Innovative PCM Storage as Power-To-Heat Unit for Process Heat Applications
Abstract
An innovative high temperature latent heat storage concept for power-to-heat application is presented. The storage is equipped with electrical heating elements, directly immerged into the phase change material to achieve best conversion efficiency. Discharging takes place by an oil cooled plate heat exchanger. For heat transfer enhancement during discharging, a new concept, using moving blades to scrape off the solidifying material, was developed. With this method, the solidified layer of phase change material on the heat exchanger surface is kept at constant thickness, allowing for constant heat flux during the major period of the discharging process. Feasibility of the concept with moving scrapers was demonstrated, showing advantages over the passive concept. First investigations on the crystal size and hardness of Sodium Nitrate were performed to improve the scraper design. A concept for separation of capacity and heat rate is described.
Keywords
Latent heat storage, Pcm, High temperature, Power-to-heat, Process heat