PERFORMANCE ANALYSIS OF PACKED BED SOLAR ENERGY STORAGE SYSTEM HAVING LARGE SIZE STORAGE MATERIAL OF DIFFERENT SHAPES

摘要

Packed bed is generally used for thermal energy storage in air based solar energy systems. Packing of large sized material elements could be used to reduce the pressure drop, which causes the energy consumption by fan to propel the fluid through the packed bed. The shape of the material elements and bed porosity are two important system parameters, which could affect the performance of the system considerably. In the present paper an attempt has been made to develop the correlations for Nusselt number and friction factor as function of system and operating parameters for predicting the thermal and hydraulic performance of the system within the investigated range of parameters. Heat transfer coefficient and pressure drop equations reported in the literature for material elements of different shapes and for different bed porosities have been used to generate the data for Nusselt number and friction factor respectively.