Numerical investigation of foam baffle designs for enhanced thermal-hydraulic performance in shell and tube heat exchangers

Abstract

This study aims to develop and evaluate an innovative design of a shell and tube heat exchanger (STHX) featuring porous sectional baffles to enhance its thermal and hydraulic performance (TPF). A numerical investigation based on computational fluid dynamics (CFD) is conducted to analyze the TPF of STHX. A parametric study is performed to evaluate the effects of baffle inclination angle and double cut ratio design on heat transfer and pressure drop characteristics. The model included six metal foam baffles with an initial cut ratio of 20 % (MFBs), and its performance was compared to that of a conventional heat exchanger with solid baffles. The effect of foam baffle inclinations at various angles (0°,10°, 20°, 30° and 30° parallel) was also analysed. Also, the effect of the double-cut ratio of the foam baffle (2×10 %, 2×15 %, 2×20 %, and 2×10 % parallel) over a range of mass flow rates between 1.2 and 2.0 kg/s and R e range (11000-16000). The results showed that the use of MFBs lead to a maximum reduction of ∆ P by 32 % with (2×10 %) design at 2 kg/s accompanied by a significant improvement in TPF. Furthermore, a 30° baffle inclination improved the TPF to 2.207 at (1.2 kg/s), accompanied by a 50 % increase in N u and a 25.5 % reduction ∆ P . The best TPF was recorded at the ratio (2×10 %), where the (TPF) = 2.389 at 1.2 kg/s, with a N u improvement of 54.4 % compared to a solid baffle. The obtained results provide useful design guidelines for STHXs widely used in energy, petrochemical, and chemical processing industries.