Analysis of Concentrated Solar Energy Storage in Packed Beds with Multiple Heat Sources and an Optical Quartz Tube

The three-dimensional computational fluid dynamics model approach is used to simulate concentrated solar energy (CSE) storage by using a novel and innovative design of packed beds of silicon carbide (SiC). The heat transfer model that was developed and verified by comparison with the experimental data using a packed bed of SiC particles was modified and used in our simulations. A new radiative heat transfer model was developed that is capable of describing the energy transfer between the surfaces inside the optical quartz tube. Gao et al. showed that using a wider incident radiative energy flux distribution would increase the energy absorption by a packed bed of SiC. Thus, a packed bed with multiple incident energy sources was simulated in the present study to distribute the incident energy more uniformly to the entire surface. Our numerical simulations showed that a packed bed system with multiple distributions of incident energy sources enhances the capacity of CSE energy storage in the system. Furthermore, our numerical simulations showed that a packed bed with a novel design of an optical quartz tube, where the radiative energy from the bed surface meets the surface of the optical tube at the center of the packed bed, results in additional distributed CSE on the tube and an increase in the energy absorption, storage capacity, and energy storage at higher temperatures.