Evaluating Solar Flux-Temperature Distribution in the STCR Cavity- A SolTrace-CFD approach

The solar assisted thermochemical H2 O/CO2- splitting process is practiced for H2/CO production. Among the many solar thermochemical processes, the CeO2 catalyst-based H2 O-splitting cycle is one of the most favorable for solar fuel generation. The conceptual design and optical analysis of the Reticulated Porous Ceria (RPC) solar thermochemical cavity reactor (STCR) to attain the optimal conditions (uniform solar flux distribution) and to achieve the favorable temperature for the reduction step has been presented. STCR is a modified geometry made from cylindrical and hemispherical shapes. The optical analysis has been carried out by considering two cases; (1) focal point is at aperture (x = 0) and (2) focal point is 20 mm inside the STCR (x = -20 mm). Results show that the case-1 with 4 mrad S.E was more uniform. Further, the case-1 with 2 mrad S.E generates 33% greater solar flux value in comparison to 4 mard S.E but the highest temperature value was achieved for the 4 mrad S.E. The focal point located inside the reactor cavity yields lower heat flux as compared to the focal point at the aperture. The catalyst temperature in the radial direction with 4 mrad S.E was higher in comparison to the 2 mrad S.E. However, in case-2, the catalyst temperature with 2 mrad S.E is higher as compared to the 4 mrad S.E in radial direction. The catalyst temperature in the axial direction, as well as the reactor cavity temperature along the centerline for case-1 with 4 mrad S.E, is the highest.