| The rapid development of society has led to an increasing demand for fossil energy,which has caused serious pollution to the environment.Unlike traditional fossil energy,solar energy is a green and abundant renewable energy source.With the increasingly perfect integration of photovoltaic architecture and intelligent daylighting concepts,solar intelligent daylighting systems have received widespread attention.This article proposes a design scheme of a solar intelligent daylighting system based on a new type of concentrator,in response to the problems in traditional solar intelligent daylighting systems,such as low optical efficiency and susceptibility to environmental influences.The new concentrator is based on the theory concerned nonimaging optics and the hybrid concentration principle.The mathematical model of the concentrator unit is established.High length and width and other parameters are calculated.The optical properties of the concentrator are analyzed within the extreme range of each parameter.Through multiple optimized simulations by using Light Tools,the concentration system can obtain an optical efficiency of 93.89%when the geometrical concentration ratio is about 70.The accuracy and reliability of the concentrator’s concentrating performance are verified by using 3D printing technology to manufacture the concentrator unit model.The relationship between the number of concentrator units and the geometrical concentration ratio and the concentration efficiency is explored by continuously changing the number of concentrator units in experiments.The solar tracking device and LED compensatory daylighting are designed using an STM32 microcontroller.The solar tracking device converts optical signals into electrical signals using photoresistors.The microcontroller further controls the direction of the stepper motor based on the voltage value of the signal,ensuring that the receiving surface of the concentrator remains perpendicular to the incident light.The LED compensatory daylighting uses a GY30 illuminance sensor to determine the ambient light intensity.The microcontroller decides whether the threshold value is reached and controls the LED to ensure the daylighting needs of the room.In addition,the optical fiber and optical diffuser are used to transmit light to the interior and uniformly diffuse light onto the work surface.The input and output luminous flux of the system are calculated.The solar light can provide more than 80%of the total luminous flux in the room in the process of operation,which is within 11 hours.Analyzing the luminous flux losses of each optical component shows that the total optical efficiency of the system is 60.19%.DIALux software is used to build a 32 m~2office.The indoor radiation distribution without and with the solar daylighting system is simulated.At 15 o’clock on a summer day,the average illuminance on the work surface with the solar daylighting system is 558 lx,and the uniformity is 0.62.The optical performance of the system is analyzed under different weather conditions.The average illuminance of the system output in clear and cloudy weather is approximately 596lx and 275 lx,respectively.The system output irradiance in different seasons is analyzed.The average irradiance of the system output in summer and winter is approximately 56 lm and 33 lm,respectively.This system provides ideas and theoretical support for the application of concentrator in the solar daylighting system.It provides effective solutions for energy conservation and emission reduction,and has a broad prospect in the field of building daylighting. |
