Numerical comparison of shell-side performance for shell and tube heat exchangers with trefoil-hole, helical and segmental baffles

Abstract

Shell-and-tube heat exchanger, is one of the most widely used heat exchange apparatus in various industrial process and research fronts. Baffle selection is critical to control and improve the thermo-hydraulic performance of this type of heat exchanger. In this paper, three-dimensional computational fluid dynamics (CFD) simulations, using the commercial software ANSYS FLUENT, have been performed to study and compare the shell-side flow distribution, heat transfer coefficient and the pressure drop between the recently developed trefoil-hole, helical baffles and the conventional segmental baffles, at low shell side flow rates. In this numerical comparison, the whole heat exchangers consisting of the shell, tubes, baffles and nozzles are modeled, the numerical model predicts the thermo-hydraulic performance with a considerably good accuracy, by comparing with experimental data for single segmental baffles. The model is then used to compute and compare the thermo-hydraulic performance for the same heat exchanger with trefoil-hole and helical baffles. The results show that the use of helical baffles results in higher thermo-hydraulic performance while trefoil-hole baffles has a higher heat transfer performance with large pressure drop compared to segmental baffles.