Experimental Research And Theoretic Analysis On Low Supercooling Of Ice Storage

Ice storage air-conditioning system utilizes the characteristics of phase change material(PCM) inside capsules in the storage tank, which releases or absorbs a great amount of latent heat during phase change process. The system makes use of off-peak electricity for cool energy which is stored in the form of latent heat. Water is widely used as the PCM for thermal storage because of such advantages as high latent heat of melting, stability, low cost and easy acquisition and etc. However, there are a few disadvantages with the use of water as PCM. One of the most serious problems is the supercooling phenomenon that occurs in the process of solidifying water of the cold storage.All nucleation in the capsules system are homogeneous and heterogeneous. The main way to decrease supercooling is adding nucleation additive at present. A series of charging experiments are performed under conditions of different mass content, inlet temperature, container materials and container volume. The supercooling will decrease when increase mass content and inlet temperature. The container materials and volume have effect on supercooling too.Based on the experimental data. Different models during the phase change of solid-liquid in ice storage are studied in this research . An annulus solid ice begin to grow slowly from the inside wall to the center region when there is no supercooling. Uniform solid-liquid mixtures shaped when there has supercooling. The numerical calculate proves the experimental conclusion.Increase the temperature of glycol will save energy. We find sand is likely to be an excellent additive when searching for other nucleation additve.