Numerical simulation of cooling a large-scale horizontal storage tank in a heavy rain event

A new CFD model has been developed for the accurate calculation of storage tank breathing during cooldown within a heavy rain event. All relevant phenomena occurring during the cooling of storage tanks in a heavy rain event were evaluated, namely temperature stratification and convection inside the tank, and heat transfer though the tank wall including a rain film on the outside. In this study, modeling for non-condensable media, such as dry air, is presented. Similar negative pressure scenarios occur during maintenance work when process plants are cleaned or when storage tanks are inertised. Here, the tank atmosphere was modeled with a Euler approach using a mixture multiphase model (MMP) to extend the functionality for condensable substances. The rain film on the outside of the tank was realized using a dispersed phase model (DMP) in combination with a thin film model in the cell closest to the wall. The model was developed using the software STARCCM+ (Siemens Industries Digital Software, 2022). The CFD model has been validated against experimental data available in the literature (Schmidt et al., 2022) for the cooling of a large scale horizontal storage tank of 191 m3. For the validation of the model, experimental thermographic data were evaluated and adapted for CFD.