基于多物理场耦合的磷酸铁锂电池组热失控及其蔓延特性仿真分析OA

To investigate the thermal runaway and propagation characteristics of lithium iron phosphate(LiFePO4)battery packs,a multi-physics numerical model coupling electrochemistry,heat transfer,and fluid dynamics was established.The model's accuracy was verified through experimental data,and the heat generation mechanism during battery puncture as well as the thermal management and propagation characteristics under different flow channel configurations were explored.The results showed that,under nail penetration conditions,the cathode deactivation zone formed a high-resistance region due to mechanical damage and material failure,which subsequently triggered localized high-temperature hotspots,with the heat radiating outward from the high-temperature region.At medium-to-high flow velocities,although the serpentine flow channels provided more significant cooling effects and temperature uniformity,they incurred substantial pressure drop losses.At a flow rate of 2.0 m/s,the cooling effect was 15.06％higher than that of parallel flow channels,while the maximum temperature difference of the battery pack was reduced by 32.30％,with the pressure drop reaching 690 412 Pa.During the thermal runaway propagation stage,a nonlinear relationship existed between the cooling effect of the flow channels and the suppression of thermal propagation.In the medium-to-high flow velocity range,an increase in the cooling fluid velocity intensified the"thermal bridge"effect,accelerating the propagation of thermal runaway.