Thermal efficiency evaluation in shell-and-tube heat exchangers: A CFD-based parametric study

Abstract

In this study, a novel approach was employed to enhance the performance of a Bowman brand EC-2028 shell-and-tube heat exchanger (STHE) by introducing perforated plates. The heat exchanger was first tested in a real system within a laboratory environment to establish baseline performance data. Computational fluid dynamics (CFD) analysis revealed that flow velocities in the middle tubes were higher due to their alignment with the main flow direction, resulting in decreased heat transfer efficiency. To address this issue, a perforated plate with concentric circles was introduced at the cold fluid entry. This plate, devoid of central holes, featured circles with radii of 9, 18, 27, 36, 45, 54, and 63 mm, each containing 6, 10, 17, 24, 30, 36, and 42 equidistant holes, respectively. The introduction of the perforated plate led to a decrease of approximately 0.33°C in the hot outlet temperatures, indicating an improvement in heat transfer efficiency. To further enhance performance, various configurations were tested by progressively closing holes from the innermost to the outermost circles. Eight different configurations, including the control, were evaluated under counterflow conditions. The CFD model was validated with experimental data before introducing the perforated plates, ensuring the accuracy of the simulations. The findings demonstrated significant improvements in heat transfer efficiency, with the optimized perforated plate configurations leading to more uniform flow distribution and reduced pressure drops. This study's novel approach of using perforated plates to modulate flow and enhance thermal performance highlights a new avenue for optimizing STHE designs, contributing to more efficient thermal management solutions in industrial processes.