SELECTING MATERIALS FOR SENSIBLE HEAT SOLAR THERMAL STORAGES

Abstract

Solar energy, being nonpolluting in nature, cleaner as well as limitless, has gotten wide- ranging attention amongst engineers and scientists. Although there are several bene ts, a signi cant aspect is that solar energy is dependent on time and intermittent in nature. Therefore another form for storing thermal energy is required for e ectively utilizing solar energy source. Maximum thermal energy storage systems in application dependent on the value of speci c heat or we can say that sensible heat storage materials, for example water, oil, salts and rock beds and these all are considered under sensible heat storage (SHS) systems. Sensible heat storage does not behave as the ultimate option if energy density is considered because the maximum values belongs to thermo-chemical storage, one more disadvantage of SHS is that it dissipates more heat to the ambient compared to other forms TES and require proper isolation. Under the present dissertation work, a study has been carried out on sensible heat based solar thermal storages (SHTES) systems using solid and liquid medium and numerical simulation of their unsteady behavior utilizing the nite element method (FEM). Unlike other investigations present in the literature, the approach for numerical model and simu- lation has simultaneously taken various aspects into consideration like thermal properties at high temperature, non approximated real geometry of the repeated storage element also the real cycle adopted foe storage. Materials thermal properties had obtained and utilized as input condition for simulation to preliminary assessment of their utilization in thermal storage. The simulation performed may also be used to improve the storage system, ther- mal characteristics are necessary with respect to the storage material. Further an e ort has also been made to review the possibility of having advantages of SHS. Based on the study, recommendations are made for improvement of reliability on solar energy.