Abstract
The Shell-and-tube heat exchangers (STHE) used in many industries to maintain high thermal efficiency are limited by the incorporated baffles, which cause a relatively large pressure drop, and thus lower overall performance. These limitations and the demand for energy-saving, necessitate the development of new baffles with enhanced performance capabilities. This research aims to examine numerically the impact of Sinusoidal Baffle (SB) amplitude (in the range of 2 mm to 10 mm) and pitch (in the range of and 10 to 50 mm) on the thermal-hydraulic performance of STHE using finite element-based computational fluid dynamic, COMSOL Multiphysics software version 5.3. The Thermal Performance Factor (TPF) of the various baffles is determined using the flow field data, such as velocities, temperatures, and pressure, obtained from the numerical simulation. Additionally, experiment was conducted to validate the accuracy of the numerical results. Both the numerical simulation and the experimental results concur. The results of the TPF of the STHE with SB for all amplitudes and pitches using air-water two-phase mixture range from 1.294 to 1.484. The highest TPF occurs at SB with 2 mm amplitude and 20 mm pitch, while the lowest TPF occurs at 10 mm amplitude and 10 mm pitch. Additionally, highest heat transfer coefficient and lowest pressure drop was provided by STHE with 2 mm amplitude and 20 mm sinusoidal baffles with the TPF of 1.42, which translates to an energy savings of more than 40%. This study established that using sinusoidal baffles can enhance heat exchanger performance.

Key words: Shell-and-tube heat exchanger, Sinusoidal baffles, Two-phase flow, Thermal performance factor.