Abstract Waste heat dissipation, using evaporation heat transfer, is highly desirable in applications involving components that generate a persistent heat flux, due to the temperature uniformity experienced during evaporation. This form of heat transfer requires continuous feeding of liquid to the entire heated surface and mitigating the formation of dry spots. With complete liquid coverage, evaporation heat transfer results in a temperature uniformity across the heated surface due to phase change at the liquid-vapor interface. Aluminum High-Temperature Conductive Microporous Coating (Al-HTCMC) is highly effective in spreading liquid over a surface. It is fabricated by brazing aluminum particles (dp = 11, 24, 66, or 114 µm) onto a flat aluminum surface. This coating is applied on a large vertical aluminum plate (50.8 mm wide × 152.4 mm tall × 3.3 mm thick). Rate of rise experiments with highly wetting fluids (ethanol, acetone, and methanol) are performed, at room temperature and atmospheric pressure, where the bottom of the coated plate is submerged in a pool of liquid to investigate the effect of the particle size on permeability and effective meniscus radius within the Al-HTCMC. Evaporation experiments are also conducted using ethanol at saturated conditions, where a 50.8 × 127 mm2 heater is attached to the aluminum plate. The effects of particle size, coating thickness, and fluid properties on the evaporation performance are evaluated. The temperature distribution across the entire surface is found to remain uniform with nearly zero superheat until the dryout heat flux occurs. A theoretical model is developed to predict the dryout heat flux based on pressure drop through the microporous layer, and the experimental results are in good agreement with the theoretical model.

中文翻译：

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铝微孔涂层上高润湿流体的蒸发

摘要 由于蒸发过程中的温度均匀性，在涉及产生持续热通量的组件的应用中，使用蒸发热传递的废热消散是非常理想的。这种传热形式需要将液体连续输送到整个加热表面并减少干斑的形成。在液体完全覆盖的情况下，由于液体-蒸汽界面处的相变，蒸发传热会导致整个加热表面的温度均匀。铝制高温导电微孔涂层 (Al-HTCMC) 可非常有效地将液体散布在表面上。它是通过将铝颗粒 (dp = 11、24、66 或 114 µm) 钎焊到平坦的铝表面上制造的。这种涂层涂在一块大的垂直铝板上（50.8 毫米宽 × 152.4 毫米高 × 3. 3 毫米厚）。在室温和大气压下使用高润湿性流体（乙醇、丙酮和甲醇）进行上升速率实验，其中涂层板的底部浸没在一池液体中，以研究粒径对渗透率的影响和 Al-HTCMC 内的有效弯月面半径。蒸发实验也在饱和条件下使用乙醇进行，其中 50.8 × 127 mm2 加热器连接到铝板上。评估了粒度、涂层厚度和流体特性对蒸发性能的影响。发现整个表面的温度分布保持均匀，过热度几乎为零，直到发生干热通量。