Numerical study on vibration-enhanced heat transfer characteristics of helical elastic tube bundle with ovality considered

Helical elastic tube bundle heat exchangers (HETB) have garnered significant interest in the industry due to their exceptional vibration-enhanced heat transfer performance. To clarify the vibration response and heat transfer characteristics of the HETB with different ovality considering the shell-side flow-induced tube vibration, the working processes of the helical elastic bundle heat exchangers with different ovality were numerically simulated. The results show that, as the ovality increases, the average vibration amplitude of the tube bundles decreases first and then increases, and the minimum value is 0.019 mm when the ovality is 1. Moreover, with the increase of the ovality, the average vibration frequency of the four tube bundles first increases and then decreases, and the maximum value is 34.014 Hz when the ovality is 1. The average heat transfer coefficients are 1134.94, 1207.57, 1239.29, and 1193.79 W center dot m(-2)center dot K-1 when the ovality of the tube is 1/3, 1/2, 1, 2/1, and 3/1, respectively, which are 3.11 %, 5.03 %, 6.30 %, 11.54 % and 4.76 % higher than that of the tube without vibration. In the parameter range of this study, the best effects of heat transfer performance can be obtained by setting the ovality as 2/1. This research illuminates how varying tube bundle design features within HETB heat exchangers impact their overall operational efficiency, providing a reference for enhancing these exchangers' effectiveness in practical applications.