Numerical Simulations of Shell and Tube Heat Exchanger with Segmental, Trefoil and Segmented Trefoil Baffles for Performance Comparison

Abstract

Shell and tube heat exchangers (STHX) are the most abundantly used heat exchangers in the industry. Baffles are the most important component involved in improving the thermohydraulic performance of STHXs. In this study, we propose a novel segmented trefoil baffle (STB) formed by imposing trefoil holes on segmental baffles (SGB). Numerical simulations have been conducted using ANSYS FLUENT 19.2 for SGBs, trefoil hole baffles (THB), and STBs at various mass flow rates to compare the heat transfer coefficients, pressure drop, thermohydraulic performance, and shell side flow distribution. Results indicate that for almost the same heat transfer coefficient, the pressure drop is significantly less for the STBs compared with the SGBs. A study of the flow field revealed that large dead zones, typical of SGBs, reduce significantly when STBs are used. Similarly, the recirculation zones, reported for THBs also decrease by incorporating the STBs. The thermohydraulic performance is enhanced by 41% and 235% compared to SGBs and THBs respectively by using the STBs. An increase in the number of baffles from 6 to 10 further enhanced the advantage of STBs over the segmental baffles from 41% to 57%. The inclusion of baffles to shell and tubes clearances does not affect the superior thermohydraulic performance of STBs over SGBs.

Disclosure statement

There are no relevant financial or non-financial competing interests to report.

Additional information

Notes on contributors

Muhammad Saad

Muhammad Saad earned his B.Sc. degree in mechanical engineering from NWFP University of Engineering and Technology (UET), Peshawar, Pakistan. He obtained fifth position in his bachelor program. His research interests include CFD, fluid mechanics, heat exchangers, and machine design.

Altamash Munir

Altamash Munir earned his B.Sc. degree in mechanical engineering from NWFP University of Engineering and Technology (UET), Peshawar, Pakistan. He obtained first position in his bachelor program in a batch of 180 students. His research interests include CFD, heat and mass transfer, fluid mechanics, and heat exchangers.

Muhammad Ali Kamran

Muhammad Ali Kamran received his B.Sc. (Hons) degree from NWFP University of Engineering and Technology (UET), Peshawar, Pakistan and Ph.D. from Loughborough University, United Kingdom. He is currently Associate Professor at UET Peshawar. His research interests include computational fluid dynamics, heat transfer, heat exchangers, and renewable and conventional energy systems. He serves as a regular reviewer of various scientific journals.