Design Method of a Stepped Integrated Natural Lighting System

To address the problems of insufficient light energy utilization and light leakage in existing concentrator lighting systems, this paper proposes a novel Stepped Integrated No-Leakage Concentrator Lighting System. This system adopts a design that combines a concentrator module array with a stepped light guide plate. By constructing a stepped integrated concentrator structure and a composite parabolic coupling configuration, the system enables efficient solar energy collection and delivery, significantly improving concentration efficiency and energy utilization. First, based on the principles of geometric optics, theoretical modeling of the concentrator modules and light guide plate was conducted. The relationships among the paraboloid coefficient, step height of the light guide plate, and the number of concentrator modules were analyzed to clarify their influence on the geometric concentration ratio and concentration efficiency of the system. Subsequently, optical performance simulations under varying structural parameters were performed using a joint simulation platform based on SolidWorks Premium 2024 SP5.0 and LightTools(64) 8.6.0 Copyright (c) 1994-2018 Synopsys, Inc. The results indicate that the proposed structure achieves excellent light-guiding performance and high optical efficiency, with a maximum concentration efficiency of 94% and a geometric concentration ratio of 50. On this basis, a physical prototype was fabricated, and experimental testing was carried out. The results validated the accuracy of the simulation, with the system reaching a concentration efficiency of 54.6% at noon, further confirming the feasibility and superior performance of the proposed design. This study demonstrates that the Stepped Integrated No-Leakage Concentrator Lighting System offers significant advantages in enhancing light energy utilization and reducing leakage losses, providing an efficient solution for natural daylighting and interior illumination in green buildings.