Optimization of micro-finned tubes in double pipe heat exchangers using particle swarm algorithm

Abstract

In this study, a particle swarm optimization approach is employed to determine the optimal micro-fin geometry which maximizes the thermal efficiency of micro-finned tubes in the double pipe heat exchangers. The considered decision variables of the micro-finned tubes are the number of micro-fins which various from 10 to 60, the micro-fin height varying from 0.0 to 0.5 mm, and the micro-fin helix angle which is between 5 and 30. The study is conducted for the Reynolds number ranging from 3 10 3 to 10 5 and for the inner diameter of the tube equal to 5, 10, 15 mm. The governing equations for the turbulent fluid flow are solved numerically employing the commercial software package ANSYS CFX v.15. The numerical procedure is validated by comparing the simulation results for the nonisothermal flow of water through a micro-finned tube with the experimental results from the literature. The simulation results are then employed in the particle swarm optimization algorithm to optimize the micro-fin geometry. The results indicate that the optimum micro-fin height increases with increasing the Reynolds number. However, the opposite trend is observed for the optimal helix angle.