In this study, a new heat dissipation device with a composite heat sink of a loop heat pipe (LHP) system was evaluated for efficient cooling of electronic components. To improve the heat dissipation ability of the high heat flux chip and its local hot spot area, LHP, which had a gas–liquid phase change as the main mechanism of heat dissipation, was selected to remove heat. The experimental results showed that the average temperature performance was improved after the graphene copper foil heat sink was fitted, and the maximum temperature under the heat loads of 80 W, 90 W, 100 W, and 120 W was reduced by 3.8 °C, 5.7 °C, 6.5 °C, and 7.7 °C, respectively, compared with without a heat sink. The hot spot temperature increased linearly with an increase in the inlet water temperature. Increasing the ambient temperature within a certain range had little effect on the heat-dissipation effect of the hot spots. To interpret the experimental results, the hot spot heat transfer performance of the evaporation section of the LHP with a composite heat sink was set up by the equivalent thermal resistance model. The CFD simulated results were in good agreement with the experimental values. This indicated that the heat sink significantly reduced the hot spot temperature and improved the cooling uniformity largely. When the transverse thermal conductivity of the heat sink is sufficiently high, the increase in longitudinal thermal conductivity is more effective in reducing the hot spot temperature than the transverse thermal conductivity. Moreover, it has been suggested that the hot spots and heating power play a major role in the actual electronic structure and heat dissipation design. In summary, the study proposes a valuable method for improving the uniform cooling of chips, which was conducive to the heat management of the system.

在这项研究中，评估了一种具有回路热管 (LHP) 系统复合散热器的新型散热装置，以有效冷却电子元件。为了提高高热通量芯片及其局部热点区域的散热能力，选择以气液相变为主要散热机制的LHP进行散热。实验结果表明，安装石墨烯铜箔散热片后平均温度性能得到改善，80W、90W、100W、120W热负荷下的最高温度降低3.8℃，5.7与没有散热器的情况相比，分别为 °C、6.5 °C 和 7.7 °C。热点温度随着进水温度的升高而线性升高。在一定范围内提高环境温度对热点的散热效果影响不大。为了解释实验结果，通过等效热阻模型建立了带复合散热器的 LHP 蒸发段的热点传热性能。CFD 模拟结果与实验值非常吻合。这表明散热器显着降低了热点温度并大大提高了冷却均匀性。当散热器的横向热导率足够高时，纵向热导率的增加比横向热导率更能有效降低热点温度。而且，有人建议热点和加热功率在实际电子结构和散热设计中起主要作用。综上所述，该研究提出了一种提高芯片均匀冷却的有价值的方法，有利于系统的热管理。