With the rise of renewable energy systems, there is an increased demand for improved designs of daylighting devices that work without any external energy source to illuminate the deep dark spaces of buildings. Most of the present designs deliver only low light levels especially during the early morning and late evening. This paper focuses on the performance evaluation of specifically designed parabolic-profile collector that redirects the low altitude incident rays of the sun efficiently into a mirror light pipe and thus enhances the lighting to desired levels in the building. Numerical analyses of the same were carried out for the summer solstice, winter solstice, and the autumn equinox for clear sky conditions. Experimental results for the proposed design validated the enhancement in light levels during low altitude sun and controlled lighting during the mid-day sun. The average lighting value obtained through the configured collector during low altitude sun was more than twice the lighting value achieved by a conventional daylight-collecting dome and was ∼20% higher than a prismatic collector.

中文翻译：

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使用抛物线型收集器提高无源管状采光装置的性能

随着可再生能源系统的兴起，对日光设备的改进设计的需求不断增加，这些设备无需任何外部能源即可照亮建筑物的黑暗空间。目前的大多数设计仅提供低光照水平，尤其是在清晨和深夜。本文重点介绍专门设计的抛物线型收集器的性能评估，该收集器将太阳的低空入射光线有效地重定向到镜面光管，从而将建筑物中的照明增强到所需的水平。在晴朗的天空条件下，对夏至、冬至和秋分进行了相同的数值分析。拟议设计的实验结果验证了低海拔太阳期间光照水平的增强和正午太阳期间受控照明的增强。在低空太阳期间通过配置的收集器获得的平均照明值是传统日光收集罩获得的照明值的两倍以上，比棱镜收集器高约 20%。