In the framework of cooling technology applied to electronics, multiple setups and coolants have been used to achieve effective methods to remove high heat density fluxes. In this paper, an innovative device based on the combination of two fluids in a closed loop two-phase thermosiphon is proposed as an effective passive system to cool electronic components. The cooling device is an external flow boiling system that uses NOVEC 7000 as a circulating boiling fluid to transport heat from an evaporator capsule to a condenser. The bubble lifting effect in the closed-loop thermosiphon accelerates the fluid circulation and creates a natural jet impingement effect in the evaporator. In the condenser, the NOVEC bubbles ascend through a water pool, achieving a highly effective heat exchange between the fluids. The advantage of this two-fluid condenser system is highly efficient condensation since the vapour of NOVEC is condensed in a water pool, which produces a high heat transfer between the fluids and is not sensitive to the presence of non-condensable gases. In addition, the movement of the NOVEC bubbles produces high agitation in the water that enhances the heat transfer to the condenser walls. The system was tested under different working conditions with several power generation rates in the heat source and operating at atmospheric pressure and in a vacuum. The system was tested to assess the effect of water in the condenser, and heat transfer coefficients were calculated for the setup operating with and without water. In addition, a numerical model was developed to predict the different temperatures in the system and extrapolate the results for different operating conditions. Several tests were performed, and the results showed robust working of the system and good control of temperatures in the element to be cooled. The system was able to maintain a temperature lower than 70 °C in the aluminium block working with a heat flux of 220 kW/m² without any extra energy consumption. The effect of water in the condenser was shown to be effective in improving heat transfer and coolant condensation. The heat transfer coefficients in the condenser can be improved by 22 to 133%. The model for temperature prediction showed reasonably good results for most of the experiments regarding both transient behaviour and stabilization temperatures.

在应用于电子产品的冷却技术框架中，已使用多种设置和冷却剂来实现去除高热密度通量的有效方法。在本文中，提出了一种基于闭环两相热虹吸管中两种流体组合的创新装置，作为一种有效的无源系统来冷却电子元件。冷却装置是一种外流沸腾系统，它使用 NOVEC 7000 作为循环沸腾流体，将热量从蒸发器胶囊传输到冷凝器。闭环热虹吸管中的气泡提升效应加速了流体循环，并在蒸发器中产生了自然的射流冲击效应。在冷凝器中，NOVEC 气泡通过水池上升，实现流体之间的高效热交换。这种双流体冷凝器系统的优点是高效冷凝，因为 NOVEC 的蒸汽在水池中冷凝，在流体之间产生高热传递，并且对不可冷凝气体的存在不敏感。此外，NOVEC 气泡的运动会在水中产生强烈搅拌，从而增强向冷凝器壁的热传递。该系统在不同的工作条件下进行了测试，在热源中具有多种发电率，并在大气压和真空中运行。该系统经过测试以评估冷凝器中水的影响，并计算了有水和无水运行的设置的传热系数。此外，开发了一个数值模型来预测系统中的不同温度并推断不同操作条件下的结果。进行了多次测试，结果表明系统运行稳健，并且对被冷却元件的温度控制良好。该系统能够在铝块中保持低于 70°C 的温度，热通量为 220 kW/m²没有任何额外的能源消耗。冷凝器中的水的作用被证明在改善传热和冷却剂冷凝方面是有效的。冷凝器的传热系数可提高22～133%。对于大多数关于瞬态行为和稳定温度的实验，温度预测模型显示出相当好的结果。