Experimental results from a pilot scale latent heat thermal energy storage for DSG power plants – Advanced operating strategies.

Since 2013, CEA has been operating a pilot scale high pressure water-steam facility called LHASSA designed to test latent thermal energy storage modules under operating conditions similar to commercial Direct Steam Generation CSP plants. A Phase Change Material (PCM) storage module connected to this facility is composed of aluminum finned steel tubes immerged into sodium nitrate and surrounded by aluminum inserts for heat transfer enhancement. This paper presents the results obtained from the third test campaign on this storage module, consisting in 25 charge-discharge cycles under a wide range of operating conditions (fixed of sliding pressure, complete and partial charge levels...). Thermal performances of the storage test section show a very good repeatability, without any performance degradation compared to the previous test campaigns. Some new operating strategies were successfully tested (charge interruption simulating a cloud transient in the solar field, discharge with fixed pressure and varying mass flows, charge-discharge transition management). [ABSTRACT FROM AUTHOR]