BOILING CURVE AND MECHANISMS OF VAPOR GENERATION IN LIQUID-LIQUID DIRECT CONTACT

本研究报告了通过可视化液体-液体接触行为来阐明沸腾特性如何变得良好以及蒸汽是否基于任何机制发生的结果。在本研究中，我们为此进行了四种不同的实验。在第一个实验中，通过将熔化的合金放入装满水的池中，在稳态下进行液-液直接接触沸腾。结果表明，传热性能的恶化是由于沸腾核的不足。然后，使熔融铅从靶上落下来，抑制水蒸气的产生，而不是在富含水的表面上，而是在水中湿润的平面上。很明显，在界面上存在着一层薄薄的水汽膜，使水变得湿润。在第三个实验中，将熔融锡滴在石英透镜上方的水膜上，因此可以使用石英透镜后面的全息干涉测量法捕获熔融锡的行为。对微小气泡的存在、喷出和消失进行了实时可视化。最后，采用了利用两种液体的界面张力差积极引起马兰戈尼对流的技术，以激活接触界面可能产生的微气泡的产生。可以猜测，结果是，它可以可视化马兰戈尼对流，并通过这种对流激活蒸汽的产生。

This study reports on the results of clarifying how the boiling characteristics became good and whether the vapor generation occurred based on any mechanism by visualizing the liquid- liquid contact behavior. In this study, four different experiments were conducted for the purpose.In the first experiment, the liquid-liquid direct contact boiling was performed at steady state by placing a molten alloy into a pooI filled with water. It was disclosed that heat transfer performance deteriorated due to an insufficiency of the boiling nuclei.Then, the molten lead was made to fall from the aim which restrained the vapor generation on not rich water surface but on the plane which moistens in the water. It became clear that the thin vapor film existed on the interface which moistens in the water.In the third experiments, the molten tin was dropped on a water film above a quartz lens, so the behavior could be captured using the holographic interferometry from behind the quartz lens. The existence of the minute vapor bubbles and its ejection and disappearance were visualized in real time.Finally, it adopted the technique which positively caused the Marangoni convection by interfacial tension difference of two liquids in order to activate the generation of the micro bubble which may arise in the contact interface. It was able to be guessed that as the result, it could visualize the Marangoni convection, and that it activates the generation of the vapor by this convection.