Numerical, analytical and experimental thermodynamic analysis of the design of an innovative ring array concentrator solar system with solar furnace containing phase change material

Abstract

The rising demand for reliable and sustainable renewable energy has increased the need for efficient thermal energy storage. This study introduces a novel solar furnace integrated with a Ring Array Concentrator (RAC) system—rarely explored in literature—and investigates high-temperature thermal storage using Phase Change Materials (PCM) through experimental and theoretical methods. Two solar storage units were developed: Model-I with a flat receiver and Model-II with finned cylindrical receiver for enhanced heat transfer. The newly developed RAC system was tested experimentally in the Trabzon province of Turkiye. Instantaneous solar irradiation for the region was also determined analytically. During a 10-hour operating period, Model-I successfully melted 0.7 kg of solar salt and 3.8 kg of Hitec salt. In contrast, the enhanced Model-II system achieved full melting of 18 kg of Hitec salt within 7 h, reaching an average temperature of 455 K. Experimental and numerical results revealed that the RAC system achieved an optical efficiency of 58.8 %, with the receiver efficiency calculated at 64.3 %. The maximum thermal efficiency and exergy efficiency of the solar furnace are determined to be 39 % with a 3.4 % uncertainty and 20 % with a 1.3 % uncertainty, respectively. A strong agreement was observed between experimental measurements and theoretical predictions for both furnace models. This work offers a novel and integrated solar thermal system by combining advanced RAC optics with PCM-based thermal storage, making a significant contribution to sustainable energy technologies through improved heat storage performance, reduced CO 2 emissions, and adaptability to varying environmental conditions.