Design optimization of a shell-and-tube heat exchanger with novel three-zonal baffle by using CFD and taguchi method

Abstract

In this study, a novel and innovative baffle design was offered in order to considerably reduce shell side pressure loss without compromising thermal performance. Computational fluid dynamics (CFD) was utilized to simulate and visualize 3-D turbulent flow field in the shell side so as to investigate various shapes of baffles for preliminary baffle design purposes. The simulation results showed that a so-called three-zonal baffle could be superior over the several other configurations considered. The set of design parameters was then identified for this shape of baffle and Taguchi method was employed to determine candidate design configurations for optimum. With the optimized design of shell-and-tube heat exchanger (STHE) with new baffle configuration, it was found that thermal performance of the heat exchanger with three-zonal baffles was slightly improved, whereas shell-side pressure drop was significantly decreased compared to the conventional baffled STHE. The shell side pressure loss was found to lower by 49%, accompanying an increase in the shell side temperature difference up to 7%. In addition, CFD analyses of the optimized STHE with three-zonal baffles were performed considering specific boundary conditions, and the results were validated with the experimental data obtained under the same conditions. The results showed that the differences between CFD analyses and experimental data were maximum 7.3% for heat transfer rate and 7.6% for the pressure drop. It was concluded that the three-zonal baffles improved the STHE performance in terms of both heat transfer rate and pressure loss points of view.