Experimental Study of Solidification and Melting Characteristics of Thermal Energy Storage (TES) System

This study is an experimental investigation of melting and solidification characteristics of phase change materials (PCM). In the present study, PCM is used as hack-up providing energy storage in the form of latent heat in solar cold storage application when there is peak power demand or power failure or no sun shines situations. Heat transfer and temperature distribution of PCM during melting and solidification is analyzed to acquire the better performance of PCM pack. The PCM pack is a rectangular (100cmx76cmx5.5cm) container made of stainless steel sheet which contains the PCM like water, salt solution, etc. along with the evaporator coil. Heat transfer enhancement for both solidification and melting phenomena is observed by inserting 10 rectangular aluminum fins in a cross-wise direction with the evaporator coil. Results found a faster solidification and melting of 40kg of water. Compared to the evaporator coil arrangement without fin the solidification time is reduced by 60min when the arrangement is with 10 fins. Salt solution (Brine solution) of 10% NaCI by weight is used as PCM for experimentation which shows phase change during melting at varying temperature rather than at constant temperature like pure water. It takes higher time for solidification and melting than water. For low temperature application eutectic brine solution vould he a better option of PCM to maintain constant temperature phase change.