Calculation of the Concentration Ratio and Solar Flux Distribution of the Truncated Pyramid Solar Concentrator Using Three-Dimensional Ray Tracing Simulation

Abstract

The Truncated Pyramidal Solar Concentrator (TPSC) is a four-mirror device configured as a square frustum, utilized in solar oven technology for medium-temperature applications. This study aims to calculate the concentration ratio and solar flux distribution on the receiver by ray-tracing incident solar radiation from the aperture until it strikes the receiver or escapes. Assumptions include solar rays as equal, symmetric straight lines tilted by the altitude angle and the solar azimuth angle, and flat, smooth mirrors with negligible absorption. This study investigates the impact of mirror height, receiver-to-aperture area ratio, and solar ray incidence angles, on flux distribution and concentration. Results indicate that flux distribution is significantly affected by height, receiver-to-aperture area ratio. At (β=φ=0), the concentration ratio increases with both height and aperture area, although the latter only up to a limit. At (β=10) and (φ=0), the concentration ratio increases with height but decreases with increasing aperture area. Comparing the two cases, the concentration ratio is found to decrease with increasing altitude angle, suggesting that the TPSC is best utilized for a short period. The solar azimuth angle also reduces concentration, but less significantly than altitude angle. We conclude that height and aperture area have a major impact on flux distribution and concentration. This mathematical model is crucial as a design tool, providing a more accurate and detailed computational framework for flux mapping on the receiver compared to previous studies, thereby enabling thermal performance optimization in solar applications.