diameter increased. Response optimizer is used to optimize the turbulator diameter to obtain the highest thermal performance in terms of highest Nu and THPI and lowest f. The results indicated that maximum performance was obtained for a diameter of 4.45 mm and for a Re of 5530. The Nu and THPI corresponding to the above combinations are 68.4 and 2, respectively.