A NUMERICAL STUDY ON THE THERMAL CONTROL OF LITHIUM BATTERIES BY COMPOSITE PHASE CHANGE MATERIALS AND METAL FOAMS

摘要

this study attempts to control the temperature peaks due to the operation of the battery itself by examining a two-dimensional model to numerically investigate the thermal control of a lithium battery of a commercial electric car. The battery has the dimensions of 8 cm × 31 cm × 67 cm and its capacity is equal to 232 Ah with 5.3 kWh. Thermal control is achieved by means of an internal layer of copper or aluminum foam and phase change material (paraffin), placed on the top of the battery and the external surfaces are cooled by a convective flow. The governing equations, written assuming the local thermal equilibrium for the metal foam, are solved with the finite volume method using the commercial code Ansys-Fluent. Different cases are simulated for different thicknesses of the thermal control system and external convective heat transfer coefficient. The results are given in terms of temperature fields, liquid fraction, surface temperature profiles as a function of time and temperature distributions along the outer surface of the battery for the different cases. In addition, some comparisons with pure PCM are provided to show the advantages of the composite thermal control system with PCM inside the metal foam.