Abstract
The demand for a refrigerant as a cold packing material at lower temperatures is growing in the field of food transportation. However, because of the existence of supercooling, refrigerant cannot freeze at melting point. It must be cooled at a lower temperature than the melting point. It needs a high electrical load on the refrigerator. Therefore, in order to reduce the high electrical load, a method of freezing supercooled solution using a membrane is introduced. A capsule having a solution with a low concentration or tap water is installed in a package having a refrigerant inside. One part of the capsule wall is made of membrane and only water can pass through the membrane. Since the melting point inside the capsule is higher than the outside, water or low concentrated solution in the capsule freezes first, and it propagates through the membrane and becomes a trigger for the refrigerant to freeze. This study is a fundamental research, and so a sheet of membrane is put between refrigerant having a high concentration of solution and water or low concentrated solution, and they are cooled together. Parameters for the experiments were selected to be a difference of melting points, the location of initial ice appearance, the cooling rate and the membrane thickness. The results were compared and the effect and phenomena of these differences were investigated.
