Modelagem do processo de resfriamento direto de células de íons de lítio cilíndricas baseado no escoamento axial

Abstract

Environmental regulations regarding the level of vehicle emissions were created and tend to become increasingly restrictive in the next years. In this context, vehicle electrification, partial or total, has become the most used option by the automotive industry. Even with the use of lithium-ion battery technology, the storage devices have sensitive points in relation to power density, lifetime and autonomy per cycle. With high correlation with the degradative effects and heat generation of the battery cells, the operating temperature of the cells is one of the main parameters to be optimized, which led to the development of several cooling strategies. Among the main cell cooling strategies are air cooling, cold plate, use of pipes and direct cooling with flow in radial and axial directions. The latter, despite some works in the literature indicating its advantages, few works evaluated the strategy in depth. Therefore, this work seeks to present itself as another reference study in relation to the direct cooling strategy with axial flow, aiming to present performance data for a real application. For this, a CFD model was developed using OpenFOAM, having its validation done by comparing the results of the model with experiments carried out using air as working fluid, obtaining an average deviation of 7.65% in relation to experimental cell surface temperature measured. From the validation of the model, comparative studies were conducted about the strategy with the use of a commercial fluid, comparing the results with other strategies from data presented in a base study. Under discharge conditions 1C and 2.5C, comparison of strategy in question presented lowest results relative to temperature gradient in pack and one of lowest pumping powers for both cases.