Computational and experimental study of solar thermal energy store for low-temperature application

摘要

This paper evaluates solar thermal energy storage (STES) systems for a low-temperature application. The STES used in this study was an annular cavity storage unit filled with heat storage material. Two latent heat storage materials (benzoic acid and stearic acid), and one sensible heat storage material (palm olein) were selected for this study. Transient thermal analysis was carried out on the STES models using ANSYS 16.0. The performances of the STES systems were evaluated by installing them in solar cookers to heat water. The heating power, sensible heat efficiency (SHE), the amount of energy and exergy stored were estimated. The temperature distribution, total heat flux and directional heat flux of the STES systems were observed to be affected by the type of heat storage materials used. The heating power, the energy stored and exergy stored reduced, while the SHE increased with an increase in the amount of water heated. In the absence of solar radiation, the STES systems sustained the temperature of 1 and 1.5 kg of water above 60 and 50 °C respectively for 200 min; this shows the suitability of the annular cavity storage unit for low-temperature applications.