Theoretical and experimental investigation of thermal energy storage with inorganic salts melted with concentrated solar energy

The importance of energy production and heat storage is increasing day by day with concentrated solar energy systems which is one of the renewable energy sources. This study includes theoretical, numerical calculations and experimental studies on latent and sensible heat energy storage with new ring array type solar concentrators which are designed and manufactured for the first time in the literature. The original value of the study is that the rays are transferred ergonomically to the solar furnace located in the focus by making a single reflection through the ring array type concentrator throughout the day. The usability of Solar and Hitec salts in the solar furnace is examined, also new Hitec XL triple salt mixture is examined for the heat storage tank which works in lower temperature applications. In experimental, analytical, numerical and calibration tests the average furnace temperatures are obtained as 437 K, 444 K, 455 K and 442 K, respectively. The average furnace thermal efficiencies are calculated as 27.7%, 28.3%, 30% and 27.3% in experimental, analytical, numerical and calibration tests, respectively. In addition, while all the Hitec salt is melted in the solar furnace in 7 hours in the charging state, heat storage is achieved for 4 more hours in the discharge state, providing heat storage for 11 hours per day. Besides, an economic analysis of installed heat storage with RAC system is made. Finally, thanks to adaptive the solar furnace, thermal performance is improved by increasing heat transfer inside furnace.