Performance enhancement of disc-and-doughnut shell and tube heat exchangers through various tube layouts and ternary nanoparticle integration

This work is aimed at enhancing the performance of the disc-and-doughnut shell-and-tube heat exchangers (STHXs) by investigating various tube geometrical arrangement configurations in concert with the addition of ternary nanoparticles. The geometrical configurations that a bundle of tubes could assume are triangular 30°(STHX-T), rotated triangular 60°(STHX-RT), horizontal 90°(STHX-SH), vertical 90°(STHX-SV), combined (STHX-C) at different shell-side mass flow rates with the aim of arriving at the most efficient one for maximum heat transfer with a minimum pressure drop. Numerical simulations using ANSYS FLUENT provided insights into the impact of each layout on thermal efficiency and hydraulic resistance. The overall heat transfer coefficient (OHT), pressure drop (PD), cold and hot fluid temperature, the ratio of HT to PD (Q / Po), and exergy were utilized to compare the investigated STHXs collectively. Based on numerical results at a shell-side mass flow rate of 2 kg/s, the triangular 30° STHX produced the greatest OHT, differing from the combined STHX by 46.03 W/m2.K, which displayed the lowest OHT. Also, Q / Po of the combined STHX demonstrated higher target efficiency than the other configurations. At a mass flow rate of 1.6 kg/s, its heat transfer to pressure drop ratio increased by 79.73 % compared to the triangular 30° STHX. Among the tested fluids, the 5 % ternary nanoparticle concentration delivers the best performance. While increasing the nanoparticle volume fraction enhances heat transfer, it also leads to a rise in PD. In this compromise, the 5 % concentration is optimal. This paper proposes a new concept in optimizing STHX by combining advanced tube configurations with the use of nanoparticles-enriched fluids, hence providing a new route for the improvement of thermal control in heat exchangers for many industries.