Development of high temperature phase-change-material storages

High-temperature PCM is a key component for storing latent heat. This is necessary for efficient energy storage in connection with the two-phase heat transfer fluid water/steam. Due to the low thermal conductivity of the nitrate salts used for high-temperature PCM storage, it is necessary to increase the heat transfer rate to meet the necessary power density demands for specific applications. A design for heat transfer enhancement using radially finned tubes has been developed by DLR and applied in a 700kWh PCM storage demonstration module.