Open AccessOptical analysis of a solar thermochemical system with a rotating tower reflector and a receiver–reactor array
Author(s) -
Lifeng Li,
Song Yang,
Bo Wang,
John Pye,
Wojciech Lipiński
Publication year - 2020
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.389924
Subject(s) - optics , radiative transfer , reflector (photography) , heliostat , nonimaging optics , parabolic reflector , distributed ray tracing , monte carlo method , physics , thermal , solar energy , ray tracing (physics) , tower , materials science , engineering , electrical engineering , mathematics , meteorology , civil engineering , light source , statistics
We propose a concept of a rotating tower reflector (TR) in a beam-down optical system to alternate concentrated solar irradiation of an array of solar receiver-reactors, realizing multi-step solar thermochemical redox cycles. Optical and radiative characteristics of the proposed system are explored analytically and numerically by Monte-Carlo ray-tracing simulations. We study the effects of the system geometrical and optical parameters on the optical and radiative performance. TR axis is required to be tilted for accommodating the receiver-reactor array, resulting in reduced optical efficiency. We demonstrate that the annual optical efficiency of a baseline system with the receiver-reactor located south of the tower decreases from 46% to 37% for the axis tilt angle of TR increasing from 2° to 20°. The optical analysis conducted in this study provides a general formulation to enable predictions of required gain of thermal-to-chemical efficiency of the receiver-reactor array for obtaining improved overall solar-to-chemical efficiency of the solar thermochemical plant.