Multi-objective Optimization of Fin Structures for a Hybrid PCM-Forced Air Battery Thermal Management System

Lithium-ion batteries (LIBS) require effective thermal management to prevent degradation and thermal runaway, with safe operation typically maintained between -۲۰-۶۰°C. This study focused on the multi-objective optimization of a hybrid Battery Thermal Management System (BTMS) for ۱۸۶۵۰ cylindrical LIBS. A semi-elliptical Phase Change Material (PCM), with RT۳۵HC material, arrangement with an aluminum shell was proposed to enhance heat dissipation, particularly from the battery's leeward side. Recognizing the low thermal conductivity of the PCM (۰.۲ W/m K), seven distinct aluminum fin structures were designed to improve heat transfer and were compared to a base geometry without fins. Numerical simulations utilizing ANSYS Fluent, evaluated these geometries under a ۵C discharge rate, equivalent to a ۳۲۵,۷۳۳.۱۹ W/m³ heat generation rate. The simulations employed a ۲ m/s inlet air velocity and a ۲۵°C ambient temperature. The primary optimization objectives, pursued through the TOPSIS multi-objective optimization method, were to minimize both the system weight and the maximum cell temperature at the end of a discharge cycle. All hybrid BTMS designs successfully maintained battery temperatures below ۴۰°C, well within the safe operating range, and demonstrated significantly enhanced heat transfer and increased PCM liquid fraction compared to non-finned systems. Through this optimization, Geometry ۳ was identified as the optimal design, featuring three ۴ mm long fins. This optimal configuration achieved a maximum battery temperature of ۳۷.۸۳°C and a total system mass of ۵.۹۲ g. This research successfully demonstrates a robust and lightweight BTMS capable of significantly mitigating thermal runaway risks and extending battery performance and lifespan. Future work should expand this methodology to multi-cell battery packs and investigate performance under dynamic operating conditions.

کلیدواژه ها:

Lithium-ion battery (LIB) ، Optimization ، Battery Thermal Management System (BTMS) ، Phase Change Material (PCM) ، Fin