Experimental investigation on enhancement of heat transfer in a latent heat thermal energy storage system using phase change material PCM containing nano particles

Abstract

Thermal energy storage (TES) is an emerging field of research owing to its ability to store thermal energy by heating or cooling a medium. The stored energy may be of sensible or latent heat that can be used for many industrial applications including drying, cooling, heating, power generation, buildings etc. In latent heat thermal storage system (LHTESS), the temperature of the medium rises to a particular temperature level beyond that it undergoes a phase change without any alteration in the temperature that helps in storing additional energy. In recent decades, phase change material (PCM) is adopted in TES systems due to its good thermal stability, compatibility and small volume change. However, the major drawback of the PCM is its low thermal conductivity due to which charging and discharging processes consume longer duration. In order to improve thermal conductivity, nanomaterials (size of the particles is between 1 and 100 nm) with varying proportion is added into the PCM. This has showed a greater improvement in thermal conductivity as reported in literatures. Therefore, the present study aims to store the latent heat using nano PCM with different volume fractions of nanoparticles. The major objectives of the present study are to (i) prepare the different volume fraction of nano enhanced PCM, (ii) fabricate the test facility to store latent heat, (iii) conduct experiments by allowing different mass flow rate of water (both charging and discharging), (iv) evaluate the performance of thermal energy storage with and without nanomaterials and (v) conduct exergy analysis based on the experimental results. newline