A review on thermal energy storage systems in solar air heaters

Abstract

Summary The drying needs of agricultural, industrial process heat requirements and for space heating, solar energy is one of the prime sources which is renewable and pollution free. As the solar energy is inconsistent and nature dependent, more often there is a mismatch between the solar thermal energy availability and requirement. This drawback could be addressed to an extent with the help of thermal energy storage systems combined with solar air heaters. This review article focuses on solar air heaters with integrated and separate thermal energy storage systems as well as greenhouses with thermal storage units. A comprehensive study was carried out in solar thermal storage units consisting of sensible heat storage materials and latent heat storage materials. As the phase change heat storage materials offer many advantages over the sensible heat storage materials, the researchers are more interested in this system. The charging and discharging characteristics of thermal storage materials with various operational parameters have been reported. All the possible solar air heater applications with storage units have also been discussed.

Thermal energy storage properties of polyethylene glycol grafted styrenic copolymer as novel solid‐solid phase change materials

“…Moreover, outdoor temperature changes and daily solar energy can be retrieved using passive solar grids including thermal energy storage (TES) setups . In this regard, compared with sensible heat‐based systems, the popularity of latent heat‐based TES frameworks working by phase change materials (PCMs) is increased day by day because they allow higher heat storage per volume and also provide better management to the released heat …”

Enhanced thermal conductivity of copper‐doped polyethylene glycol/urchin‐like porous titanium dioxide phase change materials for thermal energy storage

“…Recovering and reusing waste energy is one of the most effective methods for energy conservation and thermal pollution reduction. The purpose of thermal energy storage (TES) is to store heat under specific conditions and release it at a later stage when required . Sensible energy storage, latent energy storage, and chemical energy storage are all included in TES.…”

“…The purpose of thermal energy storage (TES) is to store heat under specific conditions and release it at a later stage when required. 1,2 Sensible energy storage, 3 latent energy storage, 4 and chemical energy storage 5 are all included in TES. The use of phase change materials (PCMs) is an effective latent energy storage technique because of the large storage capability, high thermal conductivity, and isothermal phase transition temperature PCMs have.…”

Experimental study on performance of square tube absorber with phase change material

“…7 Research and development of integration of solar air heater with thermal energy storage material have become the main focus in the field of solar engineering technology. 10,11 A review study of thermal energy storage integration with solar heaters has been conducted by Haldorai et al 12 From the study, it is concluded that solar heaters with latent heat energy storage material as a thermal energy storage component provide a better thermal efficiency when compared with solar heaters employing other types of thermal energy storage materials. The method of latent heat with the application of phase change material (PCM) has received a special attention because of its higher energy storage density compared with sensible heat energy storage material.…”

“…Methods of storing thermal energy including sensible heat and latent heat have been employed. Many solar air heater applications using latent heat energy storage materials such as hydrated salt, 13 palmitic and lauric acid, 14,15 and technical grade paraffin wax 11,12 have been studied. 8,9 It works on the principle where the material itself will store and release an amount of heat when the phase changes during the operation.…”