CFD modelling of a battery indirect cooling system for automotive application

Nowadays it is hard to satisfy the stringent policy requirement regarding the reduction of CO2 emissions using the Internal Combustion Engine vehicles. Hybrid and Electric vehicles are becoming more and more popular in the transport sector and may be an excellent alternative to the ICEs due to their high efficiency and zero tail pipe emission. Lithium-ion batteries are used in these vehicles as power source. During operating conditions, Lithium-ion batteries should be work in a narrow range of temperature because otherwise, risk of undergoing thermal runaway under uncontrolled situations, Overcharging, over-discharging, high internal temperatures, may leads towards gradual degradation of battery performance. Therefore, it is important to have an efficient Battery Thermal Management System (BTMS) to ensure optimal performance of a battery pack. The main BTMS technologies used in today's market are air cooling system and liquid cooling system. The aim of this thesis is to develop a BTMS based on indirect liquid cooling system. A battery module composed by cylindrical lithium-ion cells is on contact with a cold plate on which liquid coolant can flows inside it. The purpose of the cold plate is lowering the temperature by absorbing heat from the batteries. The thesis is divided as follows: first a characterization and problems on the cold plate design are performed, secondly based on the optimal configuration CFD simulations are conducted, analysing the variation of temperature of the batteries and evaluating the effectiveness of this proposed system. Furthermore, a comparison with the same battery module based on direct cooling system is performed.