An experimental and numerical study on the effect of inclination angle of phase change materials thermal energy storage system

The main purpose of the present study is to investigate the melting characteristics of a PCM cylindrical thermal storage system using experimental and numerical approaches. Three inclination positions are considered from vertical to horizontal. Paraffin wax has been used as the phase change material with a melting temperature ranged between 35 and 37 degrees C. The melting behaviour of the PCM inside the storage is characterised using different parameters of temperature distribution, imaging of PCM melting profiles, rate of stored heat, and liquid PCM flow within the storage. The results show that the PCM storage inclination angle has a significant effect on the PCM temperature distribution, PCM melting time and profile. It is noted that PCM in the storage in the 45 degrees inclination angle from the horizontal location has the fastest melting rate is the fastest in melting compared to the 0 degrees and 90 degrees inclination angles. The simulation models enable understanding the internal flow of liquid PCM where it has been found that the direction of buoyant force resulting from the melted liquid PCM has a major role in both melting rate and melting direction within the PCM storage. In addition, it has been observed that the charging rate has no effect on the PCM melting profile.