Significance of thermal energy storage material in solar air heaters

Thermal energy storage is among the most efficient techniques of storing solar energy from the sun for air heating when integrated with solar air heater. Thermal storage material uses in solar air heaters for heating air before and after the sunset. Solar air heater uses in drying agriculture products, store crops in warehouses, and industrial applications such as dying, dairy products, chemicals, etc. Energy storage system plays a significant role in locations where the enormous temperature difference in a whole day. Thermal storage systems eliminate power supply intermittency between supply and demand. Solar air heaters with thermal storage devices have decreased the costs and volume of one product. This review paper represents a packed bed thermal energy storage system encapsulated in a single and double pass solar air heater. A detailed investigation was conducted of solar thermal storage units comprising sensible and latent heat storage materials. Sensible heat storage includes storing thermal energy inside the storage medium by raising the temperature without changing the phase, while latent heat storage requires keeping heat energy inside the material during the transitional period. The new technique for storing thermal energy that integrates both sensible and latent storage is the combined thermal energy storage system. Solar air heaters integrated with thermal storage systems used in greenhouse applications are also emphasized in this article. The performance difference between single-pass and double-pass packed-bed solar air heaters are also examined and mentioned the recent advancement and improvements in heat transmission in solar thermal storage systems. Copyright (C) 2022 Elsevier Ltd. All rights reserved.