Numerical investigation of thermo ‑ hydraulic performance enhancement in shell ‑ and ‑ tube heat exchangers via enhanced X ‑ type baffles

This study focuses on optimizing baffle design in shell-and-tube heat exchangers, highlighting the need for an optimal trade-off between heat-transfer enhancement and pressure drop. A computational fluid dynamic (CFD) investigation was conducted under turbulent conditions using the standard k – ε model. The effects of baffle configuration, the number of cuts in the best-performing configuration within the examined cases, and the number of baffles on thermo-hydraulic performance were evaluated. Performance characteristics considered include the shell side heat transfer coefficient (HTC), pressure drop, temperature profile, and the performance evaluation criterion (PEC). Out of the five configurations considered, the X-type II baffle with two cuts was found to provide the best thermo-hydraulic performance, with a maximum PEC of 1.22 at a shell side mass flow rate of 2.5 kg/s. While increasing the number of cuts on the X-type II baffle from four to six led to a marginal PEC variation (from 1.018 to 1.022), it maintained a favorable pressure drop reduction from 1174.7 to 1169 Pa. Finally, the ten-baffle design was found to provide a heat transfer coefficient of 3302.602 W/m² ⋅ K, which was 37% higher than the four-baffle design, with a maximum PEC of 1.13 at higher mass flow rates. This investigation has shown that a six-cut X-type II baffle with ten baffles offers the best thermo-hydraulic compromise.