Modelling of latent thermal energy storage systems

In this paper phase change materials are presented, as effective thermal energy storage due to their great latent heat storing possibility. The main substance used for thermal energy storage purposes is water. Storing the energy with water is not that effective as with phase change materials, because the temperature of water has to change, and it worsen the heat exchange intensity. On the other hand, with phase change materials the temperature of the material does not have to change due to the latent heat storage possibilities. A buffer tank with two pipe coils filled with phase change materials is investigated with the aim to reduce the storage volume. An own thermodynamic model, a CFD simulation and an experimental system are presented. The models could be validated and the process of phase change could be examined with a life-size thermal energy storage system in the laboratory of the department. The performance of heat absorption and release of the phase change material could be calculated in the function of inlet water temperature and mass flow.