| Summary: | 碩士 === 國立臺灣科技大學 === 電子工程系 === 99 === In recent years, due to the awareness of environmental protection, the use of green energy gets more and more attention around the world. Industry and academia focus on the use of sunlight to provide indoor lighting and save energy.
One of the structures of solar concentrator is using lens to collect light, which features a high concentration ratio. But the acceptance of incident light angle of lens-type concentrator is quite small. If there is a tilted angle θ between parallel light and optical axis of lens, the focal point shifts from the original position and cannot be guided to light pipe. So the lens-type concentrator usually goes with dynamic sun tracking system to make the optical axis of lens parallel sunlight.
Therefore, we propose a novel static solar concentrator without high-cost sun tracking system, which contains collection and transmission parts; the collection part is the array of interlaced two-layer lenses in semi-circular arrangement and two-layer lenses comprise the first-layer lens at the top and the second-layer lens at the bottom; the transmission part is one acrylic light pipe. Furthermore, we optimize the aspheric coefficients of lens. Each first and second-layer lens is responsible for collecting sunlight at corresponding time. So sunlight with different incident angles in daytime passes through two-layer lenses that refracted to light pipe effectively.
We simulate the concentrating performance of the concentrator and only light pipe under real solar radiation in the summer solstice, vernal equinox, and winter solstice in Taipei city, Taiwan. According to the simulation results, the concentrator in this paper can provide steady luminous flux in daytime for kinds of lighting application.
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