Optical-irradiance performance investigation to optimize a solar still with internal reflectors and double external boosters

This study was performed to optimize the single slope solar still with internally reflecting walls and externally reflecting, top and bottom, flat booster reflectors using an optical irradiance model. The model uses a 3‑D hybrid recursive ray tracing method developed in this study. The model was validated in a couple of geometrical scenarios. To measure irradiance, the rays were generated using the Latin Hypercube Sampling (LHS) technique and traced to determine how many were received by the still’s basin. The different varieties of stills were considered in these regards. The results were compared with those stills with the same geometry but lacking the reflectors/boosters. The model was then used to obtain the optimum values for the boosters’ lengths and angles for various designs of stills, to gain the desired optical-irradiance performance. Due to high dimensionality of the problem, Particle Swarm Optimization (PSO) was utilized for the purpose. Contour plots were also developed to show the effects of changing the booster angles on the performance.