Phase change in spiral coil heat storage systems

In this ‎study, spiral coil tube is considered in a shell and tube heat storage unit and numerical ‎simulations are performed to predict the effect of geometrical and operational parameters such as spiral coil ‎diameter, tube diameter, HTF mass flow rate and HTF inlet temperature on heat transfer characteristics and thermal behavior of Paraffin ‎RT50 as phase change material during melting process in the shell and spiral coil tube heat ‎exchanger while HTF flows inside the tube and PCM fill the space between shell and tube. ‎Simulation results showed that spiral coil diameter plays an important role in melting process ‎and heat transfer procedure. By increasing spiral coil diameter from 50 mm to 70 mm, total ‎melting time will reduce up to 71.4%. In contrast, tube diameter has little effect on melting ‎process. It is indicated that for larger spiral coil diameter, increasing tube diameter has a ‎reverse impact on reduction of total melting time.‎