Daylight Lighting System Based On Hybrid Concentrating Method

With the rapid development of the world economy and cultural industry,the energy consumption and greenhouse gas emission in the building field have increased significantly,among which the lighting energy consumption is the main source of the total energy consumption of buildings.In recent years,daylight lighting system has attracted wide attention because it can directly use solar energy to illuminate buildings.However,the optical efficiency of traditional daylight lighting system is low and the irradiance cannot be maintained constant due to the influence of weather changes.Aiming at the above problems,this paper proposes a daylight lighting system design scheme based on hybrid concentrating method,which provides theoretical support for the application of solar concentrator in daylight lighting system,and provides experimental verification for the integrated architectural application of daylight lighting system.The solution maximizes the utilization of solar energy,and the visible and invisible light are collected and utilized separately to achieve stable indoor lighting during working hours.The main research contents of this paper are as follows:(1)Firstly,the optical design of the daylight lighting system is carried out.In the key part of the concentrator,the design scheme of double parabolic collector module and leak-free lightguide is adopted.At the same time,the mathematical model among the parameters when the light propagates in the hybrid solar concentrator is established.Optical fibers and light diffusers in the system provide a more uniform irradiance for the building,while LED auxiliary lighting is added to compensate for the lack of daylight.(2)Light Tools optical software is used for ray tracing,and the effects of different structural parameters on the optical performance of the concentrator are compared.The results show that the optical performance of the concentrator is better when the height of the collector module is smaller and the radius of the coupling structure is smaller.By testing the input luminous flux of the daylight lighting system,it is proved that the solar light can provide more than 60% of the total luminous flux for the commercial building model.The irradiance distribution of indoor working plane is obtained by DIALux software,and the irradiance uniformity of the working plane is calculated to be 0.3.According to the efficiency of each optical element in the system,the total optical efficiency of the system is calculated to reach 63.49%,and the energy saving analysis of the auxiliary lighting mode is carried out.(3)Finally,an experimental platform for solar concentrator with lightguide is built in the laboratory to verify the optical performance of the daylight lighting system in sunny and cloudy weather.The working conditions of the daylight lighting system in different seasons are analyzed.The results show that the optical performance of the daylight lighting system is better in summer than in winter.The above research results prove that the proposed daylight lighting system can provide efficient and stable lighting requirements for the interior of the building,and can still maintain good optical performance in different environments.This work provides an idea for the optical design of new daylight lighting system and has a great development space in the field of optics and architectural lighting.