Fig. 1. Fabrication process of mixed particle solar absorber

Fig. 2. Sectional drawing of the tailored quartz glass Rasching ring

Fig. 3. Schematic diagrams of the light transfer details within the mixed particle-packed receivers. (a) Schematic diagram of transmission path of the incident solar radiation; (b) schematic diagram of transmission path of re-radiation emitted from the silicon nitride particles

Fig. 4. Experimental samples of the mixed particle-packed receivers

Fig. 5. Verification of the optical transmission model of the mixed particle-packed receivers

Fig. 6. Reflection loss of the incident solar radiation for each mixed particle-packed receivers

Fig. 7. Absorption and emission characteristics of the mixed particle-packed receivers. (a) Relationship between the emissivity and the temperature of the mixed particle-packed receivers; (b) relationship between the performance αs/εr and the temperature of the mixed particle-packed receivers

Fig. 8. Influences of the temperature on the thermal efficiency of the mixed particle-packed receivers. (a) Thermal efficiency curves of mixed particle-packed receivers; (b) peak thermal efficiency among the mixed particle-packed receivers

Fig. 9. Solar heat source terms within the quartz glass particles. (a) R₅B₀; (b) R₄B₁; (c) R₁B₄; (d) R₀B₅

Fig. 10. Solar thermal flux profiles of the silicon nitride particles. (a) R₅B₀; (b) R₄B₁; (c) R₁B₄; (d) R₀B₅

Fig. 11. Axial mean distribution characteristics of the solar heat source within mixed particle-packed receivers