Simulation of Hybrid Air-Cooled and Liquid-Cooled Systems for Optimal Lithium-Ion Battery Performance and Condensation Prevention in High-Humidity Environments

Abstract

This study introduces an innovative hybrid air-cooled and liquid-cooled system designed to mitigate condensation in lithium-ion battery thermal management systems (BTMS) operating in high-humidity environments. The proposed system features a unique return air structure that enhances the thermal stability and safety of the batteries by recirculating air through the battery box, thereby utilizing residual heat to prevent condensation. Computational Fluid Dynamics (CFD) simulations were employed to analyze and optimize the system's thermal management performance under various airflow velocities and temperature conditions. The study results show that compared to traditional liquid cooling systems, the proposed hybrid system reduces the condensation area by approximately 39.68% at a wind speed of 0.5 m/s, and the temperature difference decreases by 0.35 K. The integration of flow deflectors further improves the anti-condensation effect, achieving a phase change rate greater than 0 in the cooling area, thereby enabling condensation-free operation throughout the entire cooling zone. A comprehensive evaluation using the entropy weight-TOPSIS method and nonlinear surface fitting was conducted to assess multiple schemes regarding heat dissipation, anti-condensation measures, and energy consumption. The optimal operating conditions were identified as an airflow velocity (Vair) of 1.29 m/s and a liquid flow velocity (Vwater) of 0.22 m/s, resulting in a maximum temperature difference (ΔT) of 3.98 K, a maximum temperature (Tmax) of 302.36 K, and energy consumption values (Enair and Enwater) of 0.158 J and 0.192 J, respectively. The proposed system not only addresses the thermal management challenges of lithium-ion batteries in high humidity environments, but also effectively ensures the insulation safety of electronic components. It provides a reliable solution for electric vehicles and other high-efficiency thermal management applications, demonstrating significant engineering application value.

Keywords: Condensation prevention, Battery thermal management, Hybrid cooling system, Computational fluid dynamics (CFD), Entropy weight-TOPSIS method