Immersive Cooling Battery Thermal Management System: Definition and Experimental Validation of a Methodology for Hydraulic Layout Design supported by CFD-CHT analysis

This thesis presents a comprehensive study on the Immersive Cooling Battery Thermal Management System (BTMS), highlighting the critical role of supporting BTMS design with advanced Computational Fluid Dynamics (CFD) analysis. The primary objective is to define and experimentally validate a robust methodology for designing the hydraulic layout of such systems, ensuring optimal thermal management to maintain battery performance and safety. Extensive benchmarking has revealed that achieving a temperature gradient as ambitious as 3°C within the cell and the entire battery pack is currently unattainable. However, a thorough review of existing literature shows that a more widely accepted and achievable target is a maximum temperature difference of 5°C within individual cells and 10°C at the module level. This insight guides the design and optimization efforts in this thesis. The significance of immersive cooling techniques is underscored, with a particular focus on the fluid properties and system design that ensure efficient heat dissipation. To validate the theoretical findings, various experimental tools were meticulously designed and implemented. Among these, a notable development is the dummy cell, which was engineered to simulate the thermal release of an actual battery. This dummy cell serves as a critical tool in testing and refining the BTMS design, providing essential data on thermal behavior and heat management under different operating conditions. In addition to the focus on immersive cooling, this thesis also delves into the promising potential of hydrogen as a future energy carrier in sustainable mobility. Hydrogen, with its high energy density and capability for zero-emission power generation, presents a compelling alternative for automotive and industrial applications. The study explores the integration of hydrogen fuel cells with battery systems, aiming to extend the range and enhance the efficiency of electric vehicles. This dual approach could potentially overcome current limitations in battery technology, offering a more sustainable and versatile solution for the transportation sector. Additionally, through CFD analysis, the research identifies a significant drawback of using hydrogen in internal combustion engines: a notable reduction in specific power output. This finding is crucial for guiding future developments in hydrogen combustion technology. Overall, this thesis offers valuable insights into the optimization of battery thermal management systems and highlights the transformative potential of hydrogen in achieving a greener and more efficient energy landscape. The findings contribute to the broader goal of advancing sustainable technologies and promoting environmentally friendly solutions in the field of electric vehicle thermal management. The thesis work was conducted at the Fiat Research Center in Valenzano (BA) over a period of five months.