The Design Of Indoor Solar Lighting System

With coal, natural gas, oil and other fossil fuels are depleted, human society is facing an increasingly serious energy crisis. So people is gradually turning to explore and utilize soalr energy resources,which are clean and recycled.Lighting energy consumption is one of the most building energy consumption, which accounts for about 30% of total building energy consumption. So if we can transmit sunlight into room, it will not only greatly reduces the lighting energy consumption but also benefit people health. The sunlight transmitted into room system designed in this thesis consists of sunlight focus setting system, sunlight tracking system and sunlight transmitting setting system. These three parts were introduced and analyzed in detail.In the part of the sunlight focus setting system, three common types of condensers were listed and their performance and characteristics were compared. And a large-diameter Fresnel lens was choosed to be the condenser.Now there have two sunlight tracking ways in the sunlight indoor illumination, which are sun angle tracking and electro-optical tracking.The sun angle tracking is not subject to the environmental impact from the outside, but it have the shortcomings of accumulation error and open-loop control. The electro-optical tracking method is simple, and has the advantages of high accuracy and closed-loop control, but it is influenced by the external weather conditions. In this thesis, it presented a method of tracking the sun, which uses sun trajectory based on GPS as the rough track and four quadrant silicon photocell as the calibration.This approach not only offsets the shortcomings of open-loop control of sun angle tracking, but also the environmental impact of electro-optical tracking. It is a closed-loop control system of high precision, and less environmental impacts.In the part of sunlight transmitting setting system, Various transmission optical media were introduced and their advantages and disadvantages were compared. And the plastic fiber optic cable was choose because its small loss, remote transmission distance and low-cost. In addition, filters and collimators were used to filter out the infrared, ultraviolet,γrays andβradiation in order to transmit sunlight into room.In this thesis, the system host computer program, which could record operating data of several sunlight indoor illumination systems, was also introduced. According to the string sent to the host computer, we can determine whether the current sunlight indoor illumination system is operating properly.