Basic research on the freezing phenomena of the supercooled water for the effective ice thermal energy storage

为提高冰蓄冷的性能，开展了冰蓄冷的基础研究。在第一个子课题的研究中，引入了一个特殊的表面物理参数，即（1）过冷水非均匀成核冻结的统计条件，（2）过冷水瞬时冻结的电触发启动方法，（3）过冷水冻结的瞬态热力学和流体力学过程。在非均匀形核的情况下，利用冰的出现温度、冷却速率、固体表面性质、表面积和表面条件之间的实验关系，讨论了控制过冷水冻结的因素。根据该结果，使用上述参数，确认冻结的开始由通用公式表示。 关于我们 子主题，进行了改变所提供的电压、电极之间的距离、电极的形状和过冷度来瞬时冻结过冷水的实验。通过一系列的实验，证明了电触发器对过冷水的冻结有一定的作用。同时，通过引入有关过冷度、电流和时间的关系的统计概念，澄清了冻结开始的条件。在第三课题的研究中，采用精确的枝晶生长模型，研究了过冷水管流中冰形核后枝晶的生长和固态冰的发展过程。观察和测量。根据实验和分析结果，给出了决定固体冰传播速度的一般物理关系式。流动过冷水弛豫过程的机理是过冷度的分布、固态冰的发展、枝晶的生长和消失相互影响的。少

To improve the performance of the ice thermal energy storage, basic researches were performed concerning a few subtopics. That is, (1) the statistical condition to freeze the supercooled water through the non-homogeneous nucleation, (2) the method to initiate the instantaneous freezing of supercooled water by supplying an electric trigger and (3) the transient thermal and fluid mechanical process of the freezing of supercooled water flowing through a pipe.In the research of the first subtopic, a physical parameter particular to the individual surfaces, which control the freezing of the supercooled water, was discussed for the case of a non-homogenous nucleation, using the experimental relation among the temperature of the ice appearance, the cooling rate, the surface properties of the solid, the surface area and the surface conditions. From the results, initiation of the freezing was confirmed to be expressed by a general formula, using the above parameter.In the research of the second … More subtopic, experiments to freeze the supercooled water instantaneously were performed varying the voltage supplied, the distance between the electrodes, the shape of the electrode and the degree of the supercooling. From a series of experiments, the electrical trigger was proved having an effect to freeze the supercooled water. At the same time, the condition of the initiation of the freezing was clarified by introducing a statistical concept concerning the relation of the degree of the supercooling, the electrical current and the time.In the research of the third topic, the processes of the dendrite growth and the development of the solid ice after the appearance of the ice nucleation in a pipe flow of the supercooled water was investigated through precise observations and measurements. Based on the experimental and analytical results, a general physical relation deciding the propagation velocity of a solid ice was shown. And the mechanism of the relaxation process of a flowing supercooled water, where the distribution of the degree of the supercooling, the development of the solid ice, the growth and the disappearance of the dendrite effect each other. Less