Before including the molten salts in the tanks, these must be preheated above 300 C. This ensures that the salts, which freezing point is around 224 C, do not freeze on contact with the walls of the tanks.
    The tanks preheating system should take into consideration the temperature distribution in them. The first design carried out in this project was a not adequated flow distribution, and higher temperatures than expected were needed to ensure complete heating.