THE EFFECT OF STATIC MAGNETIC FIELD ON THE SOLIDIFICATION PROCESS OF PHASE CHANGE MATERIAL (PCM) HYDRATED SALT COBALT NITRATE HEXAHYDRATE (CO(NO3)2?6H2O)

• Main Author: Rahman, Annisa
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/49918
• Institution: Institut Teknologi Bandung

Thermal energy storage (TES) system is one of the main technologies in energy conservation that can be a solution to reduce the mismatch between energy supply and demand. TES stores the thermal energy momentarily through the process of cooling, heating, melting, freezing, and vaporizing of a material. The energy will be available when the process is reversed. The materials that are used as storage medium to store energy in the form of latent heat in TES system are called phase change material (PCM). Hydrate salts are important PCM due to its characteristics e.g., high fusion latent heat per volume (? 350 MJ/m3), high thermal conductivity (? 0,7 W/m K), and economically friendly. Nevertheless, hydrate salts mostly undergo supercooling during its phase transition hence lower temperature is required for the materials to experience phase transformation. As a result, more energy is discharged to reach lower temperature thus reduces its utilization efficiency. Co(NO3)2?6H2O is one of a potential PCM to be used as storage medium for TES system application in temperature regulator in buildings. This study investigated the effect of static magnetic field (SMF) with magnitude 0–230 mT on the solidification process of Co(NO3)2?6H2O since the research on this topic is still under debate and not widely done. The magnetic field is produced by neodymium magnets placed on its opposite poles. This experiment was performed in adiabatic system with temperature 10–13 oC. Results showed that SMF increased the temperature when nucleation occurred but give insignificant effect toward the freezing temperature thus led the degree of supercooling to become smaller. It was also found that SMF led the sample to undergo nucleation earlier but did not affect the solidification period of Co(NO3)2?6H2O.