摘要 |
One or a number of subsoil cavities are employed for the storage or recovery of hot liquids. At the time of heat storage, a heat-transporting liquid is extracted at low temperature at the lower end of each cavity, heated by heat exchange with an external fluid and reinjected at the upper end. At the time of heat recovery, the heat-transporting liquid is extracted at high temperature at the upper end of each cavity, cooled by heat exchange with an external fluid and reinjected at the lower end. The system comprises flow-arresting means for maintaining a minimum operating pressure at the top of each cavity, air or gas purge means, an expansion reservoir and a safety unit for ensuring one-way flow of the heat-transporting liquid from the expansion reservoir to each cavity. |