A Comparison of Stratified Heat Storage With and Without Modular PCM Storage Through Simulation
Abstract
In the scope of the current paper stratified heat storage tanks are analyzed by computational fluid dynamics (CFD) simulations and improvements regarding the capacity and flexibility of domestic storages are suggested. Therefore, a hybrid approach is investigated, where water is used both as the heat transfer fluid and storage medium and additionally a phase change material (PCM) is added to improve the storage capacity. The PCM is inserted into the tank as macro-encapsulated paraffin in a packed bed bulk. With the same boundary conditions, a comparison between the loading process of a simple stratified storage and a stratified latent heat storage is performed. Advantages are an enhanced capacity per volume with high loading power and an easy integration into state-of-the-art storage system. To model the phase change of the PCM the simulation is based on the volume of fluid (VOF) method. Further investigations will include long-term simulations as well as different PCM-zones in the packed bed bulk.