Integration of metal hydride reactor with thermocline based heat storage system

The wide range of operating temperature and exothermic/endothermic behaviour of metal hydrides during hydrogen absorption/desorption make them suitable for various applications. The heat generated during ab-sorption is removed by various methods and then generally this heat is dissipated in atmosphere. In this study, the metal hydride reactor using LaNi5 as metal hydride is integrated with thermocline type of energy storage system using water as storage material to store the heat generated during absorption inside metal hydride reactor and then utilize this heat during desorption process. The heat is transferred from and to the metal hydride reactor by heat transfer fluid (water) flowing through helical tube embedded inside both the reactors. A 3-D mathe-matical model is developed and simulated to effectively study this integrated system. The effect of supply pressure during charging, stratification and discharging process on various performance parameters are analyzed. Further, this study is extended to perform the energy analysis of this integrated system for detailed performance evaluation. The results show that the energy generated inside the metal hydride reactor was suc-cessfully stored by thermocline energy storage system with a storage efficiency of 81.7 % when the supply pressure was 16 bar. Similarly, the thermocline energy system successfully delivers 60 % of the required heat to metal hydride reactor during desorption process with a discharging efficiency of more than 70 %. The results prove that these types of integrated systems are quite promising candidate for their use in various stationary applications.