Numerical study of heat transfer between shell-side fluid and shell wall in the spiral-wound heat exchangers

Heat transfer between heat exchangers and the surrounding environment, referred to as heat-in-leak, is a crucial phenomenon in the cryogenic applications which can substantially degrade the heat exchanger performance. Present research is organized to investigate the mechanism of heat transfer between the shell-side fluid and the shell wall of spiral wound heat exchangers (SWHEs) to determine the heat transfer coefficient used in the heat-in-leak calculations. The heat transfer characteristics are studied using computational fluid dynamics (CFD) tools. First, 20 dissimilar SWHE models with respect to the geometrical parameters are built and then numerically simulated at different Reynolds numbers. Based on numerical simulations, the thermal entrance length in which local Nusselt number varies is specified to be equal to around 80 tube bundles. Finally, the multiple regression analysis method is applied to establish the multivariate Nusselt number correlations in terms of Reynolds number and non-dimensional geometrical parameters. The average error of Nusselt number correlations in the entrance and fully developed regions are 6.2% and 5.6%, respectively.