Packed bed thermal energy storage model – Generalized approach and experimental validation

• A general heterogeneous lumped-element model of heat transfer in packed beds is developed.
• The proposed model expands the application range of existing models.
• Its applicability to different configurations of packed beds is shown.
• The implementation in Modelica favors an easy integration as a sub-model within bigger plant models.

Packed beds serve as thermal energy storages (TES) and heat exchangers (HEX) in different technological applications. In this paper, a general heterogeneous model of heat transfer in packed beds is developed. It is implemented by lumped element formulation in object-oriented modeling language Modelica and is successful validated with data sets taken from two different experiments reported in literature.The main advantages of the introduced model are the general, theory-based approach and the lumped element formulation in Modelica. The first point mentioned above should allow to simulate a packed bed TES/HEX without the necessity applying measured data for model calibration or to apply specific heat transfer correlations with restricted application. The second point establishes the possibility to integrate the TES/HEX model within plant models of larger scale without increasing the simulation time drastically.