Optical Design of a Novel Two-Stage Dish Applied to Thermochemical Water/CO(2)Splitting with the Concept of Rotary Secondary Mirror

Song Yang, Jun Wang, Peter D. Lund

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In this paper, a novel two-stage dish concentrator (TSD) with a rotary secondary mirror (SM) is presented for solar thermal water/CO(2)splitting. An in-house code for ray-tracing simulation of the concentrator was developed and validated. Among all feasible geometries, a hyperboloid with an upper sheet is the most popular option and is widely used as a secondary reflector, which is mainly discussed here. All para-hyperboloid geometric combinations can be categorized into three typical patterns (phi(1)<pi/2,phi(1)= pi/2,phi(1)> pi/2,phi(1)= field angle of PM). The initial designs of the TSD, respective to different off-axis levels for each combination, were first designed. Then a new mathematical model was introduced to reshape the SM to reach optimal truncated designs. Finally, a new concept of an off-axis primary mirror (PM) combined with the truncated SM was evaluated by using the in-house ray-tracing code. The results include the optical efficiency, concentration ratio and intercepted radiant flux. The best solutions with the highest optical efficiency fall in the range pi/2

Original languageEnglish
Article number3553
Number of pages14
Issue number14
Publication statusPublished - Jul 2020
MoE publication typeA1 Journal article-refereed


  • solar thermal
  • dish concentrator
  • ray-tracing method
  • thermochemical redox
  • CO2
  • H2O
  • H-2

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