ISSN 在线: 2688-7231
ISBN 在线: 978-1-56700-524-0
Proceedings of the 26thNational and 4th International ISHMT-ASTFE Heat and Mass Transfer Conference December 17-20, 2021, IIT Madras, Chennai-600036, Tamil Nadu, India
Thermal Performance Evaluation of Cascade Latent Heat Storage
Latent heat storage (LHS) is one of the potential energy storage technologies. The non-uniformity of the charging/discharging processes in the LHS due to the varying heat flux conditions between the heat transfer fluid (HTF) and the phase change material (PCM) can lead to poor energy storage/releasing at the end of the charging /discharging cycle of the large volume storage. This shortcoming can be overcome using multiple PCMs in a single storage unit known as cascade latent heat storage (CLHS). In this work, a comparative assessment of the single-stage storage, 2-stage CLHS, and 3-stage CLHS is performed. The enthalpy porosity method is employed to model the melting process in the storage. It is observed that the charging time of a 3-stage CLHS (KNO3/NaNO3/NaNO2) is 29.4% and 14.2% less as compared to the single-stage KNO3 storage and 2-stage KNO3/NaNO3 CLHS, respectively. The charging time of the storage can be reduced by increasing the HTF inlet temperature and the HTF inlet velocity. It was also observed that the placement of the PCMs in the decreasing order of their respective melting temperatures in 3-stage CLHS could decrease the charging time by 40% as compared to their reverse arrangement.