CFD analysis and 1D modelling of a battery direct cooling system for automotive application

Battery Electric Vehicles (BEVs) and Hybrid Electric Vehicles (HEVs) are becoming more and more relevant in the transportation sector, and it is therefore of utmost importance to find a solution to allow batteries to work safely and in a temperature range in which performance degradation or thermal runaway do not occur. To this purpose, a Battery Thermal Management System (BTMS) must be designed to ensure the correct operation of the battery pack. A BTMS can be realized in many ways; in this thesis, the BTMS that has been designed is a direct cooling system in which the battery module is immersed into the dielectric cooling liquid. The aim of the thesis is to evaluate the efficiency of the BTMS designed through CFD simulations and to realize a 1D model of the same system able to predict the temperature evolution of the cells and of the coolant much faster than the CFD simulation. The 1D model is being developed with the intention that it could be implemented in a BTMS to predict the battery module temperatures in real time, which is mandatory in EVs to allow the cells to operate in their optimal range of temperature. The results of the CFD simulation and of the 1D model are then compared to assess the accuracy of the 1D model. Additionally, it has been carried out a comparison of the realized direct cooling BTMS realized and a similar battery module with a cooling plate rather than using a direct cooling approach.