Experimental investigation on the thermal behavior of cylindrical battery with composite paraffin and fin structure
Experimental investigation on the thermal behavior of cylindrical battery with composite paraffin and fin structure
复制标题
DOI：
10.1016/j.ijheatmasstransfer.2017.02.057
复制
发表时间：
2017-06
影响因子：
5.2
通讯作者：
Zhiwei Wang;Hengyun Zhang;Xiantao Xin
中科院分区：
文献类型：
--
作者：
Zhiwei Wang;Hengyun Zhang;Xiantao Xin
通过实验测量和与其他热管理技术的对比，考察了具有复合石蜡和翅片结构的圆柱形电池的热行为。由铝制成的模型圆柱形电池具有垂直的直翅片作为扩大的传热区，浸入石蜡作为相变材料(PCM)，最高熔化温度为44℃。对于纯PCM，熔化过程可分为电池温度升高的AB段、温度平台明显的BC段和达到完全熔化的CE段，这也基本体现在电池自上而下温度变化的演化趋势中。如数值分析所示，随着未熔化的相变材料的一小部分，电池的瞬时努塞尔特数将在CE段附近增加，但尽管有不完全熔化，电池温度仍将从平台上升。实验研究了PCM-翅片的强化换热，时均Nusselt数的对数依赖关系与换热面积比有关。此外，有效热控制点C与金属外壳底部相交的熔化前沿有关，相应的热阻被用来对基于PCM的热管理系统的热性能进行基准测试。对于现有的热管理系统，这样的参数与加热功率无关，可以与熔化温度与环境温差相关联。结果表明，该复合体系具有良好的热工性能和较长的工作时间。
The thermal behavior of the cylindrical battery was examined with composite paraffin and fin structure through experimental measurements and benchmarking with other thermal management techniques. The mock-up cylindrical battery, made of aluminum, had vertical straight fins as enlarged heat transfer area to submerge in the paraffin wax as phase change material (PCM) with a maximum melting temperature of 44 °C. For the pure PCM case, the melting process could be divided into AB segment with battery temperature ramp-up, BC segment with a clear-cut temperature plateau, and CE segment to reach complete melting, which is also basically represented in the evolutionary trend for the battery top to bottom temperature variation. The instantaneous Nusselt number would increase around the CE segment with a small portion of unmelted PCM as visualized by the numerical analysis, but the battery temperature would ramp up from the plateau in spite of the incomplete melt. Thermal enhancement with the PCM-fin cases was examined experimentally and the logarithmic dependence of the time-averaged Nusselt number is correlated with the heat transfer area ratio. In addition, the effective thermal control point C is found to relate to the melting front intersecting the bottom of the metal housing, and the corresponding thermal resistance is used to benchmark the thermal performance of PCM based thermal management systems. Independent of heating power, such a parameter can be correlated with the melting temperature to the ambient temperature difference for existing thermal management systems. It is found that the present composite PCM-fin system had the advantages of good thermal performance with prolonged work time.