EXPERIMENTAL AND NUMERICAL STUDIES ON SHELL-SIDE PERFORMANCE OF THREE DIFFERENT SHELL-AND-TUBE HEAT EXCHANGERS WITH HELICAL BAFFLES

Shell-and-tube heat exchangers (STHXs) have been widely used in many industrial processes. In the present paper, shell-side flow and heat transfer characteristics of shell-and-tube heat exchanger with continuous helical baffles (CH-STHX) is experimentally studied. Correlations for heat transfer and pressure drop, which are estimated by the Nusselt number and the friction factor, are fitted by experimental data for thermal design. The computational fluid dynamic (CFD) method is also used to compare the shell-side heat transfer and flow performance of the CH-STHX, STHX with combined helical baffles (CMH-STHX), and STHX with discontinuous helical baffles (DCH-STHX). The numerical results show that, for the same Reynolds number, the shell-side Nusselt numbers of the CMH-STHX and CH-STHX are similar to 37.6% and similar to 78.2% higher than that of the DCH-STHX, and shell-side friction factors of the CMH-STHX and CH-STHX are similar to 104.1% and similar to 177.0% higher than that of the DCH-STHX. Reasonable maximal velocity ratio design can make the CMH-STHX and DCH-STHX have higher heat transfer coefficients than the CH-STHX for the same mass flow rate in the shell side.