Energy and exergy analyses of latent heat storage unit positioned at different orientations - An experimental study

The performance of a latent heat storage unit (LHSU) greatly rely on the melting/solidification rate which in turn affected by the orientation of LHSU. The orientation of the LHSU greatly influences the natural convection phenomenon, thereby affects the melting behavior of PCM. The present study is aimed at investigating the performance of a shell and tube LHSU positioned at various inclinations. Four inclinations are considered from vertical to horizontal position. Lauric acid is chosen as PCM with a melting range of 43.45 degrees C-49.94 degrees C. Both melting and solidification characteristics are analyzed with the help of energy and exergy analyses (PCM average temperature, melt fraction, energy and exergy efficiency, energetic and exergetic effectiveness). From the experimental results, it is observed that the orientation has a major influence on the melting phenomenon and solidification is unaffected by the orientation of LHSU. Melting rate is observed to be higher for horizontal configuration till the PCM in the upper half portion is melted, however total melting time is observed to be less for vertical configuration. In addition, exergy efficiency is found to be higher for vertical configuration while melting, whereas for discharging process the exergy efficiency is same for all the inclinations. (C) 2020 Elsevier Ltd. All rights reserved.