Optical performance study of different shapes of solar cavity receivers used in central receiver system plant

ABSTRACTIn the current study, we present the optical efficiency of six different shapes of cavity receivers that are mostly used in solar power tower systems. This study was conducted in applied research unit for renewable energies (URAER) at Ghardaïa province, Algeria. Each heliostat reflects the sunray into the centre point of the cavity aperture situated at 7.4 m on the top tower. In order to find the orientation of each heliostat, several parameters relating the position of the sun and heliostat tower system are estimated. Optical simulation was performed by means of TracePro® 2013 ray tracing software using the MCRT (Monte Carlo ray trace) method. The results show that conical and trapezoidal shapes perform better than other studied cavities. They mostly exhibit the highest optical efficiency reaching 92.65%, 91.81% at absorptivity 85% and an optical efficiency of 90.88% and 89.30% at absorptivity 75%.