Analysis of the Thermal Ratcheting Phenomenon in Packed-bed Thermal Energy Storage using Discrete Element Method

Packed-bed thermal energy storages (TES) play a major role in energy technology. During energy absorption, hot air flows through the content of the TES in top-down direction. During the heating process, the expansion of the heat-storing medium (bulk material) leads to a stress increase on the walls of heat-storage tanks. These occurring loads are to be considered by means of a discretized model. Furthermore, it is of interest how the loads modify during several loading and unloading processes (thermal ratcheting phenomenon). In this paper, it will be investigated how this behaviour can be modelled using the DEM approach.