Detailed system modeling of a vanadium redox flow battery operating at various geographical locations

To avoid thermal precipitation, the electrolyte temperature of vanadium redox flow batteries should be within 5–40 °C. Consequently, an online thermal management system is essential, which impacts battery efficiency. A detailed thermal analysis was performed that considered a container, inner thermal radiation, global irradiance, and the thermal relationship between the system and the ambient at eight different weather stations with different climates around the globe. To meet the safe operation threshold criteria, a hybrid thermal management system was used to minimize heating and cooling energy consumption, consisting of control dampers, cooling fans, air conditioners, and heating and cooling electrolyte flows. The simulations were performed during the coldest and hottest 10-day periods of the year to determine the necessary insulation thickness and the energy consumption of cooling and heating; the latter was only required for one location. The presented thermal management system consumes up to 11 % of the total input power in extremely hot weather conditions. The simulation results show that efficiency increases with the decrease in ambient temperature until heating becomes necessary. The presented model helps predict the efficiency at any geographical location before battery installation and evaluates the need for various heating and cooling approaches. • A comprehensive, advanced multi-physics model is presented for VRFB modeling. • Eight weather stations were modeled with detailed temperature and radiation data. • AC-free temperature control is the key to high efficiency if the weather allows it. • Pipes and the stack are the critical components for winter and summer operations. • Thermal radiaition and global irradiance remarkably affect the electrolyte temperature.