For the purpose of reducing the weight and cost of low melting point alloy (LMPA) heat sink, a novel dual-phase change material (PCM) heat sink by using both LMPA and paraffin was proposed in this paper. A numerical model was developed by considering the conduction and natural convection in paraffin and the pure conduction in LMPA. The semi-implicit pressure-linked equation algorithm was adopted to obtain the flow field of liquid paraffin. The effects of volume fraction of LMPA, fin structure and heating power on the performance of dual-PCM heat sink were studied. The performance of dual-PCM heat sink was evaluated by the managed time and melting temperature interval. The results show that, the melting processes of the two PCMs are asynchronous due to the deference of thermophysical properties. The performance of dual-PCM heat sink is comparable with LMPA heat sink during the second melting stage. However, when the third melting stage is dominated by paraffin, the temperature management ability of heat sink deteriorates rapidly during the third melting stage. Moreover, by optimizing the fin structure and the LMPA volume fraction, we can effectively extend the second melting stage and improve the synchronization of the melting processes. With proper fin structure and LMPA volume fraction, the two PCMs can finish melting at the same time, then the third melting stage is eliminated and the melting temperature interval is minimized.

为了减轻低熔点合金（LMPA）散热器的重量和成本，本文提出了一种同时使用LMPA和石蜡的新型双相变材料（PCM）散热器。通过考虑石蜡中的传导和自然对流以及LMPA中的纯传导，建立了一个数值模型。采用半隐式压力链接方程算法获得液体石蜡的流场。研究了LMPA的体积分数，翅片结构和加热功率对双PCM散热器性能的影响。通过管理的时间和熔化温度间隔来评估双PCM散热器的性能。结果表明，由于热物理性质的不同，两个PCM的熔化过程是异步的。在第二个熔化阶段，双PCM散热器的性能可与LMPA散热器媲美。然而，当第三熔化阶段以石蜡为主时，散热器的温度管理能力在第三熔化阶段期间迅速恶化。此外，通过优化散热片结构和LMPA体积分数，我们可以有效地延长第二熔化阶段并改善熔化过程的同步性。具有适当的翅片结构和LMPA体积分数，两个PCM可以同时完成熔化，然后消除了第三熔化阶段，并使熔化温度间隔最小化。在第三熔化阶段，散热器的温度管理能力迅速下降。此外，通过优化散热片结构和LMPA体积分数，我们可以有效地延长第二熔化阶段并改善熔化过程的同步性。具有适当的翅片结构和LMPA体积分数，两个PCM可以同时完成熔化，然后消除了第三熔化阶段，并使熔化温度间隔最小化。在第三熔化阶段，散热器的温度管理能力迅速下降。此外，通过优化散热片结构和LMPA体积分数，我们可以有效地延长第二熔化阶段并改善熔化过程的同步性。具有适当的翅片结构和LMPA体积分数，两个PCM可以同时完成熔化，然后消除了第三熔化阶段，并使熔化温度间隔最小化。