Performance of a coil-pipe heat exchanger filled with mannitol for solar water heating system

Solar water heating systems that incorporate latent heat storage unit deals with instabilities of insolation. But most previous studies focus on phase change materials (PCMs) with phase change temperature (T-m) below 80 degrees C. In this study, we investigate the performance of mannitol (Tm: 166.7, enthalpy of phase change gamma: 323 kJ kg(-1)) in storing solar thermal energy and producing hot water. Results show mannitol can store high-level energy and the thermal energy storage performance are affected by the inlet flow rate and temperature of heat transfer fluid. 14kg mannitol with latent heat activated can heat 100L water from 30 up to 50 degrees C in 6 hours (C) 2015 The Authors. Published by Elsevier Ltd.