STUDY OF COMBINED SENSIBLE AND LATENT HEAT SOLAR THERMAL ENERGY STORAGE SYSTEM

Abstract

The global fossil fuel resources are dwindling with the world ever-increasing energy demand and concern for environmental sustainability has attracted the attention of researchers towards the use of renewable energy resources and waste heat resources. The major technological bottleneck for preventing the effective deployment and efficient use of renewable energy resources is their intermittent nature and so the energy supply and demand have not been balanced in time. In order to minimize the discrepancy between energy supply and demand and to ensure continuous energy supply, an integration of thermal energy storage with the solar thermal systems is one of the promising technology. The thermal energy storage system plays a major role in effective utilization of resources in improving the efficienty of solar thermal systems. The use of efficient and inexpensive thermal energy storage systems can enhance the performance of solar thermal systems, as well as the widespread usage of solar energy. Thermal energy storage in a packed bed system with air as a heat transfer fluid, offers an attractive and efficient approach for storing the solar thermal energy. The thermal energy storage comprises of storage media in a storage container through which the heat carrying fluid (air) is passed to transfer thermal energy from air to the storage media. The energy stored can be retrieved by pumping the atmospheric air through the packed bed. Generally, sensible heat and latent heat storages are the two main technologies used for storing the thermal energy. The sensible heat storage system accumulates the energy by changing the internal energy without phase change and for latent heat storage, the energy is stored by changing the phase of a material.