平等電場を利用した油中の過冷却水滴の凍結促進

滴と電極板との接触挙動と凍結開始

抄録

Liquid-liquid direct contact heat transfer can be effectively utilized for the heat transfer between two immiscible liquids of small temperature difference. However, the water droplet in the oil is difficult to start freezing, because the droplet is easy to be supercooled. The charged water-droplet in oil with uniform electric field collides repeatedly with the electrode plate, because it reciprocates between the electrode plates. It is known that the collision is effective for freezing initiation of the supercooling water-droplet. The purpose of this study is to make clear the relation between the collision and the initiation of freezing. The behavior of the droplet is photographed by a high-speed video camera. For the convenience of photographing, transparent electrode plate is used as the lower electrode in the experiment. As a result, the contact behavior between the droplet and the electrode plate, change of contact area with time, position and timing of the freezing initiation, freezing progress in the droplet are clarified. The lower temperature of continuous-phase liquid and the higher electric field strength bring the position of freezing initiation close to the vicinity of three-phase boundary.