Start-up conditions in shell & tube heat exchangers involve strong thermal transients that directly influence temperature distribution, thermal stresses, and early-stage performance. In this study, the complete heat exchanger geometry was modeled using advanced CFD to accurately capture thermal mass effects and transient heat transfer behavior.
The simulations provided detailed insights into shell-side and tube-side flow patterns, heat transfer characteristics, and time-dependent temperature evolution during start-up. This enabled a realistic assessment of operational behavior that cannot be captured using steady-state methods alone.