Study on the ice formation and its removal phenomena on cooled surface

在之前的研究中，研究者考察了水溶液在导热系数相对较小的冷却板上的结冰现象。据报道，由于浮力作用于冰，在冷却的板块上形成的冰可以从板块表面移走。本研究是将除冰现象应用于实际的基础性研究。垂直冷却管周围除冰现象的研究用冷却的聚氯乙烯管对乙二醇水溶液进行冷冻。研究发现，即使在垂直方向上，由于浮力的作用，在冷却管上形成的冰晶也能被除去。这意味着通过在蓄冰容器的底部安装许多垂直管道来增加冰的形成速率的可能性。研究还发现，对于除冰现象的发生条件，存在一个合适的管长值。研究了流动水溶液冷却管内冰的形成和除冰现象。结果表明，随着水溶液流速的减小，成冰速率增大。然而，在非常低的速度下，冰晶没有从管道表面去除，在管道表面形成了一层冰。研究了不同冷却板厚度对水平冷却板除冰现象的影响，采用不同厚度的聚氯乙烯板在水平冷却板上形成冰。结果表明，1.0 ~ 1.5mm的厚度对除冰效果较好。

In the previous study, the investigator examined an ice formation phenomenon of aqueous solution on a cooled plate, whose thermal conductivity was comparatively small. It was reported that the ice formed on a cooled plate could be removed from the plate surface due to buoyancy force acting on the ice. The present study is a basic research to apply the ice removal phenomena for practical use.1. Study on ice removal phenomena around vertical cooled tubeAn ethylene glycol aqueous solution was frozen with cooling a cooled polyvinyl chloride tube. It was found that the formed ice crystal on the cooled tube could be removed due to buoyancy force even on the vertical tube. It implies the possibility of increase of ice formation rate by installing many vertical tubes on the bottom of an ice storage vessel. It was also found that an appropriate value of the tube length exists for the onset condition of ice removal phenomena.2. Ice removal phenomena in a cooled pipe with flowing aqueous solutionIce formation and its removal phenomena in a cooled pipe were examined. It was found that the ice formation rate increases with decreasing flow velocity of aqueous solution. However, for very low velocity, the ice crystal was not removed from the pipe surface and an ice layer was formed over the surface.3. Effect of cooled plate thickness on the ice removal phenomenaIce was formed on a horizontal cooled plate with using different thickness of polyvinyl chloride plate. It was found that the thickness of 1.0-1.5mm was preferable for the ice removal phenomena.